I had already did it:
http://www.diyaudio.com/forums/digi...-kit-cs8416-ak4393-5532-a-13.html#post2594885
You can use mkp, mkt, paper-in-oil type nonpolar caps here.
Off topic, I had very good results with axial tantalums as dc blocking also. Since they are polarised caps, you have to connect positive leg onto dac side. Just worth to try.
As all film caps FKP2s don't have polarity.
Though there could be a direction that is better sounding...
Usually I don't care about it...
Because of the positive posts here I bought one of these DACs with a AK4396 on it. After having changed the opamp to various types I settled with LME49860. While I am still experimenting with it I can remark a few things:
- it really needs a heatsink on the 7812 when the original R core transformer is used. BTW the R core is absolutely quiet, very nice quality !
- it needs a 100 Ohm resistor at each of the L + R outputs of the opamps to the RCA sockets
- my 2 different FN1242A (Fluency) DACs eat it for breakfast in terms of quality but they are more noisy.
I have the feeling CS4397/98 DACs are also somewhat better than these chips but unfortunately I haven't kept one of those so I can not compare. Maybe I will try this DAC again with transformer output boards as I have one of those left.
- it really needs a heatsink on the 7812 when the original R core transformer is used. BTW the R core is absolutely quiet, very nice quality !
- it needs a 100 Ohm resistor at each of the L + R outputs of the opamps to the RCA sockets
- my 2 different FN1242A (Fluency) DACs eat it for breakfast in terms of quality but they are more noisy.
I have the feeling CS4397/98 DACs are also somewhat better than these chips but unfortunately I haven't kept one of those so I can not compare. Maybe I will try this DAC again with transformer output boards as I have one of those left.
Mine measures 60°C, it's too much?
Absolutely!
Why? To adjust output level?
Did you do experiments also with caps?
They make a BIG difference...
Particularly the film caps aroud the opamp, the EROs are fine but Wima FKP2s are in another league...
Also Aluminun Solid caps are a big improvement for all digital PS in this DAC.
So far I've briefly tried (fresh, not burned in) Sanyo Oscon SEPC 470uF 6.3V, Fujitsu 100uF 16V and Sanyo WG 1000uF 6.3V (not solid), Nichicon LS 150uF 10V, NCC PSA 220uF 6.3V and finally Sanyo Oscon SC100uF 16V.
SEPCs, Fujitsu and WGs seems best but all of them are way better than stock caps.
On that topic... Looking at the schematic i see that the 3.3V and 5V regulators are LM1117. You should be careful using low ESR caps on their output. From the datasheet "The output capacitor is critical in maintaining regulator stability, and must meet the required conditions for both minimum amount of capacitance and ESR... The ESR of the output capacitor should range between 0.3Ω - 22Ω"
That is a good point.
but if you look at the distance of the track between the caps and the lm117's.
there seems to be an output cap quite close to each regulator. I'm not sure those traces are long enough to negate the other decoupling caps from the impedance that the regulator "sees".
Indeed, it should be there as I found out with long cabling.
Yes, I meant that (in broken english)
ClaveFremen, I do experiment with caps but I found my example has fine caps so I kept it like it is for now. Nichicon PW is good.
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jean-paul, which are the two Fluency DACs you are comparing this DAC to? Are they in the same price range? On last question, the quality is better overall, better detail, transient response, etc. or in specific areas?
Thanks!
Both Fluency DACs are made by myself (based on japanese kits) and they are somewhat more expensive. One has DIR9001 and the other the CS8416. The one with the DIR has only been briefly tested as I am still building it into a case. They are more musical and feel more like the real thing. It is a pity I don't have any WM8740/CS4397 DACs anymore as I get the feeling those were also better than AK4396. Especially the CS4397 is a very good DAC. I am aware that I should put more time and effort in the AK4396 DAC but in this form it was worse than the original AD1981B DAC in my Hifidelio transport which disappointed me as most DACs I built and tried were easily better than the AD1981B. I tested the AK4396 with long cheap lead wires with the bare PCB's just mounted on a aluminium sheet just like I do with all DACs I make. Just to put things inprespective....
FN1242A has the drawback that is has a higher noise floor which is audible but that does not bother me very much. It is just that I know that it shouldn't be like that in 2011
FN1242A has the drawback that is has a higher noise floor which is audible but that does not bother me very much. It is just that I know that it shouldn't be like that in 2011
I wasn't referring to PWs, I do agree they're fine.
I was talking about opamps filter caps and DAC's and receiver's PS decoupling caps.
An externally hosted image should be here but it was not working when we last tested it.
