Hi end DAC kit ebay

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#104
jstang said:
Mine was noisy at first, turned out to be the transformer wiring and grounding....

jk
Click to expand...

I see what you mean. Inside chassis there is no hum and less hiss. Still I cannot explain the "artifacts". I intend to buy a new chip TDA1541A and try to see if converters is the problem. After that, receiver and buffers.
IMG_0086.jpg

IMG_0087.jpg

IMG_0088.jpg

By the way, you still have your old TDA's?

thanks.
 
#105
#106
dvb-projekt said:
I saw on your picture that the resistors (R41,R42 & R46,R47) are still there.
Try to short them all!
Click to expand...

Hi dvb,
After many hours of testing (changing TDA's, dir9001, DS chips), finally I've found the problem, it was one of the voltage regulator LT1084 (shown in the pictures) that didn't work properly, although the voltage measurement was correct(-5V, +5V and -15V) at the TDAs. What I did, I've replaced temporary the LT1084 with LM317. No more "artifacts".
Shorted (R41,R42 & R46,R47).

jstang said:
Secondly the input coupling cap C1 is not required for a Current output Dac like the tda1541. Short that cap.

I am also thinking of removing C2.

Last put a film bypass across C4 also.

Metal film resistors will help clean up the sound too...
Click to expand...

Removed C1, raised C5 to 2,2u but kept C2.
Much better
IMG_0012.jpg

Thank you everybody for support.
 
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#108
flancfuster said:
Hi dvb,
After many hours of testing (changing TDA's, dir9001, DS chips), finally I've found the problem, it was one of the voltage regulator LT1084 (shown in the pictures) that didn't work properly, although the voltage measurement was correct(-5V, +5V and -15V) at the TDAs. What I did, I've replaced temporary the LT1084 with LM317. No more "artifacts".
Shorted (R41,R42 & R46,R47).



Removed C1, raised C5 to 2,2u but kept C2.
Much better
View attachment 153649

Thank you everybody for support.
Click to expand...

Hey! I've got the same tube out! Only I use it in my modified CD. I just tried it out but it distorts heavily when I tried feeding it after active I/V(after first part of opamp) When I played it with 10%volume recorded CD it sounds promising! I'm sure the signal is too strong... how do you connect tube buffer?
 
#110
Bassivus said:
Hey! I've got the same tube out! Only I use it in my modified CD. I just tried it out but it distorts heavily when I tried feeding it after active I/V(after first part of opamp) When I played it with 10%volume recorded CD it sounds promising! I'm sure the signal is too strong... how do you connect tube buffer?
Click to expand...

Hi Bassivus,

From my experience with the tube output from raindrop, I've noticed that the amplification coefficient is 50X(which is to big) so you have to adjust this coefficient to your output level (eg. a CD-player has around 2.5V rms, for 1Hkz signal), by changing values of resistors in the tube buffer. Try to use the values from jstang and upgrade to metal film. Give it a try with 2k or more on R2.
Regards.
 
#112
Boudy,

You should read this post...

http://www.diyaudio.com/forums/digi...building-ultimate-nos-dac-using-tda1541a.html


I have the NOS4.0 dac. Played around with it running with just 1, 2 , 3, and the 4. Also reclocked it, Linear interpolated it and other wise upgraded it. Even added 4 TDA1541 S1 chips.

10 months ago when I first started with DIY Dacs... I was not sure what I wanted to buy or what to do for that matter...

I googled and found that Ultimate DAC thread above... Really had no clue of which chip or how many... Seeing I don't like soldering if I don't have to...I dropped my money on the NOS4.0 after reading that post.

My 2 Cents : Properly tuned and setup.... 4 will sound better. Especially after the linear interpolation mod the difference will be larger. I am glad I went for the 4 and spent the time on all the mods. Even though at the time I bought it, I really did not understand the benefits.

Is it night and day between 2 & 4 chips? In STOCK FORM not really. You will heard the difference....but not night & day.

For the few extra $ it was well worth it for me. I would not think twice...actually I did think twice and bought a second one. Might upgrade to 8 dac with linear interpolation when I get the time.

jk
 
#113
Mods

I'm only looking to perform minimal mods, I'm not comfortable working with SMD components. So it has to perform well in stock form.

The thread that you refer to has gotten huge and its a pain to find the nuggets of useful information, which happens all too frequently here.
 
#118
jstang said:
I have the NOS4.0 dac. Played around with it running with just 1, 2 , 3, and the 4. Also reclocked it, Linear interpolated it and other wise upgraded it. Even added 4 TDA1541 S1 chips.
Click to expand...
There goes the NOS of the window. Sure, all say they like NOS but reality is that the 16bit, 44.1kHz sampling rate NEEDS badly some oversampling to get around that image frequencies and brick filter conundrum - if OS it is done right that is.
Of corse, OS without adding the needed dither/interpolated bits will sound almost as bad as NOS. Or rather a different kind of "bad" 🙂
 
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#120
I'm thinking about buying a newer version of the raindrop_hui TDA1541 based dacs with two TDA's in parallel and some improvements on the layout (decoupling caps very close to the chips), and with HDAM output stage.

Here's a link:
DAC Kit DIR9001+TDA1541A 2.0B OS/NOS with HDAM bei eBay.de: Eléments séparés (endet 15.04.10 14:51:48 MESZ)

Did anybody bought this one and had a listen? I'm really interested in the sound of this unit in STOCK FORM! Because, one can mod this dac, but this will lead to a never ending story. In the end one has to replace nearly ALL the parts on the pcb, and this way it doesn't make any sense to me to buy a completely assembled and ready-to-run dac module.

So, how do these modules sound without any mods?

Thanks a lot!

Martin
 
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