Here's how the stock DAC board can be modified: all "unnecessary" components have been removed and 3 discreet regulators added. I'm using MIT RTX 1uF output coupling caps. External PS is the same as in the balanced DAC. Instead of costly BG N 1000/50 I'm using here BG NX 470/16 which works fine too.
I'm also attaching Word document which was compiled by uncle_leon who tried some of the mods already.
I'm also attaching Word document which was compiled by uncle_leon who tried some of the mods already.
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Some of the components in a shunt regulator can be hard to source, so this is series regulator we've been using initially. It also works very well and the difference between those two regulators is rather subtle, although shunt seem to sound a bit better when the circuit is built exactly as described.
For 5V output, change 8k25 resistor to 5k. That regulator circuit was also developed by Bobken.
For 5V output, change 8k25 resistor to 5k. That regulator circuit was also developed by Bobken.
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Peter,
Any balanced PCBs planned? Keeping with your affinity for short traces I see Neutrik has some nice PCB mountable XLR connectors.
Regards,
Dan 🙂
Any balanced PCBs planned? Keeping with your affinity for short traces I see Neutrik has some nice PCB mountable XLR connectors.
Regards,
Dan 🙂
I think it would be really hard to convince people these days that TDA1543 can sound better that high res modern DACs 😉
Coming back to the topic, here's a DAC I built for a local customer around Christmas time. He was initially searching for Bidat, but when he audition the Bidat and this DAC in my system, there was no doubt what sounded better. His system required coupling caps so we went with 1uF TFTF V-Caps. The enclosure is a modified AMP-2 chassis.
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Is anyone sure that Peter does not have a machine shop that is not int the pictures he posts? J/K.
That is absolutely beautiful work Peter. How are the ends attached to the case? I don't see any hardware. Is this the same circuit with the addition of the coupling caps?
That is absolutely beautiful work Peter. How are the ends attached to the case? I don't see any hardware. Is this the same circuit with the addition of the coupling caps?
Do you think most people wouldn't like the Altmann Attraction DAC? 😉 Of course we all know that the Altmann is a TDA1543 based DAC.
Regards,
Dan 🙂
We trust you! 😉
Design a suitable pcb and customers will follow. You already got one at least
Those are the enclosures that I had fabricated for AMP2 mono blocks that were on a cover of hi-fi+: http://www.audiosector.com/downloads/hifi+review.pdf
The 3/4" aluminum panels are press fitted into tubing and secured with a single screw only.
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My original DAC quite favorably compared to Altman DAC: Audiosector USB DAC -- my new DAC--(and comparison)
This one, especially when balanced, seems to be much better 😉
Hello Peter,
thanks allot for sharing. Just some questions at the moment...
right at the beginning, what brand is the black five-pole connector from
psu to main circuit? And What are those bib black ´lytics on the DAC.
board?
Greetings ulf
thanks allot for sharing. Just some questions at the moment...
right at the beginning, what brand is the black five-pole connector from
psu to main circuit? And What are those bib black ´lytics on the DAC.
board?
Greetings ulf
The connectors are from Switchcraft (Multi-Con-X), digikey part# SC1221 (for female cable mount).
The caps are BG FK 2200/35 and BG N 1000/50, the latter can be replaced with BG N 470/16
The caps are BG FK 2200/35 and BG N 1000/50, the latter can be replaced with BG N 470/16
okay, GREAT...thanks allot 🙂
As my whole System is unbalanced, would you recommend building
the balanced version and use it unbalanced?
Why are you not using any output-caps in your version?
Greetings Ulf
P.S. forget about the stupid questions about outputcaps...found all the answers :-(
As my whole System is unbalanced, would you recommend building
the balanced version and use it unbalanced?
Why are you not using any output-caps in your version?
Greetings Ulf
P.S. forget about the stupid questions about outputcaps...found all the answers :-(
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If the system is unbalanced, there's no reason to built the DAC balanced, UNLESS you are using TVC which can convert balanced signal to unbalanced with the advantage of eliminating coupling caps because of zero differential offset (the 4V outputs from a DAC cancel each other when connected to primaries of the transformer)
My amps are also unbalanced.
My amps are also unbalanced.
Okay...
well i don´t have TVC but an Valve-based unbal- LinePre
But there is the possibility to use an input from bal. via
inputtransformer to unbal. Would that be an upgrade over
just using unbal. DAC directly into the unbal. pre?
Greetings ulf
P.S. What do you thing..how many TDA will be needed to
find a matching pair for using the sym. DAC
well i don´t have TVC but an Valve-based unbal- LinePre
But there is the possibility to use an input from bal. via
inputtransformer to unbal. Would that be an upgrade over
just using unbal. DAC directly into the unbal. pre?
Greetings ulf
P.S. What do you thing..how many TDA will be needed to
find a matching pair for using the sym. DAC
I think transformer may be introducing as much coloration as quality caps. It's really hard to say what's better unless you compare it directly.
The guy for whom I converted DAC in post# 21 still raves about it and it's unbalanced DAC.
I sort chips in a circuit and takes at least 20 pcs to find a reasonable match.
The guy for whom I converted DAC in post# 21 still raves about it and it's unbalanced DAC.
I sort chips in a circuit and takes at least 20 pcs to find a reasonable match.
Just because i´m curious, Peter at post 24 what for is LED
S1 S2 and p on the front?
Greetings ulf
S1 S2 and p on the front?
Greetings ulf
Yes, try it, I have a correction to what I wrote earlier though. A single inverter might be needed as well. But the Tent clock output goes directly to the BCK of tda1543, which is the jitter critical input.
I will draw a schematic later.
Best,
Alex
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It would be interesting to see if Lundahl or Jensen had any transformers that would convert balanced to unbalanced without coloring the sound.
Regards,
Dan 🙂
The main reason I'm using transformer is because it is also my preamp. I mentioned it already that I can't imagine better passive line stage than TVC: it adds gain, converts balanced to unbalanced, unbalanced to balanced, allows phase reversal and of course, attenuates. There are kits available with stepping motors that allow adding remote control function. It also sounds better than most active preamps out there, if system is set up properly.
Jensen or Lundahl are certainly fine, but then you need additional line stage, which increases complexity and certainly affects the sound.
My preamps are based on S&B TX102 which are not available for diy any longer, however, I also tried Sowter and it seems as good as S&B.
I've built one such preamp for a local guy (using Sowter 1035) and he replaced his AR Ref 3 with it. Recently he asked me to build another one.
1035 offers balance control, if that is not needed, then 9395 would be a good choice: SOWTER ATTENUATOR TRANSFORMERS TVC VOLUME CONTROL
Those are probably not much more expensive than Lundahl or Jensen, but offer so much more...
Jensen or Lundahl are certainly fine, but then you need additional line stage, which increases complexity and certainly affects the sound.
My preamps are based on S&B TX102 which are not available for diy any longer, however, I also tried Sowter and it seems as good as S&B.
I've built one such preamp for a local guy (using Sowter 1035) and he replaced his AR Ref 3 with it. Recently he asked me to build another one.
1035 offers balance control, if that is not needed, then 9395 would be a good choice: SOWTER ATTENUATOR TRANSFORMERS TVC VOLUME CONTROL
Those are probably not much more expensive than Lundahl or Jensen, but offer so much more...
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