New Tube DAC TDA 1543

[Opti-cal]

Hi guys,

having sold my 'old' tube DAC's recently I thought I'd take a punt on something a little different. Fully hand built by a German (so signal paths are efficient!) and using nice matched components.

It's a simple implementation of a TDA 1543 chip with a pair of Telefunken C3M tubes in the output stage. It uses a pair of Talema transformers for independent digital and analogue sections, which is nice. What I assume is running the analogue section does get a bit warm though. Some nice Phillips power caps in there too in a very fetching blue which matches the transformers. All very well put together in a rather neat wooden box. Certainly among the 'prettier' DAC's if there is such a thing.

https://i.ibb.co/bX6jcnL/IMG-20210430-094513-720-2.jpg (https://ibb.co/QMJ7yGn)
https://i.ibb.co/T1kbwgD/IMG-20210430-094427-423-2.jpg (https://ibb.co/w7RwdzZ)
https://i.ibb.co/F67N2m3/IMG-20210430-094439-433-2.jpg (https://ibb.co/4WN9zKt)


It's not the last word in detail, it doesn't throw as wide a soundstage as modern SS DAC's.

It does however sound wonderfully 'analogue' and lends itself incredibly well to acoustic recordings. As it's slightly rolled off there is no grain or harshness to it at all. The bass is also surprisingly good for a 1543 chip. Acoustic bass notes from a double bass or guitar have real texture and 'meat' on them, its pretty spell binding at times. Voices both male and female, are projected with an authenticity which I've found lacking on most SS DAC's (at least in my price range under £500.00).

Having said it's rolled off in the treble, what is there does have a natural 'tube' sparkle to it and certainly creates a much more 3D and enveloping image compared to say my Soncoz SGD1 which outperforms this in the soundstage and detail specs. The bass from the Soncoz also hits 'harder' but on acoustic stuff this thing sounds completely natural with bass notes taking shape in front of you and decaying all around the room.

Does have a tendency to sound a little 'congested' by complex passages but then I've basically bought it as the antidote to the aforementioned modern SS DAC's with perfect distortion figures and razor sharp detail retrieval.

It's really nice to switch between both depending on what material I'm listening to. They really do complement each other perfectly in my opinion. Luckily the Soncoz has a coax out so I can just link it to the other DAC as I do prefer the sound of coax over toslink.

I'm quite tempted to get 8 more TDA 1543 chips and do the 'solder together' mod as it improves sonics quite significantly apparently. I also wonder if a TDA 1543A and 1543T would improve/change things at all and if they are indeed swap in/out as a direct replacement. As they are not being used with any filter I would imagine so?

If anyone has any experience on this any advice or recommendations it would be most welcome.

Here is the circuit for those interested . . . .

https://i.ibb.co/J7DFgSm/IMG-20210502-164838-893-2.jpg (https://ibb.co/7WsNL0j)
https://i.ibb.co/YNLXPdL/IMG-20210502-164844-054-2.jpg (https://ibb.co/BfCGc6C)

[brian2957]

This looks interesting Chris. I don't think I've ever seen a DAC made totally of wood. Looks very well made and as you say, one of the ' prettier ' ones I've seen. I'm not a detail freak either and would rather have a more natural sound, particularly with voices. Got a link please ?

[Opti-cal]

Hi Brian,

I actually missed out on this one on ebay so I contacted the seller and luckily he managed to source another for me.

I tracked him down and communicated via google translate to tell him I wanted one. Here is the original listing, I would be happy to provide you with his email address if you wanted to make an inquiry or obviously you can go via the ebay route too (although via private email I was able to get a discount using PayPal friends and family etc).

You may have to translate the description into English if you're not fluent! Although this one is for an implementation with a TDA 1545 chip and slightly different power caps.

https://www.ebay.co.uk/itm/TUBE-DAC-D-A-Wandler-mit-Rohrenausgangstufe-NOS-non-Oversampling-Prinzip-/154363002358?nma=true&si=yXChPoBr4ZhqnqTJ4qMcOY8WJEM%253D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557

Cheers

[Firebottle]

Probably not what you want to hear Chris but the 1543 has quite high distortion at low signal levels.
Not for me though it does look to be a very nicely made unit.

[brian2957]

Now that looks very interesting Chris, thanks. Can you please give me his email address ( for a later date ) New turntable ( LP5x ) and cartridges have eaten up my budget I'm afraid.

[Opti-cal]

Probably not what you want to hear Chris but the 1543 has quite high distortion at low signal levels.
Not for me though it does look to be a very nicely made unit.

Hi Alan, yes I did do some research before purchase, with strict implementation people seem to have pretty good results with it. I'm wondering if the 1545 would have been the better sounding unit (probably). Obviously a 1541 would have been even nicer but a lot more work to build properly. As you're likely in the know about these things is it worth stacking some more 1543 chips (more strain on transformers I'm guessing?) or indeed changing for a 1543A/T version. I've read it does require some modifications.

I do love the C3M output stage though, would there be any merit in replacing the digital section for a relatively low cost upgrade? There are some 'decent' R2R designs floating about now I see and this seems to have a good chassis for some fettling.

Any ideas?

In a comparison with the SGD1 (impeccable measurements) the added distortion certainly doesn't get in the way of the enjoyment of the music, which is the most important thing to me.

[Opti-cal]

Now that looks very interesting Chris, thanks. Can you please give me his email address ( for a later date ) New turntable ( LP5x ) and cartridges have eaten up my budget I'm afraid.

PM'd you Brian.

Still enjoy my LP5 practically everyday!

Mine now wears a cork mat, seems to work better in my system.

Cheers

[Lawrence001]

Hi Alan, yes I did do some research before purchase, with strict implementation people seem to have pretty good results with it. I'm wondering if the 1545 would have been the better sounding unit (probably). Obviously a 1541 would have been even nicer but a lot more work to build properly. As you're likely in the know about these things is it worth stacking some more 1543 chips (more strain on transformers I'm guessing?) or indeed changing for a 1543A/T version. I've read it does require some modifications.

I do love the C3M output stage though, would there be any merit in replacing the digital section for a relatively low cost upgrade? There are some 'decent' R2R designs floating about now I see and this seems to have a good chassis for some fettling.

Any ideas?

In a comparison with the SGD1 (impeccable measurements) the added distortion certainly doesn't get in the way of the enjoyment of the music, which is the most important thing to me.I was wondering about the adding chips thing as I think a lot of the TDA1543 DACs I've seen have 4/8 (or even 16?) chips in them.

The other thing I've wondered is, are these still made by Phillips or are there Chinese "replicas" being made to supply the new found demand for such old chips? As I can't believe there are NOS mountains of all the chip types sitting around waiting for someone to decide if they are good again.

[Barry]

Can you explain what you mean by 'stacking some more chips' ? Do you mean literally wiring the chips in parallel, pin for pin?

Thanks
Barry

[Opti-cal]

Can you explain what you mean by 'stacking some more chips' ? Do you mean literally wiring the chips in parallel, pin for pin?

Thanks
Barry

Yup, might take a little more care + some heatsinking than this though . . . . apparently does improve most aspects of the sound. Lowers jitter/distortion somewhat (or errors at least).

https://i.ibb.co/6vqCp4c/8x1543.jpg (https://imgbb.com/)

[Opti-cal]

Actually I guess that one would be described as in 'series'.

Here is a 'parallel' example.

https://i.ibb.co/Dp94hdM/s-l1600.jpg (https://ibb.co/FV562pY)

[walpurgis]

Gives a whole new meaning to 'a portion of chips'! :)

[Barry]

Ah - I understand now. Not heard of that technique for complete ICs, but it is commonly used with transistors (and even valves) to reduce thermal noise.

The noise is reduced by the square root of the number of devices in parallel, so for 8 of them the noise will be reduced by a factor of 2.83 (or 9dB). There is no advantage in using more than 8, as the increase in the Miller capacitance will start to be a problem.

[Opti-cal]

Ah - I understand now. Not heard of that technique for complete ICs, but it is commonly used with transistors (and even valves) to reduce thermal noise.

The noise is reduced by the square root of the number of devices in parallel, so for 8 of them the noise will be reduced by a factor of 2.83 (or 9dB). There is no advantage in using more than 8, as the increase in the Miller capacitance will start to be a problem.

Makes sense, there are some advertising the use of 16 but seems the point of diminishing returns has been well reached.

Do you think the transformers will be able to handle the extra load?

I think I might order 8 just to give it a go, then if I mess it up or it doesn't work I can just put the X 1 back in (assuming it's not going to damage anything within the circuit path). I would assume we're not talking voltages that are likely to do damage to any components downstream?

[Barry]

You would have to look at the specification for the chip to see what the current consumption is. Then multiply that figure by the number of chips to see if it lays well within the current capability of the transformers (and of the voltage regulation circuitry).

[Opti-cal]

You would have to look at the specification for the chip to see what the current consumption is. Then multiply that figure by the number of chips to see if it lays well within the current capability of the transformers (and of the voltage regulation circuitry).

Thanks Barry, some DIY research coming on I feel.

[brian2957]

PM'd you Brian.

Still enjoy my LP5 practically everyday!

Mine now wears a cork mat, seems to work better in my system.

Cheers

Thanks Chris, replied. Yup, still enjoying the LP5x very much. I have a cork mat here and will give it a go. Thanks for the links etc. :)

[Firebottle]

TDA1543 typical current consumption is 50mA.

So you need to assess or test that the 5V supply can provide 400mA.

[Opti-cal]

TDA1543 typical current consumption is 50mA.

So you need to assess or test that the 5V supply can provide 400mA.

Thanks Alan, the supply is 9V (9v/115v X 2) I believe and a lot of people have had success using 7/8v supplies. It has a Secondary Current rating of 833mA so even split between the two outputs it should meet the specs. Is that right? I've literally just guessed at most of that?!

As it happens there is a school of thought that just having 1 chip gives a purer 'sound' (which does make sense) but if there is space in the unit I think I might still give it a try as it's cheap to find out.