# JDSLabs C421 Preorder is live...



## Anathallo

Two opamp choices available - one for higher impedance cans, one for lower (JDS states the one suited for higher impedance cans emphasizes bass over transparancy).  It doesn't look like they can be rolled.
   
http://blog.jdslabs.com/?p=179
   
   
  According to the blog entry, *only 95 amps will be available (at most) for preorder*.  Who's taking the dive?


----------



## i_djoel2000

looks like an arrow 4g killer..


----------



## ClieOS

Nice, the spec looks very promising and it even has my favorite opamp for portable amp, AD8620.


----------



## Hi-fi Wigwammer

I ordered my C421 yesterday, based upon positive impressions of my JDS cMOY V2.03. I'm really excited about the C421 - great price ($169), great spec and hopefully a good upgrade on his terrific cMOY.
  Judging by his cMOY John appears to share my personal sonic preferences. I think the C421 could be a real winner.


----------



## i_djoel2000

Quote: 





anathallo said:


> (JDS states the one suited for higher impedance cans emphasizes bass over transparancy).  It doesn't look like they can be rolled.


 

 and i wonder why is that? usually higher impedance cans are more source revealing, they should emphasizes transparency more over bass IMO


----------



## Josef

I've ordered mine just after the rss-feed shouted at me 
   
  I'm looking forward to listen to it after loving the CMOY.


----------



## Hi-fi Wigwammer

Indeed, I think the JDS cMOY is very underrated - a smoother, cleaner listen than the FiiO E11 to my ears.


----------



## Jonasklam

Quote: 





clieos said:


> Nice, the spec looks very promising and it even has my favorite opamp for portable amp, AD8620.


 

 Btw, was thinking, have you heard the other opamp option they offer?


----------



## kyoshiro

anyone know how this compares to the GoVibe Magnum


----------



## Hi-fi Wigwammer

I doubt anyone can answer that question. It hasn't been released yet. John Seaber has taken a pre-production prototype to the Rocky Mountain Audio show today. Maybe an attending Headfier will get to listen to it?
  Regardless it looks like a very promising amp for $169.


----------



## kyoshiro

Quote: 





hi-fi wigwammer said:


> I doubt anyone can answer that question. It hasn't been released yet. John Seaber has taken a pre-production prototype to the Rocky Mountain Audio show today. Maybe an attending Headfier will get to listen to it?
> Regardless it looks like a very promising amp for $169.


 

  
  true true, quite a damn steal for 169 (plus looks great)  for what is listed  my magnum was 300~ tho I do love it
  I wonder if the high impedence version will drive AKG K702 fine, looking into buying a pair soon (tm)


----------



## ClieOS

Quote: 





jonasklam said:


> Btw, was thinking, have you heard the other opamp option they offer?


 
  You mean AD8066? I have both in my cmoyBB. AD8066 sounds pretty good as well, but generally I'll go for AD8620 if given the choice as AD8620 sounds more refined. I think the reason for John to recommend AD8066 for high impedance headphone is because AD8066 can do rail-to-rail, which means it will give a higher output voltage over AD8620 and that is more important for high impedance headphone (to achieve higher output volume).


----------



## Anathallo

I could be 100% wrong, but I think it's because the higher impedance cans require more push in the lower end of the spectrum to even things out, so the amp has to emphasize the bass to normalize the tonal balance.
   
  Check out the Impedance vs. Frequency graph of the HD650.
   
http://www.innerfidelity.com/images/SennheiserHD650.pdf
   
  It'd be interesting to hear from someone who actually knows something about sound science, though.
  
  Quote: 





i_djoel2000 said:


> and i wonder why is that? usually higher impedance cans are more source revealing, they should emphasizes transparency more over bass IMO


 
   
   
  EDIT: and as I wrote that, ClieOS gives a much better response!


----------



## Jonasklam

Quote: 





clieos said:


> You mean AD8066? I have both in my cmoyBB. AD8066 sounds pretty good as well, but generally I'll go for AD8620 if given the choice as AD8620 sounds more refined. I think the reason for John to recommend AD8066 for high impedance headphone is because AD8066 can do rail-to-rail, which means it will give a higher output voltage over AD8620 and that is more important for high impedance headphone (to achieve higher output volume).


 
   
  Yep, i meant the AD8066.
  Great man! Exactly what i wanted to hear actually .) - and thanks for clearing things up, you just explained the differences pretty much as precise as possible - so that even a noob like me understand it


----------



## F900EX

Tempting ....  But will be interested to see how it compares to the E11 and UHA-4 and of course there cheaper Amp.


----------



## liamstrain

I see it has a USB in, but I don't see if this has a DAC processor... am I overlooking an obvious spec?


----------



## Hi-fi Wigwammer

No DAC to speak of. It is purely an amp.


----------



## Rip N' Burn

That sucks. The UHA-4 might be a better value for the money depending on how good or bad the C421 sounds.
  
  Quote: 





hi-fi wigwammer said:


> No DAC to speak of. It is purely an amp.


----------



## ClieOS

Quote: 





rip n' burn said:


> That sucks. The UHA-4 might be a better value for the money depending on how good or bad the C421 sounds.


 
   
  Actually by spec, I would think C421 is more favorable. First C421 runs on +/-7v and UHA-4 on +/-5V (which is the minimum for AD8620/10), so C421 should give you a higher voltage swing. While UHA-4 does have a PCM2706 for DAC for $30 more, you can actually get a decent standalone PCM270x DAC for less than $50. For example, the HifiMan HM-101 is about $40 and it uses the best sounding of the PCM270x series, the PCM2702 for DAC and actually has both line-out and headphone-out. Of course this is all based on spec and we won't know how good they are till someone get them both.


----------



## Mozu

Preordered.  Now I'm dying to hear some impressions.  (Also, woo, first real post.)


----------



## FlySweep

Very curious how this will stack up to the Arrow.
   
  > subscribed <


----------



## Mozu

Did _no one_ run into John this weekend?


----------



## Mozu

Well, good news - looks like they're a week ahead of schedule, so hopefully they're start shipping relatively soon.
   
  "Yep, the end plates arrived yesterday. 
	

	
	
		
		

		
		
	


	




 The pictured enclosure is from the rejected batch…camera hides the scratches. We’re expecting the replacement batch next Friday, so it’s very likely that all pre-orders will ship early."


----------



## Mozu

Mine arrived today. I opted to take early shipping on a slightly wonky enclosure, which, in hindsight was pointless, as my MS1is are off being worked-over, leaving me with HTF600s, which...let's just say they aren't nearly as awesome as folks would like them to be.

Initial impressions: SMALL, very solid feeling, tons of power, similar sound to my Penguin, but much more refined. 

That's about as good as it gets until I can get my hands on some decent-sounding cans for a real listen.


----------



## Jonasklam

Quote: 





mozu said:


> Mine arrived today. I opted to take early shipping on a slightly wonky enclosure, which, in hindsight was pointless, as my MS1is are off being worked-over, leaving me with HTF600s, which...let's just say they aren't nearly as awesome as folks would like them to be.
> Initial impressions: SMALL, very solid feeling, tons of power, similar sound to my Penguin, but much more refined.
> That's about as good as it gets until I can get my hands on some decent-sounding cans for a real listen.


 
   
  Sounds interesting.
 Did you get a shipping notice before you got yours?


----------



## Mozu

No, I saw his recent blog post about enclosure batch #2 still not being up to snuff, so I emailed him to tell him I'd take an early one.

Seems like quite a nice little amp so far. My neighbor's lending me his SR60is today or tomorrow, so I'll be able to get a real listen.


----------



## Jonasklam

Ok Cool
  I look forward to your impressions


----------



## Mozu

Finally got my hands on the SR60s, and ran through a huge range of stuff to at least compare the two amps, low-gain setting, bass boosts off, all source material in 320kpbs or FLAC.

While the Penguin has a slightly higher quantity of bass, I would say the C421 has it beat hands down in impact and quality/clarity. After listening to the two, I'd say the Penguin sounds more midrange-ey/honkey/congested. The C421 seems more neutral, although possibly tending towards a little bright - though that could be the not-quite-broken-in borrowed SR60s, as well - to my ear, and clarity/instrument separation is better.

Another thing I noticed, is that while the AD8397 in the Penguin supposedly has a lot higher output, the C421 is LOOOOOOOOOUD. LIKE REALLY *******ED LOUD if you want it to be. Not to say that the Penguin can't push things to unlistenable volumes, but...damn, and zero noise or hiss when the thing is cranked to maximum.

A few standouts were 
_Depeche Mode - Freestate (Remastered)_: Amazing separation, I could feel the drivers moving with the drums, and barely any clipping (considerably more on the Penguin)
_Tyr - Hold the Heathen Hammer High_: THUNDEROUS INTRO, I had to check to make sure the bass boost was off, and zero clipping (unlike the Penguin)
_Serena Ira from the Puella Magi Madoka Magica OST_: Amazing cello solo, sounds very natural and airy, much more of a "honk" on the Penguin
_Joy Division - Atmosphere_: This track has great...atmosphere. You can really feel the drums, rather than just hearing them, and Peter Hook's bass line stays wonderfully separated
_Blind Guardian - Fly_: I...wh...*drool*

The bad? Well, $170 for one, although, I'm pretty pleased at the moment. I could ask for a snazzier enclosure design, as well, but this is quite nice and small, so portability is not an issue at all, not to mention much, much sturdier than a mint tin. My one real gripe would have to be having the volume control in the middle, rather than off to one side.

While I'll be sad to see the Penguin go, since it's a cool collectable and all at this point, I can safely say that the C421 sounds fantastic, and I'll probably forget all about the Cmoy after a very short while.

Anyway, that's my halfassed "I've never actually reviewed anything before" review. 

(I cannot wait to listen to this thing when I get my MS1is back from Martin.)


----------



## leshka

Has anybody else received their amp from jds labs? Has anybody tried them with westone 4's?


----------



## Hi-fi Wigwammer

Mine shipped on Wednesday. I hope to receive it next week. I'll post some impressions once it arrives.


----------



## leshka

So I got my amp early this morning and I do must that after listening for a hour or so I can say that I am very happy with my purchase. When I compared the sound of the JDS C421 to that of the  JDS BB Altoids amp the difference (to my hears) is more than apparent. I do must say that I am more than impressed. Just like the Altoids the bass boast switch adds a very warm bass and at the same time it does not take away from the clarity. The set up I used was Sana fuze, LOD Cable and westone 4's. This Little amp Is just a big upgrade and it really bring my IEM's to life. I still say that the amp needs a little more burning in time but over all I enjoy this amp. This amp is very well built and small (which I personally like) as you can see. All in all I am happy with my new amp.


----------



## jseaber

All preorders will ship this week. Case manufacturing has been a huge mess (lost time and money for both companies!). So, we're moving production to a high precision shop, which will increase our enclosure cost by 300%. Full details will be posted soon.
   
  Thanks to all for the early comments!
   
  Quote: 





leshka said:


> Has anybody else received their amp from jds labs? Has anybody tried them with westone 4's?


----------



## Mozu

jseaber said:


> 300%



Jesus. Well, I look forward to a better-finished enclosure.


----------



## Grev

Quote: 





jseaber said:


> All preorders will ship this week. Case manufacturing has been a huge mess (lost time and money for both companies!). So, we're moving production to a high precision shop, which will increase our enclosure cost by 300%. Full details will be posted soon.
> 
> Thanks to all for the early comments!


 
  Nooo!  Does that mean the amp will cost more now?!  Can I still get the amp with the original enclosures?


----------



## Hi-fi Wigwammer

My C421 arrived yesterday. It has about 15 hours use on it so far (and still running in as we speak). Very very impressed with it so far running from iPod 5.5G through LOD.
  More to follow soon, but it's the best portable amp i've heard. I have a Teclast T51 en route too, should make a good partnership.


----------



## Anathallo

My tracking info so far .
   
   

 *Date* *Time* *Location* *Status* November 23, 2011 4:57 pm MARYVILLE, IL 62062 Shipment Accepted November 23, 2011      Electronic Shipping Info Received

   
  Don't know if it just isn't updating or if it actually  has been stucking in Illinois for the past week for no reason... Maybe customs? 
	

	
	
		
		

		
			





  My other orders with USPS usually tell me when they're in the process of clearing customs, though.


----------



## Mozu

USPS is hilariously bad at updating tracking info.


----------



## leshka

Too true. The usps update I received last Friday said that it was still 4 state's away and on the following day ( last Saturday) it came at my house early in the morning.


----------



## Anathallo

And just like that, the amp arrives today.
   
  Just plugged and started burning in, not listening yet, but John is correct - definitely some visible scratches on the enclosure - looking forward to the final batch.
   
  Also, there is an audible hiss at the highest volumes with my iPod 5.5g --> Fiio L9 --> C421 --> DT1350.  Don't have my higher quality LOD to test if it's the cable, though.
   
  The amp itself is quite striking, feels very solid in the hands and all the switches are very crisp (is that the right word - crisp?). Also, the amp is a lot smaller than I thought it would be, even with the published pictures.  Matches very nicely with the iPod.
   
  I'd take pictures, but all I have is a terrible camera phone.  leshka's pictures above will do it more justice.


----------



## gelocks

w00t!
   
  Thanks for the impressions so far guys!!
  Mine is in transit too!
  Can't wait!


----------



## Mozu

anathallo said:


> Also, there is an audible hiss at the highest volumes with my iPod 5.5g --> Fiio L9 --> C421 --> DT1350.  Don't have my higher quality LOD to test if it's the cable, though.




Is it set to High gain? I have a small amount of hiss on High and absolutely none on Low.


----------



## Anathallo

OK, 3 sources - Bifrost DAC, iPod 5.5g, Sansa Clip+.
   
  2 seperate LOD cables for the iPod, and 2 mini --> mini interconnects for both the iPod and the clip+.
   
  On hand are my 3 portables - DT1350s, M50s and PFE112s.
   
  When I have music playing, then pause, there is a hiss (and an odd clock-like ticking on my ipod, which is weird, but very faint).  When I STOP the music (or connect with the source turned off), there is no hiss on low, and a very faint one on high, like you mentioned Mozu.  This happened with all 3 sources, and all 4 cables.
   
  That said, there is so much power in this thing, the levels at which I am getting the hiss are far above any reasonable listening level.  When i just pause the music at my normal, or even my "rockin' out", there is no audible hiss on low or high gain.
   
  I plugged in my most insensitive cans - DT990 600s and there was no hiss at all - pause or stopped music - on low, and a very faint one on high.
   
  I've only listened to a few minutes of music while playing around with the hissing, but initial impressions are very good.  Will do a comparison to my other portable amps later.


----------



## PANGES

Just curious... so the pre-order page says that it wont ship until Feb? Or is that outdated and that it can ship out earlier? Just not sure since people are already receiving theirs?


----------



## tmd24

Quote: 





panges said:


> Just curious... so the pre-order page says that it wont ship until Feb? Or is that outdated and that it can ship out earlier? Just not sure since people are already receiving theirs?


 

 You can  request early shipment in a 2nd batch temporary enclosure. When the final cases are ready, they can ship you the new case for the cost of shipping. The following is on the pre-order page. 
   
*Current Status: You may request immediate shipment of c421 in a temporary enclosure (add a note during checkout). We're moving enclosure production to a higher quality manufacturer, which will take 8 weeks. Final enclosures will be available in February 2012 for free, plus shipping. Please check our blog for the latest updates. Thank you!
   
  I have the amp in the 2nd batch case and it's not in too bad of shape.


----------



## PANGES

Ohhh. Gotcha! Good deal. I wonder if I order now, I can get mine by Dec 24th. I'm going on vacation out of the country, and really want an amp for the 16 hour flight! 
  
  Quote: 





tmd24 said:


> Quote:
> 
> 
> 
> ...


----------



## tmd24

I live in Southern California and my order arrived in 2 business days via First Class Mail. I'm guessing if you ordered now, it would arrive before your trip. I can't vouch for the consistency of the US Post Office though.  
  
  Quote: 





panges said:


> Ohhh. Gotcha! Good deal. I wonder if I order now, I can get mine by Dec 24th. I'm going on vacation out of the country, and really want an amp for the 16 hour flight!


----------



## PANGES

Woot! Going to place my order then. I don't mind a fubbered case as long as I can get a nice one later. 
   
  Where do they ship from? 2 business days is pretty quick.
  
  Quote: 





tmd24 said:


> I live in Southern California and my order arrived in 2 business days via First Class Mail. I'm guessing if you ordered now, it would arrive before your trip. I can't vouch for the consistency of the US Post Office though.
> 
> Quote:
> 
> ...


----------



## tmd24

It looks like they're in Illinois.


----------



## PANGES

Quote: 





tmd24 said:


> It looks like they're in Illinois.


 


  You are all much smarter (and less lazy) than I. Ordered! 
   
  edit: Wow, I've already received an email from John of JDS, and he said my amp will ship tomorrow. lol. Ridiculously quick. Really looking forward to listening to this.


----------



## Hi-fi Wigwammer

Just be sure to give it at least 6 hours use before serious listening. Straight out of the box the amp sounds very open and spacious, but slightly hard and edgy. A few hours later and it was superb in every way. I'd be interested to hear some comparisons against some of the established competition. I suspect the C421 would do pretty well!


----------



## PANGES

Quote: 





hi-fi wigwammer said:


> Just be sure to give it at least 6 hours use before serious listening. Straight out of the box the amp sounds very open and spacious, but slightly hard and edgy. A few hours later and it was superb in every way. I'd be interested to hear some comparisons against some of the established competition. I suspect the C421 would do pretty well!


 


  I wish I could compare it to the Practical Devices XM6 and Headstage Arrow, but I'm still waiting on my Arrow replacement (both the input jacks are messed up and I only get sound in one channel), and I've returned the XM6, because it wasn't practical since it was physically too big to carry around; however, I suspect they would sound really similar since, if i recall correctly, all three of the amps run the AD8620.
   
  edit: Nevermind, they don't run the same opamps. lol. I had the XM6 with the AD8397. I believe the Arrow ran the same.. I can't find info on the headstage site to confirm.


----------



## raddogz

I received my C421 last week and am in absolute love with it.  
   
  I have paired it with the  V-Moda M80 headphones and it is so much better.  The sound stage is nice and open.  It definitely opened up the muddiness in the mids in the headphones.


----------



## PANGES

Just received my c421. Kudos to John for the quick shipping!
   
  The outer case has scratches and scuffs (as we were notified about before ordering), but they're not as bad as I was expecting. The faceplates don't quite line up 100%, and a couple of the screws don't really sit flush with the faceplate, but it doesn't really bother me. 
   
  I like the feel of the switches. Sturdy, but not too stiff. The volume wheel is easy to move, but not too loose. To me, the feel of the switches and volume wheel are perfect. 
   
  I brought a variety of IEM's with me to work today for some initial listening. Unfortunately for me, my UE4's are unusable with the c421. At listening volumes and low gain on the amp, I get a channel imbalance. It goes away if I turn the volume up, but then it's too loud. I was in a similar situation with the Practical Devices XM6; however, the XM6 had a 75ohm impedance switch. My Headstage Arrow didn't have this issue, either... perhaps that might be a nice addition to the c421 if John decides to make a newer version or something. I wish there was a gain setting lower than the "low" setting on the c421 for my more sensitive IEM's.
   
  As far as the bass boost goes, it wasn't quite what i was expecting. I was expecting it to add a tight, firm, punch, which it does; however, it adds a little more than that. I can't quite pin it down, but it possibly adds a little bit of warmth... almost tubey sounding? I'll listen more and figure it out tonight.
   
  Anyhoo, I'll do more listening later when it quiets down at work. I've brought a little variety of IEM's with me: Etymotic ER4S, Ultimate Ears UE4 Pro, Ultimate Ears TF10, Westone 4. I shall report back later!


----------



## gelocks

Just got mine today also!!!
  As mentioned, the casing is not in that bad of a shape. Sure it does have scratches
  and the faceplates are not all that smooth, but I don't have a major problem with that
  (and anyway they are getting replaced...)
   
  Out of the box, my bass boost switch is "broken" or just not properly attached so I'll get on it.
   
  As far as sound, just testing with my Denon D5000 and my netbook... all I can say is.. HUGE difference.
  Amp seems to drive these Denons WAY MUCH better than the JDSLabs Cmoy 2.03!!! I'll need to listen more carefully though.


----------



## PANGES

bah! I'm waiting to get off work so I can go home and try them with the D2000. 
  
  Quote: 





gelocks said:


> Just got mine today also!!!
> As mentioned, the casing is not in that bad of a shape. Sure it does have scratches
> and the faceplates are not all that smooth, but I don't have a major problem with that
> (and anyway they are getting replaced...)
> ...


----------



## gelocks

Lol!
At work is where I'll properly test it. So tomorrow I
Expect to listen to it at least for 6 hours... Already had them on
for 2 hours and it sounds excellent. As someone else mentioned
I also heard hissing when the player was paused but it definitely
was at a level in which I'll probably never listen to! :-]


----------



## PANGES

Yeah, when it comes to hiss, as long as I can't hear it at listening levels, I don't really care.


----------



## Anathallo

I only mentioned it because I know some people are super sensitive about that.  I personally am adoring the amp right now, I have no need for any other portable (whereas previously I would switch based on which can/genre of music i was listening to).
  
  Quote: 





panges said:


> Yeah, when it comes to hiss, as long as I can't hear it at listening levels, I don't really care.


----------



## PANGES

How funny... my least favorite IEM's seem to sound the best with the c421. 
   
  I've been spending some time here and there with different IEM's, and it seems my Etymotic ER4S benefit the most from this. The ER4S have never really been my cup of tea, but I've always kept them around, because I love how well they isolate when I need to go on airplanes. The reason I've never liked the ER4S is because they've always sounded really anemic/cold... if that makes sense. lol. With the bass boost on the c421, it adds some warmth and thickness to the music and just makes it sound more "full" to me... It just seems to fill the mid-low end that I always like to have in my headphones/IEM's. With the rest of my IEM's, I've been running the c421 without the bass boost, and have been enjoying it a bit more.


----------



## gelocks

Are you guys getting any kind of interference with the amp?
  I'm getting some interference/cracking sounds when I touch the enclosure
  with my fingers (i.e. if I touch it with a rubberband, my wallet, etc, it doesn't produce anything.)
   
  Right now I have my Archos 7 --> c421 --> denon D5000
   
  Also, are you guys finding this amp "bright" by any chance?
  (I'm not the best judge right now though... I have a cold!!!!  )


----------



## gelocks

Nevermind...
   
  It seems it's picking up this interference/crackling because I'M CHARGING my Archos 7.
  (i.e. the AC adapter is connected... when I disconnect it and touch the amp, it stops with the interference/crackling sound...)
   
  Not sure if it's supposed to do that though... and I'm not sure if it's the enclosure.
  At least with the Altoids tin can, this doesn't happen.
   
  Have any of you tried charging your PMPs while using the amp and see if you get
  the same thing? (the crackling sound is similar to when a TRS input in a guitar to an amp is messed up
  or something like that...)
   
   
  Thanks.
   
   
  P.S. Even with a cold, I can actually perceive a difference in sound/volume against the Cmoy 2.03!
  But I'll give more impressions when I get better!


----------



## Mozu

I haven't had any noise issues while charging and listening at the same time.

While I'm _still_ without my MS1is, this amp makes the HTF600s quite enjoyable (and I'm not really a fan otherwise), and makes the M6es that I just got my hands on sound fantastic (not that they need any sort of amping, but hey). I do get some R2-D2 noises with the IEMs occasionally - I can't actually remember doing what now - but I've read that's not out of the norm with IEMs, I assume due to the sensitivity.


----------



## Jordan8

How do c421 work with SRH940?
  Is there any other amp that matches the quality at the price?


----------



## gelocks

I haven't tested the c421 with my Shures but if it produces the bright output it produces with my "bassy" Denons, that will not be a good pairing... BTW, I do like the Shur 940s with the original 2.03 Cmoy!


----------



## idunnosoSTFU

Hi all. My c421 unit's LED won't turn off after the first time charging until now. The LED is blue all the time. It shouldn't be like that, right?


----------



## tmd24

Quote: 





idunnosostfu said:


> Hi all. My c421 unit's LED won't turn off after the first time charging until now. The LED is blue all the time. It shouldn't be like that, right?


 

 That sounds normal, assuming you left the amp plugged into the USB port. The manual showing the different LED status can be found at http://www.jdslabs.com/pdf/Instructions_C421x100.pdf


----------



## idunnosoSTFU

Except that mine will stay blue even unplugged until the battery is dead. D:


----------



## tmd24

Quote: 





idunnosostfu said:


> Except that mine will stay blue even unplugged until the battery is dead. D:


 
   
  Okay, mine doesn't do that. Shoot John at JDS Labs an email, he'll be able to help sort things out for you.


----------



## idunnosoSTFU

Quote: 





tmd24 said:


> Okay, mine doesn't do that. Shoot John at JDS Labs an email, he'll be able to help sort things out for you.


 
   
  Allright, will do. Thanks for the fast reply.


----------



## gelocks

Hello guys.
   
  So how many hours of play time have you gotten from your c421s?!?
  I forgot when I was testing to take them into consideration!! (ooopsss)
   
  I believe that charging while playing takes like 3 and a half hours to fully charge
  (i.e. amber light to go off)
   
  If I'm not mistaken, I think I got like 12 to 13 hours playing time, gain Low, Bass Boost
  mostly off, mid volumes.... not sure how it will be rated.
   
   
  P.S. Seems to sound better to my ears now... not sure if I'm getting used to them or if the amp
  needed time to "open" up. BTW, bass boost On, some Deadmau5 + Denon D5000 makes the cups
  vibrate... hard!! Had never experienced that!!!


----------



## PANGES

bah, I've been meaning to test them with my D2000's, but this week (finals week) has been kicking my ass. lol. I've probably only been able to squeeze like 2-3 hours on the c421 so far.


----------



## turokrocks

subscribed


----------



## gelocks

Quote: 





panges said:


> bah, I've been meaning to test them with my D2000's, but this week (finals week) has been kicking my ass. lol. I've probably only been able to squeeze like 2-3 hours on the c421 so far.


 

 Good luck on your finals!!! 
   
  And yep... it seems the battery only goes for like 10-12 hours...
  It's not bad... but their Cmoy lasted almost 20 on the same setting (i.e. I use my player+amp continuosly at work for up to 10 hours a day...)
   
  Still find the amp a bit bright so I think this is part of the "sound signature" with the opamp I
  bought it. It's not bad though and it's driving my D5000s well! Right now listening to Fiona Apple's Extraordinary Machine... great record
  and everything sounds crisp and clear with good instrument separation. Bass response is really good too.
   
  BTW, put up some Deadmau5 again this time with bass boost... uffff... I've never felt headphones vibrating this mad
  without producing any kind of distortion whatsoever... not sure if it's due to the capability of the amp, the headphones or both!


----------



## gelocks

Now that I'm feeling better (and have vacation days coming up  ) I'll be comparing the c421 and
  the NuForce Icon Mobile...
   
  Why the Icon Mobile?
  Because I believe this one is also a bright amp and it should be capable of driving my Denons...
   
  Anyone has compared the c421 to any other amps?


----------



## Shmitty

5 days w/out and new praise GOOD OR BAD?


----------



## gelocks

A few more impressions here:

 https://www.facebook.com/headfonia/posts/211639922252107


----------



## kyoshiro

the c421 is pushing my hd600 fine without high gain... amazing!


----------



## TheOneInYellow

I have finally, *finally*, wrote my impressions of my Custom cMoyBB v2.02 amp, John Seaber, and my future plans, in this post on this topic.
   
  So, why am I posting this bit of information here? I am going to, very soon (this week) purchase the C421, and I will be in contact with John. I will post anything of relevance from our conversation (that is not personal), and will make note on my initial impressions of the new amp when it arrives.
   
   
  This is a significant investment for me (as is the recently bought at a discount Ultimate Ears Triple.Fi 10 Pro IEM's from Amazon.co.uk), and along with some other possible purchases (a new LOD from Moon-Audio.com, custom sleeves/tips, and a replacement UE cable from Fiio, all written in my post linked above), will become a major feature of my audio rigs, home and portable, for some years.
   
  To those who own the C421 amp, could you post some impressions against other amps just for interest? Thank you


----------



## kyoshiro

Get the AD8620 if you're not driving high impedance phones. My AD8066 version is good but its probably too much on power side and not enough in clarity in my opinion. Gotta love lithium batteries though. Maybe i'll buy the AD8620 version when the new cases are ready for my Ie8s cuz man the aesthetics of this amp is superb.
   
  Quote: 





theoneinyellow said:


> I have finally, *finally*, wrote my impressions of my Custom cMoyBB v2.02 amp, John Seaber, and my future plans, in this post on this topic.
> 
> So, why am I posting this bit of information here? I am going to, very soon (this week) purchase the C421, and I will be in contact with John. I will post anything of relevance from our conversation (that is not personal), and will make note on my initial impressions of the new amp when it arrives.
> 
> ...


----------



## TheOneInYellow

Quote: 





kyoshiro said:


> Get the AD8620 if you're not driving high impedance phones. My AD8066 version is good but its probably too much on power side and not enough in clarity in my opinion. Gotta love lithium batteries though. Maybe i'll buy the AD8620 version when the new cases are ready for my Ie8s cuz man the aesthetics of this amp is superb.


 
   
  Thank you for your reply, and you have confirmed what I had always thought.
   
  I am indeed going for the AD8620 if I buy the amp (might be today 
	

	
	
		
		

		
			





), simply because the only high impedance headphones I own is the AKG K 701, which for anyone who knows, is not that high at all. Indeed, it's rating of 62 Ω is fairly efficient, though it is difficult to drive.
  Since I use my AKG K 701's so much, I prefer transparency and openness to my music, but I do like good bass. The K 701's are pretty good at this, though with my current amplifier, the NuForce Icon, it is not as detailed as my Etymotic Research ER-6i's using my JDSLabs Custom cMoyBB v2.02.
  The major selling point is the battery, portability, slimness, recharge functions, gain settings, and the Bass Boost switch. Oh, and the minimalist aesthetics; even if the Batch 2 faceplate's aren't as good as John and co like, they are still awesome looking (from the pictures I have seen), and the possibilty of getting the Batch 3 faceplate's in Feb for free (excluding the shipping cost) makes it a very good investment.
   
  So, for that reason alone, the AD8620 is essential to make my AKG K 701's really sing. 
	

	
	
		
		

		
		
	


	




 That transparency and power from the opamp will eclipse my NuForce Icon.
  More so, the bass boost feature that I use in my Custom cMoyBB v2.02 (exclusively for the ER-6i's) is also present on the C421, and looking at the spec sheet, its better than my cMoyBB; this means I can use it on my K 701 on some recordings, such as Trip-Hop and Electronica (some rock, but depends on recording), and turn it off for almost everything else, especially classical. In fact, I hate using the BB feature when using my K 701's with NIN records, as it does not work well, but I guess that's more to do with the cMoy amp; I shall test if the C421 will fair better, but I bet that Trent Reznor's music, especially his Ghost I-IV and recent soundtracks (with Atticus Ross) will sound better without the BB switched on. If I were to listen to, say, Daft Punk, then the BB will be switched on, because "_Daft Punk is playing in my house, *my house*_". 
	

	
	
		
		

		
		
	


	



  The BB will also be used for the K 701's when I play films from my PC using Dolby Digital (Asus Xonar D2X and CCCP with Media Player Classic- Home Cinema), and/or when I play Xbox 360 games (non-multiplayer or co-op) using my, poor, but cheap and decent, TurtleBeach EarForce DSS 7.1 Dolby Digital sound interface (if I play MM or co-op, I use a stereo set-up and my JohnBlue AudioArt JB3 speakers).
   
  BB will probably not be on most of the time with my UE Triple.Fi 10 Pro's (I doubt it needs the boost) except if I use it for films and Xbox 360 games (as described above), though I will test if this is necessary. Otherwise, the AD8620/Triple.Fi 10 pairing will be pretty awesome. 
	

	
	
		
		

		
		
	


	



   
  As for the ER-6i, I cannot imagine *not* using the BB _at all_, and I love how it retrieves detail from music, but it is very fatiguing. The AD8620 and BB will really help me use the ER-6i's for longer, as is the case with my Burr-Brown OPA2227P Custom cMoyBB v2.02 with BB on. 
	

	
	
		
		

		
		
	


	



   
  Yeah, I don't need the other op-amps in the C421, as I can have the best of both worlds; transparency, and bass boost. *WIN!*




   
  I like the idea of owning another C421 with a different op-amp (such as your AD8066), but instead, I might put that money towards owning the Objective2 from JDSLabs.com as part as my desktop headphone amplifier instead. That is for later (maybe sometime this year), but for now, the C421 has my heart. 
	

	
	
		
		

		
		
	


	



   
  Do you think my usage plans will work for my headphones and media?


----------



## kyoshiro

The batch 2 face plates are nice but the cutting is like 1mm off at some places lol 
  But yeah the bass boost is a good feature, however dont need bass boost when its IE8 @ max bass + AD8066 = too much lol.
  The intention at first was to actually have the C421 to push my HD600s thus AD8066 cuz of the 300ohms but 300ohms is like a peace of cake... even 600ohms thus the AD8620 op amp is sufficient for 300ohm. 
  Oh and with the Objective2... I have a PCB board coming and I just placed an order with Mouser for parts =p just gotta sort out the casing. As for desktop amp, i have 2 stationary amps atm, and will be buying a Schitt Lyr + Bifrost when the current stock arrives to HK so im sort there! 
  Dont forget the interconnect cable is also quite important =p I've found a good combination with my rectangular solid core ipod LOD with the amp.
  
  Quote: 





theoneinyellow said:


> Thank you for your reply, and you have confirmed what I had always thought.
> 
> I am indeed going for the AD8620 if I buy the amp (might be today
> 
> ...


----------



## TheOneInYellow

Ha ha, sounds like you have created a combination to make a subwoofer for your headphones! Lots of fun.
   
  As for your set-up, its great that you have gone for a modular based DAC (as they advance so very quickly these days) and a decent desktop amp. I just use my NuForce Icon, which was great at the time of purchase, but a future amp is on the cards, and the Objective2 is within a reasonable budget and looks to be a great price/performance/build/SQ.
   
  As for LOD/cables, I did own a female LOD dock and a nice male-to-male interconnect 3.5mm from ALO Audio, but the LOD dock broke a while back, so I have been using the crappy iPod output for a few years. No biggie, as I hardly use my portable rig. In fact, I had thought bout purchasing some Moon-Audio.com's LOD cables (either Blue or Silver Dragons V3), but decided against it on the basis of usage (very small), cost, and shipping costs (almost the same as the damn LOD cable!). Instead, I went for a super cheap but great FiiO L9 LOD cable; yes not the worlds greatest LOD, but it will do me fine, as it has some good reviews, seems to be well made (not comparing to expensive LOD's), and will do the job. I have no intention of spending ludicrous amounts of cash on something I will hardly use. If, however, I bought something like the ALO Audio AlgoRhythm Solo or the Fostex HP-P1, then I shall invest in a nice LOD. Until then, the FiiO L9 will more than suffice 
   
  Finally, and here is the *BIG NEWS*, I have purchased a C421 Amp today with the AD8620 opamp (just over 30 mins ago), and I beat the shipping cuttoff point by 5 mins! LOL!
  Got my tracking number too, so yay!!!
   
  Unfortunately, getting there was hard, but I can't discuss the details of why it took so long for my bank and PayPal to play nice, especially after I got my wages today. Seriously, so bad that I logged a complaint. 
	

	
	
		
		

		
		
	


	



   
  There is a lot of stuff that I want to, and allowed to (with some exceptions), write about here on this thread, mainly centring around the emails between John Seaber and myself, and how he and his staff are simply *AWESOME*! This word will be overused a lot!
  However, it's 23:09 here in the UK and I need sleep (especially after the farce above), so I shall do this tomorrow.
   
  Good night everyone!


----------



## 2000impreza

I seem to be having charging problems with the C421. While plugged in the orange charging led never turns off. Also once I pull the C421 off the usb charger and power on the unit, the red(low battery) indicator lights up right away. Does anyone else have this problem? I sent JDSlabs a e-mail this morning so I guess I'll wait for their response. I'm trying to decide if it is worth shipping this back to JDSlabs since I'm in Canada.


----------



## gelocks

No problems charging so far!
  John responses are fairly quick and his support is top-notch so maybe they can help you out without having to return it!
   
  Good luck and let us know how it goes!!


----------



## i_djoel2000

the unofficial review from headfonia is up: http://www.facebook.com/notes/headfoniacom/jdslabs-c421-impressions/316049348439769


----------



## adlkevin

exactly experiencing the same problem as yours, i have contacted with john and was told that most likely battery faulty connection. he will kindly help u out


----------



## F900EX

I'm getting all excited about amp's again .......
   
  These reviews are like a meal that look's fantastic but taste like .......
	

	
	
		
		

		
		
	


	



   
   
  Joking aside, sooo temped


----------



## jseaber

Quote: 





adlkevin said:


> exactly experiencing the same problem as yours, i have contacted with john and was told that most likely battery faulty connection. he will kindly help u out


 

  
  You two ordered the same week, and reported the same issue within 24 hours of each other. There are a number of possibilities, but we'll wait to receive and inspect both amps before drawing any further conclusions. The charging circuit is a solid reference design from Texas Instruments. It's worked flawlessly in our prototypes since 2009 and it's the one circuit which hasn't changed since then. So, I expect this to be a manufacturing flaw limited to a small number of units in the pre-production run. c421 has been in customers' hands since October without issue. Thus, it's highly unlikely to be a circuit design error.
   
  Final production will be performed by a large contract shop capable of performing in-depth testing on every single circuit board. Whatever this issue may be, it will be resolved by final release next month.
   
  Also, we're ceasing shipments of "temporary" c421's due to low inventory. New preorders will ship in late February.
   
  Edit: We've received one of three units with this known issue (not great, but not alarming out of 100). It seems to be caused by excessive solder paste beneath the charging IC. We'll make minor manufacturing adjustments, and the next batch will be tested more thoroughly and inspected by X-Ray.


----------



## adlkevin

Apart from the minor bugs in the preorder status, the listening experience that c421 gives me is really impressive. I have owned ALO RX MK2 and TTVJ SLIM before, I can just say that the c421 beats them all, no matter the potential of the bass or the rich mid, yet its resolution is even better than a harman kardon home amp, that it gives you as many detail as the songs have, really, believe it or not, you will be able to hear many more instruments at the background than before. You can try yourself, it just likes a successor of TTVJ SLIM, but please do remember that the c421 is only at half price of it!
   
  In conclusion, I recommend the c421 to you wholeheartedly, you will never regret even if you already own an expensive amp, or for a beginner, the c421 is certainly be your first choice. I am not a professional, but I just want to share my excitement with it to all head fier.
   
  In deed, it also provides you excellent customer service and after-sale support with quick respond and good communication, that I never expereince in online shopping. You will probably understand why I say that if you are a owner of Arrow amp...
   
  Now, let us wait for the final product to come out, it must the best buy in 2012!


----------



## Naim.F.C

Can't speak for this product yet, as I am yet to try it, but I can say, based off my experiences with John regarding the cMoyBB, a simple, cost effective amp that for me was comparable to amps many times it's cost, I have full faith in any new product JDS develops. It will be tremendously interesting to see how the impressions for the c421 pan out. I'm almost certain this amp will deliver in spades sonically and anticipate it to be among the best, for it's given price point, especially if the cMoyBB was anything to go by.
   
  For anyone looking for ultimate value for money, go JDS. In the mean time, great to see John on top of things with respect to ironing out any minor teething issues along the way. If I hadn't spent so much on new amps/DAC's in recent times, I'd have already jumped all over this beauty.


----------



## adlkevin

Quote: 





naim.f.c said:


> Can't speak for this product yet, as I am yet to try it, but I can say, based off my experiences with John regarding the cMoyBB, a simple, cost effective amp that for me was comparable to amps many times it's cost, I have full faith in any new product JDS develops. It will be tremendously interesting to see how the impressions for the c421 pan out. I'm almost certain this amp will deliver in spades sonically and anticipate it to be among the best, for it's given price point, especially if the cMoyBB was anything to go by.
> 
> For anyone looking for ultimate value for money, go JDS. In the mean time, great to see John on top of things with respect to ironing out any minor teething issues along the way. If I hadn't spent so much on new amps/DAC's in recent times, I'd have already jumped all over this beauty.


 


   
  looking forward to see if john will make a new product of amp and dac fusion


----------



## Naim.F.C

I'd be all over that. Hopefully something a bit more meaty and powerful. Still, a very exciting prospect.
  
  Quote: 





adlkevin said:


> looking forward to see if john will make a new product of amp and dac fusion


----------



## Kema

I have two JDS Labs c421 amps that I am going to sell because I need money badly. Comes with USB cable. One for $140 (msrp $180) and two for $240. Free Shiping. Please send message to 281-904-3976 if you are interested. link to amp description: http://www.jdslabs.com/item.php?fetchitem=c421


----------



## PANGES

^ Why do you have two? lol.


----------



## Roan3489

Quote: 





kema said:


> I have two JDS Labs c421 amps that I am going to sell because I need money badly. Comes with USB cable. One for $140 (msrp $180) and two for $240. Free Shiping. Please send message to 281-904-3976 if you are interested. link to amp description: http://www.jdslabs.com/item.php?fetchitem=c421


 


  PM sent. Just bought a cMoy v2.03 and I'm ready to add this to my collection


----------



## F900EX

I'd love to pre-order, but spending 174+ shipping for a product that, even they cannot guarantee will be ready by the end of Feb, given the history of pre-orders are never on time on HeadFi  Just does not to seem to make any sense right now.
   
  I will buy one, but just going to have to wait until they have them in stock. I'm sure I am not the only one.


----------



## gelocks

Quote: 





f900ex said:


> I'd love to pre-order, but spending 174+ shipping for a product that, even they cannot guarantee will be ready by the end of Feb, given the history of pre-orders are never on time on HeadFi  Just does not to seem to make any sense right now.
> 
> I will buy one, but just going to have to wait until they have them in stock. I'm sure I am not the only one.


 

 the amp is already done. a bunch of us have it since last year. the final enclosure is the only thing not finished but the enclosure included right now is not that bad... anyway, one of the best portable amps i've tried.


----------



## gelocks

quick pic,
   
   
   
http://twitpic.com/7y58za


----------



## syphen606

Not much talk about this amp yet I suppose? 
   
  I have 2x CmoyBB v2.03's and a Fiio E6 & E10..    (1x 9v model with OPA2227 and 1x 18v model with AD8620ARZ.) 
  I thought the Cmoy's were good. I thought the AD8620ARZ cmoybb sounded Fantastic!!!
  I got one of the 100~ so pre-order C421's in 2nd batch case.  The case really isn't all that bad, still looking forward to the finished case because it must be really nice if these were considered 'scrap'.  
   
  My C421 is AD8620 model and after about 60 hours of burn in on pink noise, white noise and various burn-in cd's (The whole process most likely wasn't needed but nor are most good-luck rituals).. this amp has pretty much wrecked all my other amps for me.
  The Cmoy's have more bass but its not as clear. Muddied if you will. This C421 is simply crystal clear to my non-audiophile ears..  With my Shure SE215's, I have to turn the bass boost off. On my Sennheiser HD 558 (foam mod), the clarity is simply amazing and I leave bass boost on to help fill these cans out.  ATH-M50's I typically leave bass boost off for my taste with this amp.
   
  Battery life so far has been hovering around 10 hours of use, maybe a little more. The switches don't operate from riding around in my backpack. Charge times are quick. 
  Love that I can listen to this amp while its charging.
   
  A very worthy amp for the money that has pretty much knocked my CmoyBB's from normal use.  Been using the E10 as a DAC only to feed it when at a desktop.
   
  I'm building an O2 amp now with PCB and faceplate from JDSlabs.. Hoping it compares to this C421 in sound signature for desktop use.


----------



## Mutnat

Tomorrow is February!  So presumably we have somewhere between 1 and 29 days to wait until they start shipping again...


----------



## PANGES

It's ready for shipment now if you don't mind their "defective" cases. I have one, and it's really not that bad. JDS says they'll offer a free replacement case when they're ready. You'd just need to cover shipping.


----------



## Mutnat

Not any more.  They ran out a few weeks ago.  If you look at the pre-order page it's been updated to say that.  I'm still kicking myself over waiting too long.
  
  Quote: 





panges said:


> It's ready for shipment now if you don't mind their "defective" cases. I have one, and it's really not that bad. JDS says they'll offer a free replacement case when they're ready. You'd just need to cover shipping.


----------



## PANGES

Oh really? I wasn't aware of that. Sorry! For what it's worth, I'm thinking about selling mine, because my Ultimate Ears UE4 Pro are too sensitive and I can't even use the amp without blasting my ears out. I was originally just waiting for JDS to offer the new cases before I sell mine, because I'm not sure if the new buyer would still be able to get a free case when they're ready if they're not the original buyer. 
  
  Quote: 





mutnat said:


> Not any more.  They ran out a few weeks ago.  If you look at the pre-order page it's been updated to say that.  I'm still kicking myself over waiting too long.
> 
> Quote:
> 
> ...


----------



## nihaz

Put me down as a happy owner of a C421, have had it for a just over a month... it certainly is an upgrade over the CmoyBB v2.03
   
  I do have a minor gripe though... I'm not sure what the correct term this should be called.. I seem to have channel imbalance? (please do correct me with the appropriate term) I hear my right earbud before the volume of my left one kicks in when I raise the volume of this amplifier, it only occurs at very low volume levels...
   
  It seems to go away (or I do not notice it anymore) once the volume reaches my desired listening level...
   
  Any C421 owners experience this?


----------



## kyoshiro

yeah its like it hasnt fully engaged yet at low volumes, i do assume its limitations with these dial things instead of going for a pot. There no imbalance that i know of beyond that point though.
  
  Quote: 





nihaz said:


> Put me down as a happy owner of a C421, have had it for a just over a month... it certainly is an upgrade over the CmoyBB v2.03
> 
> I do have a minor gripe though... I'm not sure what the correct term this should be called.. I seem to have channel imbalance? (please do correct me with the appropriate term) I hear my right earbud before the volume of my left one kicks in when I raise the volume of this amplifier, it only occurs at very low volume levels...
> 
> ...


----------



## nihaz

Quote: 





kyoshiro said:


> yeah its like it hasnt fully engaged yet at low volumes, i do assume its limitations with these dial things instead of going for a pot. There no imbalance that i know of beyond that point though.


 

 Thanks for confirming... I thought I was going deaf in one ear or something...
   
  It's not that big of an issue for me because its the volume is very low when it kicks in... It's gone by the time i reach my normal listening volume so I'm a happy chappy


----------



## PANGES

Lucky! My normal listening levels are right at where the imbalance is.. But that's just because my UE4's are really sensitive. I don't have that issue with my Ety ER4S. 
   
  ... btw: If you guys have a pair of ER4S, or can get your hands on some, I'd advise you to try them out with the C421. IMO, they pair up really really well.
  
  Quote: 





nihaz said:


> Quote:
> 
> 
> 
> ...


----------



## jseaber

Quote: 





panges said:


> Lucky! My normal listening levels are right at where the imbalance is.. But that's just because my UE4's are really sensitive. I don't have that issue with my Ety ER4S.
> 
> ... btw: If you guys have a pair of ER4S, or can get your hands on some, I'd advise you to try them out with the C421. IMO, they pair up really really well.


 

  
  We're reducing low gain in the final batch, which should lessen this imbalance. Gain of 3.5x was a bit much for the sensitive pot when combined with high sensitivity IEM's.
   
  I'm sure it will be asked: The gain resistors are very expensive and time consuming to replace by hand (not free, sorry).


----------



## PANGES

Quote: 





jseaber said:


> Quote:
> 
> 
> 
> ...


 

 About how much will it run? If this is possible, it may still be worth it for me.


----------



## nihaz

Quote: 





panges said:


> About how much will it run? If this is possible, it may still be worth it for me.


 


  +1
   
  Would be keen to have this performed if the price is reasonable.... as I will be getting some sensitive IEMs that will probably benefit from this procedure...
   
  Thanks for responding to this thread too John! It's nice to see companies stand by and provide support for their products


----------



## F900EX

Looking forward to buying this AMP ....


----------



## Yuceka

So do we know when the first batch will be ready if I order one right now?


----------



## jseaber

yuceka said:


> So do we know when the first batch will be ready if I order one right now?


 
   
  Our fabricators are on track to deliver by the end of this month (28-29th). We'll ship within 24 hours.
   
  Quote: 





panges said:


> About how much will it run? If this is possible, it may still be worth it for me.


 

 Parts, labor, and return shipping for gain modification would total about $15. Note that going from 3.5x to 2.5x is about a -3dB change, which is fairly small. I point this out because we're seeing similar concerns from our O2 customers, and the default gain is already 2.5 there.
   
  I didn't want to move from an analog to a digital pot in c421, but the trend over the past few years has been towards lower impedance, higher sensitivity headphones and these increasingly do not pair well with analog pots assuming low listening levels. To achieve excellent channel balance in such setups, one must either must forgo line-level input (i.e., reduce source volume), use a large potentiometer or stepped attenuator (not portable friendly), or go for a device with a digital pot (usually lower fidelity).
   
  Venturing off topic. Lowering gain will help slightly, but forgoing an LOD is the best fix *if* the headphone output of your source isn't too bad. Again, this is a non-issue with larger cans.


----------



## PANGES

Quote: 





jseaber said:


> yuceka said:
> 
> 
> > So do we know when the first batch will be ready if I order one right now?
> ...


 

 Oh, so even if I have this done, it still might not help me..? 
   
  Is there any chance of an impedance switch in the future (like the Practical Devices XM6.) That was the only thing that made the amp usable for me, because without it, I had a similar issue that I'm having now.


----------



## jseaber

Quote: 





panges said:


> Oh, so even if I have this done, it still might not help me..?
> 
> Is there any chance of an impedance switch in the future (like the Practical Devices XM6.) That was the only thing that made the amp usable for me, because without it, I had a similar issue that I'm having now.


 

 It might help, it might not. Depends on how far away your ears want to be from the "bad" spot at the start of the potentiometer.
   
  No impedance switch will be added. Adjusting input or output impedance dramatically alters signal behavior.
   
*EDIT:* Listening to c421 right now with the new 2.5x gain through 16 ohm, [size=small]108 dB/mW[/size] IEM's. Balance at low volumes is excellent, in my opinion. Better than many RK097's we've shipped! I'll probably regret this, but anyone who has a c421 in a temporary case may send their amp in for a complete v1.01 upgrade (new case + gain change).


----------



## F900EX

Jseaber -
   
  I know this might be a difficult question, but between the 2 Amps, O2 and your own c421, what are the biggest differences when it comes to the sound they give out.


----------



## syphen606

Quote: 





f900ex said:


> Jseaber -
> 
> I know this might be a difficult question, but between the 2 Amps, O2 and your own c421, what are the biggest differences when it comes to the sound they give out.


 
   
  On reading various thoughts around the internet, it seems they have similar sounds but the C421 is an ultra portable compared to the O2. The few comparisons are that the O2 may have the edge (ever so slightly) on sound.   You do gain the bass boost feature with the C421 which is nice if you like filling out the lows with a particular set of really bright phones that you like.   If your handy and understand electronics, there is mods to ADD a bassboost setup to an O2 which has been posted on DIY audio.
   
  I'll let you know when I finish my O2.   I have the enclosure and all internal parts sitting on the bench but am missing the PCB and faceplate (Seemingly lost in mail purgatory as my friend who orders his after me go his earlier this week!  Really hoping it shows up next week.)


----------



## Jonasklam

Hi guys,
   
  I noticed some of are interested in purchasing this amp, but don't want to wait for shipping to begin.
   
  I am welling to sell mine if any1 is interested? I have hardly used it and selling because I need money :/
  Any takers? Send me a PM 
   
  I am in EU though


----------



## Mutnat

Might be tempting were you not in the EU. 
   
  PS: I think it's important for people listing theirs for sale (or giving their impressions) to also mention which opamp they ordered their amp with.
   
  Quote: 





jonasklam said:


> I am welling to sell mine if any1 is interested? I have hardly used it and selling because I need money :/
> Any takers? Send me a PM
> 
> I am in EU though


----------



## Mutnat

JDS store now says orders will ship between Feb 29th and March 9th.  I hope mine ships on the earlier end of that range!


----------



## theotherbk

Quote: 





gelocks said:


> Good luck on your finals!!!
> 
> And yep... it seems the battery only goes for like 10-12 hours...
> It's not bad... but their Cmoy lasted almost 20 on the same setting (i.e. I use my player+amp continuosly at work for up to 10 hours a day...)
> ...


 

 Hey gelocks
  My first Head-fi post...exciting stuff! 
   
  So I've recently acquired the D5000 (loving them so far...have just over 100 hrs burn in and they just keep getting better. Bass is just a tad heavy, but worth it for the overall sound sig.).
  Which opamp option did you go for? Am getting the C421 and having trouble deciding between the 8620 and 2227? You mentioned the amp being a bit bright...would you choose the same opamp again?
   
  Thanks in advance!


----------



## gelocks

Quote: 





theotherbk said:


> Hey gelocks
> My first Head-fi post...exciting stuff!
> 
> So I've recently acquired the D5000 (loving them so far...have just over 100 hrs burn in and they just keep getting better. Bass is just a tad heavy, but worth it for the overall sound sig.).
> ...


 

 Hello!
  Welcome to head-fi! 
   
  I went with the 8620. And yes, it is a bit bright but I believe it pairs rather well with both the Denon D5000s and Beyer 770 Pro 80 (which I mostly use with the amp). The amp as-is is a huge step-up from the JDSLabs CmoyBB, the NuForce Icon Mobile and the other cheapo Cmoy I had!
   
  Would I choose it again? Probably as I don't know how the 2227 sound but some people find that the latter is more spacious and provides more mids. Mike from Headfonia put up his impressions on:
   
http://www.facebook.com/note.php?note_id=316049348439769
   
  and he raves about 2227 (he didn't really like the 8620... ).
   
  Thing is that the opamp is not replaceable (  ) so you have to take a chance to see which one you like! You could always order two and sell the one you like less! lol 
   
  Good luck!
  And keep enjoying those D5000s! (they're sweeeeeet!!!)


----------



## JRoMan

I've also got the AD8620 version and thought it bright at first. Been using it regardless mostly with my HD25 for the past 1.5 months and a bit with my HD580 in just the past couple weeks. I think the treble has settled a bit (or I'm just getting used to it). My only real comparison is my PA2V2 amp, which is decidedly warm compared with the c421. But maybe the 8620 is just neutral to slightly treble forward, rather than really "bright." Bass is still really nice and tight, though.
   
  I do wonder about the OP2227 version, and hopefully will have a chance to listen to one.


----------



## PANGES

Shameless plug, but if anyone doesn't want to wait for the preorder batch to come out, I've posted my JDSLabs C421 with the AD8620 opamp up for sale.
   
  http://www.head-fi.org/t/596207/jdslabs-c421


----------



## syphen606

My experiences of back-to-back rolling between the 2227, 8066 and 8620 all come from a JDSLabs CmoyBB.  Out of all of them, I preferred the 8620. It was a little 'brighter' if you will then the 2227 but I just found it clear and detailed.   I went ahead and ordered my C421 in 8620 and have had it for a month and a half now. Really loving it.  Sound quality it is just about on par with the O2 (bass boost off) but with the added benefit of fitting in my pocket.     My HD650's simply sound amazing with the C421 and I'll admit that I like the sound of them with the bass boost on... a feature the O2 lacks in default configuration.
   
  Safe bet, the 8620 will work for you.


----------



## sluker

..


----------



## Mutnat

Curious--how does the C421/8620 compare to the PA2V2 with the HD25's?  I know the PA2V2 is fairly well regarded, and the main thing that stopped me from trying it was the dimensions didn't seem very pocketable (would have preferred flatter even if bigger in the other dimensions, like the C421).  I'm waiting on a C421/2227 based on Headfonia Mike's recommendation, and because the HD25 is a mildly-bright can to begin with and I worried it might be too bright with the 8620. 
   
  Quote: 





jroman said:


> I've also got the AD8620 version and thought it bright at first. Been using it regardless mostly with my HD25 for the past 1.5 months and a bit with my HD580 in just the past couple weeks. I think the treble has settled a bit (or I'm just getting used to it). My only real comparison is my PA2V2 amp, which is decidedly warm compared with the c421. But maybe the 8620 is just neutral to slightly treble forward, rather than really "bright." Bass is still really nice and tight, though.
> 
> I do wonder about the OP2227 version, and hopefully will have a chance to listen to one.


----------



## jseaber

Our PCB assembler says v1.01 boards will be delivered Feb. 29th. Final cases are supposed to ship on the 28th. We'll have them overnight enough to cover preorders.
   
  It's a super tight schedule, but I'm finally happy with the progress. We added a chamfer to smooth out the rough panel edges (picture is only a sample, not final!):
   

   
  Quote: 





mutnat said:


> JDS store now says orders will ship between Feb 29th and March 9th.  I hope mine ships on the earlier end of that range!


----------



## Mutnat

Thanks for the update, John!  That chamfer (I had to look it up on Wikipedia, so I learned a new word today!) sounds like it will add some nice polish to the appearance, and it's great to hear things are on schedule.  I can barely wait to try mine!


----------



## syphen606

Looks great!  Can't wait to get the new case.  What are the 1.00 to 1.01 changes?
   
   
  Quote: 





jseaber said:


> Our PCB assembler says v1.01 boards will be delivered Feb. 29th. Final cases are supposed to ship on the 28th. We'll have them overnight enough to cover preorders.
> 
> It's a super tight schedule, but I'm finally happy with the progress. We added a chamfer to smooth out the rough panel edges (picture is only a sample, not final!):


----------



## JRoMan

Quote: 





mutnat said:


> Curious--how does the C421/8620 compare to the PA2V2 with the HD25's?  I know the PA2V2 is fairly well regarded, and the main thing that stopped me from trying it was the dimensions didn't seem very pocketable (would have preferred flatter even if bigger in the other dimensions, like the C421).  I'm waiting on a C421/2227 based on Headfonia Mike's recommendation, and because the HD25 is a mildly-bright can to begin with and I worried it might be too bright with the 8620.




 I'm in my cubicle with the HD25 and both the PA2V2 and c421/8620. I've listened to a handful of tracks back and forth. For reference, they included:

 Adele, "Rolling in the Deep"
 The Civil Wars, "Poison and Wine"
 Ella Fitzgerald, "Bewitched, Bothered, and Bewildered"
    
 and a more rocking song for good measure (well, at the end, at least)

 The Black Keys, "Little Black Submarine"
  
 I like using female vocals as it's one of the things I focus on when listening to music, so hence it is more or less my reference when evaluating headphones and the like. These tracks also include some of the following: tambourine, cymbal, piano, and guitar, which I used as an indicator of the brightness or treble emphasis. I do honestly think the c421 has smoothed out since I got it in late December. The PA2V2 I've had basically a year, so it is well run in. As I alluded to before, the PA2V2 is tilted more to the warm side and I'm guessing might be closer to the smoothness of the c421/2227 that Headfonia Mike has mentioned in his postings on FB. The 8620 on the other hand is tilted more to the upper-mid/treble, so there is a little more air under the vocals. The PA2V2 is a little more "weighty" and grounded with the vocals, and if you want to call that "smoother," I think that is what I hear. The c421 is a bit more forward and clear in the upper mid and treble (if you want to say "detailed" I can go with that - I'm still coming to grips with some of this terminology, can you tell?). It is more forward with the guitar riffs on the Black Keys' track and the piano on some of the others. The other way to look at it is there is generally a little more right hand piano emphasis on the c421/8620 and more left hand piano emphasis on the PA2V2. I think the PA2V2 might play a notch bassier, but the c421 may have a little more punch, if that makes any sense. Flipping the bass boost on the c421 brings it up like 4 notches, and it doesn't really bleed into and affect the midrange, so the vocals actually still sound about the same.
  
 To wrap up, I wouldn't say the c421/8620 & HD25 combo is TOO bright, but it might not be favorable to everyone's ears, depending on your tolerances. A month ago, I was leaning towards it being too bright. Also realize I've only had the HD25 about as long as the c421, so there may be some synergystic breaking in going on, who knows.
  
 I did have a chance to listen to some Grado SR80i and 125i with my c421 a few weeks ago and that was not really an ideal combo. It brought out a lot of sibilance, esp. with the SR80i's.
  
 Lastly, the form factor of the c421 wins over the PA2V2, though the battery life of the PA2V2 (I'm running Sanyo Eneloops) is amazing. Hope that wasn't too long winded.


Forgot to add, while I didn't notice that much this time around, in previous comparison (using Shure SRH840) the PA2V2 plays slower, while the c421 plays a quicker pace. It was actually quite interesting to hear it, because it is a somewhat abstract thing to comprehend. I found that intriguing since many reviews of the PA2V2 I've read praise it for its PRaT. It makes some sense, though, because of the darker/warmer signature that it would sound slower.


----------



## jseaber

All manufacturing changes, except for the reduced gain discussed above [settled on a low gain of 2.3x]. Much of this will come across as technical speak to non-engineers:
   
• Reduced low gain from 3.5x to 2.3x
• Manufacturing: Changed battery jack J2 from thru-hole to SMT
• Manufacturing: Decreased solder paste beneath charging IC, U2
• Manufacturing: Changed PCB finish from HASL to ENIG (better QFN solderability)
• Manufacturing: Changed PCB panel from 4-up to 3-up
• Manufacturing: Moved tab-routed mousebits inwards
• Manufacturing: Added 0.3mm reinforcement vias to SMT audio jack pads
  Quote: 





syphen606 said:


> Looks great!  Can't wait to get the new case.  What are the 1.00 to 1.01 changes?


 

 @JRoMan : You must have Mike's ears. Might want to switch to the OPA2227.


----------



## syphen606

Quote: 





jseaber said:


> All manufacturing changes, except for the reduced gain discussed above [settled on a low gain of 2.3x]. Much of this will come across as technical speak to non-engineers:
> 
> • Reduced low gain from 3.5x to 2.3x
> • Manufacturing: Changed battery jack J2 from thru-hole to SMT
> ...


 

 Thanks John!  Its gracious of you to share the on going changes of the C421.
   
  I'm fine with the gain settings where they are in my pre-order model (8620 w/3.5x). So this change is of little effect to me based on my current headphone inventory.
   
  I guess an electrical engineering background has me interested in the changes..
   
    I understand the ENIG soldering, (I haven't opened the case yet to see which components are QFN yet.. Soon enough with the new case) considering the smt components used and the scale your looking at producing (Hopefully), as well as reducing to 3-up from a cost POV if the 4th plane is not in use. Ditto to the mousebits. These changes just seem cost/quality related from a production stand point.
  It looks like the other changes revolve around mechanical strength of the jacks for both battery and audio jacks. Has there been an observeable history of issues or failures with on going use of these in the v1.00 models?
   
  And on a side note, Sennhesier HD650's & C421 with AD8620 is a real winning combo off a good DAC.


----------



## Grev

Ordered cmoys x2 then O2 x2 from John, now I might be itching to buy this one hahaha, so far my dealings with JDSLabs is pretty awesome.


----------



## jseaber

Just to confirm understanding, 4-up and 3-up refer to the number of circuit boards on a production panel (not number of layers). All c421's are 4-layer boards. The first run was arranged in a 4-up panel:
   

   
  Without delving into a long-winded explanation, we ended up with 3 boards on the v1.01 panel. Higher board cost, but easier assembly.
   
  HASL = Hot Air Surface Leveling. ENIG = Electroless Nickel Immersion Gold. HASL is the standard PCB finish with very low cost. However, and this is a lesson we paid for dearly in 2011, HASL boards have an uneven surface only good for through-hole and large SMT components (SO-8, etc.). This can result in tiny solder bridges beneath QFN parts--usually on 2-5% of boards. And this creates fun problems which arise after a board heats up for the first time, like charging circuits not charging, and misbehaving status LEDs. 
	

	
	
		
		

		
			





 ENIG raises board cost, but produces a flat surface, great for fine pitch parts. The high cost of implementation is partly why you don't see high performance QFN parts on sub-$100 amps and DACs.
   
  All battery jack failures were caught prior to shipment. The failure was either present, or it was not (will not occur over time). This was a mechanical strength issue with ground vias coupled to J2, not a jack strength problem. Easily resolved.
   
  As with any device employing SMT audio jacks, a few customers managed to rip a jack from the board. It hasn't been a major issue, but we're minimizing the possibility.
   
   
  Quote: 





syphen606 said:


> Thanks John!  Its gracious of you to share the on going changes of the C421.
> 
> I'm fine with the gain settings where they are in my pre-order model (8620 w/3.5x). So this change is of little effect to me based on my current headphone inventory.
> 
> ...


----------



## syphen606

Thanks for the info John (and the correction on the layering vs boards per panel! my mistake).


----------



## F900EX

Which opamp offers better sound stage and clarty/details ?


----------



## Mutnat

@JRoMan : thanks for the impressions, that's great.  I'm still getting used to all the terminology and what it really means, too.


----------



## Donnyhifi

Quote: 





f900ex said:


> Which opamp offers better sound stage and clarty/details ?


 


  I believe the AD8620 would be the ideal choice, I'm thinking of picking up one of these with the AD8620 since I have warmer sounding portable cans. My UM3X and Fitear MH334 Customs are a bit on the warm side but portray a high level of detail, I think this would be the best choice especially with the reduced low gain.


----------



## raysclim1568

Hello all 
   
  anyone have experience how C421 comparing with ALO Continental V2 ? 
  Below are the specification for continental V2 :-
   
   
 *SPECIFICATIONS* * *

 Tube type; one Raytheon 6111 NOS tube
 Battery: Lithium-Polymer 
 Battery Play Time: Approximately 7 - 8 hours per charge 
 Recharge Time: Approximately 3-4 hours 
 Frequency Response: 40Hz-20KHz +/- 1dB 
 Signal-to-Noise Ratio: >100dB 
 Total Harmonic Distortion: 1% 
 Stereo Crosstalk: >85dB @ 1KHz 
 Input Impedance 30K ohms Output 
 Output 300mW@ 32 ohms 
 Dimensions: 120mm (L) x 72mm (W) x 27mm (H)
  

 And Specification for C421 are below :-

  


 Run-Time: 11+ hours
 Charge Time: 2 hours to 80%, <5 hours to 100%
 Frequency Response: +0.01, -0.41 dB (20Hz-20kHz)
 SNR: Exceeded test equipment*, > 110 dB (20-20kHz)
 THD: Exceeded test equipment*, < 0.0041%
 Crosstalk: Exceeded test equipment*, < -57dB
 Output Impedance: 0.1 ohms
   
  How does the above two specification tell us ? 
  I am planning to use it to pair with my LCD2 , AKG Q701 . both are around 60Ohm impedences .
   
  Thanks 
 Raymond Lim


----------



## ClieOS

You can't look at spec and tell which is better. It doesn't work that way in most cases.


----------



## bluishgreen

Quote: 





raysclim1568 said:


> Hello all
> 
> anyone have experience how C421 comparing with ALO Continental V2 ?
> Below are the specification for continental V2 :-


 


  I was looking at the ContinentalV2 and the RSA SR-72A before the C421 came about.  Mike from Headfonia stated in his pre-release mini-review that the Continental (although I believe the original version) and the SR-72A are still better amps from a purely SQ point of view--however, it didn't appear to be by a lot, since he still recommended the C421 overall when taking into account everything like size and shape and extra features like bass boost.  When you consider that the other two amps cost more than twice as much (almost 3X for the Continental V2) it's tough not to go with the C421 if the SQ is that close.  But it will always come down to what you're looking for.  Do you want the more slim form factor of the C421 or is SQ your only criteria?  Do you specifically want a tube amp and the (usually) more natural high/treble tones that comes with it?  Is bass boost important to you?  Things like these are the real determinants, along with the price difference.
   
  I'm still leaning towards the 8620 opamp, since I find my DT880's a touch too warm with my current setup, and am hoping the said brightness of the 8620 will help a bit.  I'm guessing, though, that this opamp won't work well with my K702's, and will likely make them too abrasive.  It sounds like the 2227 would be better for K701/2s, although I'm really more concerned with tweaking my DT880's sound than the K702's.  Although, I also wonder about the clearer mids of the 2227 (at least, according to the review).
   
  Of course, I could buy two C421s--one with each opamp--and it'd still be over $150 cheaper than the one ContinentalV2 that I was going to buy.  So...that way, I'd actually be saving money...right?


----------



## theotherbk

gelocks said:


> Hello!
> Welcome to head-fi!
> 
> I went with the 8620. And yes, it is a bit bright but I believe it pairs rather well with both the Denon D5000s and Beyer 770 Pro 80 (which I mostly use with the amp). The amp as-is is a huge step-up from the JDSLabs CmoyBB, the NuForce Icon Mobile and the other cheapo Cmoy I had!
> ...




Thanks gelocks! Sorry for the delayed response...thought I had set this to email notification. :/

Mike's take is interesting...it was so definitively pro 2227. I had actually read it before but wasn't getting much of a read as to whether the 2227 would necessarily be a good match for the d5000's. It seems that in general opinions of the 8620 are fairly positive. Maybe I should get a cmoy to start, see how both the chips sound with the d5k's. I know that it's not the same but maybe close enough a read to know which c421 to get....and I could continue to try different opamps/tins with the cmoy.
I guess I could alternatively just get two c421's but given my track record I'd just end up with two c421's...I'm more a buyer than a seller.  

Thx! B


----------



## Mutnat

An update from the order page:
   
*Current Status: Now shipping preorders. All preorders will ship March 8 or sooner.


----------



## ClieOS

Saw that half an hour ago. Hopefully I'll receive mine in a week or two, finger crossed.


----------



## F900EX

Just Ordered mine, says it will ship in 2-3days.
   
  Looking forward to it ....


----------



## Mutnat

Got my shipping notice this afternoon.


----------



## wje

I should have checked this thread for the latest updates.  I just ordered my 2nd O2 amp today - this recent one being from JDS Labs.  I could have ponied in a few more $$ and had this other amp.  I guess I'll put one O2 up for sale and watch how the reviews come up on this amp comparing the two different op-amps and then decide what to choose.


----------



## Donnyhifi

Ordered an AD8620 version of the C421 and looking forward to trying it out. I borrowed my friends Go Vibe V6 AD8620 version for my diymod project and it matches up well with my Fitears, I'm figuring the JDS C421 should be a substantial upgrade.


----------



## syphen606

Quote: 





wje said:


> I should have checked this thread for the latest updates.  I just ordered my 2nd O2 amp today - this recent one being from JDS Labs.  I could have ponied in a few more $$ and had this other amp.  I guess I'll put one O2 up for sale and watch how the reviews come up on this amp comparing the two different op-amps and then decide what to choose.


 


  Its a similar quality of sound between my 8620 C421 and my O2 (With C421 bass boost off). I'd maybe give the nod ever so slightly to the O2 but not enough of a difference to my ears to really notice. BUT The C421 is true portable and offers the bass boost feature which I like for certain headphones (Like my Senn 558's).  I usually grab the C421 so far if I want to sit back on the couch or am travelling and use the O2 when at my computer.


----------



## wje

Quote: 





syphen606 said:


> Its a similar quality of sound between my 8620 C421 and my O2 (With C421 bass boost off). I'd maybe give the nod ever so slightly to the O2 but not enough of a difference to my ears to really notice. BUT The C421 is true portable and offers the bass boost feature which I like for certain headphones (Like my Senn 558's).  I usually grab the C421 so far if I want to sit back on the couch or am travelling and use the O2 when at my computer.


 

 Thanks.  It's great to know that the O2 isn't at the point yet where it's ready to be packed away in the attic with moth balls.


----------



## mikek200

Syphen,
   
  I recently got a pair of Audeze lcd2's,and I was looking to upgrade my amp..{currently own the PA2V2}},and i sent John an email concerning which c421,& if I should get.the 8620,or the 2227
  I was really looking for a desktop amp-dac...
  My thinking was that the 8620 might be a little too bright..he convinced me,that I should get the 2227.
  .
  Here is part of his reply:
  " The O2 is a large amp, best for desktop use. c421 offers similar output
power and neutrality of the audio signal, and adds bass boost and smart USB
recharging. More importantly, c421 is 4x smaller and 3x lighter. It serves
well as a portable or desktop amp"
Dealing with John is a real pleasure ,and I'm sure the tech support,will be just as good,if needed.
   
 I'm expecting delivery of my c421 on Tuesday.
I'm hoping this will work ..and I can find a good quality DAC to match....


----------



## wje

Quote: 





mikek200 said:


> Dealing with John is a real pleasure ,and I'm sure the tech support,will be just as good,if needed.


 

 You are correct on that.  He's a great guy.  Though, this weekend, I felt a little bad because he called me to verify my order in the afternoon following the large tornado in southern Illinois and I didn't confirm that things were OK for him and all.  Though, I hope that he made it through without issue.  Then, we have the big twisters (level 4) that hit Indiana / Ohio, too.


----------



## F900EX

Mine has shipped, I went with the OPA2227 as according to Headfonia's review the OPA2227 gives better clarity and sound stage.....

 I hope he's right


----------



## bobsilver

I received my 421 today with the 8620.  I currently have an JDS Cmoy 2227 low gain model and a PAV2.  For headphones I have Senn 650, Audiotechnica ATHM50 and Grado 225 as well as Etymotic ER4S.
   
  My first impressions are these.  The 8620 is not overly bright by any means.  In fact while I have not A/B them Id say the 2227 Cmoy seems to have a brighter sound but I am going on memory and as I said havent done a direct compare.
   
  The 421 sounds very good but I cant say that it is dramatically different or better then my other amps.  A big reason I did buy it was to be able to use all my phones with one amp.  Before I used the PAV2 to drive the Sennheiser 650 which it did quite well.  And the CMoy for the Grado and the ATH M50.  The Ety frankly never really sounded that good with either amp.
   
  As to my day 1 test I spent most of my time listening to my Senn's and my Etys.  The Senn's sound good (and I am using low gain).  Maybe a bit more open then with the PAV2.  Bass is good but again it wasnt an OMG experience.  Guess that speaks to how good the PAV2 is.
   
  The Ety on the other hand sound quite good.  Extremely open and light.  No congestion and sound as if they were open air phones not IEM at all.  The bass is not nearly as good as the Senn's but with the bass boost on helps quite a bit.
   
  As with any component like this it will take some time to appreciate it fully.  So far I am happy just not blown away like I was the 1st time I used my CMoy with my Grado's or my PAV2 with my Senn 650.
   
  Clearly I am at the point of deminishing returns here I suppose.
   
  But in the end it meets the needs I purchased it for.
   
  I'll report back once I have put more time into it.
   
  Bob Silver


----------



## marlonmarabe

you need to burn it in bob


----------



## mikek200

"You are correct on that.  He's a great guy.  Though, this weekend, I felt a little bad because he called me to verify my order in the afternoon following the large tornado in southern Illinois and I didn't confirm that things were OK for him and all.  Though, I hope that he made it through without issue.  Then, we have the big twisters (level 4) that hit Indiana / Ohio, too." 
   
Yes,things are not going well for a lot of people in that part of the country..it's been terrible for them.
   
I am thinking of pairing the newC421 with this DAC: 
   
http://www.mav-audio.com/base/product/tubemagic_d2 
   
Do you think it will work well?
   
Mike


----------



## mm1434

I just got my c421 today.  Been using the cMoyBB for about a month with my Monster Turbine Copper IEMs and then my Denon D2000 cans (both of which sound great on the cMoy).  My first impression c421 was..... bright and less bass (not as clear or defined).  I'm curious how long of a burn in an amp requires.  I know with the Denons (headphones) - I had to burn them in for a week or so before they started sounding right - do amplifiers need the same thing?  I got the 8620 in the c421 and have the 2227  in the cMoy... Just curious...


----------



## wje

Quote: 





mm1434 said:


> I just got my c421 today.  Been using the cMoyBB for about a month with my Monster Turbine Copper IEMs and then my Denon D2000 cans (both of which sound great on the cMoy).  My first impression c421 was..... bright and less bass (not as clear or defined).  I'm curious how long of a burn in an amp requires.  I know with the Denons (headphones) - I had to burn them in for a week or so before they started sounding right - do amplifiers need the same thing?  I got the 8620 in the c421 and have the 2227  in the cMoy... Just curious...


 
  Did you use the bass boost on your CmoyBB amp?   Are you using the bass boost on your C421?  Or, are you keeping it "off" to keep the playing field level?


----------



## mikek200

I got my 421 today,with the 2227 opamp.
  With the lcd2,I find this amp very,very close to the PA2V2.
  On some songs I used for the comparison however..I picked up very delicate parts of the music ,that I did not hear, with the pa2v2. Cymbals,brushes}..,.strange/confusing ,but nice..don't know how to explain it.
   
  It is definetly a quality product,the build quality is worth the price,and the bass boost,I'm sure I will use on my hd598's
  I sent John an e-mail about the break-in.
  here was his reply:
        "[size=11pt]Mike,[/size]
   
[size=11pt]My recommendation has always been to listen to an amplifier as soon as it arrives. Burn-in shouldn't take longer than 100 hours. The difference depends on your headphones and your ears.[/size]
    
[size=11pt]Best regards,[/size]
   
*John Seaber, E.I.*
[size=10pt]Electrical Engineer | President, JDS Labs, Inc.[/size] | [size=10pt]@jdslabs[/size] [size=10pt]| *Tel: *(573) 366-0475"[/size]
   
  I didn't spend much time with the amp last night-had to go to work..I am listening to it now,and I will start to give it 100 hours,as per Johns' advise
   
  Question:
  Have any of you guys heard a rumor about JDS labs,building a amp/dac combo unit,styled after the 02 ???
  I am in need of a dac..if his new venture has, half the quality of the C421,I'll be jumping all over it.
   
  Looking forward to your comment/,suggestions,
  Mike


----------



## mm1434

Quote: 





wje said:


> Did you use the bass boost on your CmoyBB amp?   Are you using the bass boost on your C421?  Or, are you keeping it "off" to keep the playing field level?


 

 Both of my headphones have nice bass - so I leave everything flat always.  I didn't use the bass boost on the cMoy and haven't been on the c421.
   
  I left the amp on all night while music was playing.  It has settled a little - on bass-y songs, it isn't "breaking up" but is a little smoother than it was last night.  I'm used to a sonic full rumble - not tight exactly, just smooth subsonic sound on bass and it was just crumbling last night - that is what I noticed as I was anticipating the sound.  It still isn't as pronounced.  The treble isn't as startling either.
   
  I'm thinking they just need some time.  I'm not going to listen to the cMoy for a while and then do a comparison after a week or so...


----------



## bobsilver

Quote: 





bobsilver said:


> I received my 421 today with the 8620.  I currently have an JDS Cmoy 2227 low gain model and a PAV2.  For headphones I have Senn 650, Audiotechnica ATHM50 and Grado 225 as well as Etymotic ER4S.
> 
> My first impressions are these.  The 8620 is not overly bright by any means.  In fact while I have not A/B them Id say the 2227 Cmoy seems to have a brighter sound but I am going on memory and as I said havent done a direct compare.
> 
> ...


----------



## ClieOS

Hence the reason why many (me included) like to listen to Grado with tube amp, as tube amp tends to mellow out the hardness of Grado.


----------



## bobsilver

Quote: 





clieos said:


> Hence the reason why many (me included) like to listen to Grado with tube amp, as tube amp tends to mellow out the hardness of Grado.


 


  But I will tell you the Cmoy2227 low gain with the Grados is excellent.  So point is you can still get an excellent sound with solid state.


----------



## ClieOS

Quote: 





bobsilver said:


> But I will tell you the Cmoy2227 low gain with the Grados is excellent.  So point is you can still get an excellent sound with solid state.


 

 I do have cmoyBB with OPA2227. OPA2227 is a 'flat, upfront and a bit warm' sounding opamp to me and it isn't nearly as revealing as AD8620, so I guess it can work out for Grado in some way. Personally, I just don't like OPA2227 that much and never quite care to use Grado with portable amp because of the heavy cable.


----------



## bobsilver

Quote: 





clieos said:


> I do have cmoyBB with OPA2227. OPA2227 is a 'flat, upfront and a bit warm' sounding opamp to me and it isn't nearly as revealing as AD8620, so I guess it can work out for Grado in some way. Personally, I just don't like OPA2227 that much and never quite care to use Grado with portable amp because of the heavy cable.


 


   
  Ah the heavy cable issue.  I agree and solved that.  I have changed cables on all 3 pairs of Grados (60,80 and 225) to a light weight 1/8 " plug cable.  In fact when I sent my 225 in to Grado for repair they also replaced my cable as well at request with a HQ light cable.  Easy to do by the way.
   
  And my Senn's I shortened the cable and placed a 1/8" plug on it.  Works great.
   
  Hate those heavy cables!  And I do not like being stationary when I have headphones on so this fixed all ills.


----------



## bluishgreen

Quote: 





bobsilver said:


> I then asked about Beyer DT880.  (I had been considering buying a pair).  Sound was fantastic with the 250 ohm version he claimed.  So I am taking him at his word and I ordered a pair of Beyers.
> 
> So my early feedback is this.  The 8620 is bright.  And I suppose any headphones that tend to bump the high end are not going to be a good match.
> 
> While I was hoping to have 1 amp for all my phones that doesnt seem to be the case.


 
   
   
  I'm specifically looking to buy the C421/8620 for my DT880's, which are generally my go-to phones that work well with all music--not necessarily the best with everything, but work extremely well with everything. I've always used my AKG K70*'s for purely acoustic music like classic jazz, classical, or acoustic-only singer-songwriter music, but use the DT880's for everything non-acoustic.  Although, the DT880's are exceptional for acoustic as well--just not near-perfect like the AKGs (conversely, I can't listen to any music with the AKG's if there is a single non-acoustic instrument in it).
   
  In any case, my one small complaint with the DT880's is that they are a touch warm--not a lot warm, but this is coming from a person who loves the AKG K70* line, so that should tell you something about my feelings of warmth...with the exception of maybe jazz, which lends itself to a more warm vibe.  I'm perfectly fine with the slight warmth as long as the amp I'm using doesn't add any more warmth, so I'm hoping that the C421/8620 that people see as bright will be a good, balanced pairing for my DT880's (I have the 250ohm, BTW).
   
  I recently bought the ibasso D7 DAC/amp--the DAC is exceptional for the price, and the amp is good, but is a tad warm, so I don't really like it with my DT880's.  I do love the D7 with my AKG's, in which the slight warmth from the amp balances the brightness of the AKG's--but the slight warmth of the amp plus the slight warmth of the DT880's is just a bit too much for me.  So in the end, it's all about finding balanced pairings--both with the music style and the amp.


----------



## PANGES

Soo.. Has anyone who pre-ordered with the temporary case received an email to get a new case? I followed the link to order the replacement case, but paypal wont let you order anything with a $0.00 value. lol.


----------



## syphen606

I ordered mine.. cost 1 cent!


----------



## F900EX

I got mine yesterday with the OPA2227.  Out of the box, not bad. And will review it at a later time.  Built very well and solid.


----------



## PANGES

Quote: 





syphen606 said:


> I ordered mine.. cost 1 cent!


 


  lol Yeah. I email'd John from JDSLabs and had him change the price from $0.00 to $0.01, because paypal wouldn't let me checkout with a $0.00 amount.


----------



## kyoshiro

just ordered another C421 with AD8620! And my newly cased AD8066 will be piggy riding it back with it's new enclosure!


----------



## JRoMan

Got through the new Soul Rebels Brass Band album yesterday with my HD25 and c421(8620). All those horns and not once did I think it harsh or shrill. I really think the amp has smoothed out some.


----------



## jseaber

Quote: 





panges said:


> lol Yeah. I email'd John from JDSLabs and had him change the price from $0.00 to $0.01, because paypal wouldn't let me checkout with a $0.00 amount.


 


  We were amazed how quickly everyone responded. About 20 emails came in within minutes of the automated announcement! The PayPal bug was resolved within five minutes.
   
  @bobsilver: It's fascinating how closely your opinion of the AD8620 + Grados resemble the e-mails I received from Headfonia. Hope you don't mind if I share part of our discussion from the past weekend:
   
  Quote: 





> Bob,
> 
> You're right on. When c421 was first designed, the intention was to offer a single amplifier with zero room for options or customization (AD8620 only).
> 
> Mike at Headfonia.com wasn't happy with the AD8620 sample. So we sent an OPA2227 version, which I personally don't enjoy [as much], but Mike was thrilled. The decision to offer multiple opamps was as difficult to us as it is for customers to choose a chip. There was a psychology study years back which confirmed that customer enjoyment actually drops as product options increase. Given a single option, there's nothing to fret over. . . .


 
   
  Extra choices are probably not so bad in the audio world. The focus with c421 was to build a seriously portable amp: comfortable form factor, easy recharging, but still super capable of cleanly driving most headphones. That much was accomplished. The circuits were stable and benchmarked well. About a year into development, beta testers were happy with the AD8620. So it was fairly disappointing when our first AD8620 samples received wildly mixed reviews. Thus, we scrapped the single-configuration goal. Opamp options were the only way to please everyone, short of cancelling the project and starting over.
   
  It's been asked repeatedly which chip to choose. Fairly simple:
   

 If you can't decide, choose the OPA2227. Statistically, this chip receives higher satisfaction. And it's cheaper.
 If you've tried the AD8620 before and enjoyed it, choose the AD8620. Some find it more enjoyable than the OPA2227, but not everyone. Riskier.


----------



## kyoshiro

does that make my AD8066 the rare breed? lol


----------



## jseaber

Quote: 





kyoshiro said:


> does that make my AD8066 the rare breed? lol


 

 < 3% chose AD8066 from the first batch. Some chips get no attention!


----------



## flu_fighter

Quote: 





jseaber said:


> < 3% chose AD8066 from the first batch. Some chips get no attention!


 


  I guess I am in that 3% as well. I was actually hoping for a AD827/AD847 version, would be better is AD825 could be used, but AD825 only comes in single channel versions.


----------



## mm1434

So John, the question is - after listening to the 8620 for a while - Hypothetically, if a person decided that they really enjoyed the other chip better - would there be an option to send it back to be swapped?  I do not want to put you on the spot, but after a week or so of listening back and forth to the c421 and my cMoy, it may come down to liking one better than the other sound wise.  Form factor, power and everything else the c421 is much better so I'd want my fav chip in the c421.
   
  If that isn't possible, no big deal but it would be nice to know if I had the option - shipping back and forth being my responsibility of course since you and I actually had this conversation via email before it was shipped and I said go with the 8620!
   
  Honestly - the 8620 has settled down from my first impressions - so over a short period of time I may find that I like it (for example, I'm liking it more today than I did yesterday...)


----------



## 2000impreza

Op-amps is a fairly interesting topic. My first C421 came with the AD8066. That same C421 was later replaced by John due to charging issues. The replacement C421 came with AD8620. Honestly, I could not hear any difference between AD8066 and AD8620. I actually thought the replacement had the AD8066 until I pulled the PCB and seen the AD8620 in place. I also did a blind test between OPA2227 and AD8620 in a custom CMOY I built using JDS PCB and failed at identifying any difference. Perhaps my ears are not trained enough to hear subtle difference between all three op-amps.


----------



## bobsilver

Quote: 





jseaber said:


> We were amazed how quickly everyone responded. About 20 emails came in within minutes of the automated announcement! The PayPal bug was resolved within five minutes.
> 
> @bobsilver: It's fascinating how closely your opinion of the AD8620 + Grados resemble the e-mails I received from Headfonia. Hope you don't mind if I share part of our discussion from the past weekend:
> 
> ...


 
   
   
  In my experience with the 8620 421 now with about 30 hours of burn in it is this.  With my Senns 650 the sound is amazing now.   It is a kind of take your breath away experience with the detail subtlies and a very 3 demensional sound.  It also EXTREMELY smooth with no harshness at all.  I am loving the experience.  I did an AB comparison with my ATHM50 and Cmoy 227 yesterday versus the 421/Senn 650.  It is a night and day difference.  The sound of the 421/650 sounds almost real and lifelike.  The Cmoy/ATHM50 was good but synthetic in comparision. Now I know that a these headphones are dramatically different  but I had been living with them both for the past month or so and had been doing a swap and enjoying both.  Now I have no desire to listen to anything but my Senns and the 421.  I did order a pair of Beyer 880 (per John's comment that the 8620 works great with them) but more from a point of something different as opposed to better then my Senn 650.
   
  So IMHO I would suggest to anyone buying this amp is this.  If your headphones are anything like Grados or AT ATHM50 which I would describe as somewhat bright you wont be happy with the 8620.  It is a not a good match.  But if you are using Senns or headphones that sound like them then the 8620 will take you to new level.
   
  And let me add I listen to acoustic jazz mostly.  Very little rock.  Nothing electronic.  I like classic jazz and have been listening to recent recordings as my basis for my opinion.  I am very happy with this match.
   
  Bob


----------



## bobsilver

Quote: 





bluishgreen said:


> I'm specifically looking to buy the C421/8620 for my DT880's, which are generally my go-to phones that work well with all music--not necessarily the best with everything, but work extremely well with everything. I've always used my AKG K70*'s for purely acoustic music like classic jazz, classical, or acoustic-only singer-songwriter music, but use the DT880's for everything non-acoustic.  Although, the DT880's are exceptional for acoustic as well--just not near-perfect like the AKGs (conversely, I can't listen to any music with the AKG's if there is a single non-acoustic instrument in it).
> 
> In any case, my one small complaint with the DT880's is that they are a touch warm--not a lot warm, but this is coming from a person who loves the AKG K70* line, so that should tell you something about my feelings of warmth...with the exception of maybe jazz, which lends itself to a more warm vibe.  I'm perfectly fine with the slight warmth as long as the amp I'm using doesn't add any more warmth, so I'm hoping that the C421/8620 that people see as bright will be a good, balanced pairing for my DT880's (I have the 250ohm, BTW).
> 
> ...


----------



## jseaber

Quote: 





mm1434 said:


> So John, the question is - after listening to the 8620 for a while - Hypothetically, if a person decided that they really enjoyed the other chip better - would there be an option to send it back to be swapped?  I do not want to put you on the spot, but after a week or so of listening back and forth to the c421 and my cMoy, it may come down to liking one better than the other sound wise.  Form factor, power and everything else the c421 is much better so I'd want my fav chip in the c421.
> 
> If that isn't possible, no big deal but it would be nice to know if I had the option - shipping back and forth being my responsibility of course since you and I actually had this conversation via email before it was shipped and I said go with the 8620!
> 
> Honestly - the 8620 has settled down from my first impressions - so over a short period of time I may find that I like it (for example, I'm liking it more today than I did yesterday...)


 

 Parts cost would be under $8, but labor would kill the deal at $25+.

  
  Quote: 





bobsilver said:


> But as I posted before the sound with my Grados or ATHM50 is not enjoyable.  The high end seems to be always prominent to the point of unnaturalness.


 

 Frequency response is flat up to 15kHz, and there's a very slight roll-off going to 20kHz (0.2dB or so). So if anything, highs are _not _prominent in terms of measurements.
   
  Amps and measurements aside, I can't say I've heard the same "unnaturalness" between Grados and the AD8620. I actually decided upon the AD8620 after listening to a c421 in the dark for four hours. This just goes to show that everyone hears things differently.


----------



## mm1434

Quote: 





jseaber said:


> Parts cost would be under $8, but labor would kill the deal at $25+.
> 
> 
> 
> ...


 
   
  That's cool.  I'm liking them more and more - so I don't anticipate that I'd switch.  Its like anything else - just takes some getting used to and you have to have an open mind and give it time.  Being very noobish in this arena, you sometimes have to accept the fact that you don't know what you like.


----------



## bobsilver

Quote: 





jseaber said:


> Parts cost would be under $8, but labor would kill the deal at $25+.
> 
> 
> 
> ...


----------



## mm1434

Bobsilver - I think that is what I'm finding.  I jumped to a conclusion right off the bat and now am enjoying...


----------



## Donnyhifi

Hi Bobsilver and mm1434, that is very encouraging to hear.
	

	
	
		
		

		
			





 I have experience with the AD8620 with the Go-Vibe and that's why I pre-ordered a C421 with this. The AD8620 is a very nice op-amp, I find it detailed and open but not bright or harsh in anyway. My C421 has shipped and I'm checking the mail a couple times a day in anticipation, can't wait to get my hands on it!


----------



## PANGES

I just received my replacement enclosure and swapped the stuff. It came with the black case, as well as new front and rear faceplates. Just looking at them side by side, the new ones are much nicer. There's a little bit of a grain texture to the new enclose which is pretty nice. Holding the new faceplates side by side, the new ones aren't as "silver/shiny," but look good nonetheless. Also, the one gripe I had about the old enclosures have been fixed- the edges of the silver faceplates aren't as sharp/rough anymore. The new enclosure just has a much nicer "quality feel" to them. I'm not saying the old enclosure wasn't nice, but this new enclose is definitely a step up in quality. Good job, John from JDSLabs! 
   
  edit: I should also mention that the new enclose came with 4 little stick on feet, which is a very nice touch also!


----------



## dwinnert

So I am in love with my JDS Labs CMoyBB......what will I gain with the C421......?
   
  BTW, I get free 9v batteries.


----------



## mm1434

Its really funny.  I'm kinda learning on the fly here.
   
  I thought I understood music and the sound that I like.  The cmoy with my turbine coppers was heaven.  Then I got the denon D2000 cans and was listening to them on the cmoy.  Heaven.  Then I get the c421.  Different sound.  Jumped to conclusion.  The more and more I listen to the c421 with the denons, I'm discovering a whole new aspect to my music.  Its hard to explain, but it just feels more open, complete and balanced (soundstage?).  I was listening to some old stuff (Led Zepplin) and I felt like I was right in the middle of the music as it swirled around me.  Where I was used to the bass sorta hitting me in the back of the head - I'm now enjoying a much more balanced sound and noticing all kinds of little nuances.  I've been listen to the rig (Denon/c421) a lot and am just falling in love with my music again.
   
  So, I assume its a little bit fantastic headphones and a little bit c421 amp - but I can't imagine anything sounding better right now.  I will assume, as I continue to listen and my ears get used to the sound I will gradually be looking for even more.  It appears that this audiofile thing is a bit of a journey where you never really get to the end - you just sort of evolve.
   
  Thanks for all your patience John.  And thanks Headfi for turning me on to something really cool...


----------



## 808Ronin

First time post, long time lurker. I have a question for anyone runnin c421 with westone 3 or um3x. I would really like your impressions of this combination or hear from anyone who would care to speculate on the pairing of these two iem and the c421. I currently have cmoy bb and find it enjoyable with both iem and ipod classic w/lod. Thanks


----------



## Cassadian

Panges stated earlier that he couldn't use the Westone 4's with his C421 with the original low gain settings of 3.5x due to unbearable volume.  However, with the new gain setting it may be able to fix that but it really depends on your listening levels etc.  
   
  Bought mine from Panges for an excellent deal and can't wait till I get it. :]
   
  Shoutout: I think that the information page for the JDS Labs C421 on Headgear product information is outdated, just wanted to state that.
   
  Edit he said Ultimate Ears UE4


----------



## PANGES

Quote: 





cassadian said:


> Panges stated earlier that he couldn't use the Westone 4's with his C421 with the original low gain settings of 3.5x due to unbearable volume.  However, with the new gain setting it may be able to fix that but it really depends on your listening levels etc.
> 
> Bought mine from Panges for an excellent deal and can't wait till I get it. :]
> 
> Shoutout: I think that the information page for the JDS Labs C421 on Headgear product information is outdated, just wanted to state that.


 

 I actually don't really have any issues with the c421 and the Westone 4's. My issue was actually with the Ultimate Ears UE4, which are (were) my main IEM's. I'm currently using a pair of Ultimate Ears UE11 Pro, and they're just as sensitive, so the issue is the same with these. On a side note, if I do turn the volume up to make the imbalance go away, it does sound really nice with the UE11. Just a bit loud for my comfort. In any case, I'm in the market for a portable DAC/Amp combo, so I don't mind letting go of the c421. 
   
  I'll have the amp shipped out for you tomorrow! 
   
  Side note: If you get a chance, try the c421 with the Etymotic ER4S. The c421 just really did something special for me with those IEMs.


----------



## 808Ronin

Couldnt resist, pulled the trigger and ordered with AD8620. Main selling point over other products is the great customer service / interaction, as well as the over all positive reviews from users of JDSLabs products.


----------



## cirdec

It is that good. Trust me. Just got mine today and I'm loving it. Good pairing with IE80


----------



## bluishgreen

Quote: 





808ronin said:


> Couldnt resist, pulled the trigger and ordered with AD8620. Main selling point over other products is the great customer service / interaction, as well as the over all positive reviews from users of JDSLabs products.


 


  I just ordered mine as well last night (AD8620 also).  I went with the default USPS shipping, so I'll probably get it towards the end of the week, but I've still got my new-ish (maybe a month old now) Ibasso D7 DAC/Amp to play with in the meantime...


----------



## wje

Quote: 





bluishgreen said:


> I just ordered mine as well last night (AD8620 also).  I went with the default USPS shipping, so I'll probably get it towards the end of the week, but I've still got my new-ish (maybe a month old now) Ibasso D7 DAC/Amp to play with in the meantime...


 

 I believe the default shipping is USPS Priority Mail.  You should see it as early as Wednesday.  Priority Mail has been good for me lately - seems awfully quick, and the price isn't too bad.


----------



## syphen606

Spent all day listening to Shure SE215's on the C421 (8620). Really do love this amp..


----------



## Cassadian

If only I could get my hands on those, I have no idea where'd I'd fine some for a cheap price.
  
  Quote: 





panges said:


> I actually don't really have any issues with the c421 and the Westone 4's. My issue was actually with the Ultimate Ears UE4, which are (were) my main IEM's. I'm currently using a pair of Ultimate Ears UE11 Pro, and they're just as sensitive, so the issue is the same with these. On a side note, if I do turn the volume up to make the imbalance go away, it does sound really nice with the UE11. Just a bit loud for my comfort. In any case, I'm in the market for a portable DAC/Amp combo, so I don't mind letting go of the c421.
> 
> I'll have the amp shipped out for you tomorrow!
> 
> Side note: If you get a chance, try the c421 with the Etymotic ER4S. The c421 just really did something special for me with those IEMs.


----------



## guhmo

I'm thinking about getting a C421 for use with my UM3X.  They're 125 db/MW and have 56 ohms of impedance.... synergy's hard to find with these IEMs... Would the C421 work well with it?


----------



## ClieOS

Good Stuff


----------



## Mutnat

Quote: 





clieos said:


> Good Stuff


 


  Indeed!  You can definitely see the family resemblance.  My c421 should be here any day now (shipping to Canada can take forEVER sometimes).


----------



## 808Ronin

Received c421 today (one day earlier than expected) and all i can say is WOW. Sounds great straight out the box using westone 3. Big improvment over cmoyBB and worth every penny. Im looking forward to hearing the improvement in sound once properly burned in, as reported by other forum users.


----------



## PANGES

Oh wow. I never looked at the dimensions, but I didn't think the O2 was that much bigger than the C421. lol.
  
  Quote: 





clieos said:


> Good Stuff


----------



## ClieOS

Quote: 





panges said:


> Oh wow. I never looked at the dimensions, but I didn't think the O2 was that much bigger than the C421. lol.


 

 The only thing that makes O2 a portable amp is that it is powered by batteries. It is really more of a transportable in practical use.


----------



## wje

Wow.  Seeing both amps in the same picture really puts the size issue into persepctive.


----------



## Ultrainferno

I'm listening to the C421 now, with the OPA2227. I like it a lot, only arrived last night, so can't say much yet.
  The O2 also arrived but I need to find a new AC/AC adapter first...


----------



## Donnyhifi

The AD8620 version of the C421 has arrived and it sounds wonderful after about 40+ hours of burn in. I feel that it sound quite neutral, transparent with nice clear treble, good bass extension and a wider soundstage. There is a good amount of power and the noise floor is great as well. You can only hear hiss if you crank it up but at these volumes you will have other problems to worry about such as permanent hearing damage. I can't hear any hiss on my sensitive Fitear MH334 customs or with the UM3X at normal to quite loud listening levels. This is a quality piece of equipment and I'm quite satisfied with the sound and build quality of this product.


----------



## wje

Just a quick thought ... is anyone (US Based) interested in trading their C421 for a genuine JDS Labs O2 amp that is only a few weeks old?  Of course, a small amount of cash (PayPal) would be supplied to off-set the price difference between the O2 and the C421.  The O2 features everything that JDS Labs offers when they ship - Black allied aluminum case, silver front panel, nice aluminum knob with 2 rubber rings so it can easily be turned, (2) 9V rechargeable batteries, Triad power supply.
   
  If you might be interested, let me know.  I have (2) O2 amps and was interested in trying the C421, too.
   
  Thanks,


----------



## bluishgreen

After almost 50 hours of burn-in, I started listening to the C421 w/AD8620, which sounds really good.  One thing that that really strikes me is how similar it sounds to my Ibasso D7--maybe a little wider soundstage with the C421 on some recordings (not deeper, but wider) but extremely similar in tonality and SQ.  The funny thing is, previously I was looking at this as an alternative to the built-in amp on the D7, which I thought was a tad too warm for me after 100+ hours of use.  But since then, it seems like the D7 has actually become less warm even after the 100 hours (it has a lot of caps).  When I first got the D7, it seemed just as warm as my Fiio E10, but now it seems a bit brighter than the E10.
   
  I'm now liking the D7/DT880 combo more and more, prior to even hearing the C421.  Now that I have it, I plug the C421 into the line-out of the D7 and switch back-and-forth between the D7 DAC/D7 Built-in amp combo vs. the D7 DAC/C421 amp combo, and am surprised by how similar they sound in tonality and SQ--at least with only around 50 hours of burn-in on the C421.  According to posts in other threads, Ibasso support said that the D7 uses the OPA1611.  I don't have any great cable connecting the devices, though, and am just using a stock cable that came with another amp, so that could limit things.
   
  Doing the same A/B testing (using the same cable) with the Fiio E10, I definitely notice an uptick in SQ with the C421 as amp vs. the E10's built-in amp--but it's harder to detect a difference with the D7.  Although I do also like the combo of the E10 as DAC-only with the C421 as amp.  I've only used the C421 on its own (no DAC) for a little bit, but it sounds great by itself using an LOD into an iPhone 4S as well as a basic 3.5mm cable into an Amazon Kindle, listening to some "-q9" Vorbis files.  Very clear and defined on both devices without any over-the-top brightness or obvious sibilance.
   
  In terms of phones--since they sound very similar to me, I'm liking the C421/DT880 combo every bit as much as the D7/DT880 combo.  The AD8620 suits the slightly-warm DT880's extremely well.  What I didn't expect is that the AD8620 works fairly well with the K702's--although admittedly, I haven't tested them nearly as much as the DT880's, only listening to one album with the K702's.  Keep in mind that I only use my K702's when listening to 100% acoustic instruments, so I can't vouch for anything else.  In any case, I had expected the combo to be too harsh, but haven't found the K702's to be harsh so far.  Maybe because of all the prior talk of "brightness", it skewed my expectations…but I don't find the AD8620 to be extremely bright--I find it to be pretty neutral and defined.
   
  Also, there's more than enough power to drive the K702's, DT880's, and DT990's, although I've only tried the DT990's with one song, so I can only speak on power for those right now, not SQ.  In any case, like others here, I'll continue playing around with things…


----------



## Cassadian

Would it make sense that to me the amplifier would make no difference considering I the C421 is my first amplifier?  + I just realized how softly I listen to my music as I often am teetering on the edge of imbalance with my low impedance headphones.


----------



## bluishgreen

Quote: 





cassadian said:


> Would it make sense that to me the amplifier would make no difference considering I the C421 is my first amplifier?  + I just realized how softly I listen to my music as I often am teetering on the edge of imbalance with my low impedance headphones.


 


  Or rather, it's your first external amplifier...you can always compare it to the built-in amplifiers of whatever devices/computers you currently use...  
   
  The external amp is more about sound quality than sound quantity/volume, although it serves both purposes with higher-impedance phones.  However, it also isn't a silver bullet if you are unhappy with the quality of your current phones' sound (especially if they are already more than loud enough) or if your source output that you plug it into is noisy/low-quality.  Except for bass boost features, ideally the amp shouldn't be changing the sound at all, other than amplifying it, so it's only going to improve things if your built-in amp is the weak link and degrading things.  And even then, if you plug the external amp into that same built-in amp/output (because maybe it's your only available output) then it's just going to forward-on a louder version of what you didn't like to begin with, unless you have a line-out port or use an external DAC to bypass the built-in amp/output/soundcard.
   
  In any case, if you are referring to the opamp and whether it matters which one you buy--I've only listened to the AD8620, but the general consensus seems to be from the main two choices:  the AD8620 has a neutral-to-slightly brighter sound signature, while the OPA2227 has a neutral-to-slightly warmer sound signature.  There may be other subtleties, but that's probably the most prominent aspect you'd notice, and a decent rule-of-thumb to go by.  There's also a third choice, although JDSLabs seems to recommend the AD8066 specifically for higher-impedance phones, which doesn't really apply to you.  So, I think I'd just go by what basic sound you are looking for in general--do you usually prefer a slightly brighter sound or a slightly warmer sound--and go with that.  Keep in mind that we're talking about subtleties here, since again, the amp should generally be neutral and shouldn't be radically changing your sound, other than cleaning-up the non-neutrality that another amp left behind...


----------



## Cassadian

Great post.  Thanks for the information,  I guess it makes sense that the line out from my iPod into the JDS Labs C421 shouldn't make too much of a difference if the AD8620 is neutral/bright as stated.
  
  Quote: 





bluishgreen said:


> Or rather, it's your first external amplifier...you can always compare it to the built-in amplifiers of whatever devices/computers you currently use...
> 
> The external amp is more about sound quality than sound quantity/volume, although it serves both purposes with higher-impedance phones.  However, it also isn't a silver bullet if you are unhappy with the quality of your current phones' sound (especially if they are already more than loud enough) or if your source output that you plug it into is noisy/low-quality.  Except for bass boost features, ideally the amp shouldn't be changing the sound at all, other than amplifying it, so it's only going to improve things if your built-in amp is the weak link and degrading things.  And even then, if you plug the external amp into that same built-in amp/output (because maybe it's your only available output) then it's just going to forward-on a louder version of what you didn't like to begin with, unless you have a line-out port or use an external DAC to bypass the built-in amp/output/soundcard.
> 
> In any case, if you are referring to the opamp and whether it matters which one you buy--I've only listened to the AD8620, but the general consensus seems to be from the main two choices:  the AD8620 has a neutral-to-slightly brighter sound signature, while the OPA2227 has a neutral-to-slightly warmer sound signature.  There may be other subtleties, but that's probably the most prominent aspect you'd notice, and a decent rule-of-thumb to go by.  There's also a third choice, although JDSLabs seems to recommend the AD8066 specifically for higher-impedance phones, which doesn't really apply to you.  So, I think I'd just go by what basic sound you are looking for in general--do you usually prefer a slightly brighter sound or a slightly warmer sound--and go with that.  Keep in mind that we're talking about subtleties here, since again, the amp should generally be neutral and shouldn't be radically changing your sound, other than cleaning-up the non-neutrality that another amp left behind...


----------



## bluishgreen

Quote: 





cassadian said:


> Great post.  Thanks for the information,  I guess it makes sense that the line out from my iPod into the JDS Labs C421 shouldn't make too much of a difference if the AD8620 is neutral/bright as stated.


 

  
  The C421 with a line-out (LOD) made a noticeable improvement with my iPhone 4S--both in quality and volume--although that was while using larger phones that I'd never actually use outside the home.  I haven't tried it with my usual "outside world" phones, which are nothing special--Sennheiser PMX 680i, which I love for the price and the purpose I bought them for, but are by no means audiophile or anything.
   
  Also, just to clarify--when I was talking about "subtleties", I was referring to the subtle difference between the two main opamp choices of the C421.  I didn't mean to imply that you would only get a subtle improvement if you bought an amp compared to your existing setup (ie, I wasn't trying to dissuade you from getting one).  Although I was trying to explain that nothing is guaranteed.  You may get a big, noticeable improvement, and you may get little-to-no improvement--it's hard to say unless someone has the same equipment as you.


----------



## Cassadian

Ah, I already have one.  It's just I haven't noticed any gigantic differences, but the fact is that I haven't really been using FLAC, nor my over ear headphones.


----------



## SteveSatch

I currently use a Fiio E11 with iPod and Fiio L9 LOD and Brainwavz HM5 headphones.  Anyone think I would gain anything over the Fiio E11 in this setup if I got a C421?


----------



## bluishgreen

Quote: 





cassadian said:


> Ah, I already have one.  It's just I haven't noticed any gigantic differences, but the fact is that I haven't really been using FLAC, nor my over ear headphones.


 

  
  OK--I misunderstood and thought you were still determining whether to buy...
   
  Of course, even if it doesn't do what you hoped with your current headphones, a great amp like this will serve you well if you plan to buy other headphones--especially higher-impedance ones that need an external amp to drive them.


----------



## Cassadian

Could it run the Denon AH-D7000?
  
  Quote: 





bluishgreen said:


> OK--I misunderstood and thought you were still determining whether to buy...
> 
> Of course, even if it doesn't do what you hoped with your current headphones, a great amp like this will serve you well if you plan to buy other headphones--especially higher-impedance ones that need an external amp to drive them.


----------



## bluishgreen

Quote: 





cassadian said:


> Could it run the Denon AH-D7000?


 


  That'd be more a question for someone who has those headphones--I've never really tried them to know how they'd sound.  In terms of power, the C421 seems to have enough power to drive most phones, and it is transparent enough that it should sound good with most phones (it shouldn't "get in the way" of a good set of phones) but whether the two sound good together is always a subjective thing.  Although it can help when a person does have both and somewhat objectively describes them for others.


----------



## gelocks

Quote: 





cassadian said:


> Could it run the Denon AH-D7000?


 

 It should.
  I run my D5000s easily!


----------



## JRoMan

So I had the chance to borrow an OPA2227 c421 for almost 2 weeks. I have had the AD8620 opamp version for over 2 months and it gets daily weekday use. The other amp was brand new, so I tried to put about 20-30 hours on it before comparing directly, which I did over about 3 separate sessions in the past few days.
   
  In the end I thought the difference between the two were not easily perceptible to my ears even though I had preconceptions about how I thought it was going to sound. This was tested mostly with HD25-1 II and iPhone 4S as source. Tracks ranged from 256kbps AAC to 320 kbps mp3 and 16-bit Apple Lossless.
   
  YMMV


----------



## Mutnat

My C421-2227 finally arrived yesterday!  It actually shipped March 1st, so it must have been stuck in Canadian Customs for a while.  For anyone from Canada thinking of ordering, the stated value on the customs form was $174 (the price at the time I ordered--I think it's gone up a few dollars since then?) and I was assessed HST (12% so just under $21) plus the standard $8.50 handling fee Canada Post always charges if you get dinged at customs.
   
  I've had it playing (shuffling my iPod) for about 13 hours now to start the burn-in process.  I've listened to a few tracks during the process and so far I'm pretty impressed.  Using my HD25-I-II's.  I'll check back in later with more impressions, and try to compare it a bit to my D-Zero and just the iPod's output w/o an amp sometime over the next week or two.
   
  EDIT: I also meant to say that I was surprised just how small the C421 is...  it looks bigger in pictures.  I'll take a comparison photo with the D-zero and iPod at some point.


----------



## Mutnat

Quote:


jroman said:


> In the end I thought the difference between the two were not easily perceptible to my ears even though I had preconceptions about how I thought it was going to sound. This was tested mostly with HD25-1 II and iPhone 4S as source. Tracks ranged from 256kbps AAC to 320 kbps mp3 and 16-bit Apple Lossless.


 


  Interesting!  Thanks for posting that.  I kept putting off ordering for days trying to figure out which op-amp to order.  It sounds like with similar equipment (same cans and a 4th gen iPod Touch) that there may not be a night and day difference, so that makes me feel a bit better about my choice.


----------



## JRoMan

Quote: 





mutnat said:


> Quote:
> 
> 
> Interesting!  Thanks for posting that.  I kept putting off ordering for days trying to figure out which op-amp to order.  It sounds like with similar equipment (same cans and a 4th gen iPod Touch) that there may not be a night and day difference, so that makes me feel a bit better about my choice.


 

 Yup. I feel better now, too!


----------



## SteveSatch

What rechargable battery does it use and where is a good buy to buy a spare or two?


----------



## ClieOS

I have received a loan unit of OPA2227 based C421 this morning to compare to my AD8620 version as well. I haven't put enough time on the new comer but suffice to say, I can already tell the subtle difference between the two C421. It is almost like the last time I compared the stock cmoyBB (which is OPA2227 based) to the AD8620 rolled cmoyBB, except this times both C421 sound much better than both the cmoyBB in every way. Like last times, the AD8620 wins over OPA2227 for me again. Not something night and day, but enough to call out a winner.
   
  However, this is not to say AD8620 crashes OPA2227 in every way. I love the AD8620, but I can understand why someone would find it V-shaped sounding and prefer the OPA2227 instead. It has more to do with the slight difference in presentation between the two opamps (and I had observed the same in cmoyBB as well) - AD8620 has really great soundstage and portrays the image in a very 3D fashion. In a way, it is almost better in imaging (especially in depth) than the O2 and that's quite an amazing feat on its own. OPA2227 on the other hand puts everything upfront with a sense of rich and warmness between the tones. If we were to take O2 as our reference for what 'totally neutral' / standard should be, then AD8620 would be the equivalence of what 3D TV meant to normal TV (where you get the surreal 3D effect) while OPA2227 would be equivalence of sitting close to a HD TV vs. at normal distance (where you get to see the fine detail in individual element but not quite so over the whole picture).
   
  As mainly an IEM user where soundstage is generally more limited, the extra layer of depth that AD8620 brings to the table is a real killer feature to me. It just goes really well with all kind of IEM (*the synergy with Etymotic ER4S is unbelievably good for an IEM that is always considered to be flat sounding). But that same extra layer of depth might not be that appreciated for full sized headphone user (where soundstage is already good) or simply for those who rather prefer an upfront presentation. Instead, I would think they will find AD8620 adds a sense of hollowness to the presentation which might not be to their liking. That's probably why AD8620 is interpreted as V-shaping by some, even though the FR curve is perfectly flat for both opamps.
   
  So what is my early conclusion? I'll still recommend C421 with AD8620 over OPA2227 for its more rounded presentation. But for those who rather like a little bit more richness over imaging, the OPA2227 based C421 could work out better for them. Both are really great sounding amps, and I think the choice is every bit personal preference as it is performance.
   
  Will write a more completed review once I have enough time with them, and will include a comparison to JDS's own O2 as well as cmoyBB (plus a few others).


----------



## kyoshiro

So I have received my new AD8620 and my AD8066 back. Noticeable difference between the 2 op amps in terms of clarity 
  Still gotta test the AD8620 with my HD600 and see if it still has the power to push em


----------



## ClieOS

Quote: 





stevesatch said:


> What rechargable battery does it use and where is a good buy to buy a spare or two?


 

 It is li-ion and it is a generally a bad idea to buy a li-ion battery for spare unless you want to throw it into a freezer. Li-ion battery. like lead-acid and most rechargeable battery, will begin to degrade once it is manufactured. Given a li-ion battery usually lasts at least a year or two, buying a spare li-ion now means you won't use it for another year or two. By that time, you can expect a major portion of the battery capacity will have degraded away (if not destroyed by over-discharging). You can store it in a freezer (with proper packaging) to slow down the process, but the smarter way is to buy a replacement battery from JDS on a later time.


----------



## ClieOS

Oh, here is an updated picture of JDS family portrait.


----------



## bluishgreen

Quote: 





clieos said:


> But that same extra layer of depth might not be that appreciated for full sized headphone user (where soundstage is already good) or simply for those who rather prefer an upfront presentation. Instead, I would think they will find AD8620 adds a sense of hollowness to the presentation which might not be to their liking.


 

  
  I mainly use larger phones, and found the soundstage depth as pretty much the same as my other portable amps (Ibasso D7 & Fiio E10) however I did find the soundstage to be a little bit wider on the C421/AD8620 than the other two.  Like you alluded to, I did get the feeling of a "bigger picture" with the C421 vs my other amps, although I don't have a C421/OPA2227 to compare with.  Not sure if I'd describe it as V-shaped--maybe a bit more distinct highs, but I don't sense any emphasis on bass.


----------



## bluishgreen

Quote: 





jroman said:


> In the end I thought the difference between the two were not easily perceptible to my ears even though I had preconceptions about how I thought it was going to sound. This was tested mostly with HD25-1 II and iPhone 4S as source. Tracks ranged from 256kbps AAC to 320 kbps mp3 and 16-bit Apple Lossless.
> 
> YMMV


 
   
  Quote: 





mutnat said:


> Quote:
> 
> 
> Interesting!  Thanks for posting that.  I kept putting off ordering for days trying to figure out which op-amp to order.  It sounds like with similar equipment (same cans and a 4th gen iPod Touch) that there may not be a night and day difference, so that makes me feel a bit better about my choice.


 

  
  Yeah--that was also why I wanted to point-out before that the differences are usually "subtleties".  A lot of times in forums like these we talk quite a bit about differences in exaggerated form, which is the nature of trying to describe something in detail, but unfortunately as a side affect can lead people just starting out to think that it's like an equalizer setting with everything up on one product and everything down on another product.  It's good every once in awhile to show a frame of reference for people learning, and point-out that these differences are generally subtle (much of the time).  Not to mention the issue of actual differences vs perceived differences due to preconceptions.


----------



## ClieOS

Quote: 





bluishgreen said:


> I mainly use larger phones, and found the soundstage depth as pretty much the same as my other portable amps (Ibasso D7 & Fiio E10) however I did find the soundstage to be a little bit wider on the C421/AD8620 than the other two.  Like you alluded to, I did get the feeling of a "bigger picture" with the C421 vs my other amps, although I don't have a C421/OPA2227 to compare with.  Not sure if I'd describe it as V-shaped--maybe a bit more distinct highs, but I don't sense any emphasis on bass.


 

 I think it has to do with the synergy of the whole setup. I can easily tell the difference between amps using some IEM but not so much on others - thus the problem of Head-fi's discussion in general as someone's 'huge' might be another person's 'subtle' simply because the same gear is used on different setup, not to mention the how different level of perception and interpretation. It is all part of the learning to take everything we read with a grain of salt.


----------



## JRoMan

Quote: 





clieos said:


> I think it has to do with the synergy of the whole setup. I can easily tell the difference between amps using some IEM but not so much on others - thus the problem of Head-fi's discussion in general as someone's 'huge' might be another person's 'subtle' simply because the same gear is used on different setup, not to mention the how different level of perception and interpretation. It is all part of the learning to take everything we read with a grain of salt.


 
   
  Quote: 





bluishgreen said:


> Yeah--that was also why I wanted to point-out before that the differences are usually "subtleties".  A lot of times in forums like these we talk quite a bit about differences in exaggerated form, which is the nature of trying to describe something in detail, but unfortunately as a side affect can lead people just starting out to think that it's like an equalizer setting with everything up on one product and everything down on another product.  It's good every once in awhile to show a frame of reference for people learning, and point-out that these differences are generally subtle (much of the time).  Not to mention the issue of actual differences vs perceived differences due to preconceptions.


 


  Yup. Well said, both.


----------



## Donnyhifi

Quote: 





stevesatch said:


> What rechargable battery does it use and where is a good buy to buy a spare or two?


 


 I opened up the C421 and found that it uses an Apple IPOD 4G battery, super easy to find a replacement if it wears out.


----------



## Donnyhifi

Quote: 





clieos said:


> I think it has to do with the synergy of the whole setup. I can easily tell the difference between amps using some IEM but not so much on others - thus the problem of Head-fi's discussion in general as someone's 'huge' might be another person's 'subtle' simply because the same gear is used on different setup, not to mention the how different level of perception and interpretation. It is all part of the learning to take everything we read with a grain of salt.


 


  Excellent advice, my Fitear MH334 is more sensitive but is benefiting the most with this amp whereas with the UM3X I hear much smaller gains even though it needs more power than the Fitears to attain similar volume levels.


----------



## 2000impreza

Looks like the review by Headfonia is up. Not sure if I agree with the sonic differences between AD8620 and OPA2227 opamps but still a good read.
   
http://www.headfonia.com/flyin-high-jdslabs-c421/


----------



## ClieOS

Quote: 





2000impreza said:


> Looks like the review by Headfonia is up. Not sure if I agree with the sonic differences between AD8620 and OPA2227 opamps but still a good read.


 

 Me and you, mate. I already find myself reaching an opposite conclusion on quite a few Headfonia's past amp review (especially on PA2V2, among others). Guess I'll have to disagree with his finding on AD8620 vs. OPA2227 this time as well. The impression is so different from mine that it makes me wonder if they could have received an lemon unit or not. Maybe we just have too different an interpretation on amp.


----------



## shotgunshane

ClieOS- how is transparency, dynamics and black background compared to the O2?


----------



## ClieOS

Quote: 





shotgunshane said:


> ClieOS- how is transparency, dynamics and black background compared to the O2?


 

 Compared to the AD860 version, everything is slightly better on the O2, and I do really mean just slightly. If you are not doing a direct ABing, you might not notice any difference at all except that the AD8620's has more depth while O2 has equal amount of depth and width. The OPA2227's version is more noticeably different because it has an upfront presentation and a richer overall tone. That being said, AD8620's sounds closer to O2 than OPA2227's.


----------



## Mozu

clieos said:


> Me and you, mate. I already find myself reaching an opposite conclusion on quite a few Headfonia's past amp review (especially on PA2V2, among others). Guess I'll have to disagree with his finding on AD8620 vs. OPA2227 this time as well. The impression is so different from mine that it makes me wonder if they could have received an lemon unit or not. Maybe we just have too different an interpretation on amp.




I was surprised at how similar his experience with the AD8620 was to mine, actually. /shrug


----------



## ClieOS

Quote: 





mozu said:


> I was surprised at how similar his experience with the AD8620 was to mine, actually. /shrug


 

 I posted my initial impression on C521's AD8620 vs. OPA227 a page back, in case you might be interested - here.


----------



## Mozu

I'd read it before, and felt like I was reading a review of a completely different amp from the one I owned. It makes me wonder if there was something up with some of the early batch AD8620s, as I found the Headfonia review to be spot-on with my experience with it.


----------



## jseaber

Words of caution: It took months to find an honest battery brand. Quite a few vendors claimed 1200, even 1300mAH, but these were nothing more than re-badged 700mAH batteries. One even had its original 700mAH sticker visible beneath a 1200mAH label! The easiest way to spot a deceptive Li-Ion vendor is by comparing widths of batteries marked for use with the same product. A true 1200mAH Li-Ion is something like 2mm thicker than lower capacity batteries.
   
  Unless cycled excessively, these should last years. The test iPod on our bench is 4 years old. It gets charged once a week.
   
  Don't top off a Li-Ion. Keep it about halfway charged/empty (depending on your mindset) for longest lifespan.
   
  Quote: 





donnyhifi said:


> I opened up the C421 and found that it uses an Apple IPOD 4G battery, super easy to find a replacement if it wears out.


----------



## jseaber

Words of caution: It took months to find an honest battery brand. Quite a few vendors claimed 1200, even 1300mAH, but these were nothing more than re-badged 700mAH batteries. One even had its original 700mAH sticker visible beneath a 1200mAH label! The easiest way to spot a deceptive Li-Ion vendor is by comparing widths of batteries marked for use with the same product. A true 1200mAH Li-Ion is something like 2mm thicker than lower capacity batteries.
   
  Unless cycled excessively, these should last years. The test iPod on our bench is 4 years old. It gets charged once a week.
   
  Don't top off a Li-Ion. Keep it about halfway charged/empty (depending on your mindset) for longest lifespan.
   
  Quote: 





donnyhifi said:


> I opened up the C421 and found that it uses an Apple IPOD 4G battery, super easy to find a replacement if it wears out.


 
   
  Only the low gain resistor changed.
   


mozu said:


> I'd read it before, and felt like I was reading a review of a completely different amp from the one I owned. It makes me wonder if there was something up with some of the early batch AD8620s, as I found the Headfonia review to be spot-on with my experience with it.


----------



## Ragno7

This post is exactly the place I was looking for... Last saturday I ordered my c421/AD8620 ...and... An Ibasso d7.... Still waiting for both to come. I'll be using with my Beyer DT880, my Sennheisser HD518, my M-Audio IE10.

I'm a bit impatient but both seem to arrive on monday, so I'll have to wait.

I was a bit concerned over headfonia's review (i ordered the AD8620 ones), but now that you guys said that staging is better on this opamp I feel relieved, that's what I was aiming at (the ibasso d7 also).

I'll report how I did with both devices once I test them further.

I wonder if the lousy review for the AD8620 in headfonia came because he didn't burn in the device beforehand... Or maybe he did get a lemon after all, or something happened there...


----------



## 808Ronin

Quote: 





clieos said:


> Me and you, mate. I already find myself reaching an opposite conclusion on quite a few Headfonia's past amp review (especially on PA2V2, among others). Guess I'll have to disagree with his finding on AD8620 vs. OPA2227 this time as well. The impression is so different from mine that it makes me wonder if they could have received an lemon unit or not. Maybe we just have too different an interpretation on amp.


 


 +1


----------



## Mutnat

Damn, I wish there was some way I could try an 8620 version without having to buy both. 
   
  EDIT: anyone in the greater Vancouver BC area with a C421-8620?


----------



## Cassadian

I would've lent you mine if you were in the Chicago area.  Alas...
  
  Quote: 





mutnat said:


> Damn, I wish there was some way I could try an 8620 version without having to buy both.
> 
> EDIT: anyone in the greater Vancouver BC area with a C421-8620?


----------



## tattare

Can anyone comment on this with HiFiman's HE-400 or HE-500?


----------



## Ultrainferno

Quote: 





tattare said:


> Can anyone comment on this with HiFiman's HE-400 or HE-500?


 


  I've got both. I'll try them this weekend and get back to you


----------



## tattare

Ohh word thanks!  Looking forward to your thoughts on it with the HE-400 as im looking for a portable to drive them.
  
  Quote: 





ultrainferno said:


> I've got both. I'll try them this weekend and get back to you


----------



## jseaber

Mike's first e-mail to us came no more than 12 hours after he'd received the AD8620 c421. I'm not sure if he tried additional break-in. We were quick to ship out an OPA2227 edition, so maybe he set the AD8620 amp aside...
   
  It was no lemon. He de-soldered the AD8620 and soldered in an OPA2227 to compare v1.00 to v1.01. This wasn't mentioned in the review, since the experiment produced no worthwhile discussion.
  
  Quote: 





ragno7 said:


> I wonder if the lousy review for the AD8620 in headfonia came because he didn't burn in the device beforehand... Or maybe he did get a lemon after all, or something happened there...


----------



## Terps Fan

Guys, I'm using the AD8620ARZ and it took my cMoy built by John over the top.  Don't hesitate if your sitting on the fence.


----------



## Ultrainferno

Quote: 





tattare said:


> Ohh word thanks!  Looking forward to your thoughts on it with the HE-400 as im looking for a portable to drive them.


 


  I just tried it with both the He-400 en 500 and it drives them both just fine.
  The He-400 is the best match in my opinion, it doesn't need a lot of power and it makes it sound just fine. Bass boost on to keep the good bass and normal gain sounds best. With high gain it sounds as if the mids get a nice boost which also is enjoyable but a little to aggressive to my liking
  It also drives the He-500 just fine but you don't get out of it what it can do, compared to a full desktop amp, or my fav, a tube amp. It just doesn't sound as smooth and relaxed; I guess I just miss the tube sound but in all objectivity, the C421 does a good job driving the He-500 too, I didn't expect it to do this good. What I'm missing most with the HE-500 and C421 is the bass quality and quantity and the smoothes I so love with this headphones
   
  Anyway, for driving the HE-400, which is your main goal, I can only recommend it.
   
  Hope this helps


----------



## BGRoberts

Does the opamp in the cMoy from JDS just "pop out" ?
  
  Quote: 





terps fan said:


> Guys, I'm using the AD8620ARZ and it took my cMoy built by John over the top.  Don't hesitate if your sitting on the fence.


----------



## Terps Fan

Quote: 





bgroberts said:


> Does the opamp in the cMoy from JDS just "pop out" ?


 

 Hi BG.  No, you will need a extraction tool.  I bought mine at Radio Shack for like ten bucks or so.  The optional opanp came in a foil baggy, my heart went into my throat when I saw that I had to do it myself, but it was easy.


----------



## syphen606

Quote: 





terps fan said:


> Hi BG.  No, you will need a extraction tool.  I bought mine at Radio Shack for like ten bucks or so.  The optional opanp came in a foil baggy, my heart went into my throat when I saw that I had to do it myself, but it was easy.


 


  Yes.. top secret extraction tool:   
   
  Just be very careful and don't apply any more pressure then needed to gain grip on the opamp.  Wiggle it back and forth a little as some opamp legs and bind a little in the socket depending on if they have been pre-bent a lot.


----------



## Raines

choosing between the O2, c-421 8620 or 2227...
   
   
  i have a cmoy 2227 and love it
   
   
  use sennheiser hd 555 and alessandro ms-1


----------



## Mutnat

Quote: 





clieos said:


> However, this is not to say AD8620 crashes OPA2227 in every way. I love the AD8620, but I can understand why someone would find it V-shaped sounding and prefer the OPA2227 instead. It has more to do with the slight difference in presentation between the two opamps (and I had observed the same in cmoyBB as well) - AD8620 has really great soundstage and portrays the image in a very 3D fashion. In a way, it is almost better in imaging (especially in depth) than the O2 and that's quite an amazing feat on its own. OPA2227 on the other hand puts everything upfront with a sense of rich and warmness between the tones. If we were to take O2 as our reference for what 'totally neutral' / standard should be, then AD8620 would be the equivalence of what 3D TV meant to normal TV (where you get the surreal 3D effect) while OPA2227 would be equivalence of sitting close to a HD TV vs. at normal distance (where you get to see the fine detail in individual element but not quite so over the whole picture).
> 
> So what is my early conclusion? I'll still recommend C421 with AD8620 over OPA2227 for its more rounded presentation. But for those who rather like a little bit more richness over imaging, the OPA2227 based C421 could work out better for them. Both are really great sounding amps, and I think the choice is every bit personal preference as it is performance.


 

 Yeah this is probably a good analogy.  I can't speak for the C421-8620, but the C421-2227 is quite rich and forward.  It really seems to pair well with my HD25-1 II's, which are also nicely forward.  The result is excellent energy for rock, metal, pop, hip hop.  It even seems to have a fair amount of finness for jazzier stuff (at least modern up-tempo electric jazz).  I'm very happy with this combo so far!  (Source: iPod Touch 4G with Fiio L9 LOD.)


----------



## BGRoberts

Thanks for that info!





  
  Quote: 





terps fan said:


> Hi BG.  No, you will need a extraction tool.  I bought mine at Radio Shack for like ten bucks or so.  The optional opanp came in a foil baggy, my heart went into my throat when I saw that I had to do it myself, but it was easy.


----------



## PANGES

Quote: 





mutnat said:


> Quote:
> 
> 
> 
> ...


 
   
  Hehe. I find it kind of interesting that you want a more forward sound with the HD25-1 II. I find mine already to be really forward, and I tend to try and pull them back a bit with my tube amp.


----------



## Mutnat

Quote: 





panges said:


> Hehe. I find it kind of interesting that you want a more forward sound with the HD25-1 II. I find mine already to be really forward, and I tend to try and pull them back a bit with my tube amp.


 


  Oh yeah sorry they are forward by default for sure.  I didn't necessarily mean I wanted them more forward, nor that the C421 make them sound more forward.  I do really like the forward presentation, so what I didn't want to do was take a step back by using an amp that's particularly laid back.  I find that the C421 nicely preserves the forward nature of the headphones, while introducing a ton of clarity and details that were lost driving the cans directly off the iPod.


----------



## SteveSatch

I currently use an iPod, Fiio E11 amp, Fiio L9 LOD and Brainwavz HM5 headphones.  Does anyone have any comment on if If I'd have any sound improvement if I got the C421 and used that instead of the Fiio E11?
  Thanks,
  Steve


----------



## Ultrainferno

Quote: 





stevesatch said:


> I currently use an iPod, Fiio E11 amp, Fiio L9 LOD and Brainwavz HM5 headphones.  Does anyone have any comment on if If I'd have any sound improvement if I got the C421 and used that instead of the Fiio E11?
> Thanks,
> Steve


 


  the C421 is better for sure, in all ways


----------



## Jargon

Anyone knows how this fares against the UHA-4?


----------



## ClieOS

stevesatch said:


> I currently use an iPod, Fiio E11 amp, Fiio L9 LOD and Brainwavz HM5 headphones.  Does anyone have any comment on if If I'd have any sound improvement if I got the C421 and used that instead of the Fiio E11?
> Thanks,
> Steve




C421 is indeed better in most area, especially in sound - but given the price difference, that should be expected.



jargon said:


> Anyone knows how this fares against the UHA-4?




I will, but in a few weeks as I have just ordered the UHA-4 yesterday when it comes back in stock.


----------



## Mutnat

Oh...my....God....  Wow.  My mind has just been blown.  I've been listening to some Use Your Illusion era Guns N' Roses through my setup (iTouch 4G -> Fiio L9 LOD -> C421-2227 amp -> HD25-1 II's, and this is without a doubt the best these albums have ever sounded to me.  By miles and miles.  I had no idea they had this amount of fidelity.  I've always known the albums (double album) to contain some very complex, layered rock, but I've never heard it like this before.  Heavenly.  The sound has so much more depth, width, texture, richness, energy, wow. 
   
  Sorry it's hard to describe accurately.  In the past, I've always enjoyed the music on these albums but hated the sound/production.  I've always though the bass was lean, that the midrange was thin and cold, and that the treble was harsh, dominant, and over-extended.  This was through various home stereo systems, cars, and portable audio setups over the years.  But what I'm hearing today is the exact opposite.  The bass (with bass boost enabled on the c421) is thick and rich as well as impactful, the mids and now silky and organic, Axl's voice is smoother than ever and no longer shrill when he hits the high registers, and the upper registers aren't bothering my ears. 
   
  Okay, guess I've gone on long enough.  But I've definitely found some new demo material, especially for anyone whom is a fan of these albums to begin with.
   
  Cheers!


----------



## Ragno7

I foolishly started a new thread when all I wanted was to post here.... Here goes my initial impressions:


Ok... so I said on a previous post I would review this once I got it... I thought it would arrive past monday but it arrived today... My Ibasso D7 (Sidewinder) did arrive past monday so I had time to burn it in a bit more... 
 
The Ibasso D7 is a great little DAC, the Wolfson Chip it uses is really great and it's internal Class A amp is also very good, even though I felt that it lacked a bit of volume for my Beyer DT880.  The soundstage is really amazing, with great separation of instruments, great clarity, great midrange, highs and lows (even though the lows could be a bit better imo), also very good "black" background that makes for an immersive experience.  I had been enjoying it a lot throughout the week listening thru Audirvana and upsampling Redbook flacs, as well as listening to SACD, HDTracks.Com stuff and some really amazing hi-res vinyl rips.
 
Now, adding the C421 (AD8620 version) connecting the Ibasso's line out to the C421's "source" input really took the setup to another level... let me put some perspective on this;  I tried pairing the Ibasso with my CMoyBB, but I felt the  CMoy was just too forward, to warm and too boomy,it just everything good the DAC has to offer out of the picture... the Ibasso's internal Amp was so much better in every way that it just didn't pair well no matter what I did.... but with the C421, it has really great synergy with the Ibasso... both have a really great soundstage... so adding the C421 increased the soundstage while at the same time allowing for a better separation of instruments... My Beyer DT880 (250ohm version) lack a bit of low end punch.. but the bass boost in the new amp is so much better balanced than the one on John's CMoy... it is not as boomy, not as smeared... so much smoother and cleaner...
 
I know I still have to burn-in the device for a lot more hours, but truth be told, listening to my first album with this setup was pure bliss, I totally forgot I had my headphones on, which is hard because my Beyer's are quite heavy and one can't help but feel them pushing on the top of your head... but the sound was so immersive I just closed my eyes and enjoyed pure bliss with all the clarity I was expecting to achieve.  This is without a doubt a great little amp.
 
I'll post more once I have a chance to burn in the device a bit more.
 
Cheers.


----------



## Daemos

Quote: 





clieos said:


> C421 is indeed better in most area, especially in sound - but given the price difference, that should be expected.
> I will, but in a few weeks as I have just ordered the UHA-4 yesterday when it comes back in stock.


 


  How does it compared to the ibasso T5 which is similar in price?


----------



## ClieOS

daemos said:


> How does it compared to the ibasso T5 which is similar in price?




Volume matched using a SPL meter to wihtin 0.3dB of each other, I'll say there is no distinct advantage in SQ for T5. Overall, C421 (both AD8620 and OPA2227 version) sounds more detail and specious than T5, while T5 has the unique rich and smooth tone that usually associated with balanced amp (T5 has BTL ground, a type of active balanced ground). Technically, I'll say C421 is slightly ahead of T5, but the difference is small and quite subtle IMO.


----------



## bluishgreen

Quote: 





ragno7 said:


> The Ibasso D7 is a great little DAC, the Wolfson Chip it uses is really great and it's internal Class A amp is also very good, even though I felt that it lacked a bit of volume for my Beyer DT880.  The soundstage is really amazing, with great separation of instruments, great clarity, great midrange, highs and lows (even though the lows could be a bit better imo), also very good "black" background that makes for an immersive experience.  I had been enjoying it a lot throughout the week listening thru Audirvana and upsampling Redbook flacs, as well as listening to SACD, HDTracks.Com stuff and some really amazing hi-res vinyl rips.
> 
> I know I still have to burn-in the device for a lot more hours, but truth be told, listening to my first album with this setup was pure bliss, I totally forgot I had my headphones on, which is hard because my Beyer's are quite heavy and one can't help but feel them pushing on the top of your head... but the sound was so immersive I just closed my eyes and enjoyed pure bliss with all the clarity I was expecting to achieve.  This is without a doubt a great little amp.


 

 The amp strength is the only real issue I have with the D7, which is a bit weak--even relative to other USB-powered amps.  It's still good enough for 90% of things, but the issue shows-up for those albums that aren't done too well.  I've found the D7 and C421 amps to be somewhat similar in terms of sound signature, so it's nice to be able to switch without having too radical of a difference between the two.  The differences become somewhat more apparent when you turn them louder, since the D7 has to be pushed out of its comfort zone more, but I don't listen to loud music or music (in general) loudly too often, and the two devices are fairly similar at moderate levels.  When the D7 alone gets to the point of struggling, I find that I can switch to using the C421 with the D7 as DAC, and it almost acts as a continuation without too much of a departure.  In general, I really like the synergy between the two devices.  I don't use the bass boost, though, since I've never really liked any amp-based bass boost--they never sound natural to me, plus I prefer a more neutral sound anyway.  I didn't notice too much of a burn-in change with the C421 beyond the initial 20 hours or so, but the D7 seemed to change more with time--even well beyond 100 hours.
   
  I find the DT880's to be my most comfortable phones--but then again, that's relative to things like the AKG 701/702's, which for some reason have medieval torture devices for headbands.  I can barely last an hour with the AKG's without one of my "hard-core mods" (ie, sticking folded tissue underneath the band/bumps...).  In any case, the DT880's do work really well with the C421/AD8620 combo.


----------



## Ragno7

I agree with you in all aspects bluishgreen. I usually don't like the bass boost from amps either... John's CmoyBB bass boost is a true excess, but this boost sounds better I think... It seems to boost 100 hz to 250hz region, which I think is good, and it sounds less artificial to my ears... But I only use it on certain albums.

My Beyer's are the 2003 version... Great sounding indeed... They are 250 ohm version, but they do weight a lot on my head... What version are yours?

I'm thinking of getting some d2000 denon's, I'd like a different flavour, any insights?


----------



## Mauricio

Quote: 





bluishgreen said:


> In any case, the DT880's do work really well with the C421/AD8620 combo.


 


  How many ohms are those DT880?  600?


----------



## Mutnat

Has anyone tried the C421 with a Cypher Labs AlgoRhythm Solo (CLAS)?  I'm very curious how well the two mesh, and if the result really is that much better than say a C421 through an LOD without the CLAS?


----------



## bluishgreen

Quote: 





ragno7 said:


> I agree with you in all aspects bluishgreen. I usually don't like the bass boost from amps either... John's CmoyBB bass boost is a true excess, but this boost sounds better I think... It seems to boost 100 hz to 250hz region, which I think is good, and it sounds less artificial to my ears... But I only use it on certain albums.
> My Beyer's are the 2003 version... Great sounding indeed... They are 250 ohm version, but they do weight a lot on my head... What version are yours?
> I'm thinking of getting some d2000 denon's, I'd like a different flavour, any insights?


 
   

 I tried the bass boost for a little bit, but it still didn't sound right to me--but again, I'm not really a bass person to begin with.  Actually, probably the only bass boost that I sort of found as OK was surprisingly the cheapest amp I ever owned--the Fiio E10.  But generally, I prefer switching headphones to using an amp boost.  If I find an album to be poorly recorded or too thinly produced, I like to switch to my DT990's to give it more body/weight, which they're great for--maybe not basshead phones, but they do add just enough to "fix" things for me.  I call the DT990's my "first-aid" phones.
   
  Both 880/990 are the 2005 versions.  Unfortunately, I've never used Denon phones, so I can't say.
   
   
  Quote: 





mauricio said:


> How many ohms are those DT880?  600?


 
   

 Both 880/990 are 250ohm versions, although I'd think that the C421 would drive the 600ohm versions OK as well, which I've used in the past, but not for several years.


----------



## xanlamin

Anybody tried c421 with Beyer T5p?


----------



## 808Ronin

How many hours of battery time are you guys averaging with your amp?


----------



## ClieOS

808ronin said:


> How many hours of battery time are you guys averaging with your amp?




The longest run I have in one go is around 11~12 hrs continuously, and I didn't even run the battery dry. My guess is it will probably run for another hour or two for the least since the 45 minutes warning LED light didn't come up.


----------



## gelocks

Yep, gotten from 10 to 13 hours consistently...
  I'll probably wear the batteries in a few months though! LOL
  (I use the amp every day in my cubicle at work...  )


----------



## 808Ronin

I was a little worried, seemed i was getting much less run time, but never tested it previously to make sure. Decided to leave it running last night and checked back after about 9 hrs and was still running and the red light had not come on . Im pretty sure it would have kept running a while longer so i am satisfied. Is it possible that the battery still drains even after shutting off the unit? On my nuforce icon portable the charge wouldnt even hold a week and thats while sitting idle and i had two of them and they were both the same.


----------



## gelocks

The NuForce Icon Mobile amp DRAINS battery while not in use.
  The c421 does not... (of course, every battery drains if you don't use it... but this amp definitely doesn't do the same as the Nuforce one...)


----------



## blucaller

Quote: 





> Originally Posted by *ClieOS* /img/forum/go_quote.gif
> So what is my early conclusion? I'll still recommend C421 with AD8620 over OPA2227 for its more rounded presentation. But for those who rather like a little bit more richness over imaging, the OPA2227 based C421 could work out better for them. Both are really great sounding amps, and I think the choice is every bit personal preference as it is performance.


 

 Thanks for your review. I've never heard the OPA2227, so I never knew what I was missing. I was still curious when this recent debate started, but I think I'm more at peace with my C421 AD8620 after what you said.


----------



## ClieOS

blucaller said:


> Thanks for your review. I've never heard the OPA2227, so I never knew what I was missing. I was still curious when this recent debate started, but I think I'm more at peace with my C421 AD8620 after what you said.



The debate started where Headfonia's review stated that the C421-OPA2227 sounds much better than C421-AD8620. Of course, that's something not all of us agree on. Anyway, I'll be writing a review of both as well since not that many have the chance to listen to both side by side.

I noticed the latest batch has already been out-of-stock by now (which is not surprising), but John has stopped offering the AD8066 version as well. I guess that's just not enough people interested in it.


----------



## bluishgreen

Quote: 





clieos said:


> I noticed the latest batch has already been out-of-stock by now (which is not surprising), but John has stopped offering the AD8066 version as well. I guess that's just not enough people interested in it.


 

 Also interesting is that the OPA2227 is now the default on the order page, as well as the #1 recommendation under the Customization tab section.  Actually, the whole Customization tab section is an interesting read, given all the debate here.


----------



## ClieOS

Well, a business decision and a 'safe' recommendation no doubt. As I have said in my $100 amp shootout, often I have seen people opt for (sound) signature rather than performance when it comes to portable amps, but at least both version of C421 do have high performance.


----------



## jseaber

Quote: 





clieos said:


> The debate started where Headfonia's review stated that the C421-OPA2227 sounds much better than C421-AD8620. Of course, that's something not all of us agree on. Anyway, I'll be writing a review of both as well since not that many have the chance to listen to both side by side.
> I noticed the latest batch has already been out-of-stock by now (which is not surprising), but John has stopped offering the AD8066 version as well. I guess that's just not enough people interested in it.


 

  
  About 97% of c421 customers chose the AD8620 or OPA2227 edition, so we removed the third choice for simplicity. We'll continue to stock the AD8066 and offer it upon special request.


----------



## pdiddypdler

So from what I gather from all the ad8620 vs opa2227 talk is that 
   
  opa2227 is warmer sounding with more bass and mid range emphasis and a more forward signature
  ad8620 seems to be slightly better technically with slightly better soundstage, detail and a brighter signature. This seems to be similar to the o2 sound signature if I'm reading correctly.
   
  Obviously the differences will be relatively small and both will sound great most likely.
   
  Am I correct with these assumptions?
  I think I'm leaning towards the opa2227 variant as I've read it would be a safer bet if unless I've heard the ad8620 before.
   
  Should what opamp i chose depend on what type of headphones I'm using with the amp?
  I'll probably mostly be using IEM's on the go but maybe occasionally my pro900 at home.


----------



## ClieOS

Yes, I'll say your assumption is closely mimic my experience with both version of C421. AD8620 version is indeed closer sounding to O2 than OPA2227 version. If you are using IEM mostly (which I am), I would think AD8620 is most likely the better pairing of the two. OPA2227 version would be a better pairing for full size headphone IMO.


----------



## pdiddypdler

Thanks for the advice ClieOS
   
  So the AD8620 would be more neutral and clean and doesn't add its own flavour to the sound but just makes everything better whereas the OPA2227 does change the sound more so.
   
  Yes?
   
  Maybe the AD8620 is what I want but I'm not sure a neutral/bright amp would pair well with my pro900's (that is my second priority anyway because I have my E10 for them).


----------



## ClieOS

I think the most important point why I recommend AD8620 over OPA2227 is the fact that AD8620 gives much better imaging and soundstage to IEM (which is something IEM always seems lacking when compared to full size). OPA2227 on the other like to put thing upfront - it might seems wider on the side, but the true is you are not getting as much depth as you can. With IEM, where depth is generally a weak spot, the AD8620 offers something OPA2227 doesn't have. As for brightness - I won't say AD8620 is very obviously bright compared to OPA2227. AD8620 just handle the detail more delicately, and makes the listener listen to the detail more plainly. But the true is I can hear just as much detail in OPA2227 as well, but they are generally hidden behind ./ obscured by the richness of the tone and you'll have to pay more attention to find them out.


----------



## syphen606

I can't compare C421's, but I have 2 CmoyBB's... one with an OPA2227 and one with a AD8620. I find the 2227 pairs well with my brighter headphones like my Senn HD558's as it warms them up a little.  My 8620 model pairs better with my mid-centric cans like my HD650's as it fleshes out the sound.
   
  I think its a personal choice based on what you have for cans or iems already.


----------



## placebo-fi

So, the ODAC (an USB-powered 24/96 DAC with probably more measurements than you can dream of) is coming next month in the same enclosure as the c421. http://blog.jdslabs.com/?p=309. The CLAS + ALO Rx Mk2 combo finally found its long lost brother! At one forth the price and unrelated whatsoever to Apple!
   
  Which other c421 users will be attaching the ODAC to their c421? I certainly will. Seems like a strong competitor to the Pico, UHA-6S.mk2, Cruise, D12, DacPort, etc


----------



## pdiddypdler

But the ODAC doesn't take the digital out of an ipod like a clas though right?


----------



## ClieOS

The ODAC in the C421 enclosure looks great. Won't mind getting one myself in later time.


----------



## placebo-fi

I was just talking about the form factor. Hence "unrelated whatsoever to Apple"
  
  Quote: 





pdiddypdler said:


> But the ODAC doesn't take the digital out of an ipod like a clas though right?


----------



## pdiddypdler

Ah ok, I wish it was though.


----------



## bluishgreen

Quote: 





placebo-fi said:


> So, the ODAC (an USB-powered 24/96 DAC with probably more measurements than you can dream of) is coming next month in the same enclosure as the c421. http://blog.jdslabs.com/?p=309. The CLAS + ALO Rx Mk2 combo finally found its long lost brother! At one forth the price and unrelated whatsoever to Apple!
> 
> Which other c421 users will be attaching the ODAC to their c421? I certainly will. Seems like a strong competitor to the Pico, UHA-6S.mk2, Cruise, D12, DacPort, etc


 

 I'm definitely interested in the standalone version.  I've always looked at getting an O2, and the idea of an integrated O2/ODAC sounds really cool, but since the way I work and listen to music requires not being tied to a wall power source (even with my computer) the non-battery-O2 option wouldn't work for me.  But a USB-powered, standalone version in a C421 enclosure sounds even more practical anyway.
   
  One thought after looking at the prototype images--since both the USB and output are on the same side of the device, and usually people want the more bulky USB/power source cables facing the "back" to avoid cable clutter around the front amp controls, this means that (when paired with the C421) the ODAC output and the C421 input would be on separate sides, being too long a distance for most people's stock short 3.5-3.5 interconnects.  Not a big deal for those making custom cables, but it may be a good idea to either include or offer separately a good interconnect at a length specific for pairing with the C421.


----------



## syphen606

I'll be pre-ordering the standalone ODAC in C421 case when available. I can hook it up to my C421 or my O2 then!!  Very excited for it.


----------



## Mutnat

I know it's probably a pipe-dream, but I'd love to see JDS make an affordable, great-sounding, battery-powered & USB charged, CLASS competitor in the C421 case.  I'd be all over that, as a competitor to the CLAS + Rx stack.  For now, I'll make do with the DAC in my iPod feeding my C421/2227 via an LOD but it would sure rock to have a JDS iPod DAC in the middle instead!


----------



## pdiddypdler

Quote: 





mutnat said:


> I know it's probably a pipe-dream, but I'd love to see JDS make an affordable, great-sounding, battery-powered & USB charged, CLASS competitor in the C421 case.  I'd be all over that, as a competitor to the CLAS + Rx stack.


 


  + a million


----------



## Ultrainferno

That would be nice indeed!


----------



## guhmo

I think there's a reason behind the costs of the CLAS/HPP1 though     (pessimist mode)


----------



## Cassadian

Yeah, but when you get that kind of technology approved by Apple (you need Apple's approval to even be able to truly have a line out and bypass the internal DAC and AMP), there's a premium immediately stamped on it.


----------



## guhmo

Quote: 





cassadian said:


> Yeah, but when you get that kind of technology approved by Apple (you need Apple's approval to even be able to truly have a line out and bypass the internal DAC and AMP), there's a premium immediately stamped on it.


 


  True, guess so.  Wonder how much the licenses from Apple cost.


----------



## Yuceka

Any info on the DAC chip used in ODAC? And with the stand alone DAC, what basically is going to happen is to use the ODAC's line out into any headphone amp?


----------



## Yuceka

Looks like from the picture on the website, it's a Sabre chip?


----------



## ClieOS

Yep, it is a TE7022 feed into a ESS Sabre.


----------



## Grev

Quote: 





clieos said:


> Yep, it is a TE7022 feed into a ESS Sabre.


 
   
  I'm clueless, does that mean it's good...?


----------



## ClieOS

grev said:


> I'm clueless, does that mean it's good...?




Chip isn't everything. Implementation is the key. But given the track record of the circuit designer, it should alright. Anyway, TE7022 is a fairly good chip and widely used as USB receiver on many 24/96 DAC, and ESS Sabre is also a very well received DAC chip. On the surface, they should be quite good.


----------



## Gofre

Just ordered my C421, hopefully it won't too long to reach this side of The Pond.


----------



## Hi-fi Wigwammer

Quote: 





gofre said:


> Just ordered my C421, hopefully it won't too long to reach this side of The Pond.


 
   
  As a previous UK owner of both the JDS C421 and cMoy I can say that both amps arrived to my door in 5 days flat. Enjoy the C421 its the best portable amp i've ever owned. Only sold it because I now have a DX100.


----------



## Gofre

Quote: 





hi-fi wigwammer said:


> As a previous UK owner of both the JDS C421 and cMoy I can say that both amps arrived to my door in 5 days flat. Enjoy the C421 its the best portable amp i've ever owned. Only sold it because I now have a DX100.


 
   
  Good to hear, although I never realised that they used the address registered to your paypal account automatically so I've emailed them asking to send it to my term time address. Hopefully they'll be able to oblige!
   
  Custom IEMs, an iMod and a new amp in two weeks, I think I can stop assaulting my wallet now =P


----------



## Yuceka

I'm about the pull the trigger but I am torn in between this and Headstage Arrow 4G. Anyone heard both amps?


----------



## Gofre

Quote: 





yuceka said:


> I'm about the pull the trigger but I am torn in between this and Headstage Arrow 4G. Anyone heard both amps?


 
   
  Headfonia made a brief comparison in their C421 review;
   
  "*Comparison to the Headstage Arrow 3G and 4G*
 The Headstage is a nice amp and is still the slimmest one of the bunch. Build quality wise, it is still better than the C421 (in fact I think the D-Zero also has a better build quality than the C421). However I always find its soundstage to be quite flat. The 3G variant has a dark tonality and was quite full sounding in the mids and lows. The 4G version changed things a little by adding more treble to the mix, and you get a slightly more airier sound. Still it didn’t improve on the overall soundstage performance (airy sound is not the same as true three dimensional soundstage), and the treble area was dryer in comparison to the 3G.

 In many areas I find the C421 to be better sounding than both the 3G and the 4G Headstage amps. The soundstage performance was clearly better, as it possess both width and depth not heard on the Headstage. Midrange was also sweeter and clearer, the treble more airy while still very smooth. The only advantage the Headstage has over the C421 is in the bass section, where the Headstage has a more proper bass punch."


----------



## kenji458

Does the C421 benefit SE535 Ltd Ed or Sony EX1000 listening from iphone 4 as dap? Or generally iems wouldn't need an external amp.
   
  On a side note, I've already ordered the O2+ODAC for my Q701s..


----------



## Gofre

Received my C421 today, very prompt delivery, taking 5 days compared to the projected 6-10 which is always nice. Initial impressions are that it sounds great, although this is just from the opening ten minutes =P Can't wait to get it burned in and paired with my customs!


----------



## LoveKnight

If you can, please write a review of C421. I could not find any review of C421 on Head-fi yet. Thanks!


----------



## guhmo

I just ordered mine (8620)! Can't wait 'till I can be enjoying it


----------



## Gofre

Quote: 





loveknight said:


> If you can, please write a review of C421. I could not find any review of C421 on Head-fi yet. Thanks!


 
   
  My opinion won't be worth too much, I'm very much a beginner at this! I've never owned an amp before, the rig I've assembled over the last month (iMod>>C421>>Minerva Mi-3 Customs) is the first bit of audiophile gear I've ever owned =P I'll try my best to provide thoughts that people might find useful though [=


----------



## Mutnat

Quote: 





loveknight said:


> If you can, please write a review of C421. I could not find any review of C421 on Head-fi yet. Thanks!


 
   
  There are definitely some impressions throughout this thread.  I'm not an expert either but I am really loving my C421-2227.  Is there anything in particular you want to know?


----------



## Puffery

Just wanted to give some quick insight. I received my c421-2227 yesterday, up until now I have been using a cmoy BB 2.03. This is the only portable amp I can compare to the c421.
  
 I have put hundred of hours into the cmoy->hd25 II combo I use in my daily commute. I listen to a lot of electronic music and the Bass Boosting feature from the cmoy produces spine chilling bass from the HD25. However, the cmoy does little to hide the 7kHz peak of the HD25 and ssss notes from Adele's royal albert hall live album are a little bit bothersome.
  
 As soon as I tried the c421 I noticed a couple of things, namely:
  
 The mids and highs are smooth, engaging and non-fatiguing, the spike in the HD25's treble was handled much better and it sounded very nice. The sss notes from before were no longer bothering me and I could really just relax and enjoy the music.
  
 The lows are not as punchy/tight as the Cmoy, although still good. The bass seems a little loose even with the c421 bass boosting feature. 
  
 The noise floor is lower/blacker background
  
 The resolution, imaging and soundstage are all a good step up from the cmoy.
  
 These impressions are all without burn-in so I will update if anything changes. For electronic music I might still reach for my cmoy, but for everything else the c421 will be the way to go.


----------



## Mutnat

Quote: 





puffery said:


> These impressions are all without burn-in so I will update if anything changes. For electronic music I might still reach for my cmoy, but for everything else the c421 will be the way to go.


 
   
  I do recall mine improving with burn-in.  I've never had the cmoy to compare the bass with, but the bass is definitely more impactful than it was with the D-Zero as my amp.


----------



## Hi-fi Wigwammer

I had the JDS cMOYBB V2.03 and C421 at the same time. I found the bass much tighter and less bloomy on the C421. The cMOY sounded fantastic for the money, but the C421 bettered it in all areas. At the time this was driving UM Customs, iGrados, Alessandro MS-1i and V-Moda M80 phones.
  I did find the C421 a bit bright sounding out of the box, but after 6 hours or so it improved immensely. The C421 is a terrific amp and the cMOY is no slouch either.


----------



## LoveKnight

Quote: 





mutnat said:


> There are definitely some impressions throughout this thread.  I'm not an expert either but I am really loving my C421-2227.  Is there anything in particular you want to know?


 
   
  Yes. I am interested in using C421-2227 with Hifiman HE-500. Does anyone try to pair them together? Thanks.


----------



## Mutnat

Quote: 





loveknight said:


> Yes. I am interested in using C421-2227 with Hifiman HE-500. Does anyone try to pair them together? Thanks.


 
   
  Great question!  I don't recall seeing anyone having tried it with planar headphones.


----------



## Yuceka

Quote: 





mutnat said:


> Great question!  I don't recall seeing anyone having tried it with planar headphones.


 
  Someone already did that in this thread. You just have to go back several pages back to find it.


----------



## gelocks

Quote: 





loveknight said:


> Yes. I am interested in using C421-2227 with Hifiman HE-500. Does anyone try to pair them together? Thanks.


 
   
  http://www.head-fi.org/t/575633/jdslabs-c421-preorder-is-live/240#post_8251636


----------



## darren700

listening to my c421 opa2227 right now. paired with ipod 5.5 rockbox and my monster copper pro turbines. the sound absolutly blows away the ibasso d10 that i had before. everything just sounds so much clearer and lots of bass without even using the boost. the boost works very well btw but is not needed for me because the rockbox eq is awesome. the sound is very refined in this amp imo, i am able to pick up most of the microdetails that i usually omly hear in my desktop rig. soundstage sounds great for iems also. 
   
  still have to test my denon d1100s on it but im sure they will sound great.
   
  doesnt have quite enough juice to drive my lcd2s but thats what my jds O2 is for. 
   
  this will definately be my portable ipod amp for a long time, i love the pairing so far, especially the small form factor.
   
  will also try it out with my odac when it arrives, should make a nice pair. i just wish there was a dac like the odac that can pull a digital signal from the ipod. those dacs are way to expensive right now!


----------



## guhmo

Just got my c421/8620... imaging is superb, sound is lusher and clearer all around.  Treble has improved, and my UM3X are even more revealing and intolerant of bad quality files


----------



## thrand1

Hi everyone!
   
  I was considering the O2 headphone amplifier to go with my Shure SRH-940's, but wanted something in a more portable package. From some impressions I've read in this thread, it seems like the C421 is similar to the O2 in some regards but in a smaller package. I would just like to have an amplifier to utilize with a line out dock for my iPod that doesn't overly "color" the sound, and it seems like the C421 is a good compromise when you want something similar to the O2. Are my impressions somewhat accurate?
   
  Also, I have been reading up on the op-amps, if I wanted the one that would add the least coloration and provide the most neutral sound signature, is the AD8620 the way to go?
  
  Thank you in advance for your helpful feedback- I have been searching far and wide for an amp that is similar to the O2 in most regards but in a more compact form factor, and I think this may be the one.
   
  Thanks again!


----------



## guhmo

Quote: 





thrand1 said:


> Hi everyone!
> 
> I was considering the O2 headphone amplifier to go with my Shure SRH-940's, but wanted something in a more portable package. From some impressions I've read in this thread, it seems like the C421 is similar to the O2 in some regards but in a smaller package. I would just like to have an amplifier to utilize with a line out dock for my iPod that doesn't overly "color" the sound, and it seems like the C421 is a good compromise when you want something similar to the O2. Are my impressions somewhat accurate?
> 
> ...


 
   
  Yep, it seems you've found what you're looking for.  I've got the AD8620 version and the sound signature is pretty much nonexistent but for a (extremely tiny) bit of treble and bass emphasis.  It's also very compact - slightly bigger than a deck of cards - and fits under my iPod classic perfectly.


----------



## ClieOS

Yes, C421-AD8620 is very similar to O2 in sound, but not so much with C421-OPA2227.


----------



## WasabiTree

I would not get the AD8620 with IEMs -- gonna try my ER4-PTs again with it once I have the cable converter to ER4-S.


----------



## Yuceka

Quote: 





wasabitree said:


> I would not get the AD8620 with IEMs -- gonna try my ER4-PTs again with it once I have the cable converter to ER4-S.


 
  And why is that?


----------



## Hi-fi Wigwammer

I used the AD8620 version with UM Customs and it was a brilliant match. Go ahead and buy it, best portable amp i've owned. It did sound similar to the EHP-O2 I had in a lot of ways.


----------



## ClieOS

wasabitree said:


> I would not get the AD8620 with IEMs -- gonna try my ER4-PTs again with it once I have the cable converter to ER4-S.




I beg to differ. Haven't heard any better portable amp with ER4S than C421-AD8620, which also goes really well with most of my IEM.


----------



## marlonmarabe

Quote: 





clieos said:


> I beg to differ. Haven't heard any better portable amp with ER4S than C421-AD8620, which also goes really well with most of my IEM.


 
  x2


----------



## Mutnat

For anyone looking for a Canadian source, I just noticed that Vancouver-based Headphone Bar has them on their site.  I have no affiliation with them, and the only thing I ordered from them so far is a couple of inexpensive Fiio items (L9 LOD and an L2 cable, both of which have been replaced by a combo of SendStation and L8 since) but they seemed good to deal with.  They also have a physical store downtown, though I've never been there.
  
  EDIT: forgot to mention they don't seem to state which opamp is included so you may want to email or call them first to confirm.


----------



## Syracuse

I'm interested as well in a C421. I'm driving my Fischer Audio DBA02 mkII's now with the PA2V2 and although it really contributes I find the vocals to become harsch quickly and the bass response low. I've read that for IEM's the AD8620 is recommended. Is it something recommendable with brighter headphones or should I really look elsewhere?


----------



## ClieOS

C421-AD8620 is pretty neutral all-around. I won't say it particularly good or bad for bright IEM, it will just present music as it is (which is a good thing btw). PA2V2 is much more colored in comparison, ear pleasing in a lush way.


----------



## Syracuse

Thanks for your input


----------



## mosshorn

Just got my AD8620 C421 in, and here's my initial impressions from my V-Moda M80's. (via headphone out of an 5g Ipod, don't have my LOD in yet)
   
   
  When I first tried this, I was slightly disappointed. I've always been a fan of a lush, rich sound, and this seemed rather weak in comparison. The sub bass didn't reach as far down as I was thinking, and overall the presentation wasn't as powerful as I was originally thinking.
   
   
   
  Then I listened to "In My Time of Need" by Opeth, and it hit me. Sure this isn't a crazy meaty, let's make everything syrup type of sound. But that's the point. This isn't burnt in by any means, but this amp is passing on the music just how it needs to be: unadulterated, and as close to sounding like a perfect recording as possible. I can't really explain too much, but this is my first experience hearing what I feel is true neutrality. One thing I will give to this amp, the timbre of instruments is to die for. They aren't accentuated like some other amps I've tried (where they almost sound echoey), but everything just feels perfectly organic and natural. Guitars are entrancing with this amp, or so I feel. So are cymbals. My word, cymbals sound good. Neutrality is sometimes a scary word. My mind goes to the AKG K702 when people utter "neutral", and I shudder, thinking that neutrality is only good for reference classical and light rock. For anyone afraid of this over the OPA2227, take the dive. It's worth it.
   
  Next up was Hans Zimmer's "160BPM". The timbre got to me again. I guess in this case it would be the combination of timbre and soundstage for this one, along with Hans just being a general badass. This song sounds great. There are one or two smaaaalll parts where I wanted a little more bottomless-ness in my bass, but hey, I'm not complaining when everything else was right.
   
  Got something a little quicker now, "Valhall Awaits Me" by Amon Amarth. The double bass at the beginning didn't rumble as much as I like, but again, quite a few things could attribute to this. Johan, however, sounds awesome. His growls are (if this makes any sense) clear, and he sounds aggressive and legible. This is usually one of my tests of any new piece of gear I get, because I've always found it's very easy to make Amon Amarth sound muffled, and the lyrics to be unintelligible. This amp passes, quite well actually  The oddest thing about this test, however, is that I found it to sound equally good with bass boost ON. This confused me, but added the meat that I do occasionally crave with AA. I continued on to "Runes To My Memory" with bass boost on, and it sounded fantastic. Interesting, the bass is indeed boosted, but it is by no means sloppy sounding (see: Fiio E7).
   
  Last (but not least for now, I'll be doing a formal review once I get my LOD), is an excerpt from Bach's Solo Partitias, the Courante section of the 1st one, performed by Oleg Kagan. While the M80's aren't particularly known for their high end sparkle, I find this to be very enjoyable. I've played violin for around 8 years, so I guess if there's one instrument I get picky on when listening, it's this. Since I know the limitations of my headphones, I'll say, this amp is EXCELLENT for classical. Great detail retrieval, great soundstage, and just a great clean sound.
   
   
  All in all, I feel this is well worth the money. I've been wanting to make a portable rig for a while, getting tired of being tethered to my computer while listening to good music. Some have swayed me, saying that portable amps/rigs are either useless, or not worth nearly what you pay. I feel that I got exactly what I paid for here, the ability to enjoy my music wherever I go, and hell, I feel that I could use this as a desktop amp as well until I get enough to buy in the $500 range.
   
   
  Next goal: Diymod 
	

	
	
		
		

		
			





 if anyone wants to pm me with how hard it is to fit internal caps for it, I would greatly appreciate it ^_^
   
   
  Now for pics. I was curious how this would stack with an Ipod, and here it is (with a 60GB 5g Ipod):


----------



## Mutnat

Quote: 





mosshorn said:


> Just got my AD8620 C421 in, and here's my initial impressions from my V-Moda M80's. (via headphone out of an 5g Ipod, don't have my LOD in yet)


 
   
  Congrats on your purchase!  And yes your impressions are pretty consistent with what most are experiencing with this amp.  It actually isn't totally neutral, but for most music listening, that's a good thing.  It's got a very pleasant timbre to it that makes it quite fun to listen to, as you are experiencing.  And yes a bit more bottom end punch is a common wish list item for people with this amp.  The bass boost does definitely help, though!  And does so as you mention without muddying up the mids or high end.


----------



## marlonmarabe

just wanted to say i am purely amazed by the quality of my c421 ad8620. in fact, i cant live without it.


----------



## Mauricio

I, too, am satisfied with my C421 (AD8620).  Nothing to fault, really.


----------



## politechnica

Hello there,
   
  i tryed to get an answer for my question by reading through all posts here, but the question still remains open.
   
  My current gear (for outside...):
   
  - iPhone 4 (no LOD yet)
  - BeyerDynamics DT 1350 (AKG K550 on their way)
   
  The sound on the headphones is awesome, yet i lack some more volume on the iPhone. Just a tiny little bit louder would be OK.
   
  So here's my question:
   
  Will the c421 help me in that regard? I don't want my ears to bleed, but the iPhone is so darned "silent".
  Currently i'm in the process of burning-in a NuForce Icon Mobile... But until now, there is no real improvement on the volume issue...
   
  Help would be appreciated.
   
  Cheers,


----------



## gelocks

Wait ... what?!?
  Your Iphone should adequately drive those 2 headphones loud-enough without problems!! Where are you using the headphones? Anyway, yep, that's the job of the amp, provide you with a bit more volume and body. I'm sure you will be satisfied with the c421s.


----------



## politechnica

Quote: 





gelocks said:


> Wait ... what?!?
> Your Iphone should adequately drive those 2 headphones loud-enough without problems!! Where are you using the headphones? Anyway, yep, that's the job of the amp, provide you with a bit more volume and body. I'm sure you will be satisfied with the c421s.


 
   
  Thanks for the quick reply...
   
  I use the DT1350 on the balcony when i'm out for a smoke or read... or when i'm in public transportation.
  Environment doesn't really matter since the DT1350 block every noise from outside (so good).
   
  I think i'll give the c421 a try, since it's not that expensive...


----------



## gelocks

Even with my Archos 7 (a media player from a company in France that actually LOWER the volume of the players before selling due to EU regulations) I just put the volume to 75-90%, connect it to the c421 and if I'm not careful I could hurt my ears! lol
   
  So yep, get it and let us know how you like it! 
	

	
	
		
		

		
			




   
  Enjoy!


----------



## politechnica

Quote: 





gelocks said:


> Even with my Archos 7 (a media player from a company in France that actually LOWER the volume of the players before selling due to EU regulations) I just put the volume to 75-90%, connect it to the c421 and if I'm not careful I could hurt my ears! lol
> 
> So yep, get it and let us know how you like it!
> 
> ...


 
   
  Ha, will do so. It will take 2-3 weeks for the order and shipping and... But i'll give a feedback asap.
   
  P.S. should i get a LOD cable too? I could order the Fiio L3 from JDS Labs too, since i'll be already placing the order?


----------



## Mauricio

The average volume setting with the DT770Pro 250Ohm is about 2/3rds on low gain.


----------



## Yuceka

politechnica said:


> Ha, will do so. It will take 2-3 weeks for the order and shipping and... But i'll give a feedback asap.
> 
> P.S. should i get a LOD cable too? I could order the Fiio L3 from JDS Labs too, since i'll be already placing the order?




Yes you should get a LOD cable otherwise you'll be double amping which is not ideal


----------



## gelocks

Quote: 





yuceka said:


> Yes you should get a LOD cable otherwise you'll be double amping which is not ideal


 
   
  This.


----------



## ExpatinJapan

Quote: 





politechnica said:


> Ha, will do so. It will take 2-3 weeks for the order and shipping and... But i'll give a feedback asap.
> 
> P.S. should i get a LOD cable too? I could order the Fiio L3 from JDS Labs too, since i'll be already placing the order?


 
  You might want to think about a Fiio L9 LOD, low profile (doesnt stick out so much).


----------



## Mauricio

Quote: 





mauricio said:


> The average volume setting with the DT770Pro 250Ohm is about 2/3rds on low gain.


 
   
  I hooked up the C421 earlier this morning to a stand-alone CD player.  Due to the higher line voltage, I was able to hear my 250Ohm cans on 1/3rd volume on low gain.


----------



## LoveKnight

Oh, really? Then C421s probably have more than enough power to drive my Sennheiser HD 598 without problems at all at low gain. I am saving money to buy C421 - OPA2227. However, I am considering which 3.5mm interconnect cable I should buy with C421 on JDSLabs website?
   
  This one Fiio L2 http://www.jdslabs.com/item.php?fetchitem=L2 or this one iSimple http://www.jdslabs.com/item.php?fetchitem=ISVE913 . Which one is better? My DAC now is Fiio E10. Thanks for answer this question.


----------



## Mauricio

I got my Fiio line out cable at Amazon.


----------



## zeitfliesst

Has anyone tried using the C421 with a sensitive IEM? I want to use this with my ES5, but I did see someone mentioning that this amp was too loud for his UE4, so I'm kind of worried.


----------



## Yuceka

Quote: 





zeitfliesst said:


> Has anyone tried using the C421 with a sensitive IEM? I want to use this with my ES5, but I did see someone mentioning that this amp was too loud for his UE4, so I'm kind of worried.


 
  I have been using them with my 1964 Ears Quads and I don't think they are too loud with the C421. But it can get to loudness leves that would be very harmful for your hearing but that's dependent on the user and not the design of C421. Unless you like to listen to music in whispering levels, no it won't be too loud but I don't know how sensitivity differs between Westone ES5 and my own Quads.


----------



## zeitfliesst

Thanks for sharing that. They have nearly the same sensitivity (118 vs.120), but yours has a higher impedance @ 46 ohm vs. the es5 @ 20 ohm. I'm not sure how that plays out, but I guess I will be fine? I even contacted the manufacturer and they assured me that they brought the low gain a notch down several months ago, and that they use it with sensitive IEM's so yeah... I'm exchanging the digizoid ZO2 for the C421 (the ZO2 had a terrible hiss and the volume was way too loud)
   
  Oh, and just curious. How much do you turn the knob around to get to your comfortable listening level with the 1964 quads?
   
  Quote: 





yuceka said:


> I have been using them with my 1964 Ears Quads and I don't think they are too loud with the C421. But it can get to loudness leves that would be very harmful for your hearing but that's dependent on the user and not the design of C421. Unless you like to listen to music in whispering levels, no it won't be too loud but I don't know how sensitivity differs between Westone ES5 and my own Quads.


----------



## Yuceka

Quote: 





zeitfliesst said:


> Thanks for sharing that. They have nearly the same sensitivity (118 vs.120), but yours has a higher impedance @ 46 ohm vs. the es5 @ 20 ohm. I'm not sure how that plays out, but I guess I will be fine? I even contacted the manufacturer and they assured me that they brought the low gain a notch down several months ago, and that they use it with sensitive IEM's so yeah... I'm exchanging the digizoid ZO2 for the C421 (the ZO2 had a terrible hiss and the volume was way too loud)
> 
> Oh, and just curious. How much do you turn the knob around to get to your comfortable listening level with the 1964 quads?


 
  Well it's not stepped nor like Arrow or Leckerton UHA-4 (I don't remember what their implementation is called now) so it's hard for me to describe in writing but maybe just two notches or 3/10 or 4/10 if that helps at all? But I doubt you'll have any issues with it. 
   
  One thing, I have used Zo2 extensively and never heard any hiss with my Quads but I can say that the Zo2 was much louder than the C421.


----------



## zeitfliesst

Yeah sorry, I mean the disk shaped dial thingies...Yeah 3/10 isn't too bad at all.
   
  And regarding the ZO2, the hiss on mine was pretty bad, although I can understand how some people might choose to live with it. It's like that slightly annoying background noise when you listen to the radio at odd channels. Or maybe I simply have a bad unit. In any case I'll be holding back another purchase from digizoid until the next version (most likely the rumored full implementation of their Smartvektor tech)
  Quote: 





yuceka said:


> Well it's not stepped nor like Arrow or Leckerton UHA-4 (I don't remember what their implementation is called now) so it's hard for me to describe in writing but maybe just two notches or 3/10 or 4/10 if that helps at all? But I doubt you'll have any issues with it.
> 
> One thing, I have used Zo2 extensively and never heard any hiss with my Quads but I can say that the Zo2 was much louder than the C421.


----------



## Guizan

Has anyone tried the C421 with the Sony EX1000 or JVC FX700? I'm just wondering which op-amp would suite these particular iem's best. Just from what I'm gathering, the 8620 doesn't sound like a good fit for the FX700's at all.


----------



## Yuceka

zeitfliesst said:


> Yeah sorry, I mean the disk shaped dial thingies...Yeah 3/10 isn't too bad at all.
> 
> And regarding the ZO2, the hiss on mine was pretty bad, although I can understand how some people might choose to live with it. It's like that slightly annoying background noise when you listen to the radio at odd channels. Or maybe I simply have a bad unit. In any case I'll be holding back another purchase from digizoid until the next version (most likely the rumored full implementation of their Smartvektor tech)




Hmm I never used the zo2 with radio channels. It makes sense now. I'm listening to my c421 now with my iPhone and i can confirm that it goes dead silent befor you turn the dial all the way down. So that should tell you that it won't get ridiculously loud before you know it. I like the instrument separation and the soundstage improvement


----------



## Mustvid

Is the C421 a significant step up from the Cmoy?


----------



## mosshorn

Quote: 





mustvid said:


> Is the C421 a significant step up from the Cmoy?


 

 Yes. At least it was to me.


----------



## Mustvid

Quote: 





mosshorn said:


> Yes. At least it was to me.


 
  Interesting. Can you please elaborate a little more? What's your source and what headphones?


----------



## mosshorn

Coming from a 5G Ipod running rockbox to V-Moda M80's, the JVC FX40's, and my modded pair of Fostex T50RP's, I notice an improvement across the board. The soundstage is improved, but the main thing I noticed was detail. Everything just seemed more articulate. It also has quite a bit more power, being able to run my T50RP's better than the CMOY or even my Audioengine D1. The bass boost is also significantly better, and I'm sure most on this thread would agree. IMHO, the C421 probably has one of the cleanest sounding bass boosts I've heard.


----------



## zeitfliesst

That's just the thing I wanted to hear 
	

	
	
		
		

		
			





. The two things I want most out of this amp is a portable solution for a clean bass boost that doesn't bleed into mids and highs, and also an improvement in soundstage, since the ES5 feels a bit narrow relative to say the UE11, which I also owned for 4 years almost.
   
  Quote: 





mosshorn said:


> Coming from a 5G Ipod running rockbox to V-Moda M80's, the JVC FX40's, and my modded pair of Fostex T50RP's, I notice an improvement across the board. The soundstage is improved, but the main thing I noticed was detail. Everything just seemed more articulate. It also has quite a bit more power, being able to run my T50RP's better than the CMOY or even my Audioengine D1. The bass boost is also significantly better, and I'm sure most on this thread would agree. IMHO, the C421 probably has one of the cleanest sounding bass boosts I've heard.


----------



## zeitfliesst

Oh sorry to confuse you. I was just using an example to illustrate how bad the hiss was for me. I don't listen to the radio (they don't play anything worth listening here...).
   
  Quote: 





yuceka said:


> Hmm I never used the zo2 with radio channels. It makes sense now. I'm listening to my c421 now with my iPhone and i can confirm that it goes dead silent befor you turn the dial all the way down. So that should tell you that it won't get ridiculously loud before you know it. I like the instrument separation and the soundstage improvement


----------



## Mutnat

Quote: 





mustvid said:


> Is the C421 a significant step up from the Cmoy?


 
   
  The Headfonia guys definitely think so:  http://www.headfonia.com/flyin-high-jdslabs-c421/I
   
  I've never had a Cmoy amp but I am in love with my C421-2227.  (No, not literally, but I like it a whole lot.)


----------



## zeitfliesst

Heh, good thing you made it clear you didn't mean it literally. I'm sure some people on head-fi don't say that as a joke 
	

	
	
		
		

		
		
	


	




.
   
  On a more serious note, what do you think about the 2227 opamp vs. the 8620 (if you haven't heard it, based on what everybody's saying)? Would it pair well with the ES5, which is generally a warm IEM with slightly forward mids and gentle highs?
  Quote: 





mutnat said:


> The Headfonia guys definitely think so:  http://www.headfonia.com/flyin-high-jdslabs-c421/I
> 
> I've never had a Cmoy amp but I am in love with my C421-2227.  (No, not literally, but I like it a whole lot.)


----------



## Mutnat

Quote: 





zeitfliesst said:


> On a more serious note, what do you think about the 2227 opamp vs. the 8620 (if you haven't heard it, based on what everybody's saying)? Would it pair well with the ES5, which is generally a warm IEM with slightly forward mids and gentle highs?


 
   
  Wow, I wish I knew what to suggest there but I don't really.  If your IEM's have gentle highs and forward mids then yeah the 8620 *might* be a better choice.  Maybe someone else can weigh in?


----------



## guhmo

Quote: 





zeitfliesst said:


> Heh, good thing you made it clear you didn't mean it literally. I'm sure some people on head-fi don't say that as a joke
> 
> 
> 
> ...


 
  I think it depends on what sound signature you want. Do you want to retain/increase the ES5's warm sound signature, or would you like to brighten up the highs? For me, I decided to go with the more neutral, slightly v-shaped 8620 over the warmer 2227 for the UM3X to make it more lively in the treble department.


----------



## zeitfliesst

I guess I want the best of both worlds, but that looks like asking for too much. I guess brightening up the ES5 would be a welcome change, but I just don't know how I would like it. On the other hand, I would also like to enhance the bass, make it more punchier for bass heavy metal genres like djent. Is the 2227 really that noticeably warm?
   
   
  Or maybe a good compromise would be to get the 8620 and use the bass boost feature for djent. But then, the headfonia review seems to be stopping me from doing that since he does mention better soundstage with the 2227 (not sure if everyone agrees with this or not). This is becoming a tough decision...


----------



## guhmo

Better soundstage with the 2227? From what I've read it seems that the 8620's soundstage is better, probably because of the treble. From personal use the 8620 widens up the UM3X's deliberately small soundstage slightly, and it improves the instrument separation to godlike levels. 
   
  I think the opamp differences are extremely subtle. Even the most minuscule differences are amplified (no pun intended) by us audiophiles... On the UM3X there is a slight treble increase due to the opamp, but nothing like EQing from my iPod.


----------



## ClieOS

When compared to AD8620, OPA2227 gives slightly better width but it totally loses in depth, layering and transparency. Unless you only like your soundstage from side to side but not from near to far, I'll say AD8620 is hands down much better in soundstage.


----------



## zeitfliesst

Ah I see. Thanks for your input. The headfonia review is really throwing everyone off including me. I think I've made up 75% of my mind to get the 8620. Will have to think a bit further.
  Quote: 





guhmo said:


> Better soundstage with the 2227? From what I've read it seems that the 8620's soundstage is better, probably because of the treble. From personal use the 8620 widens up the UM3X's deliberately small soundstage slightly, and it improves the instrument separation to godlike levels.
> 
> I think the opamp differences are extremely subtle. Even the most minuscule differences are amplified (no pun intended) by us audiophiles... On the UM3X there is a slight treble increase due to the opamp, but nothing like EQing from my iPod.


----------



## zeitfliesst

Thanks for your opinion. I've seen that you do prefer the 8620 over the 2227, and so does a lot of other head-fiers. Now I think I'm 85% set on getting the 8620 
	

	
	
		
		

		
			




   
  Quote: 





clieos said:


> When compared to AD8620, OPA2227 gives slightly better width but it totally loses in depth, layering and transparency. Unless you only like your soundstage from side to side but not from near to far, I'll say AD8620 is hands down much better in soundstage.


----------



## 808Ronin

Quote: 





guhmo said:


> I think it depends on what sound signature you want. Do you want to retain/increase the ES5's warm sound signature, or would you like to brighten up the highs? For me, I decided to go with the more neutral, slightly v-shaped 8620 over the warmer 2227 for the UM3X to make it more lively in the treble department.


 
   
  Quote: 





guhmo said:


> Better soundstage with the 2227? From what I've read it seems that the 8620's soundstage is better, probably because of the treble. From personal use the 8620 widens up the UM3X's deliberately small soundstage slightly, and it improves the instrument separation to godlike levels.
> 
> I think the opamp differences are extremely subtle. Even the most minuscule differences are amplified (no pun intended) by us audiophiles... On the UM3X there is a slight treble increase due to the opamp, but nothing like EQing from my iPod.


 
  I couldnt agree more. I have both UM3X as well as W3 The c421 with 8620 has been the perfect amp for all the reasons you have stated. It really has improved areas of these iem and elevated them. I also used the cmoybb with the 2227 prior to the c421 and while i did like it and the sound was great, the c421 took the sound to a new level.


----------



## zeitfliesst

OK, that's it. I'm going with the 8620 now 100% 
	

	
	
		
		

		
		
	


	




. The ES5 has better highs than the um3x, but I still feel it's behind the UE11 so I guess brightening it up would be a good choice. 
   
  Quote: 





808ronin said:


> I couldnt agree more. I have both UM3X as well as W3 The c421 with 8620 has been the perfect amp for all the reasons you have stated. It really has improved areas of these iem and elevated them. I also used the cmoybb with the 2227 prior to the c421 and while i did like it and the sound was great, the c421 took the sound to a new level.


----------



## drakeforte

Is the c421 really better than the cmoybb?  I rolled an AD8620 on my cmoybb and that make a big difference with the cmoybb.  The bass is now punchier and thicker when bass boost is on but not muddy unlike the OPA2227.
   
  What sort of improvements will I get from the AD8620 cmoybb to the c421 with AD8620?  
   
  My HP are hd595 and grado sr225i and I especially like the HD595 with the cmoybb AD8620.  The grado pairing sounded good too, as I am not affected with the brightness that others seem to get with the AD8620.  Although, the mids are thinner on the AD8620 than on the OPA2227.
   
  Also, with the cmoybb on OPA2227, the sound was so slow and laid back that it made the lively grado boring to listen to that I ended up using the HPs straight to the zune hd.  
   
  Do you still get that slow and laid back/amost boring sound with the C421 OPA2227 combo. Or does the C421's design brought out the best out of the OPA2227?
   
  I am on the fence whether I want the OPA2227 or the AD8620 on the c421.
   
  Thanks.


----------



## zeitfliesst

Well, I had a reason to be hesitant since I've never had experience with these op-amps (or any rollable op-amps for that matter), but if you heard both the 2227 and the 8620 and you liked the latter better, it's pretty clear that you should go with the 8620. This is what JDS recommends: "Choose AD8620 if you've heard the chip before, or if you certainly prefer an analytical sound signature over the "warmer" characteristic output of the OPA2227."
   
  The real question you should be asking is how much of an improvement you will gain by going from cmoy to c421. The headfonia review was pretty clear about the improvement though.
  Quote: 





drakeforte said:


> Is the c421 really better than the cmoybb?  I rolled an AD8620 on my cmoybb and that make a big difference with the cmoybb.  The bass is now punchier and thicker when bass boost is on but not muddy unlike the OPA2227.
> 
> What sort of improvements will I get from the AD8620 cmoybb to the c421 with AD8620?
> 
> ...


----------



## gelocks

I had JDSLabs CmoyBB before buying their c421... lemme just say, c421 wipes the floor with the Cmoy in terms of... EVERYTHING! More power, better soundstage, great deal of details and versatile (love that it is USB also.).


----------



## 808Ronin

I initially chose the c421 for its sleeker profile to match with my ipod classic. I also was very confident that it would be an improvement over the cmoybb strictly based on the positive comments of other people on here that have dealt with JDS labs and John Seaber.  He does come across in his posts as a guy who has a wealth of knowledge as well as someone that charges a fair price and dosent mark up his products strictly based on the hype or because he can. Recently i contacted him regarding a defective face plate where some of the print was fading and i had a weird film that i couldnt get off. I explained it to him and he sent me a new one, no problem, no charge. I am pleased i chose JDS i just hope as they grow things stay the same as far as quality and customer service.


----------



## drakeforte

Thanks for the feedback. Am now gearing towards pulling the trigger on the c421 ad8620. I returned a asgard recently because i did not like the sound signature i was getting. I want more thickness and fullness - basically more bass and c421 will fit the bill. And based on this i really am not a audiophille but rather somebody who just wants to enjoy the music the way i want it to sound like. Will post my findings and maybe compare the cmoybb and c421 and asgard from memory since i dont have it anymore.


----------



## Mauricio

Quote: 





guhmo said:


> Even the most minuscule differences are amplified (no pun intended) by us audiophiles...


 
   
  Ain't that the truth!.  Witness on this here thread alone the hyperbolic flights of fancy and imagination.  With not an iota of care to account for the influences in perceptions due to the signal, listening level and the headphone involved.  And they speak with stone cold certainty.  How laughable these threads can be.


----------



## BrainFood

I know very little about portable audio, so excuse the potentially dumb question. 
   
  With my samsung phone (no pure line out), I'd have to turn its volume up to max, which would effectively mean that the signal would be going through two stages of amplification (the samsung's and C421's). That wouldn't be the end of the world by any means, but not exactly ideal either.
   
  Which devices/ players out there that have a pure line out?


----------



## Matt head 777

LOD cable with iphone is like line out.


----------



## BrainFood

Quote: 





matt head 777 said:


> LOD cable with iphone is like line out.


 
  Thanks
   
  Any non-apple suggestions?


----------



## Raines

I have the cmoy and the 2227 c-421...
   
   
  I can only say that now the cmoy sounds "mudy".... i havent touched it since i have the c-421.
   
   
  One question... is best to put the gain in HIGH or LOW? for the same volume it seems the HIGH has better SQ


----------



## stv014

Quote: 





> Originally Posted by *Raines* /img/forum/go_quote.gif
> 
> One question... is best to put the gain in HIGH or LOW? for the same volume it seems the HIGH has better SQ


 
   
  I do not know about the design details of the C421, but in general low gain is technically better (even if it is not necessarily audible) if the amplifier does not have stability issues. However, people tend to hear high gain as "better" simply because it is louder, and accurately matching the volume is difficult without measurements; it takes less than 1 dB of increase in loudness to "improve" the perceived sound quality.


----------



## zeitfliesst

You could be right that the two gains have different sounds, but it could also likely be placebo. Wait for someone else who owns a c421 to confirm or reject that.
  Quote: 





raines said:


> I have the cmoy and the 2227 c-421...
> 
> 
> I can only say that now the cmoy sounds "mudy".... i havent touched it since i have the c-421.
> ...


----------



## guhmo

Quote: 





brainfood said:


> Which devices/ players out there that have a pure line out?


 
   
  I believe the Sony Walkmans have a line-out, and the Sansa Fuze+ does as well. If I'm not mistaken there is a USB dock you can buy for your Samsung phone for line-level audio... although that may be desktop only.


----------



## ClieOS

guhmo said:


> I believe the Sony Walkmans have a line-out, and the Sansa Fuze+ does as well. If I'm not mistaken there is a USB dock you can buy for your Samsung phone for line-level audio... although that may be desktop only.




Fuze+ doesn't have a line-oiut, Fuze does. Fro what I have read / experience, Samsung and Sony's line-out are probably not true line-out, a least not in the traditional meaning of the world. They are more like semi- / pseudo- line-out, but it is not to say they won't sound as good or better than amping the headphone-out.


----------



## guhmo

Quote: 





clieos said:


> Fuze+ doesn't have a line-oiut, Fuze does. Fro what I have read / experience, Samsung and Sony's line-out are probably not true line-out, a least not in the traditional meaning of the world. They are more like semi- / pseudo- line-out, but it is not to say they won't sound as good or better than amping the headphone-out.


 
   
  Oh, sorry haha; my bad.


----------



## Mutnat

Quote: 





raines said:


> One question... is best to put the gain in HIGH or LOW? for the same volume it seems the HIGH has better SQ


 
   
  I think it all depends on your headphones and what sounds best to you.  If you have high-impedence or difficult to drive headphones, you might benefit from the high gain setting, and if you have lower-impedence then low is probably the way to go.  I use low on my HD25's and there's PLENTY of headroom left.


----------



## BrainFood

Quote: 





clieos said:


> Fuze+ doesn't have a line-oiut, Fuze does. Fro what I have read / experience, Samsung and Sony's line-out are probably not true line-out, a least not in the traditional meaning of the world. They are more like semi- / pseudo- line-out, but it is not to say they won't sound as good or better than amping the headphone-out.


 
   
  Lol, surprisingly few options, then. I'm put off by comments about short battery life on the Fuze. The search continues...


----------



## guhmo

Quote: 





brainfood said:


> Lol, surprisingly few options, then. I'm put off by comments about short battery life on the Fuze. The search continues...


 
   
  Ah yes, the HiFiMAN HM 60x, HM 80x and upcoming HM 901 also have line-outs, I think. But I doubt you'll be needing a separate dedicated amplifier on those players.


----------



## ClieOS

brainfood said:


> Lol, surprisingly few options, then. I'm put off by comments about short battery life on the Fuze. The search continues...




What kind of battery life are you looking for anyway? I never feel Fuze has a short battery life but then again I never need to live very far of a power socket. At least for most part, Fuze can easily out last most smartphone.


----------



## BrainFood

Amazon user reviews; How is sound quality anyway?
   
  Considering it costs £50, you start to think about devices with potentially better DAC chips inside. It's a fast changing market and the original Fuze is a few years old. I don't need its video capabilities either;


----------



## ClieOS

Unless you are going for the route of audiophile player (HM801, DX100, C4, etc) or iPod specialty DAC (CLAS, HP-01, etc) , you are not really getting any much better DAC chip for most DAP in the market. Sure, Apple and Samsung do put Wolfson or Cirrus Logic in their player, but they are mostly low power type and generally won't offer you much better SQ than what is in Fuze. At least with Fuze, it has been measured (in the case of Clip+ which shares mostly the same inner) and known to be good performer.


----------



## BrainFood

Quote: 





clieos said:


> Unless you are going for the route of audiophile player (HM801, DX100, C4, etc) or iPod specialty DAC (CLAS, HP-01, etc) , you are not really getting any much better DAC chip for most DAP in the market. Sure, Apple and Samsung do put Wolfson or Cirrus Logic in their player, but they are mostly low power type and generally won't offer you much better SQ than what is in Fuze. At least with Fuze, it has been measured (in the case of Clip+ which shares mostly the same inner) and known to be good performer.


 
   
   
  Nice summation of what's out there.
   
  Well if the Fuze (not Fuze+) is what it takes to get a pure line out (the feature I'm most interested in) then fuze it is. Shame the Fuze+ doesn't have it
   
  Might as well order the 4GB one because I have spare micro SD cards


----------



## Voodoo002

Hi guys,
  Just to let you know we're running a charity raffle to *win an C421* and other gear courtsey of JDS labs:
   
http://www.charitygiving.co.uk/jdslabscharityraffle
   
  It's only £2 per entry and Nick at JDS will be picking the lucky winner.
   
  It *closes this Sunday 10th June* so hurry


----------



## Yuceka

deleted


----------



## zeitfliesst

Well why don't you see for yourself? I emailed them and John (CEO) got back to me pretty soon and was very helpful. The amp shipped on the same day of payment too. Awesome customer service so far if you ask me.
    
  Quote:


yuceka said:


> From your experiences how responsive are the guys at JDS Labs in answering questions? I'm seriously considering getting an O2 for my HE-500


----------



## ostewart

I just won the Raffle! so happy, yet so undecided between the O2 and C421, im thinking to get the AD8620 C421 as i dont really need a home amp, my listening is pretty much all on the go.


----------



## racoiaw

Wow lucky you. Im currently using the c421 ad8620 as my on the go amp too and so far im enjoying it alot


----------



## ostewart

yep, i never thought i would win.
   
  i asked for the C421 AD8620, it is being sent today  cant wait to get it!!!


----------



## gelocks

Congrats!!! And enjoy!!


----------



## ostewart

thanks, you tried it with your SRH440? as i have some too


----------



## gelocks

I no longer have the 440s but I did try them with the JDSLabs CmoyBB and they sounded great so my guess is that they should open up a bit more with the c421.


----------



## ostewart

thanks, i really cannot wait to get the C421


----------



## e30ernest

Hello!
   
  I've been lurking these forums for a while.  I'm now looking at getting a C421 amp to pair with my Nexus S and iPod Video (1st gen).  Has anybody tried this amp with Shure SE425 IEMs?  I was wondering which of the 2 versions of the amp would be better suited for these monitors.  
   
  I am a drummer so I like listening to a lot of technical music such as progressive rock and jazz fusion.  Ideally I'd like to improve soundstage while getting better separation between instruments.  I'm not a basshead, but I do appreciate some bass to be able to listen to and learn some of the kick-drum patterns over the bass guitar licks on my music.  Mids and trebles would be great so that I can hear cymbal dynamics and snare ghosts better.
   
  I'd appreciate your feedback.
   
  Cheers!


----------



## sregor

Quote: 





e30ernest said:


> Hello!
> 
> I've been lurking these forums for a while.  I'm now looking at getting a C421 amp to pair with my Nexus S and iPod Video (1st gen).  Has anybody tried this amp with Shure SE425 IEMs?  I was wondering which of the 2 versions of the amp would be better suited for these monitors.
> 
> ...


 
  I use the amp (AD8620 op amp) with some Shure SE215's and I am very very happy with it. I mostly listen to metal/rock.


----------



## e30ernest

Thanks for your reply!  What differences did you notice between un-amped and amped with your 215s?  Thanks!


----------



## zeitfliesst

Seems to me most people (at least on Head-fi) are going with the 8620 opamp. Hope I've made the right choice.


----------



## Mutnat

Quote: 





zeitfliesst said:


> Seems to me most people (at least on Head-fi) are going with the 8620 opamp. Hope I've made the right choice.


 
   
  I've never heard the 8620 version but I imagine you will be pretty happy.  From comparisons others have made, it sounds like the differences are pretty subtle.  I guess in the end they're both good products, it's a matter of which will mesh better with your gear and your personal tastes.


----------



## LoveKnight

I am going to order a C421 with 2227 because I am a fan of smooth, warm vocal. Do not be so sad, I am going to join you soon. About 2 or 3 months from now 
	

	
	
		
		

		
			





.


----------



## sregor

I have never used them unamped, actually. So I am not sure.


----------



## imackler

Quote: 





sregor said:


> I have never used them unamped, actually. So I am not sure.


 
  have you tried the HD600 w/ the C421 for kicks?


----------



## gelocks

Quote: 





imackler said:


> have you tried the HD600 w/ the C421 for kicks?


 
   
  I have, and they sounded really good! The c421 has enough power to drive these either in low or high gain!


----------



## Ultrainferno

Quote: 





imackler said:


> have you tried the HD600 w/ the C421 for kicks?


 
   
  I use a HD650 daily at work with the C421 and while it sounds good it of course doesn't show what the Senns are capable of with a decent full desktop setup


----------



## miow

Guys, just a doubt: does the C421 provides more bass than the FiiO E11? If so I will order it now. Just need to know this.
   
  Oh, and what can I expect in terms of sound improvement for the E11? Better instrument separation perhaps? That would make me pull the trigger (along with the bass). And are we talking big differences or very subtle, almost unnoticeable ones?
   
  Please save me the $200


----------



## TheKarakiri

Where do you guys order you C421 from? The JDS website? I am currently in the US. One more question: Which do you guys prefer? The OPA2227 or the AD8620?


----------



## Ultrainferno

Quote: 





thekarakiri said:


> Where do you guys order you C421 from? The JDS website? I am currently in the US. One more question: Which do you guys prefer? The OPA2227 or the AD8620?


 

 JDSLabs! The OPA question again. Check this tread for multiple answers


----------



## zeitfliesst

Read this thread from post #1. That should really give you enough answers.
   
  Quote: 





thekarakiri said:


> One more question: Which do you guys prefer? The OPA2227 or the AD8620?


----------



## Raines

I have the 2227 and i love it.
   
  Short answer it seams that 2227 is warmer, more "fun" and full.
   
  8620 is more analitical, some people say is thin or dry .... maybe is more true to the sound
   
   
  i went with the 2227


----------



## ostewart

Mine arrived today, what can I say, build quality is fantastic, form factor, a little wider than my iPod classic, and the sound is a big step up from the fiio E11.

I have the AD8620 as I like a neutral sound.


----------



## zeitfliesst

How could you really tell that it was neutral? It's one of those words I don't seem to like so much in the audio world, so it's got me worried I made the wrong choice here.
  Quote: 





ostewart said:


> Mine arrived today, what can I say, build quality is fantastic, form factor, a little wider than my iPod classic, and the sound is a big step up from the fiio E11.
> I have the AD8620 as I like a neutral sound.


----------



## miow

From what I've been reading the AD8620 OPamp is more analitycal, which should make a better marriage for darker phones, I guess.


----------



## zeitfliesst

Guess what, I just got the c421 in the mail. Gotta love that fresh scent of electronic equipment (you guys probably know what I'm talking about). Despite my concerns over the 8620 opamp, it sounds great paired with the ES5. My only gripe is that the minimum volume level required to get out of the channel imbalance stage is just a bit above what I would normally prefer. Other than that, I'm loving this thing already.


----------



## zeitfliesst

OK, so to get around the problem of too much volume I just applied a gain of -6.0db using mp3gain and I now have much better control of the volume. This is going to be bad news for my car audio because the volume maxed out on that poor thing barely satisfied my needs. Oh well, I guess I just need to upgrade the damn thing.


----------



## zeitfliesst

Does anyone have a good solution to prevent the gain switch from moving? I get incredibly anxious of accidentally tripping it and blowing my ears and brains out when using the ES5. I wish the switch was recessed (like the RSA amps) or at least harder to move.


----------



## ClieOS

A bit paranoid, won't you say?


----------



## zeitfliesst

Not at all. The switches, dials and jacks are so close to each other so it's not inconceivable that I accidentally touch the gain switch. You might not have experiened incredibly high volumes with sensitive IEM's, but when you do, you probably won't call me paranoid.
  Quote: 





clieos said:


> A bit paranoid, won't you say?


----------



## ClieOS

I have been using my C421 for a few months now, never did I accidentally flip any of the switches when adjusting the volume. They are on 90 degree angle of each other after all. 

Well, if you are really that worry, you can file down the switches themselves so it is much less likely you will flip them accidentally.


----------



## zeitfliesst

I am not much worried about the dial as much as I am about the bass boost switch. I plan on switching it on/off occasionally and so I have to be quite careful. I have just applied a temporary fix with some tape and it seems to be doing its job.
   
  Quote: 





clieos said:


> I have been using my C421 for a few months now, never did I accidentally flip any of the switches when adjusting the volume. They are on 90 degree angle of each other after all.
> Well, if you are really that worry, you can file down the switches themselves so it is much less likely you will flip them accidentally.


----------



## ostewart

I never said the amp was neutral. I dislike the laid back burr Brown sound, I much prefer analytical than warm. I only said the AD8620 was more neutral than OPA2227, to my ears anyway.


----------



## ostewart

heres mine:


----------



## Ultrainferno

Looks exactly like mine, how weird!


----------



## ostewart

Quote: 





ultrainferno said:


> Looks exactly like mine, how weird!


 

 haha, i just thought i'd add a few more pics, the same as others.
   
  but you get the size comparison vs iPod Classic


----------



## e30ernest

Quote: 





ostewart said:


> heres mine:


 
   
  I see you are using Shure SE425s with the amp.  How has the amp affected that particular IEM?  I have the same IEM so I would love to hear what you think of the pairing.
   
  Cheers!


----------



## ostewart

it seems to highlight their strenghts, the bass becomes more articulate with better control, and the soundstage widens quite a bit.
   
  not a huge difference but it is a difference and for the better. i really like the pairing, as they continue with the excellent detail, but with better bass/highs balance, to compliment those lovely upfront mids.
  i have been listening to this setup since 11 this morning (now 16:30) and have been loving every bit of it.


----------



## Mutnat

Quote: 





zeitfliesst said:


> I am not much worried about the dial as much as I am about the bass boost switch. I plan on switching it on/off occasionally and so I have to be quite careful. I have just applied a temporary fix with some tape and it seems to be doing its job.


 
   
  Good call.  I did this once, flipped from low to hi gain trying to change the bass boost setting without paying enough attention.  Let's just say I won't make that mistake again....


----------



## zeitfliesst

Ah see, I'm not the only one 
	

	
	
		
		

		
		
	


	




. It has happened to me several times with different equipment and I can tell you it's not something you want to experience ever again.
   Quote:


mutnat said:


> Good call.  I did this once, flipped from low to hi gain trying to change the bass boost setting without paying enough attention.  Let's just say I won't make that mistake again....


----------



## miow

Faithfully you have golden ears


----------



## zeitfliesst

As in golden "crisp" ears? lol
   
  Quote: 





miow said:


> Faithfully you have golden ears


----------



## TheKarakiri

Hey guys,
   
  Which Portable DAC would work well with this AMP and an Ipod Classic? Would the AD8620 or the OPA2227 be better with the HD-25?


----------



## Mutnat

Quote: 





thekarakiri said:


> Hey guys,
> 
> Which Portable DAC would work well with this AMP and an Ipod Classic? Would the AD8620 or the OPA2227 be better with the HD-25?


 
   
  Sadly, you need a specialized DAC to work with an iDevice (iPods, iPhones).  The only stand-alone one portable iDevice DAC I know of is the Cypher Labs Algorythm Solo (or CLAS).  Unfortuantely, it is expensive ($580 USD).  Other options include a few integrated iDevice DAC + AMP devices such as the Fostex HP-P1 or the V-Moda VAMP, but both are even more expensive than the CLAS, and include an amp which is redundant in your set up.  I think a lot of us just make do with the internal DAC in the Ipod and use an LOD (line out dock) such as the Fiio L9 or others (they range from a few bucks to several hundred) and an amp such as the C421.  Personally I have the same headphones as you, and an iPod Touch (4G), and I bought the OPA2227 version of the C421.  I couldn't be happier with the pairing!  The 8620 might tend to the bright side with the HD25's, but then I've never had the opportunity to try it.


----------



## zeitfliesst

Maybe I'm going to have to sell this amp... I need to adjust the gain of my mp3 files and bring it down to 72db in order to get proper volume control with my ES5. And after having compared for a little while, the improvement is quite marginal from the ipod H/O that I'm starting to think that it's not worth it. Somebody at hydrogenaudio is calling me a "stupid hipster" for using portable amps for IEM's because this decreases fidelity and increases gain. Well I've seen many people using portable amps with IEM's on head-fi, so are we all stupid hipsters or what 
	

	
	
		
		

		
		
	


	




?


----------



## Mutnat

Quote: 





zeitfliesst said:


> Maybe I'm going to have to sell this amp... I need to adjust the gain of my mp3 files and bring it down to 72db in order to get proper volume control with my ES5. And after having compared for a little while, the improvement is quite marginal from the ipod H/O that I'm starting to think that it's not worth it. Somebody at hydrogenaudio is calling me a "stupid hipster" for using portable amps for IEM's because this decreases fidelity and increases gain. Well I've seen many people using portable amps with IEM's on head-fi, so are we all stupid hipsters or what
> 
> 
> 
> ...


 
   
  Are you using an LOD?


----------



## zeitfliesst

I sure am.
   
  Quote:


mutnat said:


> Are you using an LOD?


----------



## gkanai

Quote: 





zeitfliesst said:


> Well I've seen many people using portable amps with IEM's on head-fi, so are we all stupid hipsters or what
> 
> 
> 
> ...


 
   
  No clue about that other forum.
   
  Many IEMs (not all, of course) benefit from amplification but of course your source file and formats also matter too. If you've got a lossy mp3 then you're starting from a lesser-fidelity position than if you had a lossless file to begin with.


----------



## Mutnat

Quote: 





gkanai said:


> Many IEMs (not all, of course) benefit from amplification but of course your source file and formats also matter too. If you've got a lossy mp3 then you're starting from a lesser-fidelity position than if you had a lossless file to begin with.


 

 These are good points.  It's possible that your particular IEMs don't benefit much from an amp. 
 I'd also be curious if you have let the amp burn in a bit.  Leave it running over night (even for a couple of days) on a shuffle of your source library and see if the sound changes for the better.  Mine definitely improved a bit vs. out of the box.


----------



## zeitfliesst

Quote: 





mutnat said:


> These are good points.  It's possible that your particular IEMs don't benefit much from an amp.
> I'd also be curious if you have let the amp burn in a bit.  Leave it running over night (even for a couple of days) on a shuffle of your source library and see if the sound changes for the better.  Mine definitely improved a bit vs. out of the box.


 
   
  Totally forgot the burn-in. I'll make sure to give it some time and see if I like it better.


----------



## mmayer167

Just ordered a c421 2227. I'll be comparing it to the O2, source being the JDS ODAC. I hope to add another opinion to the mix sometime next week   
   
  -M


----------



## alphaphoenix

I have the very setup and I prefer the pairing of the C421/ODAC vs the O2/ODAC.  Between the amps, the bass is more prominent on the C421 over the O2 and that's with the switch set to flat.


----------



## idunnosoSTFU

I've had battery problem with one of my C421 amps before. Recently, the same problem occurred on another C421 amp of mine. It can't charge at all.  Anyone having the same problem?


----------



## Ultrainferno

Quote: 





idunnosostfu said:


> I've had battery problem with one of my C421 amps before. Recently, the same problem occurred on another C421 amp of mine. It can't charge at all.  Anyone having the same problem?


 
   
  Never heard of a C421 charging problem. Contact JDSLabs?


----------



## LoveKnight

Quote: 





idunnosostfu said:


> I've had battery problem with one of my C421 amps before. Recently, the same problem occurred on another C421 amp of mine. It can't charge at all.  Anyone having the same problem?


 

 Then I guess you have to plug your C421 in your laptop or desktop overtime 
	

	
	
		
		

		
		
	


	




, right?


----------



## Mauricio

No problem charging mine.


----------



## jseaber

Quote: 





idunnosostfu said:


> I've had battery problem with one of my C421 amps before. Recently, the same problem occurred on another C421 amp of mine. It can't charge at all.  Anyone having the same problem?


 
   
  This was an issue way back in one of the early batches (1-2% production error), but it was easily resolved. You'll find posts in this very thread about it.
   
  We now double check charging of every c421 to ensure proper operation. Four charging test points are measured after production, then we completely charge each amp. Not a single amp has failed this test since the production fix. Please contact us if you have trouble.


----------



## mmayer167

I am really liking my c421 with the 2227 op. It is a little meatier sounding and maybe a bit more sparkly than the O2 at times. Detail retrieval is excellent and as good as the O2 imo. But, the previous statement may be due to the c421 seeming a bit more snappy in the treble. This amp is definitely worth it paired with the ODAC! Killer combo, looks, size, function, and build are excellent. It handles the Paradox, which can be hungry at times, pretty well (with bass boost on and low gain). The D2000 are excellent out of it as well, at times the treble can be hot with the Denon since I think the odac is a bit treble hot mixing with the Denon smiley face freq (note: my d2k are partial markl modded). For me the O2 still wins when I want truth, but dang is the c421 enjoyable.
  
 Thought I would jot down some impressions after 5 days with the c421. 
  
 -M


----------



## Danconia

drakeforte said:


> Thanks for the feedback. Am now gearing towards pulling the trigger on the c421 ad8620. I returned a asgard recently because i did not like the sound signature i was getting. I want more thickness and fullness - basically more bass and c421 will fit the bill. And based on this i really am not a audiophille but rather somebody who just wants to enjoy the music the way i want it to sound like. Will post my findings and maybe compare the cmoybb and c421 and asgard from memory since i dont have it anymore.




Wondering about the Asgard vs C421 vs o2 for HD600. I too would like a little bass boost. Coming from E11 which is okay but want some improvement. 

On iPhone (power/internet service knocked out in dc area) so apologize if this has been covered.


----------



## Yuceka

I'm finally able to use my standalone ODAC paired with my C421 to 1964 Ears Quads... Am I floored? Yes! Absolutely. I've used so many different USB DACs but this ODAC + C421 combo is absolutely amazing. Probably one of the best purchases I've ever made. The form factor is also very cool. It's like the equivalent of CLAS + ALO MKII only without breaking the bank. I want to thank JDS Labs for putting out such amazing products without actually killing our wallets. It is possible to produce great products without actually ripping your customers off, read: ALO


----------



## Ultrainferno

Quote: 





yuceka said:


> I'm finally able to use my standalone ODAC paired with my C421 to 1964 Ears Quads... Am I floored? Yes! Absolutely. I've used so many different USB DACs but this ODAC + C421 combo is absolutely amazing. Probably one of the best purchases I've ever made. The form factor is also very cool. It's like the equivalent of CLAS + ALO MKII only without breaking the bank. I want to thank JDS Labs for putting out such amazing products without actually killing our wallets. It is possible to produce great products without actually ripping your customers off, read: ALO


 
   
  How is the channel imbalance with the C421 and the 1964 Quads at lower volume? With my other iems it's a bit too obvious and I have to turn up the volume more as I wish. I'm planning on getting the Quads


----------



## LoveKnight

Quote: 





yuceka said:


> I'm finally able to use my standalone ODAC paired with my C421 to 1964 Ears Quads... Am I floored? Yes! Absolutely. I've used so many different USB DACs but this ODAC + C421 combo is absolutely amazing. Probably one of the best purchases I've ever made. The form factor is also very cool. It's like the equivalent of CLAS + ALO MKII only without breaking the bank. I want to thank JDS Labs for putting out such amazing products without actually killing our wallets. It is possible to produce great products without actually ripping your customers off, read: ALO


 
  Oh my god. Are you kidding me? CLAS + ALO MKII is about $1000 and you compare this combo to ODAC + C421. That really makes me want to buy ODAC + C421 so badly. Thanks for your comment!


----------



## Ultrainferno

True, the O2 can't be compared to the CLAS as it can not extract a digital signal from an iDevice


----------



## Yuceka

Quote: 





ultrainferno said:


> True, the O2 can't be compared to the CLAS as it can not extract a digital signal from an iDevice


 
  I wasn't making a full comparison as they are apples and oranges but in terms of performance, I find the ODAC+C421 a ridiculously better value than CLAS+MKII. If JDS Labs had the permission to make a unit compatible with iDevices, I assume they'd have to pay to Apple some money for that and that would raise the price of the ODAC, I am aware of this fact but again for this price this combo is simply stunning. I have no further desire to upgrade really.
   
  Quote: 





ultrainferno said:


> How is the channel imbalance with the C421 and the 1964 Quads at lower volume? With my other iems it's a bit too obvious and I have to turn up the volume more as I wish. I'm planning on getting the Quads


 
  I haven't noticed any but again my hearing is not 100% intact so take it as that but again I don't know why anyone would listen to music around those levels that channel imbalance occurs. I've never had that problem with the C421.


----------



## LoveKnight

Oh yeah yeah. What do you think about ODAC and Bifrost? On ODAC some people said that Bifrost is slightly better than ODAC and I think they are right because Bifrost is over $300 but hey if you want to have USB port on Bifrost you have to pay $100 more so it could be over $400.
   
  May I ask what OPA you order in your C421? 2227 or the other, Yuceka?
   
  The more I read about ODAC and C421, the more I want to buy them immediately but my wallet does not want me to buy them now 
	

	
	
		
		

		
			





. Look like ODAC + C421 combo is a hot bomb. This hot bomb.


----------



## SteveSatch

I hope the 8620 is a good match for headphones.  I don't use in ear.  I mostly use Brainwavz HM5 and Denon A-HD2000.  I bought the C421 used and the 8620 chip is what it had.


----------



## miow

I think the A8620 must be a good match for dark headphones. Let us know how it works when you get it.


----------



## pekingduck

The C421 and ODAC combo, although sounds decent, is too loud for my UM3X. I suppose quite a few head-fi'ers are buying the amp for their IEMs? Perhaps JDS Labs should consider lowering the gain.


----------



## Ultrainferno

Quote: 





pekingduck said:


> The C421 and ODAC combo, although sounds decent, is too loud for my UM3X. I suppose quite a few head-fi'ers are buying the amp for their IEMs? Perhaps JDS Labs should consider lowering the gain.


 
   
  You can always ask JDSLabs to lower the gain when ordering, unfortunately I didn't do so


----------



## zeitfliesst

That's a great idea. Completely escaped my mind when I ordered... Although after playing with replaygain and the pre-amp gain on rockbox, I get a pretty good control over volume where a minimum required to escape channel imbalance isn't too loud with my ES5's. Loving this amp.
   
  Quote: 





ultrainferno said:


> You can always ask JDSLabs to lower the gain when ordering, unfortunately I didn't do so


----------



## pekingduck

ultrainferno said:


> You can always ask JDSLabs to lower the gain when ordering, unfortunately I didn't do so




Me neither...but I have sent the amp back to JDS Labs for that


----------



## jseaber

Quote: 





pekingduck said:


> The C421 and ODAC combo, although sounds decent, is too loud for my UM3X. I suppose quite a few head-fi'ers are buying the amp for their IEMs? Perhaps JDS Labs should consider lowering the gain.


 
   
  Gain is already low at 2.3x, which is lower than O2 and many other amps on the market.


----------



## Yuceka

Quote: 





jseaber said:


> Gain is already low at 2.3x, which is lower than O2 and many other amps on the market.


 
  Yep. I don't find the gain to be too much at all.


----------



## SteveSatch

I should have my C421 8620 in a few days.  If I find I would have rather got the 2227 I'll see if anyone here wants to trade.


----------



## ostewart

Quote: 





stevesatch said:


> I should have my C421 8620 in a few days.  If I find I would have rather got the 2227 I'll see if anyone here wants to trade.


 

 i love my 8620, and am glad i got it instead of 2227, as i find burr brown too mellow sounding for my tastes.
  your going to love this amp im sure.


----------



## miow

Can you define too mellow sounding, please?


----------



## Mutnat

Yeah I was under the impression the 8620 was more laid back and spacious whereas the 2227 was more up-front and lively.


----------



## ostewart

Well, I.rolled opamps in a cmoy, the burr brown opa2134, and it was slow and mellow with tubby bass, then I had the LME 49720 and that was fast, lively with details a lot easier to pick out.
Burr brown was not for me. The mids are smooth and warm, tubby bass with fairly good highs. I prefer lively, a little bright, fast and detailed.


----------



## Mutnat

Quote: 





ostewart said:


> Well, I.rolled opamps in a cmoy, the burr brown opa2134, and it was slow and mellow with tubby bass, then I had the LME 49720 and that was fast, lively with details a lot easier to pick out.
> Burr brown was not for me. The mids are smooth and warm, tubby bass with fairly good highs. I prefer lively, a little bright, fast and detailed.


 
   
  Oh, then you're earning your name as being the random kid!  You're comparing totally different opamps in a different amp and using those to make judgements about the sound of the two C421 options.  Somehow, I don't think it works that way.  Just because you found the OPA2134 to sound a certain way doesn't mean the OPA2227 will sound similar; likewise with the LME 49720 and the 8620.


----------



## ostewart

Quote: 





mutnat said:


> Oh, then you're earning your name as being the random kid!  You're comparing totally different opamps in a different amp and using those to make judgements about the sound of the two C421 options.  Somehow, I don't think it works that way.  Just because you found the OPA2134 to sound a certain way doesn't mean the OPA2227 will sound similar; likewise with the LME 49720 and the 8620.


 

 no mean to offend, look here, the AD8620 is know to be fast and detailed, and a little bright just like the LME49720, and i have had both as you know.
   
  also the OPA2134 is very similar to the 2227:
  http://tangentsoft.net/audio/opamps.html
   
  Read please


----------



## Mutnat

Quote: 





ostewart said:


> no mean to offend, look here, the AD8620 is know to be fast and detailed, and a little bright just like the LME49720, and i have had both as you know.
> 
> also the OPA2134 is very similar to the 2227:
> http://tangentsoft.net/audio/opamps.html
> ...


 

 No offense taken, and none intended in my reply, but I still think it's an unfair judgement. 
   
  For example:  the link you provided (which I have seen before but thank you) concludes about the 2227: "This is a good alternative to the OPA132. It is arguably even a significant upgrade."  Furthermore, different amps with the same opamp can sound quite different, based on implementation of the amp.  Some have remarked that CmoyBB-2227 compared to C421-2227 is quite different, with the latter sounding better.  I believe I read someone that had rolled an 8610 or 8620 into a CmoyBB also and favoured the 8620 in the C421 better than in the Cmoy, but I might be remembering this part wrong.


----------



## ostewart

That is true. All cool now. But the general consensus us that burr brow have a laid back smooth sound, whereas AD have a more detailed agressive sound


----------



## SteveSatch

How tight is the headphone jack on your C421?  Mine allows some wiggling of the headphone cable and the sound cuts in and out and makes some popping, static noise when the cord is moved.  JDS Labs was super cool about it and I sent it back.  They will take care of me so I'm not worried, but I wondered if it was just me.  They were very nice about it.


----------



## gelocks

No problems on mine and I haven't heard much regarding this. So maybe it's an isolated thing!?


----------



## Mutnat

Quote: 





stevesatch said:


> How tight is the headphone jack on your C421?  Mine allows some wiggling of the headphone cable and the sound cuts in and out and makes some popping, static noise when the cord is moved.  JDS Labs was super cool about it and I sent it back.  They will take care of me so I'm not worried, but I wondered if it was just me.  They were very nice about it.


 
   
  Mine's snug as a bug.  Fortunately as you're experiencing, John is great to deal with.  I hope you get it back quickly.
   
  Quote: 





ostewart said:


> That is true. All cool now. But the general consensus us that burr brow have a laid back smooth sound, whereas AD have a more detailed agressive sound


 
   
  Cool.  I'd really like to hear the 8620 version now!  Maybe someone will have one at the upcoming Vancouver meetup that I can listen to.  It's funny, I wouldn't describe the sound from my setup as laid back and smooth at all, so I'm really curious what a more aggressive version would sound like!  (My HD25's contribute to this though, since they are already rather forward and aggressive in PRaT).


----------



## SteveSatch

John was very kind so I'm sure he'll take care of me.  I'm not worried.


----------



## jseaber

Quote: 





gelocks said:


> No problems on mine and I haven't heard much regarding this. So maybe it's an isolated thing!?


 
   
  Yes, it's an isolated part defect. I hoped everyone who encountered this had already had their amps replaced...
   
  c421 uses Switchcraft audio jacks. When we ran the last production batch, we noticed that appearance of the jack terminals was gold instead of silver. I confirmed the part numbers and tested a few pieces; all seemed great, until we tested the amps after production. About 5 amps shipped out, then we realized that all 500 jacks from this batch were defective (weak connection). Switchcraft admitted to a serious revision error and offered to replace every jack. Unfortunately, that's not very helpful when you have 500 parts soldered to circuit boards!
   
  We've manually de-soldered and replaced every 3.5mm jack of this batch. It's a tedious process, but the problem is fixed.


----------



## SteveSatch

Like I said, top notch customer service and I was not worried at all.  I also plan on buying a second C421 (the 2227 so I can compare it to the 8620).  Have no fear buying the C421 from JDS Labs.


----------



## SteveSatch

JDSLabs already got my C421 with the faulty headphone jack, has replaced the jack, and is shipping it back today.  Wow.  A+ customer service.


----------



## Raines

JDS rocks. I am in portugal and i already have a cmoy and a c-421 2227 and john has been amazing and so have been the products


----------



## miow

Hey Raines. Long time no talk. How are you mate?  Seems that we have the same amp, uh? Fabulous, simply fabulous.


----------



## gelocks

I wonder if John would ever get to do full size amps and Dacs... I for one would definitely get them!!!!


----------



## ClieOS

gelocks said:


> I wonder if John would ever get to do full size amps and Dacs... I for one would definitely get them!!!!




It's called O2 with ODAC.


----------



## gelocks

Quote: 





clieos said:


> It's called O2 with ODAC.


 
   
  LOL!
  Not his design though... and input for the ODAC is limited to just USB... I meant FULL featured amps/dacs...


----------



## wje

Quote: 





gelocks said:


> I wonder if John would ever get to do full size amps and Dacs... I for one would definitely get them!!!!


 
   
  The talk of a larger O2 or (desktop sized) amp has been going around for quite a bit of time.  When we'll see NWAudioGuy produce these is anyone's guess.  However, since the ODAC has been launched, I'm assuming that time and focus now might be able to be applied to that other amp size.


----------



## Raines

Quote: 





miow said:


> Hey Raines. Long time no talk. How are you mate?  Seems that we have the same amp, uh? Fabulous, simply fabulous.


 
   
   
  hey my friend
   
  here we go again in audio journey
   
   
   
  C-421 2227?  wonderful!!! much better than the cmoyBB
   
   
   
  not waiting for denon 5000


----------



## SteveSatch

I now have two C421 8620s.  If anyone has a C421 2227 and wants to trade for one of my 8620s let me know.  I'd like to be able to compare the differences.
  Thanks,
  Steve


----------



## LoveKnight

Has anone tried the laser machine of JDSLABS Engraver yet? I think it is really beautiful and awesome. Oh by the way, JDSLABS said that it is free, just order when you buy new ones from JDSLABS. I am thinking what logo or picture on my  C421 in the near future.


----------



## Raines

i only saw it after getting them...


----------



## miow

I loved it.


----------



## tzjin

All the more tempting now.
   
  Question to owners. Does the supposedly high output impedance affect your use with 32ohm headphones?


----------



## alphaphoenix

If yo mean in a bad way - nope.  The sound is clean, impactful, and the dynamics full when listening with my Grado or Yuin PK1. It's an impressive amp.  I tried the OP2227 and was impessive, but like others, I prefer the AD8620. Either one will provide the current for 32ohm headphones.


----------



## tzjin

I think in Tyll's review, the C421 measured at almost 10 ohms output impedance, so I was worried about the 1/8th rule. Thanks for the quick reply!


----------



## Mutnat

Quote: 





tzjin said:


> I think in Tyll's review, the C421 measured at almost 10 ohms output impedance, so I was worried about the 1/8th rule. Thanks for the quick reply!


 
   
  Yeah I believe John replied that the output impedance is a result of extra ferrites (IIRC) that were added just before the output to help minimize/prevent electrical interference (cell phones, etc).  I've yet to run into any issue, though my cans are 70ohm so not as far off the rule you mentioned.  John also mentioned that you could request him not to add the ferrites on a custom build if you were concerned about the output impedance.


----------



## miow

Quote: 





alphaphoenix said:


> If yo mean in a bad way - nope.  The sound is clean, impactful, and the dynamics full when listening with my Grado or Yuin PK1. It's an impressive amp.  I tried the OP2227 and was impessive, but like others, I prefer the AD8620. Either one will provide the current for 32ohm headphones.


 

 Hi alphaphoenix,
   
  What do you prefer exactly on the AD8620?


----------



## tzjin

Quote: 





mutnat said:


> Yeah I believe John replied that the output impedance is a result of extra ferrites (IIRC) that were added just before the output to help minimize/prevent electrical interference (cell phones, etc).  I've yet to run into any issue, though my cans are 70ohm so not as far off the rule you mentioned.  John also mentioned that you could request him not to add the ferrites on a custom build if you were concerned about the output impedance.


 

 Alright, thanks for the impressions. Since nobody seems to have commented on how it impacted their sound, I'm guessing it's not a huge deal.


----------



## alphaphoenix

Quote: 





miow said:


> Hi alphaphoenix,
> 
> What do you prefer exactly on the AD8620?


 
   
  Between the two, I can say that to my ears, the OPA2227 is definitely more exciting and has immediate impact.  The mids are very forward and comes right out.  If you've ever listened to or use to a recessive sound, the sound from the OPA2227 pulls it up front.  It's like listening to the SE530 and then the MTPC.  That's kind of how I compare the two opamps. The AD8620 is more balanced sounding to me and pulls more micro details over the OPA2227.  You really can't go wrong either way. IMO, the OPA2227 will put an immediate smile on your face and is a much more forgiving opamp to mediocre recordings, and the AD8620 is just the opposite where it really shines with well made recordings.  I hope that helps.


----------



## miow

That totally responds to my question. Thanks a tone, mate ; )
   
  I'm an analytical guy, I value the micro-detail immenselly, so who knows if the A8620 isn't the best for me. I got the AD2227 already, but can sell it eventually (although I'm VERY impressed with it, compared to the FiiO E11)


----------



## LoveKnight

I am looking for a good combo to relax. My main genres are vocal, instrument, zen, new age. I have Fiio E10 and HD598, now I wonder which version is good for my choice, OPA2227 or OPA 8620, but according to above comments I think I am going to choose OPA2227 because I want unoffensive treble, not focusing micro detail too much, forgiving opamp to mediocre recordings. I also think HD598 is forward headphone so a forward amp can complement my HD598, and the bass, bass boss setting can help for improving the bass of HD598 for sure, right?. Thanks!


----------



## miow

With those (cough, cough...) phones, the AD2227. And yes, it will improve the bass, but don't expect miracles from such (cough. cough...) "anemic" phone. I have tried them bi-amped (being one of them the ZO2) and even so...


----------



## Mutnat

Quote: 





alphaphoenix said:


> Between the two, I can say that to my ears, the OPA2227 is definitely more exciting and has immediate impact.  The mids are very forward and comes right out. [...] IMO, the OPA2227 will put an immediate smile on your face and is a much more forgiving opamp to mediocre recordings, and the AD8620 is just the opposite where it really shines with well made recordings.  I hope that helps.


 
   
  Yeah that helps re-affirm my 2227 choice, as I enjoy the more forward presentation and the forgiving nature (since I'm not a lossless guy).  I'd still love to hear and 8620 one day.
   
  Quote: 





loveknight said:


> I am looking for a good combo to relax. My main genres are vocal, instrument, zen, new age. I have Fiio E10 and HD598, now I wonder which version is good for my choice, OPA2227 or OPA 8620, but according to above comments I think I am going to choose OPA2227 because I want unoffensive treble, not focusing micro detail too much, forgiving opamp to mediocre recordings.


 
   
  I'm thinking for those genres you might actually benefit from the more laid-back presentation (less forward) of the 8620.  The 2227, especially paired with already-forward cans, might be too much?  That's just speculation though.


----------



## LoveKnight

Yes, you have your right point there but I am also a fan of vocal and C421 with 8620 seems to be like a V shape according to someone who tried it. Moreover, I am not a fan of laid-back. I think vocalist should be at forward position, center at 12 o'clock, in front of the audience or listeners.


----------



## putente

Subscribed...


----------



## Raines

the c-421 2227 seems to be a good match for may coming denon  5000


----------



## Mutnat

Quote: 





loveknight said:


> Yes, you have your right point there but I am also a fan of vocal and C421 with 8620 seems to be like a V shape according to someone who tried it. Moreover, I am not a fan of laid-back. I think vocalist should be at forward position, center at 12 o'clock, in front of the audience or listeners.


 
   
  Ah well when you put it that way, then the 2227 is definitely a better choice for you.


----------



## putente

I'm planning to buy one of these C421 (2227) amps to use with my recently bought iPod Classic 160GB (Rockbox'ed) with a LOD. Anyone here using this setup?


----------



## zeitfliesst

Quote: 





putente said:


> I'm planning to buy one of these C421 (2227) amps to use with my recently bought iPod Classic 160GB (Rockbox'ed) with a LOD. Anyone here using this setup?


 
   
  I have that setup except with a 240GB ipod and 8620 opamp version. Very nice with my ES5.


----------



## miow

I always had this doubt: does the LOD really make a difference? For eg, would a ipod Classic with LOD beat a Sony A865 with headphone out and a silver cable? (amped, of course)


----------



## putente

Quote: 





miow said:


> I always had this doubt: does the LOD really make a difference? For eg, would a ipod Classic with LOD beat a Sony A865 with headphone out and a silver cable? (amped, of course)


 
   
   
  About the first question, from what I've read around here before I recently bought mine, yes it does! About the second question, I guess it would, because headphone out is already amped, so when you use it with another external amp, you're amping the original signal twice!


----------



## miow

So the external amp is not making any effect on SQ over the internal amp, or is it working as a pre-amp?


----------



## putente

Quote: 





miow said:


> So the external amp is not making any effect on SQ over the internal amp, or is it working as a pre-amp?


 
   
   
  Not sure I understood your question but using a DAP with true LOD and an external amp, the signal will only be affected/amped by the last stage, the external amp. When using HO and external amp, the signal is affected/amped twice, by the DAP internal amp and then by the external amp itself... Does this answer your question?


----------



## miow

Quote: 





putente said:


> Does this answer your question?


 
   
  Yes, it does : )


----------



## putente

For those of you in Europe that ordered the C421 recently with the "Standard International (Recommended)" shipping, can you tell me how long did it took to arrive?


----------



## Raines

i didnt order the c-421 , but i ordered a cmoy.. and it was about one week to portugal


----------



## putente

Quote: 





raines said:


> i didnt order the c-421 , but i ordered a cmoy.. and it was about one week to portugal


 
   
   
  Thanks! I'll be ordering a C421 (2227) soon...


----------



## Vanquiz

Quote: 





putente said:


> Thanks! I'll be ordering a C421 (2227) soon...


 
  Nice, I might have to wait a bit to get 8620 version, a bit broke at this time .... Dont forget you can customize engraving the amp, I already prepared a tribal dragon tattoo design for my C421.


----------



## putente

Quote: 





vanquiz said:


> Dont forget you can customize engraving the amp, I already prepared a tribal dragon tattoo design for my C421.


 
   
   
  First time I read about that costumization option... Where did you see that option at JDSLabs? Any pictures of already costumized C421's around?


----------



## miow

Have a look at this : )
   
   
  Quote: 





loveknight said:


> Has anone tried the laser machine of JDSLABS Engraver yet? I think it is really beautiful and awesome. Oh by the way, JDSLABS said that it is free, just order when you buy new ones from JDSLABS. I am thinking what logo or picture on my  C421 in the near future.


----------



## putente

Thanks! I'll start thinking if I want my future C421 engraved with something...


----------



## gelocks

Darn it!
  Now I want to engrave mine!! LOL


----------



## Vanquiz

Quote: 





putente said:


> First time I read about that costumization option... Where did you see that option at JDSLabs? Any pictures of already costumized C421's around?


 
  You can choose whatever you want ... 
   
  Quote from JDS Labs when I emailed them about what to do if I want to engrave the amp ...
   
  "For custom engraving, please describe your special request in the order
notes, then email us a grayscale image of at least 600dpi. It's helpful if
you reply to the Order Confirmation with your artwork."


----------



## wullymc

Is anyone using a 421 with Monster Pro Coppers?  Does it really help?  Is there any hiss?
   
  Thanks very much.  Looking at getting one of these but don't want to be disappointed.


----------



## SteveSatch

I put one of my two C421s in the for sale forum:
   
  http://www.head-fi.org/t/621125/jds-labs-c421


----------



## Pingupenguins

Uhg! I've been waiting forever for John's latest end plates on his C421. Where are they!!! I want to get my C421!!!!


----------



## SteveSatch

Quote: 





pingupenguins said:


> Uhg! I've been waiting forever for John's latest end plates on his C421. Where are they!!! I want to get my C421!!!!


 

 What are the differences on the new end plates?


----------



## Pingupenguins

Quote: 





stevesatch said:


> What are the differences on the new end plates?


 
   
   
  Custom milled by Nick and laser etched markings. The ones now are fine, but the prospect of getting even better quality end plates has made me wait.


----------



## SteveSatch

Quote: 





pingupenguins said:


> Custom milled by Nick and laser etched markings. The ones now are fine, but the prospect of getting even better quality end plates has made me wait.


 

 Cool, I did notice the "regular" ones have words that can fade off.  Do you know if current owners can buy the upgraded ones?


----------



## Pingupenguins

Quote: 





stevesatch said:


> Cool, I did notice the "regular" ones have words that can fade off.  Do you know if current owners can buy the upgraded ones?


 

  
  I do not, but I'm sure John has something for you guys. Just email him like I did!


----------



## dimmockg

i dont suppose anybody knows what the delay on these are do they?
   
  or expected arrival of said faceplates?
   
  cheers


----------



## Pingupenguins

Quote: 





dimmockg said:


> i dont suppose anybody knows what the delay on these are do they?
> 
> or expected arrival of said faceplates?
> 
> cheers


 
   
  John told me August. Here I am... waiting....


----------



## tzjin

Quote: 





stevesatch said:


> What are the differences on the new end plates?


 

 Back in black


----------



## SteveSatch

Is there info on the JDS website or blog about the new end plates?


----------



## Pingupenguins

Quote: 





stevesatch said:


> Is there info on the JDS website or blog about the new end plates?


 
   
  Sorta? He reported that he bought a 700 lbs CnC machine and is churning out test plates. I emailed him about new plates for the C421 and he told me sometime August.


----------



## SteveSatch

Thanks for the info.  So all the words/icons will be etched in rather than painted on or however it is now?


----------



## Pingupenguins

Quote: 





stevesatch said:


> Thanks for the info.  So all the words/icons will be etched in rather than painted on or however it is now?


 
   
   
  I was talking to him about the subpar silk screening and I believe he implied he was lasering it. As you can see by the blog posts, he is getting the plates brushed and anodized then lasering it. So I hope it will be the same for the next batch of plates. I personally can't wait. My DIY cMoy BB v2.03 isn't cutting it anymore. Too much noise in the circuit.


----------



## LoveKnight

Oh my god, I just ordered a C421 OPA2227 last week. Now ... okey anyway what have done is done. Hopefully no internal things have been changed in C421s, just the end plate is okey.


----------



## Pingupenguins

Quote: 





loveknight said:


> Oh my god, I just ordered a C421 OPA2227 last week. Now ... okey anyway what have done is done. Hopefully no internal things have been changed in C421s, just the end plate is okey.


 
   
  Lol, I'm not trying to create a uprising. Nothing is different with the amp. Just the end plates.


----------



## mosshorn

So would an impedance adapter be more beneficial for this amp with low z iems? I know that usually the adapters bring the low end forward but I'm curious to try one with my SM3s.


----------



## ClieOS

mosshorn said:


> So would an impedance adapter be more beneficial for this amp with low z iems? I know that usually the adapters bring the low end forward but I'm curious to try one with my SM3s.




It will just mess up thr FR curve of the IEM if you didn't have a properly 
matched and built adapter. No mach a point on using one.


----------



## BobJS

Subscribed!   C421-OPA2227 should be delivered in a day or 2.  Also owner of a JDS Cmoy (love it) and a JDS O2.  I was originally planning on returning the recently ordered O2 against the C421 .... but I think I may just keep both now....
   
  Sources:
   
  - Dragonfly DAC/amp from computer
  - Fuze w LOD
  - ipod Touch 4G w LOD
   
  Out:
   
  IEM:
  Vsonic GR07
  Westone 4
  EX1000
   
  HP:
  HD25-1 II
  HD600
  SHR940


----------



## LoveKnight

Oh, you will be having the combo which I really want to pair if I have a chance, is Dragonfly and C421 OPA2227. Waiting for your thought about the results when you pair with Sennheiser HD25-1 II and Westtone 4. Thanks a lot BobJS.


----------



## Slickman

Hey guys, I recently just ordered a new pair of Terminator V4 headphones(Darth Beyers). Do you guys think they would sound good powered by a C421? I was thinking of getting the 2227 one. I would also get it with a matching odac. All these years I've only listened to music through my X-Fi sound card so I'm anxious to hear the difference.


----------



## Slickman

Quote:


loveknight said:


> Oh, really? Then C421s probably have more than enough power to drive my Sennheiser HD 598 without problems at all at low gain. I am saving money to buy C421 - OPA2227. However, I am considering which 3.5mm interconnect cable I should buy with C421 on JDSLabs website?
> 
> This one Fiio L2 http://www.jdslabs.com/item.php?fetchitem=L2 or this one iSimple http://www.jdslabs.com/item.php?fetchitem=ISVE913 . Which one is better? My DAC now is Fiio E10. Thanks for answer this question.


 
   
  I got the L2, I didn't order the C421 yet though. I ordered the odac first and on my next check I'm ordering the C421(2227). Another really nice interconnect I saw online was this one: http://www.practicaldevices.com/cables.htm I may get it as well even though it's more expensive and just use the one I like more. I figured I'd post it because before I found this thread it was hard for me to find quality short mini to mini cables.


----------



## LoveKnight

Oh. There are not too many choices of choosing interconnections in my country so I am going to buy this interconnection. I think it is better than Fiio L2.
   
  http://i683.photobucket.com/albums/vv196/nhatminh2007/ic2.jpg
   
  from this manufacture http://www.cryo-parts.com/index.php/hook-up-wire/cryoparts/the-wire-copper


----------



## LoveKnight

I received my C421 OPA2227 with a little image engraved on it. The first impression of  this amp is really good but I can not feel the true warmth on my HD598 maybe because of the Fiio E10 DAC I am using with now. Fiio E10s are , harsh, unclear, not smooth to my ears and now I really hate Fiio E10 and asked myself why I bought it (of course just because I wanted to save money).
   
  Look like my ears like dark, warm sound sonic. Another problem is I found out my new combo makes most of my songs feel like the mid is far far away (and before that Fiio E10 + HD598 was like that too but worse now it is better). Next I will try other headphones such as HD650, Hifiman 400 or shure 1980 to tackle this issue or maybe I am going to buy other DAC/AMP such as AudioQuest Dragonfly.
   
  Oh one more thing. Now my experience of watching movies is on a new level. I can hear the dialogues better, clearer, smoother and the sounds from objects are overall better too.
   
  I am burning-in my little amp now. Hopefully the situation will be better and better.
   
  Thanks JDSLABS for this little fantastic headphone amplifier. You are one of the best manufactures out there, keep going. Thanks again.


----------



## Ultrainferno

Quote: 





loveknight said:


> I received my C421 OPA2227 with a little image engraved on it. The first impression of  this amp is really good but I can not feel the true warmth on my HD598 maybe because of the Fiio E10 DAC I am using with now. Fiio E10s are bright, harsh, unclear, not smooth to my ears and now I really hate Fiio E10 and asked myself why I bought it (of course just because I wanted to save money).


 
   
  Fiio E10 bright? Are you sure it's not a fake E10


----------



## LoveKnight

Yes, I was wrong, sorry. I should not have used the bright word. I am still just a newcomer in audio world , and of course I bought my Fiio E10 at a local shop near my house which is authorized by Fiio.


----------



## farfly

This amp have enought power for the hd600 for example? Its much better than the fiio e11?


----------



## olear

I thought the C421 definitely had enough power for my HD600.


----------



## Pingupenguins

Quote: 





farfly said:


> This amp have enought power for the hd600 for example? Its much better than the fiio e11?


 
   
  John told me it has enough power for even the LCD-2. So don't take its diminutive size for lack of power. It's comparable to the O2 in terms of driving capability.


----------



## zeitfliesst

Has anyone had experience with sending the amp in so that the gain adjustment could be lowered? I just sent JDS an email, so I guess I'll soon find out what happens. I'm currently using the ES5 with the c421, and a lot of times I would like the volume to be a bit lower than the lowest I can get without going into channel imbalance territory.


----------



## Ultrainferno

Quote: 





zeitfliesst said:


> Has anyone had experience with sending the amp in so that the gain adjustment could be lowered? I just sent JDS an email, so I guess I'll soon find out what happens. I'm currently using the ES5 with the c421, and a lot of times I would like the volume to be a bit lower than the lowest I can get without going into channel imbalance territory.


 
   
  I'd like that too. Please keep us posted


----------



## zeitfliesst

Bad news. This is what JDS Labs said:
   
  Quote: 





> ```
> [size=13px][color=rgb(42, 42, 42)] Mike, All c421 v1.01's have the lowest possible gain of 2.3x. These began  shipping in March 2012, so gain is already at 2.3x for your unit. Gain  below 2.0 is not feasible. The difference would also be audibly  negligible. Additionally, the volume potentiometer taper is responsible  for volume tracking, not the gain of the amplifier. Perhaps you can use a standard input cable with your ES5's, to reduce  source volume? Sorry we can't help more![/color][/size]
> ```


 
   
  It's a bit disappointing, but I guess I'll just have to bear with it. Anyone know what they mean by using a standard input cable? I already have my rockboxed ipod set to -16.0db pre-amp, so I can't further lower source volume. Any suggestions?


----------



## jseaber

Quote: 





zeitfliesst said:


> Bad news. This is what JDS Labs said:
> 
> 
> It's a bit disappointing, but I guess I'll just have to bear with it. Anyone know what they mean by using a standard input cable? I already have my rockboxed ipod set to -16.0db pre-amp, so I can't further lower source volume. Any suggestions?


 
   
  'Standard input cable' means you may have to resort to a 3.5mm to 3.5mm cable from the headphone jack of the iPod, if the LOD signal is too strong. Not an ideal solution--but it will give greater flexibility with high sensitivity IEM's.


----------



## zeitfliesst

Quote: 





jseaber said:


> 'Standard input cable' means you may have to resort to a 3.5mm to 3.5mm cable from the headphone jack of the iPod, if the LOD signal is too strong. Not an ideal solution--but it will give greater flexibility with high sensitivity IEM's.


 
   
  Ah I see. Thanks for the clarification. Yes, I really do like the sound from the LOD so I might just as well stick with it, despite the volume issue.


----------



## putente

There are some updates to the c421, with the new black faceplates and a new internal tweak! Details here: http://blog.jdslabs.com/?p=419


----------



## ostewart

Me want! 

I wonder how much if I sent mine in, as I'm loving the black


----------



## Ultrainferno

Quote: 





ostewart said:


> Me want!
> I wonder how much if I sent mine in, as I'm loving the black


 
   
  I already did last week.


----------



## putente

Quote: 





ostewart said:


> Me want!
> I wonder how much if I sent mine in, as I'm loving the black


 
   
   
  You can order just the new black front plates, for around $20 shipped!


----------



## putente

Quote: 





ultrainferno said:


> I already did last week.


 
   
   
  Did you sent it just for the new black front plates swap, or also for the new internal change?


----------



## dimmockg

my all black c421 (2227) has just arrived from the USA to the UK (took 6 days in all)
   
  cannot wait to try this baby out later
   
  will keep you all posted


----------



## nkoulban

Me too


----------



## putente

And I'd like to know what effects or differences in sound does the new internal change has:
    
  Quote:


> The c421 Black Edition actually marks a small internal change. In response to In Ear Matters review in June, we swapped output ferrites from an 11 ohm part to a 2 ohm part (PCB has not changed). It’s an extremely subtle change which can be made to any c421.


 
   
  John, care to explain, please?


----------



## Ultrainferno

Quote: 





putente said:


> Did you sent it just for the new black front plates swap, or also for the new internal change?


 
   
  I think it's just for the black front plates, didn't know of any new internals


----------



## ikeGT

Could you recommend me what chip for C421 should i buy?
   
  Now i own TF10 and HE-300 with d-zero and plan to sell d-zero to get C421.
   
  Thanks!


----------



## putente

Quote: 





ikegt said:


> Could you recommend me what chip for C421 should i buy?
> 
> Now i own TF10 and HE-300 with d-zero and plan to sell d-zero to get C421.
> 
> Thanks!


 
   
   
  I think it depends on the kind of sound you want. On the JDSLabs c421 page you have the following under "Customization":
   
    
  Quote:


> Two options are available for the primary stage opamp: AD8620, or OPA2227. Our #1 recommendation for c421 is the OPA2227, which gives smooth, refined output and an excellent soundstage. If you cannot decide, it's safest to choose OPA2227. This chip receives excellent feedback from c421 owners.
> 
> We also greatly enjoy the AD8620. Some users love the AD8620, but feedback is admittedly mixed (either loved or hated). Choose AD8620 if you've heard the chip before, or if you certainly prefer an analytical sound signature over the "warmer" characteristic output of the OPA2227.


 
   
   
  I think it pretty much tells you what you need to know to make your decision! I have the OPA2227 version and I like it very much...


----------



## zeitfliesst

The Headfonia review prefers the OPA2227 and I found a lot of head-fi users on this forum to prefer the AD8620. I don't think you could really go wrong with either one.


----------



## Ultrainferno

Quote: 





zeitfliesst said:


> The Headfonia review prefers the OPA2227 and I found a lot of head-fi users on this forum to prefer the AD8620. I don't think you could really go wrong with either one.


 
   
  Exactly, it's smoothness versus detail I think. I prefer the smoothnes (OPA2227)


----------



## Jdhmtl

I am sending my 421 in this week to switch from the 2227 to the 8620. I found with my Westone ES5,JH 13 and Senn 598 the tone of the 2227 was not for me. I am looking for more clarity and detail and soundstage. I found the 2227 too warm,slow,less precise for my ears and set of phones,especially the ES5. The black plates look nice too. Oddly,my old XIN is still my go to reference.


----------



## ostewart

Just sent mine off for black plates, ferrite change and custom engraving! Can't wait to see the results


----------



## putente

Quote: 





ostewart said:


> Just sent mine off for black plates, ferrite change and custom engraving! Can't wait to see the results


 
   
   
  Do you know the effects of that ferrite change?


----------



## ostewart

Lowers output impedance, better for low impedance IEMs and headphones, had to do with damping factor. As the previous 11ohm output was very high. It affects the frequency response, mainly the bass I think


----------



## putente

Quote: 





ostewart said:


> Lowers output impedance, *better for low impedance IEMs* and headphones, had to do with damping factor. As the previous 11ohm output was very high.* It affects the frequency response, mainly the bass I think*


 
   
   
  Damn, you shouldn't have told me that! Now I also want to send mine back! Damn, damn, damn...


----------



## ostewart

Look up output impedance importance, and damping factor.

The ferrite change is free

I'm a IEM guy, so important for me.


----------



## putente

Quote: 





ostewart said:


> Look up output impedance importance, and damping factor.
> The ferrite change is free
> *I'm a IEM guy, so important for me.*


 
   
   
  And I'm becoming one too, as more and more I just use IEM's! PM...


----------



## 808Ronin

Just received my upgraded black end plates yesterday and they look fantastic. They are 2-3 mm thicker than the original silver so the switches will sit a little more inward on the unit.  I have to wait to install them though as i shipped my unit to JDS for the ferrite swap/mod which i decided to do after i had already ordered the plates. John stated that it was a 10 min procedure so im hoping the turn around is quick and i ll have it back in hand next week.


----------



## SteveSatch

Quote: 





808ronin said:


> Just received my upgraded black end plates yesterday and they look fantastic. They are 2-3 mm thicker than the original silver so the switches will sit a little more inward on the unit.  I have to wait to install them though as i shipped my unit to JDS for the ferrite swap/mod which i decided to do after i had already ordered the plates. John stated that it was a 10 min procedure so im hoping the turn around is quick and i ll have it back in hand next week.


 

 What was the shipped cost for the new endplates?


----------



## jseaber

Quote: 





stevesatch said:


> What was the shipped cost for the new endplates?


 
   
  Steve: $15 + shipping.
   
  We increased endplate thickness from 1mm to 2mm to give a more solid look and feel.


----------



## putente

*jseaber*, can you tell us the advantages of the new ferrite change? And do you have any plans to make these new upgraded endplates also in silver? I actually like the original c421 look, with the black body and silver endplates...


----------



## jseaber

putente: "randomkind" has given a reasonable answer. Output-Z should be no more than 1/8 the value of your headphone impedance. So, a 10 ohm source (amp) should be paired with 80+ ohm headphones to minimize impact on frequency response. The entire audible frequency range can be altered, not just bass.
   
  In simplest terms, lower output-Z means more ideal performance with lower impedance headphones.


----------



## putente

Quote: 





jseaber said:


> putente: "randomkind" has given a reasonable answer. Output-Z should be no more than 1/8 the value of your headphone impedance. So, a 10 ohm source (amp) should be paired with 80+ ohm headphones to minimize impact on frequency response. The entire audible frequency range can be altered, not just bass.
> 
> In simplest terms, lower output-Z means more ideal performance with lower impedance headphones.


 
   
   
  Ok, thanks! I also wanted to know what you had to say about the ferrite change... 
	

	
	
		
		

		
		
	


	



   
  But what about the new endplates in silver? Any plans on making them also in silver in the near future, or they'll be only available in black?


----------



## ClieOS

I think they are making everything in black now.


----------



## putente

Quote: 





clieos said:


> I think they are making everything in black now.


 
   
   
  Yes, it seems so. I actually like the original c421 color scheme, with the black body and silver endplates. Well, I guess I have to join the dark side too...


----------



## jseaber

Quote: 





putente said:


> Ok, thanks! I also wanted to know what you had to say about the ferrite change...
> 
> 
> 
> ...


 
   
  We'll keep a small inventory of new endplates in silver, so you're welcome to make a special request. Couldn't have called it Black Edition if we kept it silver, now could we?


----------



## alphaphoenix

John,  the all black is damn sexy. Do you have to add in the notes step in the order process to request the ferrite change for lower impedance headphones and such?


----------



## jseaber

Quote: 





alphaphoenix said:


> John,  the all black is damn sexy. Do you have to add in the notes step in the order process to request the ferrite change for lower impedance headphones and such?


 
   
  Thanks! No need to ask for the newer ferrites. All Black Edition c421's have the latest set of parts.


----------



## alphaphoenix

Thanks John.  You should see my order in the queue.


----------



## Ultrainferno

Headfonia received the new C421 already: https://www.facebook.com/media/set/?set=a.470467849664584.116467.145341288843910&type=1


----------



## putente

Quote: 





ultrainferno said:


> Headfonia received the new C421 already: https://www.facebook.com/media/set/?set=a.470467849664584.116467.145341288843910&type=1


 
   
  Thank you! Now that I had the chance to see both colors side-by-side, I started to enjoy the black version a bit more...


----------



## willmax

I bought the new All-Black edition of the c421 amp early last week, it shipped on the 25th heading to the land down under.
  Can't wait to receive my new toy from JDS Labs, hopefully it will be here before the weekend


----------



## SteveSatch

If anyone buys the new end plates and doesn't need their old ones please PM me.  The writing is getting rubbed off of mine and I don't have the funds to buy the new ones.  If your old ones are just going to collect dust I could use them
  Thanks,
  Steve


----------



## jseaber

Quote: 





stevesatch said:


> If anyone buys the new end plates and doesn't need their old ones please PM me.  The writing is getting rubbed off of mine and I don't have the funds to buy the new ones.  If your old ones are just going to collect dust I could use them
> Thanks,
> Steve


 
  Steve: Drop us an email. We have 100+ old sets that will go unused...


----------



## SteveSatch

Thanks-e-mail sent


----------



## gelocks

And more praises for John (well deserved)
   
  http://news.cnet.com/8301-13645_3-57526726-47/jds-labs-overachieving-headphone-amplifiers/
   
  No c421 talk but still


----------



## dentonnn

i love my new amp!!!! thank you john for this amazing wonder!


----------



## edn4x4

i would also like to praise John for his customer service.  He has been very responsive to my emails - under an hour response time - even on the weekend! 
	

	
	
		
		

		
		
	


	



  I am now going through amp withdrawal since I sent it in the other day - I had no idea how much I like this amp until it was gone!


----------



## Makiah S

Quote: 





dentonnn said:


> i love my new amp!!!! thank you john for this amazing wonder!


 

 Gawd John I'm going to go broke man, I got your cMoy bb 2.03 2x9V and it's not quite enough power for my Dt 880s although I love it with my Bass heavy Xb700s and it's wonderful when used with my PC, still though I'm curious how does the c421 AP8260 sound with DT 880s, is it strong enough to power a 250 Ohm can, in addition the Ap8260 is the transparent opamp is it not? My cmoy has the 2227 and I'd like a little more bass but with more control to it as well as more power over all because the cMoy is ALMOST enough but not quite enough as I'm starting to notice... but I do like it <3
   
  But I'm soon to jump on a c421 Ap 8620 soon and well the reviews r wonderful for it so hoping it will be worth the money I shouldn't be spending on it <3


----------



## gelocks

Quote: 





mshenay said:


> Gawd John I'm going to go broke man, I got your cMoy bb 2.03 2x9V and it's not quite enough power for my Dt 880s although I love it with my Bass heavy Xb700s and it's wonderful when used with my PC, still though I'm curious how does the c421 AP8260 sound with DT 880s, is it strong enough to power a 250 Ohm can, in addition the Ap8260 is the transparent opamp is it not? My cmoy has the 2227 and I'd like a little more bass but with more control to it as well as more power over all because the cMoy is ALMOST enough but not quite enough as I'm starting to notice... but I do like it <3
> 
> But I'm soon to jump on a c421 Ap 8620 soon and well the reviews r wonderful for it so hoping it will be worth the money I shouldn't be spending on it <3


 
   
  My c421 could power my Senns HD600s on High Gain well enough (but I don't listen to ear-shattering levels though... volume was great to my ears and I believe the HD600s are 300ohm...)


----------



## Makiah S

Quote: 





gelocks said:


> My c421 could power my Senns HD600s on High Gain well enough (but I don't listen to ear-shattering levels though... volume was great to my ears and I believe the HD600s are 300ohm...)


 

 I'm not talking Power for Volume because the cMoy can power them WAY louder than I'll even listen [heck my crappy Fiio E6 can get teh Volume high] the issue is The bass Quality... with my E6 the bass sounds well terrible it's VERY crackly and... has NO impact or anything... just BAD
   
  I'm noticing that same quality with some songs on my cMoy
   
  Nujabes Luv Sic Part 1 [Shing02] is the first I noticed it in ....


----------



## gelocks

Oh oh got you!
  You are talking about distortion then...
   
  No distortion with the c421.
  In fact, I bought the c421 at first to drive my Denon D5000s (which are actually not that power hungry!) because on my CmoyBB, sound distorted a lot when increasing volume. Same headphone on the c421, clean as a whistle (even with bass boost active! though I did not use this function a whole lot!)


----------



## ostewart

Got my amp back today, very quick, amazing service, it looks sooo nice, will post pics tomorrow and impressions if the ferrite change changed sound quality


----------



## Makiah S

Quote: 





gelocks said:


> Oh oh got you!
> You are talking about distortion then...
> 
> No distortion with the c421.
> In fact, I bought the c421 at first to drive my Denon D5000s (which are actually not that power hungry!) because on my CmoyBB, sound distorted a lot when increasing volume. Same headphone on the c421, clean as a whistle (even with bass boost active! though I did not use this function a whole lot!)


 
  Yea and it's not the cMoy this I have confirmed... it's the files and ALL OF THEM, that WHOLE album sound like garbage... I must got a bad rip of it sadly...
   
  That being said I'm sure I'll still buy the c421 [you have the AP8620 one yes, my cMoy has the 2227 chip and I don't want another amp with that chip, one is plenty <3]
   
  But yea the cMoy is fine it's the files... such a shame! Still though as I said b4... I'm sure I'll buy this amp just for the heck of it <3


----------



## edn4x4

Quote: 





mshenay said:


> .. I'm curious how does the c421 AP8260 sound with DT 880s, is it strong enough to power a 250 Ohm can..


 
   
  I have used it with my DT 880 600 Ohm cans it it sounded really good - even on the low setting.  IMO it isn't going to give my 600Ohm version everything it needs to make them shine, but it was a very satisfying experience.  I am awaiting the return of my beloved amp... I got an email today stating it was shipped today!  Less than a week turnaround time 
	

	
	
		
		

		
			




  More Kudos to John.  I will give it another listen when I get it back and post a fresh impression. 
   
  The amp was sent in for the ferrite change and the black end plates- I doubt it will affect the DT 880 sound, but it should on my IEMs.  I am sure the black end plates will make it sound even more awesome! (just don't ask me to do any A/B tests or provide any measurable results 
	

	
	
		
		

		
		
	


	




)


----------



## Makiah S

Quote: 





edn4x4 said:


> I have used it with my DT 880 600 Ohm cans it it sounded really good - even on the low setting.  IMO it isn't going to give my 600Ohm version everything it needs to make them shine, but it was a very satisfying experience.  I am awaiting the return of my beloved amp... I got an email today stating it was shipped today!  Less than a week turnaround time
> 
> 
> 
> ...


 
  Good to hear <3


----------



## deftonez

Just ordered my c421 op2227 a few days ago, has anyone ordered it from singapore? im want to know an estimate for delivery. Found out the free engraving after I ordered, sent an email few hours later and they managed to personalize my name on it. I'd say thats freaking great service! By the way, anyone has an experience with the c421 op2227 with the westone um3x and ipod classic?


----------



## ostewart

Ferrite change did up the sound, as my Shure SE535 did sound a bit muffled and the bass wasnt tight or quick with severe roll-off before, now they are much better balanced and defined. Great work John
   
  and now for the work of art (so sexy in my opinion):


----------



## putente

Great pics! Well, I must admit I'm enjoying the black endplates more, so I think I'll go for those too...


----------



## gelocks

Quote: 





ostewart said:


> Ferrite change did up the sound, as my Shure SE535 did sound a bit muffled and the bass wasnt tight or quick with severe roll-off before, now they are much better balanced and defined. Great work John
> 
> and now for the work of art (so sexy in my opinion):


 
   
  AAARRGHHH I FREAKING HATE YOU!!!! hehehe
   
  (I love Thursday!)


----------



## Makiah S

What exactly did you upgrade?


----------



## deftonez

dammit, i didnt have time to design anything. noooo


----------



## ostewart

Black endplates, also replaced 11ohm ferrite with a 2ohm one

Thursday truly were amazing


----------



## Makiah S

Quote: 





ostewart said:


> also replaced 11ohm ferrite with a 2ohm one


 
  e.e what did that cost


----------



## ostewart

nothing, John is a great guy, he will replace the ferrite for free, you pay for the black end plates and you can get free custom engraving with every order.
   
  mine went from portugal to the US and back in less than 2 weeks, amazing service and super quick. also the work is top notch, i highly reccomend JDS Labs.


----------



## deftonez

arent the black plates a standard now? i just ordered days back. they said black edition


----------



## putente

Quote: 





deftonez said:


> arent the black plates a standard now? i just ordered days back. they said black edition


 
   
   
  Now they're a standard with the "Black Edition" c421, but who bought it before this new edition, it came with thinner silver plates...


----------



## Makiah S

Quote: 





ostewart said:


> nothing, John is a great guy, he will replace the ferrite for free, you pay for the black end plates and you can get free custom engraving with every order.
> 
> mine went from portugal to the US and back in less than 2 weeks, amazing service and super quick. also the work is top notch, i highly reccomend JDS Labs.


 

 yea I liked the cMoy Bb i got from them, you think he would replace the Ferrites for me if I palced an order for a NEW c421 Vlack edition? Like asked for the replacement on the new model as opposed to sending it back later


----------



## putente

Quote: 





mshenay said:


> yea I liked the cMoy Bb i got from them, you think he would replace the Ferrites for me if I palced an order for a NEW c421 Vlack edition? Like asked for the replacement on the new model as opposed to sending it back later


 
   
   
  The new "Black Edition" c421 already comes with the ferrite mod. See here: http://blog.jdslabs.com/?p=419


----------



## ostewart

sorry for any confusion, All new orders will ship with Black end plates, and the 2Ohm Ferrite, i sent mine in for the upgrade as i had the older version.


----------



## LoveKnight

How does changing ferrite from 11Ohm to 2Ohm can improve the sound? Not sure because I am not a technical guy but with my old version C421 and with my HD598, I use low gain and turn up the volume knob just a little bit but it is very loud to my ears. Maybe with this changing C421s will drive more IEMs better but it could be a disadvantage to fullsize headphones. Do you guys think so?


----------



## ostewart

It has to do with output impedance and damping factor. It is better for low impedance headphones and IEMs.

High output impedance used with low impedance phones can change the whole frequency response...

The output impedance should never be higher than 1/8 of the headphones impedance.


----------



## Mutnat

Yeah I'm really debating if I should send mine in for the ferrite swap or not... my HD25's are 70 ohm, so > 8x the 10.5-11 ohm of the original ferrite.  That said, I can't say that I've really noticed any sloppiness to the low end that would call out for greater dampening.  But maybe I just don't know what I'm missing.  Tough call.  I'd hate to be without the amp for a while to do it.  And shipping from John to Vancouver BC (Canada) is quite slow, so I'd likely be without the amp for the better part of a month considering the full round-trip.  Or pay a fortune for expedited shipping.  Neither option is especially appealing.
   
  A NOTE TO PEOPLE DOING THE FACEPLATE SWAP with the black plate kit... be careful with your screws!  I was trying to but still accidentally let one get away on me and it got lost in my deep shag area rug .  Admittedly, this was a bad place to be doing the work.  But those screws are very tiny!  So be careful.  That said, if you DO happen to lose one, and you have a PS3 around, you can steal one of the screws from the PS3 controller to tide you over till you get a proper one. It's not a perfect cosmetic match with the other C421 screws, but it does fit despite being a bit longer and seems to work okay.


----------



## RingingEars

Quote: 





mutnat said:


> be careful with your screws!  I was trying to but still accidentally let one get away on me and it got lost in my deep shag area rug .  Admittedly, this was a bad place to be doing the work.  But those screws are very tiny!  So be careful.


 
  Get yourself a good magnet like an old speaker magnet and go over the area. You'll find it.


----------



## Makiah S

Quote: 





ostewart said:


> It has to do with output impedance and damping factor. It is better for low impedance headphones and IEMs.
> High output impedance used with low impedance phones can change the whole frequency response...
> The output impedance should never be higher than 1/8 of the headphones impedance.


 

 I suppose that would be good, but for a 250 Ohm can would the lower impedeance unit work better... you'd think the 10 ohm ouput would drive them better


----------



## ostewart

It has nothing to do with power or driving them better, only about controlling the driver better


----------



## Makiah S

Quote: 





ostewart said:


> It has nothing to do with power or driving them better, only about controlling the driver better


 

 Well Power=Control unless there's to much
   
  The issue I have now with my cMoy is there is not enough power to properly control the driver, granted it doesn't sound bad but it still needs a little more juice to sound like it should
   
  So I'm wondering if the c421 has the extra power needed for the superior control oh a High Impedance can


----------



## ostewart

Ok, not controlling the driver better, just damping the driver better


----------



## Mutnat

Quote: 





mutnat said:


> be careful with your screws!  I was trying to but still accidentally let one get away on me and it got lost in my deep shag area rug


 
   
  Quote: 





ringingears said:


> Get yourself a good magnet like an old speaker magnet and go over the area. You'll find it.


 
   
  Actually I emailed John and, true to his excellent customer service reputation, he replied very quickly, and has already put a couple of screws in the mail to me, on the house.  John's a great guy to deal with, for sure!


----------



## RingingEars

Quote: 





mutnat said:


> Actually I emailed John and, true to his excellent customer service reputation, he replied very quickly, and has already put a couple of screws in the mail to me, on the house.  John's a great guy to deal with, for sure!


 

 Nice.
  I've heard nothing but good things coming from JDS, performance and CS wise.
  Now that the C421 went all black I'm pretty sure this will be my next amp.


----------



## Makiah S

Quote: 





ostewart said:


> Ok, not controlling the driver better, just damping the driver better


 
  Indeed, now what is damping x[


----------



## Bill-P

Sent my C421 in for a ferrite change. To my pleasant surprise, I got an upgrade to black faceplate as well.
   
   

   
   

   
  And she sounds phenomenon!


----------



## deftonez

is there such thing as a usb to 3.5mm jack for computer to an amp? i dont have a dac, and im not sure how good my computer sound card is, i use my ipod more often. but  im thinking of using my computer for movies and stuff. so is there such a cable that can bypass the internal amp in my laptop?


----------



## deftonez

or is the bypasing of the sound card the only option with a usb dac?


----------



## ostewart

It's only possible with a DAC


----------



## Makiah S

U guys are making me so jelly :[. well I'm doing more car shopping today so hopefully in 2 months I'll ahve one of these <3


----------



## edn4x4

Quote: 





mshenay said:


> still though I'm curious how does the c421 AP8260 sound with DT 880s, is it strong enough to power a 250 Ohm can,


 
   
  Quote: 





edn4x4 said:


> I will give it another listen when I get it back and post a fresh impression.


 
   
  Today I received my C421 back with the ferrite changes and the black end plates installed.  One weeks time there and back 
	

	
	
		
		

		
			




  Way to go John - big thanks.
  So I hooked up my DT880 600Ohm and pressed play - no sound - getting nervous... DOH! power switch needs to be in the ON position 
	

	
	
		
		

		
		
	


	




  I was in such a hurry forgot to power it up!  To be fair I had it plugged in and the light was illuminated. And yes I took my phones off my head turned down the volume before I turned it on - no ears harmed in this exercise.
   
  How did they sound - GREAT.  Ok that is a little bit of an overzealous _generalization_, but I really missed my amp.
  I initially listened on the low setting and was getting more that enough "loudness" around 3/4 volume without bass boost.  I then turned up to the high gain setting and I felt it drove them better and to very loud levels.  I did not use the bass boost in either position as it made them sound a bit boomy.  I almost always use it with my IEMs though.
  So I am happy to report you should have more than enough umph to drive the 250Ohm version - I would suggest trying the low level first.
  FYI I used Disturbed - Stupify.flac with my iMod 5.5 Rockboxed / T1 RWA  Isabellina HPA to compare against - it was a very fun and ear exciting experience.
  The C421 is one heck of an amp - great value, great sound - period.


----------



## Makiah S

YAY


----------



## willmax

Finally got my new All Black C421 in the mail. This is really an amazing feature packed little amp, today I was listening and did not notice the low battery indicator and it shut itself down very quietly without a glitch - different to my O2 amp that does not turn off and starts popping like crazy with low battery almost giving me a heart attack 
	

	
	
		
		

		
		
	


	



   
  The LED lights are a neat treat, and the engraving is very stylish
   

   
  The little switches also go very well with the amp design, JDS Labs really has an eye for detail
   

   
  The only thing that got me thinking was the gain switch arrangement beside the bass boost switch - I thought it would make more sense to have LOW gain at the bottom beside FLAT and HIGH gain at the top beside the BASS boost -  the same position like an on/off switch - at the moment I find it a bit messy 
   
  All in all the amp is great, again kudos to John and his team. I would highly recommend to anyone looking for a nice portable amp.


----------



## Ultrainferno

I notice your switches are grey. I figured mine were black. must check


----------



## LoveKnight

Mine is the silver plate and also has grey switches. I bought it in August.


----------



## deftonez

cant wait for mine to arrive


----------



## Makiah S

Quote: 





deftonez said:


> cant wait for mine to arrive


 
  can't w8 to get a job and buy mine <3


----------



## deftonez

What does "Processed at USPS sort facility" mean exactly? This is for my C421.
   
  My previous experience with USPS saw my package go through this process,
  Acceptance, Processed at USPS sort facility, Depart USPS sort facility, Processed through USPS sort facility, Processed through USPS sort facility (the second time two days later)
   
  So, if this is the required process, my C421 has been stuck for some time already.


----------



## Mutnat

Quote: 





ultrainferno said:


> I notice your switches are grey. I figured mine were black. must check


 
   
  Quote: 





loveknight said:


> Mine is the silver plate and also has grey switches. I bought it in August.


 
   
  Yeah mine are black, too!  Originally silver plates but orderd the black plate upgrade kit ($15 very well spent!--it looks great!).  I bought the amp back in the late spring I believe.


----------



## Mutnat

Quote: 





deftonez said:


> is there such thing as a usb to 3.5mm jack for computer to an amp? i dont have a dac, and im not sure how good my computer sound card is, i use my ipod more often. but  im thinking of using my computer for movies and stuff. so is there such a cable that can bypass the internal amp in my laptop?
> 
> or is the bypasing of the sound card the only option with a usb dac?


 
   
  Well, sort of.  You don't need a separate component, per se, you can use a "dac cable" from Headstage.  You can order it for $70 here http://www.headstage.com/USB-DAC-Cable/USB-DAC-Cable-with-35mm-Mini-Plug-75cm-30::10134.html, but what you will receive is the newer generation, reviewed here:  http://www.headfonia.com/the-headstage-usb-dac-cable/.  Sounded pretty favourable overall.
   
  Another budget DAC you could consider is the Fiio E7, which I think falls around that same retail price:  http://www.headfonia.com/fiio-e7-portable-dac/ 
   
  OR, if you're okay spending a bit more, and already ordering a C421 from JDS anyway, you could consider a "standalone ODAC":  http://www.jdslabs.com/item.php?fetchitem=46


----------



## Ultrainferno

There's also the small E10 from fiio and don't forget the tiny Dragonfly!


----------



## Makiah S

Quote: 





mutnat said:


> OR, if you're okay spending a bit more, and already ordering a C421 from JDS anyway, you could consider a "standalone ODAC":  http://www.jdslabs.com/item.php?fetchitem=46


 
  There's a pricey set up lol!


----------



## Mutnat

Quote: 





ultrainferno said:


> There's also the small E10 from fiio and don't forget the tiny Dragonfly!


 
   
  It wasn't meant to be an exhaustive list....  I excluded the E10 cuz it's also an amp if I read correctly.  The Dragonfly was a good catch, though!
   
  Quote: 





mshenay said:


> There's a pricey set up lol!


 
   
  Yep.  I gave him the cheaper options first!


----------



## RingingEars

Quote: 





mutnat said:


> OR, if you're okay spending a bit more, and already ordering a C421 from JDS anyway, you could consider a "standalone ODAC":  http://www.jdslabs.com/item.php?fetchitem=46


 
  That would make a nice "separates" laptop/desktop rig...


----------



## Makiah S

Quote: 





mutnat said:


> It wasn't meant to be an exhaustive list....  I excluded the E10 cuz it's also an amp if I read correctly.  The Dragonfly was a good catch, though!
> 
> 
> Yep.  I gave him the cheaper options first!


 
  Yea you did and I'm talking about myself, lol because I may end up with that kinda of rig LAWL 
   
  Also listening to my First 24/88.6 [it's not 94hrz sample sadly] on the Dt 880s and omg 40khrz white noise never sounded so clear! I have this like 16bit Flac that's well not even have as good... there's just SO much missing from the Sax! mm nothing like Japanese Remastered Super High Quality Classic Jazz! 
   
  Dave Brubeck Quartet Three to Get Ready!


----------



## deftonez

WOW. Thats an interesting solution. Though it looks sketchy to me. How is it that a DAC can be packed into a USB cable when so many other companies are coming up with monstrosities for a budget USB DAC? Makes me wonder where all the space saving went.hmmm


----------



## deftonez

I wish i'd had that much cash, LOL.


----------



## Makiah S

Oh gawd I dropped my yes I dropped my cMoy today, it fell about 10 inches and now for the FIRST time ever after about 2mins of audio it's making a TERRIBLE hissing just unbearble noise... and I checked it with 2 different DAPS and Cans it's the amp
   
  I hope that just means It needs to charge, other wise I'm prepared to discuss with JDS labs how I can maybe get it repaired or replaced [because SERIOUSLY I'm not one to drop stuff ever but IF I DO, and from all of 10 inches... I mean it should still work...]
   
  Still though I also saw that JDS labs recommends that you inform them if u use a Line out you need to tell them so that they can modify the amp to be more compatible with that... I didn't know that! So I'm hoping [if a charge does not fix it] that I can get her reapired and upgraded [for a HOPEFULLY small fee]


----------



## ClieOS

mshenay said:


> Oh gawd I dropped my yes I dropped my cMoy today, it fell about 10 inches and now for the FIRST time ever after about 2mins of audio it's making a TERRIBLE hissing just unbearble noise... and I checked it with 2 different DAPS and Cans it's the amp
> 
> I hope that just means It needs to charge, other wise I'm prepared to discuss with JDS labs how I can maybe get it repaired or replaced [because SERIOUSLY I'm not one to drop stuff ever but IF I DO, and from all of 10 inches... I mean it should still work...]
> 
> Still though I also saw that JDS labs recommends that you inform them if u use a Line out you need to tell them so that they can modify the amp to be more compatible with that... I didn't know that! So I'm hoping [if a charge does not fix it] that I can get her reapired and upgraded [for a HOPEFULLY small fee]




Most likely just the opamp getting loose in the socket. Push it down should fix that.


----------



## Makiah S

Quote: 





clieos said:


> Most likely just the opamp getting loose in the socket. Push it down should fix that.


 
  Nah it was in reality the battery dieing, but if I have an issue with it again [on a full charge] I'll b sure t puch that opamp back in place


----------



## deftonez

Its finally arrived! USPS made a mess of the packaging and ripped off my address, it got sent back to jdslabs and I was given a free upgrade to Express Mail International! only 5 days to Singapore! Awesome customer service I'd say. So far the bass boost is phenomenally great with my UM3X. It really appreciates with it as many have said. So far I have only tested it for 48mins, played "Octavarium" by Dream Theater twice. It's wonderful!


----------



## ostewart

glad your enjoying your new amp, they are great! still love the Thursday logo on mine


----------



## deftonez

Did anyone have any problems with volume balance? For low volume levels, the it seems louder in my right ear quite significantly, and i mean low as in barely audible. When I turn it up to normal listening levels, it seems fine, Im not too sure.
   I did the following
   
  1) Ipod > L3 LOD > c421 > Apple earphones (imbalance at low levels)
  2) Ipod > L3 LOD > c421 > UM3X (imbalance at low levels)
  3) Ipod > 3.5 to 3.5 > c421 > apple earphones (no imbalance)
  4) Ipod > 3.5 to 3.5 > c421 >no imbalance
   
  Could it be just that the line out from the 3.5mm from the ipod is already balanced properly? Or could it be the LOD? Or is it the amp? :O


----------



## ostewart

It's the amp, most amps with analogue volume adjustment suffer channel imbalance at low volumes


----------



## deftonez

oh, thats a relief, i thought mine had defects. thank you very much!


----------



## Makiah S

Oh it's good to see how small it is! Compared to a iPod Classic. I still want mine... I'm thinking of buying it in place of a E17... because well quite frankly I can live without a DAC amp Combo for the time being....


----------



## falcon1125

Hope people dont mind i'm posting this here too..xP


----------



## LoveKnight

Wow, it is so beautiful. I want to ask a question. Could we order ferrite and change by ourselves?


----------



## falcon1125

Not sure if the backplate=ferrite, i think its not the same i dont know, but for end backplate yes u can order and change it by yourself
   
http://www.jdslabs.com/item.php?fetchitem=64


----------



## ostewart

I looked inside mine, the ferrite change looks pretty tricky to desolder and then solder in new ones, best leave it to the professionals.

At least if you order the faceplates you get custom engraving.


----------



## Mutnat

Quote: 





falcon1125 said:


> Hope people dont mind i'm posting this here too..xP


 
   
  Nope, don't mind at all...nice rig! 
   
  Hey out of curiosity, what LOD is that?  It looks nice!!


----------



## falcon1125

Quote: 





mutnat said:


> Nope, don't mind at all...nice rig!
> 
> Hey out of curiosity, what LOD is that?  It looks nice!!


 
  Its DIY Lod i bought from one of the head fier, but to my ears fiio LOD sounds better than that~ 
   
  =)


----------



## burrrcub

Anyone getting interference with the 8620?  My cell phone is my source.


----------



## miow

My second C421 AD2227 is for sale. Has had almost no use. If someone's interested...


----------



## gelocks

Quote: 





burrrcub said:


> Anyone getting interference with the 8620?  My cell phone is my source.


 
   
  I used to get a bit of interference with mine (I also get interference with my Leckerton and the new Magni amp from Schiit...).
  I'm not sure if the new updates help with this or not (probably not...)


----------



## Bananaheadlin

Anyone getting the new Schiit? I heard its about the same in SQ as the C421, but with less soundstage and a lot more power. 

The Asgard or Lyr by any chance a worthwhile upgrade?


----------



## Makiah S

Quote: 





bananaheadlin said:


> Anyone getting the new Schiit? I heard its about the same in SQ as the C421, but with less soundstage and a lot more power.


 
  less sound stage :[, ewww


----------



## SteveSatch

Loved my C421 but traded it for a Fiio E12.


----------



## Makiah S

Quote: 





stevesatch said:


> Loved my C421 but traded it for a Fiio E12.


 
  eww, why [did u need moe power]


----------



## SteveSatch

Quote: 





mshenay said:


> eww, why [did u need moe power]


 

 I like trying new things.  I can always sell or trade the E12 and pick up another C421 or get the new C5 : )


----------



## willmax

stevesatch said:


> I like trying new things.  I can always sell or trade the E12 and pick up another C421 or get the new C5 : )




So how does it compare against the c421 then?


----------



## Bill-P

I just received the amp. Thanks, Steve!
   
  Initial impression: very different from the last C421 I owned. Maybe I had OPA2227?
   
  Soundstage is larger. In fact, I think it's also larger than O2. 
  Overall sound signature is very clean and smooth.
  Low gain sounds horribly compressed to me. Like playing back 64kbps MP3 without the distortion.
   
  From memory, I heard better bass with E12, and also warmer, more textured mid.
   
  Let's see what Steve has to say about E12.


----------



## Makiah S

Quote: 





bill-p said:


> I just received the amp. Thanks, Steve!
> 
> Initial impression: very different from the last C421 I owned. Maybe I had OPA2227?
> 
> ...


 
  hmm neat, I like big sound stage, clean is nice... less bass and less textured mids eww
   
  still I don't like Fiio amps tbh. The two I've owned have always sounded very dark... love fiio with my edm cans but not anything elese xD
   
  N I hope the C5 will b cleaner than the C4


----------

