Actually there is no pcb yet. This is my first tryout , the original pcb was a dual TDA1541 schematic . I have changed it to single TDA1541 (single TDA1541 is quiter) and did a lot of modifications on it . ( There are some jumpers and wire cuts )
I will add to this circuit a USB receiver chip and finalize the pcb . I think this will take some time
I will add to this circuit a USB receiver chip and finalize the pcb . I think this will take some time
My Quad TDA1541 produced almost ZERO noise....till I went to a Tube output .... Want to try a pure resistive output one of these days....
jk
I have downloaded some pure sine waves starting from 5Khz up to 15 Khz and burned into a cd and i did distortion tests using these hf sine tracks. Above 8Khz i can see on the oscilloscope the distortion for dual TDA1541 configuration . That can be because of my bad implementation , i am not sure...
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Hi jk,
witch tube circuit do you try? I have also a quad TDA1541A with Lampizator/Tube-I-zator circuit.
With my avantgarde acoustic Duo Omega Horns (107dB/m) there is no noise!
Best regards,
Oliver
What do you mean by "dem filter" is it magnetic filter ? Resistors in digital lines is ok but not a big improvement .
We have to use a coupling capacitor to eliminate the dc offset. Is there other solution to that ?
You mean 637 is better than 627 ?
This design is not a balanced architecture so we allways need to use an output cap.
Of course it will do distort. That 33 ohm I/V resistor to the ground is a BAD aproach. Philips (and any other DAC manufacturer) choose the OpAmp feedback loop for a reason.
But hey, you can try, like all others that try that aproach, to prove them wrong...
This tread is about some smart way of doing a interpolated DAC. You can create your own thread about the "don't do it like this DAC", it is simple.
14caps
If you need maximum sound quality then you need pay attention of all "small" things, such as calculate optimum values of this resistors depending on PCB parameters and design etc etc etcMany solutions to cancelling DC offset in current or voltage domain
wow, simplest way look at Dsheet
Please Look at the first message of this topic . If you read carefully you will see that there the are same subjects, I/V resistors , TDA1541 output voltage etc. It is not something about smart way of doing TDA1541 dac. Later on people discussed other ways of doing that but you can not say this is a special topic.
14caps
Many solutions to cancelling DC offset in current or voltage domain
wow, simplest way look at Dsheet
Thanks Nazar,
I have seen your schematic , It is very different , you eliminate the dc in a different way .
4.7uF DEM filter is quite high what is the sonic benefit / deficiency of that ?
current offset generators, difamplifiers, discrete stages etc
Sound transparency, to prevent multiplying of DEM clock with out music http://www.diyaudio.com/forums/digital-line-level/11949-tda1541-dem-reclocking-17.html#post1994743
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Hello Nazar,
Can you share with us some differential amplifier or discrete stages circuit suitable for TDA1541A other than opamp base? tube or solid state base is ok.
Can you also share with us why did you go with the chosen circuit instead of others? Did you design purely based on engineering sense or with intensive listening test?
By the way, have you compared your power supply regulating method with other shunt or super regulator like Jung's ? If so, whats your finding?
Can you share with us some differential amplifier or discrete stages circuit suitable for TDA1541A other than opamp base? tube or solid state base is ok.
Can you also share with us why did you go with the chosen circuit instead of others? Did you design purely based on engineering sense or with intensive listening test?
By the way, have you compared your power supply regulating method with other shunt or super regulator like Jung's ? If so, whats your finding?
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some discrete circuits is in my blog, but it has positive feedback in input stage and can be not stable, difamps and others I can draw circuits if i have time
At the end we listen to music, and that is most importantly, but without engineering no one can do well sounded device, at best a mirage
I use engineering - listen
engineering - listen
engineering - listen
...
I build (and listen of course) many, nothing really new, one things well - other bad. In Overture v2.3 I used CRC filters, the last my "standard"(with electrolytics) design.
Honeycomb homemade resistors
Well, back to topic.
Hi -EC-. Sorry for the long silence: blame it to too much work, plus another hobby that I found plus the long wait until the resistance wire arrived. They had only 28ohm/m in stock. I will have to wait for the 100ohm/m...
Today, finally, I swapped the I/V resistors from my "scrambled/interpolated DAC", which are four 110ohm resistors ( 15PPM and not quite cheap) for 4 honneycomb resistors, which are not so pretty as John's but seem to work quite well: the difference in sound is most significant! This DAC has the DIFFAMP as active output. The bass is superb and very "analog", fat but with plenty of definition and harmonics. Textures and timbres of instruments are sweeter and more defined (Thanks Onno!). Increase in detail is huge.
This little DAC deserves more tweaking: I will improve the V regulators and use your low noise Vref for the DIFFAMP.
I cannot wait to make the 500ohm I/V resistors of the passive output DACs.
I will also swap every significant resistor for the DIY ones.
You did it again...you are good... (with Robert De Niro's voice)
Many thanks,
M.
John's biggest fan.
Well, back to topic.
Hi -EC-. Sorry for the long silence: blame it to too much work, plus another hobby that I found plus the long wait until the resistance wire arrived. They had only 28ohm/m in stock. I will have to wait for the 100ohm/m...
Today, finally, I swapped the I/V resistors from my "scrambled/interpolated DAC", which are four 110ohm resistors ( 15PPM and not quite cheap) for 4 honneycomb resistors, which are not so pretty as John's but seem to work quite well: the difference in sound is most significant! This DAC has the DIFFAMP as active output. The bass is superb and very "analog", fat but with plenty of definition and harmonics. Textures and timbres of instruments are sweeter and more defined (Thanks Onno!). Increase in detail is huge.
This little DAC deserves more tweaking: I will improve the V regulators and use your low noise Vref for the DIFFAMP.
I cannot wait to make the 500ohm I/V resistors of the passive output DACs.
I will also swap every significant resistor for the DIY ones.
You did it again...you are good...
(with Robert De Niro's voice)Many thanks,
M.
John's biggest fan.
My Autographs never sounded so good; so revealing, even with the Beyma coaxial instead of true Tannoy; so deep and powerful bass; so warm and textured the timbres od instruments and voices!
Some picks:
Picasa Web Albums - mauricio
Picasa Web Albums - mauricio
Picasa Web Albums - mauricio
Picasa Web Albums - mauricio
Dear forum mates, what are you waiting for? Run, don't walk, to build your own resistors!
Cheers,
M.
Some picks:
Picasa Web Albums - mauricio
Picasa Web Albums - mauricio
Picasa Web Albums - mauricio
Picasa Web Albums - mauricio
Dear forum mates, what are you waiting for? Run, don't walk, to build your own resistors!
Cheers,
M.
Hi maxlorenz,
I have been very busy too (solving problems).
Seems we have to wait until after 20 May for the resistance wire.
Your home made I/V resistors look great, I know how difficult it is to make these.
I am currently testing a common gate JFET current buffer for the TDA1541A DAC module. My I/V converter now consists of 2 parts, one selected JFET and one 500R passive I/V resistor.
I have been very busy too (solving problems).
Seems we have to wait until after 20 May for the resistance wire.
Your home made I/V resistors look great, I know how difficult it is to make these.
I am currently testing a common gate JFET current buffer for the TDA1541A DAC module. My I/V converter now consists of 2 parts, one selected JFET and one 500R passive I/V resistor.
My Autographs never sounded so good; so revealing, even with the Beyma coaxial instead of true Tannoy; so deep and powerful bass; so warm and textured the timbres od instruments and voices!
Some picks:
Picasa Web Albums - mauricio
Picasa Web Albums - mauricio
Picasa Web Albums - mauricio
Picasa Web Albums - mauricio
Dear forum mates, what are you waiting for? Run, don't walk, to build your own resistors!
Cheers,
M.
That enclosure is very small and everything is very close to the unshielded power transformers, especially the I/V resistors.
Same goes for EC designs dac.
Ever had a look at a cd player ?
Trafo in one corner, dac in the other, at greatest possible distance.
Doesn't matter...