# Best In-Line Attenuator?



## Orpheus

hi.

 i think my CD out is too hot for my preamp. so, i need an in-line attenuator.

 so far, i found this:

http://headphone.com/layout.php?topi...tID=0060220000

 and this:

http://www.rothwellelectronics.co.uk...attenuator.asp

 which do you think is better? ...anyone know of higher grade ones? (anyone know which brand resistors are used in these attenuators?)

 thanks,
 orpheus


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## sacd lover

I know my modded sony 555es is to hot for my preamp. Thanks for sharing this idea and the information where to purchase them.


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## jpelg

Thanks Orpheus! I suspected this was a problem I've been having with the output from my DAC this week. Your thread is very timely. I'll be ordering the ones from HR this week.


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## Orpheus

actually, i wasn't posting to recommend these products. i was really asking for an opinion................. ha ha.... but i'm glad you guys found those links useful anyway. 
	

	
	
		
		

		
		
	


	




 just wondering which in-line attenuator out there is theoretically the most transparent. i haven't found any others though.... anyone know of other high quality in-line attenuators?


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## Hirsch

I've tried inline attenuators from MCM Electronics, and the Harrison Labs inline attenuator sold by Headroom (still have them, actually, and if anyone wants them after the rest of this post PM me). My conclusion after trying these is that the best inline attenuator in no inline attenuator. The Harrison Labs is better than the MCM, but both produce significant audible degradation of the sound. Use only in case of dire emergency when no other option is available.

 The only situation where a source might be too hot for a preamp is if there's active circuitry in front of the volume control, and it's causing distortion. Otherwise, you've already got an inline attenuator in your setup...your volume control. With high output devices, you can learn small volume control movements (doesn't worked with stepped attenuators, but if your amp is good enough to have a SA, you *really* don't want to undo the sound with an inline attenuator, and may want to look at other solutions.)


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## sacd lover

Well back to the drawing board. I was hoping this was the solution to my problem.
	

	
	
		
		

		
		
	


	




 But I dont want to undo the gains I get with the stepped attenuator.


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## Hirsch

Quote:


 _Originally posted by sacd lover _
*Well back to the drawing board. I was hoping this was the solution to my problem.
	

	
	
		
		

		
		
	


	




 But I dont want to undo the gains I get with the stepped attenuator. * 
 

I haven't tried the Rothwell's linked to above, and they may well be better. The ones I have tried, however, have all affected the sound adversely.


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## HighwayStar

I had a strange experience with the Harrison Labs attenuators. I bought a pair to tame the output of my ART D/IO. HeadRoom was out of them for quite some time so I ordered from a car stereo joint online. When I got them they appeared normal but they were loose. They wouldn't stay on no matter where I installed them. The weight of the ICs would pull them right off the amp. And due to the design you couldn't crimp/bend them to make them grab tighter. Ended up returning them. Didn't really listen to them.


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## Dusty Chalk

I have not heard these, myself, but the best that I've heard _of_ is the EVS Nude Attenuator (EVS == Electronic Visionary Systems, I think).

 Priced a little too high for me to just try them.


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## nately

I've been wanting to try these for a while, since I have plenty of gain in my system, but my preamp's pot sounds kind of crappy, you know, scratchy at the low end. And it's impossible to fine tune the volume via the remote - the motor's too fast. And I'm not upgrading my speaker system anytime soon.

 sacd lover, if you have a stepped attenuator I'm not sure I understand the problem. Are you stuck using the first few clicks on the dial?

 (Sorry Orpheus, I'm like these other guys - same problem, no answers!)


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## Orpheus

Quote:


 The only situation where a source might be too hot for a preamp is if there's active circuitry in front of the volume control, and it's causing distortion. 
 

well, i dunno too much about designing amps and preamps and stuff.... but i do have lots of experience with too hot sources. for instance, my Tascam professional CD player/recorder puts out a VERY VERY VERY hot signal. that signal is louder than even the max volume on many audiophile preamps. the volume is fine going into my mixer, but into my consumer tube preamp, i can hear it clipping, even on the lowest volumes.

 also, when using this preamp with that CD player, powering my Monarchy solid state amp is impossible. you see, the preamp uses stepped attenuators, and after 3 steps, the speaker volume is already too high.

 so, as you can see, an in-line attenuator is necessary if i'm gonna be using this preamp.

 ......but it's not just this preamp that has problems. i've also had problems with my sampler being too loud. on this one piano piece i'm writing, the dynamic range is pretty big, so in order to record lower-level signals at a proper volume, the output has to be at least at a decent level. however, at a good level, the peak is so loud that it overloads my mixer, even with the trim pot ALL the way down. it doesn't matter where my fader is, +10 or -40db, ........it still distorts. so, i have to compromise my music when i do the final recording and change the levels from what i would like.

 so, anyway... my point is, attenuators are very helpful.

 ...............................so, can i please buy yours off you? i'll pm you.

 thanks.


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## sacd lover

nately, I dont even have the stepped attenuator gilmore v2se yet, the signal is to hot with just my regular pot gilmore v1, coming from my sony 555es. My Monarchy sm 70 pro amp is to sensitive and has a high input impedence (100kohms), so its very easy to drive. I can barely open the pot, or its to loud with the above mentioned components. Because I am using the gilmores pot at the very bottom of its range, it doesnt balance well right to left. I am having a gain switch installed in the v2 se, but the in-line attenuator seemed like a great idea to make the stepped attenuator have an even greater range. But, if its going to compromise sound quality I dont really want to use such a filter.


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## Orpheus

hey, you got one of 'em Monarchy SM 70 Pro's too huh? heh he. yup, like i said, third step in my preamp and it's already too loud to listen to.

 but i think the negative effects aren't nearly as bad as Hirsch made them out to be. i believe that these in-line attenuators are just made with resistors and the plugs themselves. in fact, someone here posted a DIY design... but i prefer something more professional looking. but if i remember correctly, his design only used two resistors... and if most of these in-line thingies are about the same design, they really shouldn't affect the sound THAT much.......... i mean, look inside your amp... it has like 50 or so resistors all over the place right? well, what's one or two more gonna do? 
	

	
	
		
		

		
		
	


	




 but i dunno. maybe they do not work that well. we'll see. i bought hirsch's pairs, so i'll let you guys know.


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## Rob N

I've tried the Rothwell ones.They are well made and (as far as I can tell) don't affect the quality of the signal at all


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## sacd lover

Rob N, which level of attenuation did you get? I saw some on the Parts Expess website, by another company, that were 3db, 6 db and 12 db. Is the Rothwell available in another amount besides 10db?


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## Rob N

I think the Rothwell one is only available in one level of attenuation.


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## wallijonn

wouldn't adding a resistor to the input do the same thing? i take it that these are linear pots and not logrithmic pots. if they are linear, wouldn't adding a resistor to the middle tang reduce the overall sound level? (say 1/4 to 1/2 of what the pot is rated for). 

 remember this from another thread?:


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## sacd lover

Probably wallijon, if we knew how to do it
	

	
	
		
		

		
		
	


	




 I broke down and ordered a set of the rothwell attenuators. They will be here in a week.


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## wallijonn

it's a bitch when everything is pcb mounted.

 i, fortunately, know how to use an exacto knife and a soldering iron. 
	

	
	
		
		

		
		
	


	




 baring that, you'd have to unsolder the rca jacks and replace with free floating ones. then you'd add the resistor and a ground wire. heaven help you if you lift an etch. 

 if you know how to make cables, all you would do is add a resistor between the centre pin and the centre wire. but then you can't use those cables anywhere else. you'd have to label them for future reference.

 let's do the math:
 a 3 dB drop would have to be 1/2 power, and a 6 dB drop would be about 3/4 power... a 50k ohm pot woulkd therefore have to be 3/4 of 50,000 = 15,000, so i would add a 15k resistor in the signal path.

 in the case of adding the resistor to the middle tang, you could never get it completely quiet, (same as if you put the resistor from one tang to ground [break the ground going to the resistor and inserting a resistor in it's place])

 the easiest way would be to put a pot in it's place (of the resistor), adjust for best sound movement, remove the pot, measure the resistance, replace with same value resistor.

 do they make 1% metal oxide 1 watt and 2 watt resistors?


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