Wolfson WM8740 DIR9001 PCM2706 DIY DAC - Page 12

cobretti · 28th January 2012, 01:19 PM

Quote:

Originally Posted by Antonside

Ive got 1.5 version too. I replaced the diodes and regulators to originals and i ordered ELNA Cerafine caps from ebay but i afraid that they are fake too

May I ask where those caps are coming from? If they come from east, they might be (will be) most likely fakes as well. Why don't you use good Nichicon caps? Just a thought.

Antonside · 28th January 2012, 02:58 PM

They coming from china. Now i use nichicon capacitors in my dac but they can be fakes although they looks genuine they come with the kit.
Maybe some one know a good seler on ebay who sale original parts ?

tornislv · 28th January 2012, 05:07 PM

Since ELNAs from eBay are mostly fake, I switched to Panasonic, Sanyo, Rubycon and Nichicon, available from Farnell, Mouser and ELFA. With such suppliers you can always start a dispute about the quality and I haven't encountered counterfeit goods from these suppliers.

cobretti · 29th January 2012, 11:36 AM

Mouser, Digi-Key, Newark won't sell you fakes. If you can't buy from suppliers like these and let them ship it to you, then, I think it's better to find reputable local dealer instead of buying parts on eBay. I would never buy anything from China again, I have bad experience... not even kitchen knives.

dtses · 15th February 2012, 07:53 PM

hi,

found very interesting article how to improve standard LM317 regulator circuit. I wonder would it give any improvement with DAC's 7812 & 7912 regs

cobretti · 12:07 AM

Well, it depends what the existing noise looks like. As a matter of curiosity, I just measured my output stage (L7912ACV from ST , can not read the positive one) and I got 35uV of noise on both positive and negative rails. You would have to try the specific circuit for yourself and compare it if gives you any audible benefit. 35uV is low enough number for me, hence I will not try to do any mods. If you want a tip on a low noise regulator, I measured SSR01 from Sjostrom and it produces about 2.3uV (add some percentage +- for error) of noise. I used cheap OPA134 opamp in SSR01. I think if you put genuine regulators, not those like mine I received in the kit, you shouldn't worry too much. But on the other hand, I would love to hear feedback from some experiments.

TheGimp · 20th February 2012, 01:58 PM

Is anyone using both oscillators (22.5792MHz, and 24.576MHz) and muxing them?

gfiandy · 20th February 2012, 05:26 PM

I haven't done it with this set up but I have designed multiple clock systems in the past. If you want to do this I recommend creating a kill circuit for the clock you are not using as the ineraction between the two sees to be enough to cause audible degradation. Presumably by introducing decision threshold jitter.

Regards,
Andrew

miklos · 20th February 2012, 06:33 PM

Quote:

Originally Posted by cobretti

Mouser, Digi-Key, Newark won't sell you fakes. If you can't buy from suppliers like these and let them ship it to you, then, I think it's better to find reputable local dealer instead of buying parts on eBay. I would never buy anything from China again, I have bad experience... not even kitchen knives.

That's interesting, considering everything you own comes from China

dtses · 21st March 2012, 08:11 AM

cheers,

I wonder how many people ordered and built this DAC?

It has one feature that needs to be improved for sure. I guess everybody experienced it. When you turn the power switch off, cracking noise comes from the analog output to the amp and it's quite annoying and even terrible on high volume. As I've understood it happens due to direct opamp output and some filter or muting circuit should be added, am I right?

16th February 2012, 12:05 AM	#116
cobretti diyAudio Member Join Date: Feb 2011 Location: Taxachusetts	Well, it depends what the existing noise looks like. As a matter of curiosity, I just measured my output stage (L7912ACV from ST , can not read the positive one) and I got 35uV of noise on both positive and negative rails. You would have to try the specific circuit for yourself and compare it if gives you any audible benefit. 35uV is low enough number for me, hence I will not try to do any mods. If you want a tip on a low noise regulator, I measured SSR01 from Sjostrom and it produces about 2.3uV (add some percentage +- for error) of noise. I used cheap OPA134 opamp in SSR01. I think if you put genuine regulators, not those like mine I received in the kit, you shouldn't worry too much. But on the other hand, I would love to hear feedback from some experiments. Last edited by cobretti; 16th February 2012 at 12:07 AM.

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28th January 2012, 02:58 PM	#112
Antonside diyAudio Member Join Date: Jan 2012	They coming from china. Now i use nichicon capacitors in my dac but they can be fakes although they looks genuine they come with the kit. Maybe some one know a good seler on ebay who sale original parts ?

28th January 2012, 05:07 PM	#113
tornislv diyAudio Member Join Date: Sep 2010 Location: Riga	Since ELNAs from eBay are mostly fake, I switched to Panasonic, Sanyo, Rubycon and Nichicon, available from Farnell, Mouser and ELFA. With such suppliers you can always start a dispute about the quality and I haven't encountered counterfeit goods from these suppliers.

29th January 2012, 11:36 AM	#114
cobretti diyAudio Member Join Date: Feb 2011 Location: Taxachusetts	Mouser, Digi-Key, Newark won't sell you fakes. If you can't buy from suppliers like these and let them ship it to you, then, I think it's better to find reputable local dealer instead of buying parts on eBay. I would never buy anything from China again, I have bad experience... not even kitchen knives.

15th February 2012, 07:53 PM	#115
dtses diyAudio Member Join Date: Nov 2009 Location: UK, Manchester	hi, found very interesting article how to improve standard LM317 regulator circuit. I wonder would it give any improvement with DAC's 7812 & 7912 regs

20th February 2012, 01:58 PM	#117
TheGimp diyAudio Member Join Date: Aug 2009 Location: Johnson City, TN	Is anyone using both oscillators (22.5792MHz, and 24.576MHz) and muxing them?

20th February 2012, 05:26 PM	#118
gfiandy Audio Engineer diyAudio Member Join Date: Jul 2003 Location: Cambridge UK	I haven't done it with this set up but I have designed multiple clock systems in the past. If you want to do this I recommend creating a kill circuit for the clock you are not using as the ineraction between the two sees to be enough to cause audible degradation. Presumably by introducing decision threshold jitter. Regards, Andrew

21st March 2012, 08:11 AM	#120
dtses diyAudio Member Join Date: Nov 2009 Location: UK, Manchester	cheers, I wonder how many people ordered and built this DAC? It has one feature that needs to be improved for sure. I guess everybody experienced it. When you turn the power switch off, cracking noise comes from the analog output to the amp and it's quite annoying and even terrible on high volume. As I've understood it happens due to direct opamp output and some filter or muting circuit should be added, am I right?