# Is it worth the trouble to build a DAC with TDA1541?



## AudioCats

Supposedly the 1541 is one of the oldest dac chips, is it worth the trouble to build a DAC with it? ( I have read that some folks think it is still the best out there.)


----------



## Paul J.

I'm a big fan of the 1541. But are you thinking of scratch building a DAC with it? That sounds intense. Here is the schematic I'd use. Thorsten is less involved in DIY today, as he is now designing for AMR! (last I knew)

 If you are looking for a less involved project, there are several TDA1541 PCB's on ebay. Or, my personal take to is buy an old CD player that used the chip and convert the DAC to NOS (non oversampling) mode. There are plenty of fairly pedestrian Philips and Marantz Models that used the chip. (They circuits are identical, the made in Japan Marantz's are purported to be better than the made in Belgium Philips models). Magavox CD players from the late 80's are Philips players too. Look through this list to figure out which players have the 1541.

 I can find them for $10-40 on craigslist (just got a Magnavox 582 in great shape for $10). I'd look for the later players with the 1541A and a CDM 4 transport, but if you can find an early machine cheap, go for it. All of the mid-fi Philips players had similar parts quality. Some models just had more functions that you should disconnect anyway (variable output levels, extra control logic, etc). The Marantz CD-40 is simple, for example, where as the CD-50 and CD-60 have progressively more stuff. The basic mods are free: pull out the muting transistors, disconnect the extra junk, and convert to NOS. 

 If your budget is a little higher, I would strongly suggest getting a Rotel 855 or 955 (the latter is newer with the A chip). They run around $100, but are a much better value: robust power supplies with Black Gate caps, film decoupling caps on the 1541, etc. Basically, for another $50, you get a huge upgrade in parts quality. There are even nicer machines with the 1541 (the high end Philips, audiophile units like Arcam, Revox, etc). I'm not sure they are worth the $$ over the Rotel. And, keep in mind that old players are a gamble. You will find units with shelled out transports and lasers. If you aren't interested in NOS (the mod is too complex) there are some incredibly well made high end Sonys out there. (227ESD, etc). 

 I know that you may not be interested in shiny silver discs. I have pondered getting a USB to I2S converter and trying to hook it up to one of these old players to just use the DAC. I haven't tried it yet though. If you do play shiny discs, the nice thing about these old machines is that the transports are quiet, unlike most newer reasonably priced machines. No matter what, they are good cheap fun. Save those 1541s from the dump!

 Paul


----------



## Pars

Several commercial products still use the TDA1541A, including Thorsten with AMR IIRC. I believe the Altmann Attraction DAC is also a TDA1541A. Both the Rotel 855 and 955 use the TDA1541A (not the plain 1541). This is a good list of CD/DACs with the DAC chip, receiver and transport listed:
http://www.marantzphilips.nl/the_com...verter_list/#M

 Pedja Rogic's DACs sem to be well thought of and I believe are still available in DIY form:
Audial :: Do It Yourself


----------



## AudioCats

I was thinking about building from scratch, using perf boards. The Chip is full size dip and circuitry is simple enough.

 my main concern is what kind of limitation the 1541 has by itself. This chip ask for a lot of external support components and three voltages (good thing, since the design was not compromised for simplicity), build cost can be very high, if I throw in $400 (1541 x2) will I get the sound of commercial $1000 DAC's?


----------



## AudioCats

do you guys know where I can find these chips? any version, doesn't matter if it is a "A" or "S" or crown or anything..... Preferably from a US vender.

 Thanks


----------



## digger945

ecp.cc


----------



## AudioCats

I am looking for chips, not boards...

 Anybody?


----------



## Pars

Check on diyaudio.

diyAudio - Search Results
 The ones that jean-paul has are quite good. I have one in my Rotel 855 right now, and like it; wouldn't mind having another one. I would be very suspect of any single or double crown chips. Remember that the different grade chips were simply specially selected TDA1541as. Since they didn't test all chips for grade (probably low % of total production), you could get a plain chip that really is a double crown.

 Philips' fabs were in asia, so many for sale will be from that region; no need to doubt them if the seller seems legit.


----------



## AudioCats

Thanks. 

 The search link doesn't work for me, I might have to register first...

 any idea what kind of price Jean-paul might be asking right now?


----------



## dsavitsk

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_ecp.cc_

 

 Quote:


  Originally Posted by *AudioCats* /img/forum/go_quote.gif 
_I am looking for chips, not boards..._

 

Well, I have neither


----------



## AudioCats

dsavitsk, if I remembered right you have mentioned there are better NOS chips than the 1541, do you mind share some "secrets"? and what is the main limitation of the 1541's?

 Thanks


----------



## dsavitsk

Quote:


  Originally Posted by *AudioCats* /img/forum/go_quote.gif 
_dsavitsk, if I remembered right you have mentioned there are better NOS chips than the 1541, do you mind share some "secrets"? and what is the main limitation of the 1541's?_

 

Better is a stronger word than I'd use -- lots of folks with more experience than me prefer the 1541 to anything else. In my own builds, I have had better luck with the AD1865N-K. I find it has a less dark sound, clearer midrange, and overall less distortion. But, I am comparing the K version of that chip to the basic version of the 1541. The J version of the 1865 does not sound as good to me as the basic 1541, so maybe a crown or two on the 1541 would elevate it over the top.

 No real secrets other than that the power supply matters a lot, and the output stage matters even more. I also found with the TDA1543 that using it differentially was a huge improvement over using it single ended. Though, again, it may be the output stage that matters there.


----------



## Pars

Quote:


  Originally Posted by *AudioCats* /img/forum/go_quote.gif 
_Thanks. 

 The search link doesn't work for me, I might have to register first...

 any idea what kind of price Jean-paul might be asking right now?_

 

That would be a good idea. IIRC, the one from jean-paul was around $30 or so. There are a number of tda1541a's on ebay as well. Probably legit?


----------



## erin

The TDA1541 is a great sounding DAC. I prefer it when running in non oversampling mode.
 You can buy them easily on ebay. 
 There are NO fake TDA1541 IC's. (only the S1 and S2 variety)

 There is an ebay seller selling an AD1865N-K fully assembled DAC kit.

 You can also get a TDA1541 DAC kit off ebay - I recomend the one sold by analogmetric. TDA1541A DAC DIY Kit (CS8412 & NE5534)_USB DAC/DAC Kit_Analog Metric - DIY Audio Kit


 If you just want something to do because you are bored I would recomend building and or modding the above kits to suit your own taste.

 If you want to design one from scratch on vero boards you would most likely at best get something that sounds as good as the above kits but it would take you much, much longer to build than the kits, and at worst would not sound good due to the track layout etc.

 Save yourself the time and get a kit.

 Modding a TDA1541 CD player is a resonable idea, but results will vary as the PCB layout is not good on some of them and simply converting to NOS is not a guarantee of good sound with these players.
 For example the Marantz CD40 is a POS no matter what you do to it, it does not sing. The PCB is all wrong. This is from personal experience.
 Just my 2c.


----------



## Spacehead

Quote:


  Originally Posted by *Paul J.* /img/forum/go_quote.gif 
_I'm a big fan of the 1541. But are you thinking of scratch building a DAC with it? That sounds intense. Here is the schematic I'd use. Thorsten is less involved in DIY today, as he is now designing for AMR! (last I knew)

 If you are looking for a less involved project, there are several TDA1541 PCB's on ebay. Or, my personal take to is buy an old CD player that used the chip and convert the DAC to NOS (non oversampling) mode. There are plenty of fairly pedestrian Philips and Marantz Models that used the chip. (They circuits are identical, the made in Japan Marantz's are purported to be better than the made in Belgium Philips models). Magavox CD players from the late 80's are Philips players too. Look through this list to figure out which players have the 1541.

 I can find them for $10-40 on craigslist (just got a Magnavox 582 in great shape for $10). I'd look for the later players with the 1541A and a CDM 4 transport, but if you can find an early machine cheap, go for it. All of the mid-fi Philips players had similar parts quality. Some models just had more functions that you should disconnect anyway (variable output levels, extra control logic, etc). The Marantz CD-40 is simple, for example, where as the CD-50 and CD-60 have progressively more stuff. The basic mods are free: pull out the muting transistors, disconnect the extra junk, and convert to NOS. 

 If your budget is a little higher, I would strongly suggest getting a Rotel 855 or 955 (the latter is newer with the A chip). They run around $100, but are a much better value: robust power supplies with Black Gate caps, film decoupling caps on the 1541, etc. Basically, for another $50, you get a huge upgrade in parts quality. There are even nicer machines with the 1541 (the high end Philips, audiophile units like Arcam, Revox, etc). I'm not sure they are worth the $$ over the Rotel. And, keep in mind that old players are a gamble. You will find units with shelled out transports and lasers. If you aren't interested in NOS (the mod is too complex) there are some incredibly well made high end Sonys out there. (227ESD, etc). 

 I know that you may not be interested in shiny silver discs. I have pondered getting a USB to I2S converter and trying to hook it up to one of these old players to just use the DAC. I haven't tried it yet though. If you do play shiny discs, the nice thing about these old machines is that the transports are quiet, unlike most newer reasonably priced machines. No matter what, they are good cheap fun. Save those 1541s from the dump!

 Paul_

 

You seem to have a lot of knowledge about these DACs. I have one Technics CD player, that has PCM54 DAC. Would it be possible to extract that circuit from that cd player and some how utilize the PCM54 dac chip?


----------



## AudioCats

Thanks for the inputs guys.

  Quote:


  Originally Posted by *erin* /img/forum/go_quote.gif 
_If you want to design one from scratch on vero boards you would most likely at best get something that sounds as good as the above kits but it would take you much, much longer to build than the kits, and at worst would not sound good due to the track layout etc.

 Save yourself the time and get a kit.

 ._

 

not really. If I do build it I want to use all teflon for the by-pass caps and likely all battery power supply. Then it is much easier to just use perf board. 

 The "king of dac chip" gets the special treatment I guess. Then I won't need another dac for a long long time. The DAC technology keeps on changing, I want to make something that I can just stick with. 

 one more question: is it better to go "4x 1541 in parallel, no buffer" , or "1x 1541 followed by a 5687 srpp stage"?


----------



## dsavitsk

Teflon? You are aware that you need 14 bypass caps?

  Quote:


  Originally Posted by *AudioCats* /img/forum/go_quote.gif 
_one more question: is it better to go "4x 1541 in parallel, no buffer" , or "1x 1541 followed by a 5687 srpp stage"?_

 

Neither. 4x chips still won't give nearly enough voltage or current. And, SRPP is totally inappropriate. It was a fashionable tube stage in the 90's, but can be bettered by a simple grounded cathode stage in this position.


----------



## rds

Quote:


  Originally Posted by *AudioCats* /img/forum/go_quote.gif 
_Supposedly the 1541 is one of the oldest dac chips, is it worth the trouble to build a DAC with it? ( I have read that some folks think it is still the best out there.)_

 

I guess it depends how you feel about solid state progress over the last 30 years. As far as I'm aware basically every piece of IC has improved by orders of magnitude in that time. Perhaps DACs are the one exception that actually get worse with technological progress and increased sophistication. But it's worth a little research imo before embarking on what seems to be a very antiquated project.

 Having said that I do like tube amps, and not because I believe that they are doing a better job amplifying the signal. I actually like tubes because they are so antiquated, kind of like a classic car.


----------



## qusp

I dunno, but I would be a little surprised if just throwing a few teflons at something that seems to need pampering to sound its best working as intended. you need to supply a high grade power supply, regulation and good quality clock to something like this, especially if you plan on using NOS. teflons will just make the track lengths longer with more induction IMO I cant see that solving more problems than it causes personally. with these it seems the surrounding circuitry is at least as important as the chip itself. high grade SMD films by evox/rifa or wima to make up the entire circuit is much more likely to do as intended IMO and would be cheaper, even allowing you budget to get the boards made if you are up for a project in eagle or whatever. there are actually a couple of high end projects on DIYAUDIO at the moment using these chips, I know you are keen to do this yourself, so I wont push, but I really think that for a build like you are wanting you would be better to use another chip not so fussy, perhaps a sabre 9022 or PCM1704. also i'm under the impression that bypassing high speed circuits needs to be in much closer proximity than largish axial lead caps will allow for it to do the job, someone correct me if i'm wrong.


----------



## erin

Quote:


  Originally Posted by *Spacehead* /img/forum/go_quote.gif 
_You seem to have a lot of knowledge about these DACs. I have one Technics CD player, that has PCM54 DAC. Would it be possible to extract that circuit from that cd player and some how utilize the PCM54 dac chip?_

 

The PCM53/54 DACs sound awesome so I understand why you would want to use it but they are parallel input not i2s so are quite difficult to work with these days unless you are able to design some "glue logic" or able to program an FPGA to convert SPDIF or I2s to parallel input.
 Good luck with that project.


----------



## erin

Quote:


  Originally Posted by *AudioCats* /img/forum/go_quote.gif 
_Thanks for the inputs guys.



 not really. If I do build it I want to use all teflon for the by-pass caps and likely all battery power supply. Then it is much easier to just use perf board. 

 The "king of dac chip" gets the special treatment I guess. Then I won't need another dac for a long long time. The DAC technology keeps on changing, I want to make something that I can just stick with. 

 one more question: is it better to go "4x 1541 in parallel, no buffer" , or "1x 1541 followed by a 5687 srpp stage"?_

 

Mate, if you looked at the link i gave you, The analogmetric kit has enough room for you to use whatever capacitor you want. You could also run it off batteries if you wanted. You can also just buy the PCB from them for about $20. 

 There are enough fans of the TDA1541 for you to easily google and see the popularity of this DAC. Yes it is a good one. Use it. No matter which DAC you choose there will always be someone to tell you that your choice is wrong and others to tell you you are right.

 If you want to build your own from scratch go ahead and do it. From my own experience it is much easier to solder onto a PCB than to perf board.

 These kits are are good although the PCB layout could have been a little better, its good enough.
 They are much better than most Philips PCB layouts using the TDA1541.

 Should you use SRPP? Well that depends upon whether you like tube sound or not. Or what tube you are prepared to use?

 I think you would be better off trying an op-amp first.
 4X TDA1541 is excessive for a first go.
 2X TDA1541 will give you the benefits of paralleling without the $ cost of four ICs. I personally think the buffered output sounds better than passive.


----------



## erin

I also agree with qusp above.

 If you want to see a good TDA1541 design using SMD caps for the decoupling capacitors look at this CD player Whoor!!!!!

 I'd like to hear this one:

6moons audio reviews: Abbingdon Music Research CD-77 and AM-77


----------



## fran

I have 2 dacs here that use that chip in different ways. You should really take a look at the Audiosector dac, available as a kit - and I can tell you it sounds very good. 

 Theres also the DDDac which tackles the current output by stacking a bunch of the chips together. 

 But, really while you will get a working version by building on perfboard, I think it would be hard to get it sounding its best in that set up. I think for any kind of high speed digital stuff, very careful layout is required, and most likely at least 2 layer boards.

 the chip, when properly implemented sounds great.... really on a par with anything else out there. If you are going to have a go I would suggest using a Pass D1 output stage for the I/V conversion.

 Heres some links for you:

audiosector thread

DDDAC 2000

 Pass D1 output stage

Pass D1 I/V for TDA1545 - diyAudio

The Pass D1 For Tda1543 - diyAudio


 and theres lots there but you will need to search....


 Watch your power supplies - they make a large difference!! Shunts all the way....


 Fran


----------



## leveller1642

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_I guess it depends how you feel about solid state progress over the last 30 years. As far as I'm aware basically every piece of IC has improved by orders of magnitude in that time. Perhaps DACs are the one exception that actually get worse with technological progress and increased sophistication. But it's worth a little research imo before embarking on what seems to be a very antiquated project.

 Having said that I do like tube amps, and not because I believe that they are doing a better job amplifying the signal. I actually like tubes because they are so antiquated, kind of like a classic car._

 

Despite that i know absolutely nothing, this what i suspect. 

 I have a circa 1989 Marantz CD-80 CDP and a PM-75 amp that also has a DAC. They both use the TDA1541 and both DACs sound identical. They sound way too dark for my tastes.


----------



## Pars

Part of what you are hearing may be the output (I/V) stage. Probably NE5532/34 opamps implemented straight out of the datasheet.

 Speaking of output stages, I use this one currently in my rotel rcd855 w/tda1541a:

Less simple I/V for TDA1541 - diyAudio

 My primary concerns were low input impedance and DC coupled. Running more current thru the stage could get the impedance even lower. I would guess in my implementation it is probably in the range of 5 ohms or less (hopefully), but I haven't tried to model it or calculate it. Not even sure how to go about that


----------



## AudioCats

Thanks for the inputs guys.


  Quote:


  Originally Posted by *dsavitsk* /img/forum/go_quote.gif 
_Teflon? You are aware that you need 14 bypass caps?



 ._

 

actually a bit more. It seems that the msb by-pass should be larger, so I might do 0.6uf, 0,4uf, 0.2uf, 0.2uf, 0.1uf, 0.1uf, 0.1uf (msb to lsb). I will use 0.1uf/200v FT2's, that will be 17 caps per side, 34 per 1541. I know, they are huge. That is why I don't want to use commercial boards. 

 It turns out that I can't do 4x1541 anyway, not when I want to stay with teflon-only. I only have about 100 FT2 laying around. I do also have 30 some FT3 0.22uf for the tube buffer output. 

 going with vitQ's will be much easier, but they require teflon by-pass anyway so the size won't be that much smaller.

 I have 5687 right now, what tube do you guys recommand? Do I need interstage transformer to do the I/V, or is a fancy resistor good enough?

 does anybody know the (ball park) current draw of each supply voltage? It will help me to figure out how many batteries I might need.


----------



## erin

Quote:


  Originally Posted by *AudioCats* /img/forum/go_quote.gif 
_Thanks for the inputs guys.




 actually a bit more. It seems that the msb by-pass should be larger, so I might do 0.6uf, 0,4uf, 0.2uf, 0.2uf, 0.1uf, 0.1uf, 0.1uf (msb to lsb). I will use 0.1uf/200v FT2's, that will be 17 caps per side, 34 per 1541. I know, they are huge. That is why I don't want to use commercial boards. 

 It turns out that I can't do 4x1541 anyway, not when I want to stay with teflon-only. I only have about 100 FT2 laying around. I do also have 30 some FT3 0.22uf for the tube buffer output. 

 going with vitQ's will be much easier, but they require teflon by-pass anyway so the size won't be that much smaller.

 I have 5687 right now, what tube do you guys recommand? Do I need interstage transformer to do the I/V, or is a fancy resistor good enough?

 does anybody know the (ball park) current draw of each supply voltage? It will help me to figure out how many batteries I might need._

 

The TDA1541 is the ultimate tweakers DAC where you can tune the sound to your own taste. No one variety of capacitor will be universally declared "the winner" you will have to find out for yourself which caps sound best to you for the decoupling pins.

 The 5687 is a very nice sounding tube for a pre amp. I dont know how it will sound in a DAC output stage.

 For current draw check the datasheets.

 Allow me to refer you to this site which will give you some ideas:
Updates lampizator references postings


----------

