I added a list of the components the DAC uses to the main page of the wiki.
I've been running mine through and Audio-GD Earth discrete op-amp but would like to try transformer output. I also plan to upgrade the power supply.
Just a quick question, has anyone tried replacing the clock on the upsampling board with an aftermarket model yet? I'd be curious to know if much/any improvement can be heard.
Cheers.
I've been running mine through and Audio-GD Earth discrete op-amp but would like to try transformer output. I also plan to upgrade the power supply.
Just a quick question, has anyone tried replacing the clock on the upsampling board with an aftermarket model yet? I'd be curious to know if much/any improvement can be heard.
Cheers.
Results with PCM1798 and damn server!
God damn server! I lost my post!
Well, I'll make it short this time.
First of all I want to thank Legarem for his precious help.
When I received the PCM1798 adaptor, I wanted to try first my UTC A-20 transformers but they had to be connected in the good way for that current output DAC: 50 Ohms at the primary an 500 Omhs at the seconday. That makes about a 1:3 ratio. Legarem suggested me different configurations and finally the option with a 100R at each output of the DAC to the ground gave good sonic results.
Few hours and I will be able to make comparisons with the CS4398.
God damn server! I lost my post!
Well, I'll make it short this time.
First of all I want to thank Legarem for his precious help.
When I received the PCM1798 adaptor, I wanted to try first my UTC A-20 transformers but they had to be connected in the good way for that current output DAC: 50 Ohms at the primary an 500 Omhs at the seconday. That makes about a 1:3 ratio. Legarem suggested me different configurations and finally the option with a 100R at each output of the DAC to the ground gave good sonic results.
Few hours and I will be able to make comparisons with the CS4398.
I'll wait to get your results about sound quallity with the PCM1798.
At least current output dacs don't have crappy op amps in their outputs like voltage output dacs.
I abandonned the CS4398 dac and now use a Behringer SRC2496 ultra modified with an output stage made of course.... with transformers.
It beated the chinese dac all the way. I suppose that the AKM dac chip (AK4396) which replaced the stock AK4393 in the Behringer is really a great dac. As I bought two of these dac chips, the remaining one will perhaps be used with a special board to adapt it to the chinese dac to replace the CS4398. Big project !
That is direct to RXP0 and RXN,and yes it works,but don´t yet know if it is an improvement or not..
BILL FUSS:Thanks for the scematic.
The other cap that I was talking about is C57 at RXN,and it is bypassed now as I connected the trafo direct to the CS8416.
I would leave the cap to ground on RXN, I'm sure it's needed to use the other inputs. You can still wire the trafo direct to RX0 and RXN.
PCM1798: good, very good...
Hi guys,
After 10 hours of "warming up" leading to a serious listening session, I can say that converter with the PCM1798 module (outputs directly to transformers) represents a step over the CS4398. The sound is "richer" and "warmer". More analog I should say. Some new informations in the soundstage bring a nice touch of realism to the music (for exemple, a recording of choir in a cathedral gives now plenty of echoes).
However the UTC A-20 is not quite the right transformer for the job in that current mode application: I had to crank up the volume to obtain an adequate level especially with some recordings. Maybe the PCM1794 could be an alternative because it has twice the output of the 1798 but I don't know their sonic differences. Considering the results at 1:3 ratio with the A-20 (50 Ohms prim/500 Ohms sec) I will look for a higher gain transformer.
The PCM1798 adaptor cost me 25$. It needs a little "clean-up" before wiring the trafos so I removed the two opamps under the board and all the parts in the signal path: resistors and Vima caps. After I put one 100R linked to the ground at each output and finally wired the outputs to the 50 Ohms taps of transformers.
Worth the try.
Pierre G.
Hi guys,
After 10 hours of "warming up" leading to a serious listening session, I can say that converter with the PCM1798 module (outputs directly to transformers) represents a step over the CS4398. The sound is "richer" and "warmer". More analog I should say. Some new informations in the soundstage bring a nice touch of realism to the music (for exemple, a recording of choir in a cathedral gives now plenty of echoes).
However the UTC A-20 is not quite the right transformer for the job in that current mode application: I had to crank up the volume to obtain an adequate level especially with some recordings. Maybe the PCM1794 could be an alternative because it has twice the output of the 1798 but I don't know their sonic differences. Considering the results at 1:3 ratio with the A-20 (50 Ohms prim/500 Ohms sec) I will look for a higher gain transformer.
The PCM1798 adaptor cost me 25$. It needs a little "clean-up" before wiring the trafos so I removed the two opamps under the board and all the parts in the signal path: resistors and Vima caps. After I put one 100R linked to the ground at each output and finally wired the outputs to the 50 Ohms taps of transformers.
Worth the try.
Pierre G.
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You can get the adaptor from two sellers on eBay (that I know):
eBay Store - gigawork shop: Amplifier Kits, Component, DAC Kits and
eBay Seller: snow48 6: Electronics items on eBay.com
I asked the question because it was not listed.
Headphone output
Hello,
I would like a headphone output to this DAC, for a Sennheiser HD600, 300ohms.
I could not yet find another kit with headphone output and same characteristics (CS4398 and 192kHz upsampling).
I'm complete novice, but it looks like to me that the NE5532 (or replaced by OPA627AU)
could be adapted to the required tension and impedance.
And a DACT stepped attenuator to control the output volume.
Do you think it is possible to simply adapt to a headphone ? (without destroying it).
Will the sound still be good ?
Or is a dedicated headphone amplifier necessary ?
Thanks,
Raiatea
Hello,
I would like a headphone output to this DAC, for a Sennheiser HD600, 300ohms.
I could not yet find another kit with headphone output and same characteristics (CS4398 and 192kHz upsampling).
I'm complete novice, but it looks like to me that the NE5532 (or replaced by OPA627AU)
could be adapted to the required tension and impedance.
And a DACT stepped attenuator to control the output volume.
Do you think it is possible to simply adapt to a headphone ? (without destroying it).
Will the sound still be good ?
Or is a dedicated headphone amplifier necessary ?
Thanks,
Raiatea
Hi Raiatea,
I connected an headphone to the RCA jacks with an adapter.
It works but the output level is low, it apparently needs a preamplifier.
I connected an headphone to the RCA jacks with an adapter.
It works but the output level is low, it apparently needs a preamplifier.
I cracked, and replaced the 1000uf Elna RJB's in the PS section with 1800uf Panasonic FC's 🙄
Result?
A small but noticeable improvement in weight, and definition 😀
Result?
A small but noticeable improvement in weight, and definition 😀
If I'm using only Optical input and no usb, do I still need power for both 12v and 8v, or just 8v?
Anybody got any of the Edcors lying around they're not using?😉
Anybody got any of the Edcors lying around they're not using?😉
Any pictures of this PCM1798 module/adaptor crazyfrog?
Is this a direct replacement over the CS chip?
See the attached file. You can put it directly instead of the CS4398 module on the converter board.
How about the caps and resistors is it necessary or not....I heard that you don't use it....am I right...?
Soldering tssop....hmmm newer done it before....😕