latest update, I made some additional upgrade with Caps as below, analog supply part has now all caps as per schematics with Nichicon KA version, top of that I change those BC aluminum esr caps with ultra low Nippon Chemicon version, I couldn't hear any audible difference, but last week I upgraded analog part with HDAM modules as visible on the picture, hard to describe it properly but it's amazing, more dynamics, more punchy bass, no harshness at all, absolutely happy man
An externally hosted image should be here but it was not working when we last tested it.
free picture upload
HDAM modules :
Where can we find these modules ?.
Thanks
Serge
Thanks NinoSimona.
By the way, I am planning to use a tube output for this DAC and I have an UTO (universal tube output) that I bought from diyhifisupply.com sitting in my drawer. This UTO does not have samples to connect a balanced input to single end output. Is it possible to ground the -ve ouput from AK4399 and use the +ve as Vin to the module?
Hi NinoSimona, if I connect the UTO to outputs of AK4399 after the 11K resistors, do I need to solder the 390pF between the +ve and -ve output?
By the way, I am planning to use a tube output for this DAC and I have an UTO (universal tube output) that I bought from diyhifisupply.com sitting in my drawer. This UTO does not have samples to connect a balanced input to single end output. Is it possible to ground the -ve ouput from AK4399 and use the +ve as Vin to the module?
Hi NinoSimona, if I connect the UTO to outputs of AK4399 after the 11K resistors, do I need to solder the 390pF between the +ve and -ve output?
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If you need single ended output, you should use + leg and ground. You shouldn't connect - pin to ground. DAC chips particularly very sensitive to analog output's load.
With unbalanced output, max voltage swing will be half if tube circuit doesn't apply any extra gain.
Hi Serge,
modules here Marantz HDAM module-like DIP-8 operational amplifier Item?s description , $8.40 is for pc, total price with china airmail delivery is around $25-30 for pair, just make sure if you place the order that you change weight to 43 gram per pcs, in default is set to 4.3Kg, don't know why...
Hi lomonosoff,
I'm also happy with my modules, incomparable with standard OPA...
modules here Marantz HDAM module-like DIP-8 operational amplifier Item?s description , $8.40 is for pc, total price with china airmail delivery is around $25-30 for pair, just make sure if you place the order that you change weight to 43 gram per pcs, in default is set to 4.3Kg, don't know why...
Hi lomonosoff,
I'm also happy with my modules, incomparable with standard OPA...
I purchased this dac as a kit for experimenting different power supply circuit which is also based on LT1085 and LM337. These regulator chips tend be more linear if they draw ~50 mA current at least.
Maybe sound difference you observe is the consequence of more current draw of these discrete opamp circuits. You can test it by adding 2W load resistors to each rail (330R/2W at +15V to ground, -15V to ground) for drawing ~45-50 mA current from rgulators. You can also test it at 5V analog supply of AK chips coming from LT1085's. Load resistor is going to be 110R/1W in this case.
latest update, I made some additional upgrade with Caps as below, analog supply part has now all caps as per schematics with Nichicon KA version, top of that I change those BC aluminum esr caps with ultra low Nippon Chemicon version, I couldn't hear any audible difference, but last week I upgraded analog part with HDAM modules as visible on the picture, hard to describe it properly but it's amazing, more dynamics, more punchy bass, no harshness at all, absolutely happy man
An externally hosted image should be here but it was not working when we last tested it.
free picture upload
And about soundstage? Is the same or not?
Inviato dal mio SM-N9005 utilizzando Tapatalk
Discrete opamps
I tried a number of opamps for this DAC and found the two discrete opamps that I used outperform every other opamps in my system.
Dexa - clean and detail but lack of airy. Suitable for symphonic music.
US$80 per pair.
Op01 - clean and airy. Suitable for all type of music.
US$17 per pair.
I tried a number of opamps for this DAC and found the two discrete opamps that I used outperform every other opamps in my system.
Dexa - clean and detail but lack of airy. Suitable for symphonic music.
US$80 per pair.
Op01 - clean and airy. Suitable for all type of music.
US$17 per pair.
Attachments
keres: it think it's pretty much the same but I would say more refined and separation of the instruments is better, it might be subjective due to fact that more dynamics giving you bigger imagination, hard to say, I'll try to test it again with standard OPA and let you know...
Sunsun22: I didn't tried OP01 as yet as I'm waiting for extension adapter, can't fit it due to output caps which are higher than OPA socket
Sunsun22: I didn't tried OP01 as yet as I'm waiting for extension adapter, can't fit it due to output caps which are higher than OPA socket
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