Hey guys! I made this mod, but i didnt found R14 and R17 on board! Can somebody help me? After removing L+ / L- / R+ / R- capacitors i hear a very big distortion! (at the attached picture not shown, but i shorted 4 capacitors links)
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Check the photo.... You have links in place of 1 k resistors which is most likely the reason for distortion.
Remove all parts that are not needed and bring ALL the tracks to ground potential
Feed the signals from Out1 and Out2 to relay pins 13 and 4 respectively.
NOTE: my arrows point to the relay coils - that is a mistake!!!
Cut the tracks around pins 13 and 4. The remaining coper should be brought to ground potential
What I haven't shown is the wires underneath connecting Out1 and Out2 to relay pins 13 and 4... various IC’s will require careful routing and / or series resistors…
DC level at the output is less than 4 mV with good IC....
For the proper symmetry (high frequency attenuation on both halves of balanced signals coming from the DAC), the capacitors should be matched as per my photo; 4 X 1nF and 4 X 100 - 200pF (choose the value between 100 to 200pF…. that suits your taste and your system. I use 4 X 150pF). Use FKP2 if possible. The cost of this DAC (with mods shown) is around $130 and that’s with the mains transformer included in price – truly unbelievable… the mods shown will give you very good sound.
Installed in nice box (another $100), this DAC with the mod shown will easily match $1000 - $1500 commercial DAC's...
Boky
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coupling caps
Does it sound ok with caps back in instead of links at L+ / L-/ R+ / R-? How much dc is on the RCAs?
Does it sound ok with caps back in instead of links at L+ / L-/ R+ / R-? How much dc is on the RCAs?
Yes, if i remove links, all works ok. DC in both situations is about 10mV. I think, electrolythic capacitors in signal line is not very good for sound, maybe just replace them with film caps?
Yes, after removing links it sounds OK. DC in both situations is about 10 mV. Maybe just replace caps with film caps? (i think electrolythic caps in signal path is not the best thing)
I've spent some time trying to get absolute best from this DAC for bare minimum spent in parts; I found interesting thing while minimising noise on Vcc / Vss pins....the only DAC chip that will give some reasonable results is in fact 4397 - all other plug in modules are seriously compromised...
Boky
Boky
Does anyone know if someone is building a fully modded and finished version of this dac? I'm an audio fan, but I have no electronic experience to assemble one myself. Obviously one would be remunerated for this.
Thanks very much, Mike.
Thanks very much, Mike.
Hi,
I connected two Jensen JT-11-EMCF at the output of the DAC and the sound is absolutely phantastic. At the moment i have two 500K resistors and one 1nF before the transformer and one 1k + 1nF after the transformer.
The bass and dynamic is weaker than with opamps. Should i try bigger or smaller resistors before Jensens if i want to have better bass and dynamic ?
Second question - the usb part is disabled - ps cap & lm317 for usb is cut out. The +15,0,-15V for the anogue power is no more connected. Should i remove the four small electrolyt caps at the output of the dac, or can i leave them in place ?
🙂
I connected two Jensen JT-11-EMCF at the output of the DAC and the sound is absolutely phantastic. At the moment i have two 500K resistors and one 1nF before the transformer and one 1k + 1nF after the transformer.
The bass and dynamic is weaker than with opamps. Should i try bigger or smaller resistors before Jensens if i want to have better bass and dynamic ?
Second question - the usb part is disabled - ps cap & lm317 for usb is cut out. The +15,0,-15V for the anogue power is no more connected. Should i remove the four small electrolyt caps at the output of the dac, or can i leave them in place ?
🙂
Drop R1-2 down to 200 ohms or so.
I don't know exactly what you have left in the original output circuit, you can pull the caps if you are careful, or pull the resistors that follow them. Leaving them in place should be OK as long as there is no path to ground through anything else.
I don't know exactly what you have left in the original output circuit, you can pull the caps if you are careful, or pull the resistors that follow them. Leaving them in place should be OK as long as there is no path to ground through anything else.
For anyone looking for a suitable SPDIF transformer, the one I ordered is a Murata 76601/2C; Digi-Key part number 811-1281-5-ND. Should come to less than $5 even with shipping.
i am using DAC in orig. configuration, but when using optical input there is relay clicking noise from time to time, tried with different source but no difference, dac works fine, but clicking is quite annoying, any ideas what to check?
thanks
thanks
