Hi end DAC kit ebay

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
F

flancfuster

Member
Joined 2009
4xTDA1541A

Hi everyone. I've just got my 4xTDA1541A from raindrop_hui. After installation, I've notice a few things:

1. there is a noticeable hiss on the output of DAC (even without any input signal, or analog output amplification)
2. I can hear some "artifacts(distorted sound like)" on music(specially on classical music in the quieter parts of the music).
I've compared with the output from my CD-Player to check if the recording
was the problem, but it wasn't(these artifacts are missing on my
CD-Player).

Did anyone of the owners of this DAC encountered this issues? Is the hiss normal for this DAC?

Regards
 
dvb projekt

dvb projekt

Member
Joined 2009
Paid Member
flancfuster said:
Hi everyone. I've just got my 4xTDA1541A from raindrop_hui. After installation, I've notice a few things:

1. there is a noticeable hiss on the output of DAC (even without any input signal, or analog output amplification)
2. I can hear some "artifacts(distorted sound like)" on music(specially on classical music in the quieter parts of the music).
I've compared with the output from my CD-Player to check if the recording
was the problem, but it wasn't(these artifacts are missing on my
CD-Player).

Did anyone of the owners of this DAC encountered this issues? Is the hiss normal for this DAC?

Regards
Click to expand...

Hi flancfuster,

please tell a little more, how you connected the DAC (with pictures if possible).
 
F

flancfuster

Member
Joined 2009
dvb-projekt said:
Hi flancfuster,

please tell a little more, how you connected the DAC (with pictures if possible).
Click to expand...

Hi dvb,

I've received from HUI 4xDAC, Tube module and multi-input. The power supply (9V and 18V) is connected as per markings on PCB. I'm using a separated transformer for tube module.
First, I tried using twisted pair cable for SPDIF input and for output connection from DAC to Tube. The hiss (tape like) was there.
After I've changed to coax cable to see if there was something wrong with cables. Same thing, the hiss was there.
I've tried to use the DAC without multi-input module, direct on SPDIF, no change. After that tried using DAC without any output amplification, no change....
Regards.

IMG_02261.jpg
 
F

flancfuster

Member
Joined 2009
jstang said:
I see a missing ground wire on the Tube output. Did you use Rain_drop's transformer?

The wiring on the power supply side is mostly were the noise is coming from.

jk
Click to expand...

Thanks for reply,

I did not use the transformers from Raindrop, I've ordered from a company that makes custom transformers. I've used the raindrop's specs to order the transformers. They have ground wire.
I intend to put everything in a proper chassis and see any improvements.

What do you recommend for wiring? Shielded, twisted, silver?

Regards
 
F

flancfuster

Member
Joined 2009
dvb-projekt said:
I think you should check two things:

1st - are all pins of the 2nd DAC-Board (on top) in the socket of the Main-DAC Board?

2nd- If yes, measure all Voltages at the 4 DAC´s (+5V, -5V, -15V) if they are correct.


Please keep us updated.
Click to expand...

Hi dvb,

1. I've checked 2nd DAC-board, all pins in socket, although without 2nd DAC-Board attached the "artifacs/distortions" are less.
2. Voltages checked. All correct (+5V, -5V and -15V).

Just wanted to ask if your DAC is without any hiss at all(or very low), like let's say a brand CD-Player.

Thanks.
 
J

jstang

Member
Joined 2008
Not related to your hiss....

For the tube output you should try different resistors and a different input/output caps.

I upgraded the resistors ( metal foils ) and caps.... It will take the sound to the next level of detailing.

I also upgraded to S1 chip, bit pricey...but worth it.

jk
 
F

flancfuster

Member
Joined 2009
Thank you all for messages.

Sorry for late reply, I was busy with the holidays:).

Hi dvb,
I've tried the other position on the I2S/SPDIF jumper. There was no output signal after the change, so I've switched back(see photo below)
IMG_02631.jpg
After several tries, I've noticed that I have less "artifacts" and hiss with signal from laptop to usb, so I'm guessing maybe is something wrong with the signal from optical output(cd-transport, cables...). I've tried to connect SPDIF coax directly to DAC, without the multi input module. No change. I'm using Real Cable for optical connection, and coax cable between multi input module and SPDIF in from DAC. CD transport ONKYO Integra DX-6850.
Can you tell me what cables you recommend for SPDIF in to multi input connection?

Hi jstang, do you have the tube output from raindrop? If yes, then what caps did you use for replacement? Thanks
 
dvb projekt

dvb projekt

Member
Joined 2009
Paid Member
This was one step of the complete upgrading of the DAC.

With every OS-Con´s in the powerlines you will make a step forward,
but to be honest in the Input-Stage there is not much difference.

Back to your problem. I think you should send a mail to raindrop_hui, because
he knows his schematics from the I/V-Tubestage best.
I had absolute no problem with my Tube-Stage. ;)


Best regards,
Oliver
 
gabrielbecheanu

gabrielbecheanu

Member
Joined 2006
Hi Oliver
My brother Sorin alias flancfuster put all the boards in a enclosure with proper cable and ground connections. The hum still coming from the tube stage without signal and when we play music especially classic music with low level signal we can hear some unusual noise (like an FM radio station not on the right frequency) and also a lot of hiss. When we stop the music the hiss disappears. The hiss is more perceptible on the SPDIF and Optical connection then USB. We try to connect the SPDIF directly to the DAC bypassing the multi input board with the same results. We use only two TDA, we interchange the DAC s, same result. I think that the input digital stage has a problem but we don’t know where to lok to fix it. I will send this message also to raindrop_hui to see what he think about this problem
If someone knows how to fix it or how to find the problem let us know
Best regards
 
Last edited:
dvb projekt

dvb projekt

Member
Joined 2009
Paid Member
I forgot something!!!!

Did you short the two resistors under each DAC (4x)? They are not necessary :nownow: and definitely wrong in the schematic.

So please have a :magnify: look to the resistors (R41,R42 & R46,R47)


Best regards,
Oliver
 

Attachments

  • IMG_0951.jpg
    IMG_0951.jpg
    252.9 KB · Views: 460
Last edited:
F

flancfuster

Member
Joined 2009
jstang said:
Not related to your hiss....

For the tube output you should try different resistors and a different input/output caps.

I upgraded the resistors ( metal foils ) and caps.... It will take the sound to the next level of detailing.

I also upgraded to S1 chip, bit pricey...but worth it.

jk
Click to expand...

Hi jk,
I see you've upgraded to S1 chip, can you tell me where to get S1 chips? or 1541A chips? I've tried several online parts sellers including "findchips.com"
Thanks.
 
J

jstang

Member
Joined 2008
Some of the tube output board have a .68uf output cap C5 that is polyester... Not the best sounding cap... I have two tube boards from raindrop...one has a larger 1uF output metalized polypropylene, that output has better bass and cleaner highs....


Secondly the input coupling cap C1 is not required for a Current output Dac like the tda1541. Short that cap.

I am also thinking of removing C2.

Last put a film bypass across C4 also.

Metal film resistors will help clean up the sound too...

R Values on my tube board:

R1 120k
R2 1k
R3 51k
R4 350k

I bought my S1 chips from a person that used to work for CD manufacture, NOS chips never used.

You should read Lampizator page index .... lots of good info on tube output....


jk
 
Last edited:
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom