phase: the "L" shape in green color are both RR14&LR10 in signal path(100R) you are looking for. please share more details of better resistors.
i don't have a scope and don't even know how to use it.
Orange circule color is the RC3 in opamp feedback path, installed a socket for the mica cap 220p.
- removed the C6 (104) film capacitors next to clock, i guess the oscon has enough low esr.
or i may try put CP0/X7R SMDs if i can get some of it.
- replaced the R5 (110R) for dale, no idea which series it is, original come with bejing718factory 1%.
- installed socket(in blue circule) for TU1 and TU3, may try some mkp or kp series and see what it will sound.
I will let the R5 run in then i will try the mica capacitor. I want to try the low impedence resistor from vishay s102 for R2, R5, LR4&8, RR4 and RR8 (feedback resistor and coxial input), any better/cheaper suggestions?
The s102 aren't cheap(lots $$$)...after i replaced parts, i can immediately heard the difference.
i will just let it run 24hrs for a few days with low volume.
test fitting for u860 diodes, it looks doesn't fit very well.
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So you have removed the 104 from the clock, was it in parallel with the oscon?
Thank you for the diagram, I will let you know if there is any difference that would be worth the money spent.
Those film resistors are expensive. The ones I had were Caddock mp930, probably will need some time, like nearly any other change.
What type of mica capacitors are you using?
Thank you for the diagram, I will let you know if there is any difference that would be worth the money spent.
Those film resistors are expensive. The ones I had were Caddock mp930, probably will need some time, like nearly any other change.
What type of mica capacitors are you using?
TE7022L info
Hi,
I too want to use the minishow0328 TE7022 USB module / board as a standalone USB to S/PDIF interface dev board.
minishow0328 has generally been helpful but hasn't been able to help with my problem - then again the guy's a vendor selling with small margins, there is no reason he should help with such unintended use of the board.
Dr.M, did you have any luck?
Mine is connected, I'm powering by supplying +8V DC to pin 4 (Pins 5&6 are ground; the USB interface goes to pins 1,2,3).
The PC recognises a USB connection but says it is faulty and seems not to have loaded the driver, which is installed on the PC. I'm wondering if this is due to absent signals that would normally come from the DAC mobo?
Hi,
I too want to use the minishow0328 TE7022 USB module / board as a standalone USB to S/PDIF interface dev board.
minishow0328 has generally been helpful but hasn't been able to help with my problem - then again the guy's a vendor selling with small margins, there is no reason he should help with such unintended use of the board.
Dr.M, did you have any luck?
Mine is connected, I'm powering by supplying +8V DC to pin 4 (Pins 5&6 are ground; the USB interface goes to pins 1,2,3).
The PC recognises a USB connection but says it is faulty and seems not to have loaded the driver, which is installed on the PC. I'm wondering if this is due to absent signals that would normally come from the DAC mobo?
Please let us know how is your the caddock(mp930) doing.
Yes. 104 film. Parallel with the oscon(upright position) on right hand side, just above the XO.
This is the mica i'm using for last 2 weeks. Treble has extend further and more transparency. I may pick up some philips silver mica and try later.
After various mod, bass and treble has extend, however i find out 3 negs:
1. mids now become very dull & thin(e.g. paino solo).
2. the 317/337 regulator output is almost 17v, i had a 16v 100uf as output capacitor.
3. the pcb has tons of plating through hole, some capacitors are way too far from regulator
Done something:
removed the 104 smd from pcb for 8805 digital supply underneath, which is connect together with oscon.
Yes. 104 film. Parallel with the oscon(upright position) on right hand side, just above the XO.
This is the mica i'm using for last 2 weeks. Treble has extend further and more transparency. I may pick up some philips silver mica and try later.
After various mod, bass and treble has extend, however i find out 3 negs:
1. mids now become very dull & thin(e.g. paino solo).
2. the 317/337 regulator output is almost 17v, i had a 16v 100uf as output capacitor.
3. the pcb has tons of plating through hole, some capacitors are way too far from regulator
Done something:
removed the 104 smd from pcb for 8805 digital supply underneath, which is connect together with oscon.
TE7022L Basic data sheet
---------------------
TE7022L pinouts and basic data are linked from manufacturer's website here:
TE7022L - GFEC
Since my last post by co-incidence within 5 minutes I got another email from minishow0328 [that's an eBay handle by the way and I can vouch he is a very good eBayer with good English].. I now have schematics for the USB interface daughter card. Won't post them here as they are someone else's work -but I think it's fair use to give the CONA pinouts for the daughter board:
_Pin________Funct___
01 USB Vbus
02 USB DM
03 USB DP
04 D8V (8V dc in from DAC)
05 GND
06 GND
07 LRCK2
08 DATA2
09 BCK2
10 SCK2
I assume pins 7 through 10 are the I/\2S interface to the DAC.
The TE7022L SPDIF pins do not go anywhere on this little board except of course for the pads on the IC outline, but it should be possible to connect to them with a couple of bits of kynar wire. So far I haven't done anything about that as getting the USB endpoints established first seems the logical way to proceed.
If anyone else here has tried this, I'd love to know how you got on...
---------------------
TE7022L pinouts and basic data are linked from manufacturer's website here:
TE7022L - GFEC
Since my last post by co-incidence within 5 minutes I got another email from minishow0328 [that's an eBay handle by the way and I can vouch he is a very good eBayer with good English].. I now have schematics for the USB interface daughter card. Won't post them here as they are someone else's work -but I think it's fair use to give the CONA pinouts for the daughter board:
_Pin________Funct___
01 USB Vbus
02 USB DM
03 USB DP
04 D8V (8V dc in from DAC)
05 GND
06 GND
07 LRCK2
08 DATA2
09 BCK2
10 SCK2
I assume pins 7 through 10 are the I/\2S interface to the DAC.
The TE7022L SPDIF pins do not go anywhere on this little board except of course for the pads on the IC outline, but it should be possible to connect to them with a couple of bits of kynar wire. So far I haven't done anything about that as getting the USB endpoints established first seems the logical way to proceed.
If anyone else here has tried this, I'd love to know how you got on...
DAC7 Weiliang noise with 192khz 24 bit signal
Hi.
I would ask to Mr. Weiliang how to solve a problem discovered with my DAC7 unit. I have bought 2 units of this dac (equipped with CM6631 usb module) from Minishow seller. The unit works fine but I have a problem with the CM6631 when I try to play wave files at 192khz 24 bit. The unit works but several times is possible to hear scratches noise. These noises are not preriodic and are not dipendig on level of digital signal. I think there is a problem between the unit and the computer (TOSHIBA TECRA and WINDOWS7 64 bits but with other Pcs tested the resault is the same) and someone told me that the problem could be in driver or (more probably) in the firmware.
Do you have a solution (maybe a specific firmware and a guideline to install it) to fix this problem?
It's a pity to have a DAC that works at 90% ...
Waiting for an answer. Thank you in advance.
R. Marin.
P.S. my email: roberto.marin@mail.wind.it
Hi.
I would ask to Mr. Weiliang how to solve a problem discovered with my DAC7 unit. I have bought 2 units of this dac (equipped with CM6631 usb module) from Minishow seller. The unit works fine but I have a problem with the CM6631 when I try to play wave files at 192khz 24 bit. The unit works but several times is possible to hear scratches noise. These noises are not preriodic and are not dipendig on level of digital signal. I think there is a problem between the unit and the computer (TOSHIBA TECRA and WINDOWS7 64 bits but with other Pcs tested the resault is the same) and someone told me that the problem could be in driver or (more probably) in the firmware.
Do you have a solution (maybe a specific firmware and a guideline to install it) to fix this problem?
It's a pity to have a DAC that works at 90% ...
Waiting for an answer. Thank you in advance.
R. Marin.
P.S. my email: roberto.marin@mail.wind.it
phase, yes, the mica's had burn in. love them.
which series of caddock do you prefere?
Brought some more mica's (CDM and philips), some RN55c resistor for signal line, some philips MKP418 and a new toroidal , see how they preform.
I've heard the CM6631a has less scratches noise. Some say using newer asus firmware will solve the problem(read in a taiwan forum). I use cm6631a too.
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Glad to hear things are working there. I haven't used any other Caddocks than the 930 ones, but I want to try the thin film variety next.
I also just purchased another transformer, a toroidal one as well. My headphone amplifier burned out the one I had in it. While I am waiting for the package to arrive, I replaced the small wima capacitors in the headphone amp with some of the ERO 1837 I had. It sounds better already just using the laptop earphone jack as a source! Those things really work.
Considering a discrete op amp for the buffer next, maybe...
I also just purchased another transformer, a toroidal one as well. My headphone amplifier burned out the one I had in it. While I am waiting for the package to arrive, I replaced the small wima capacitors in the headphone amp with some of the ERO 1837 I had. It sounds better already just using the laptop earphone jack as a source! Those things really work.
Considering a discrete op amp for the buffer next, maybe...
I did try the wima, don't like it too. i drop a pair of op627 to replace the old 49720 few months ago, wasn't my preference, then went back to 49720.
Last week i try with the op627 again and replace the tl072 with 49720, what a huge different. love this setup.
will try the mkps' and few micas then i will finally assemble in the box. brought more components today , with a RA audio resistor, will try on the coax input section. i know circuit schematic is most important, but sometimes some good components will make a difference.
i try the op627 on tl072 with 49720, suprisingly i got oscillation in R channel.
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power supply caps
I removed all the 100nf bypass capacitors and the all the cheap round 100uf's.
Once you remove the bypass it enables you to use 3 of the 5mm holes for much better larger caps and the other 3 are a much smaller 2mm spacing. I ended up using what I had. My next mod will be to change the digital decoupling (currently silmac ll) 2mm spacing with Nichicon LF, one is laying down and the other is by the reg.
How does it sound?
Imho the dac5 was always lacking in the low end which if very abnormal for the Wolfson chips, the top end was gritty and seemed to be raised .Now after removing and replacing these caps the frequency response has levelled out. It has more of that beautiful low end grunt and a much flatter natural top end. There is more air and spacing between instruments. I am amazed at how much the power supply has changed the sound. The original caps are not doing anyone any favours. Especially the bypass 100nf.
Enjoy
I removed all the 100nf bypass capacitors and the all the cheap round 100uf's.
Once you remove the bypass it enables you to use 3 of the 5mm holes for much better larger caps and the other 3 are a much smaller 2mm spacing. I ended up using what I had. My next mod will be to change the digital decoupling (currently silmac ll) 2mm spacing with Nichicon LF, one is laying down and the other is by the reg.
How does it sound?
Imho the dac5 was always lacking in the low end which if very abnormal for the Wolfson chips, the top end was gritty and seemed to be raised .Now after removing and replacing these caps the frequency response has levelled out. It has more of that beautiful low end grunt and a much flatter natural top end. There is more air and spacing between instruments. I am amazed at how much the power supply has changed the sound. The original caps are not doing anyone any favours. Especially the bypass 100nf.
Enjoy
Attachments
The most noticeable change really was from the 100nf caps, cost a about $7,replacing them made the opa627 able to be heard. I have an opa2134 coming to replace the tl072, should be here by now actually.
Nice to have it sorted out ill bet, it has been fun sprinkling a few dollars onto a great design and hear it come to life. I did spot some Aerovox capacitors at a surplus site however, but is hard to justify replacing the Samwhas so soon.
I'm now replacing my shady fusing to be safer and more reliable now that I'm about to let it rest for now. I had both the dac and headphone amp running off the same set of fuses, not the best by any means.
Happy listening...
Nice to have it sorted out ill bet, it has been fun sprinkling a few dollars onto a great design and hear it come to life. I did spot some Aerovox capacitors at a surplus site however, but is hard to justify replacing the Samwhas so soon.
I'm now replacing my shady fusing to be safer and more reliable now that I'm about to let it rest for now. I had both the dac and headphone amp running off the same set of fuses, not the best by any means.
Happy listening...
Phase,
I am not referring to any part of the op-amp circuit. Only the power supplies for all the wm8805-wm8741 and clock. I have completely bypassed the op amps with a tube amp. The lager caps bring in the low end bass and removing the 1nf bypasses on the decoupling caps (primarily) levels out the top end.
I am not referring to any part of the op-amp circuit. Only the power supplies for all the wm8805-wm8741 and clock. I have completely bypassed the op amps with a tube amp. The lager caps bring in the low end bass and removing the 1nf bypasses on the decoupling caps (primarily) levels out the top end.
I had some Samwhas come with v1.7/1.9, that was horrible(guess due to minimal cost)
replaced with a nichicon(unknown series) at very begining ( come with v1.3 labels were buried, markings were all fade out not sure if fake, but maybe old stock).
Got tired try to get better mids, replaced with a bigger & better nichicon kg . I agreed that main capacitor makes a significant different. Before the mids were dull, percussions were appear in front of the volina . now they locate where they should be.
Here is what done recently.
replaced with a nichicon(unknown series) at very begining ( come with v1.3 labels were buried, markings were all fade out not sure if fake, but maybe old stock).
Got tired try to get better mids, replaced with a bigger & better nichicon kg . I agreed that main capacitor makes a significant different. Before the mids were dull, percussions were appear in front of the volina
. now they locate where they should be.Here is what done recently.
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I haven't found many caps that will fit where the large ones are, most are 30mm at least.
Maybe I should just get the aerovox...
I have heard that the crossing frequencies don't always sound natural when bypassing, maybe Ill try taking a couple out the next time I'm in there. I do like how more room is created by removing the small ones to make way for some decent parts.
The os-cons sound very good on the clock, and on the dac chip also.
I think it would be very cool if better parts were offered from the start, with some specs to back it up, would save on shipping charges. But it wouldn't be nearly as much fun however.
Maybe I should just get the aerovox...
I have heard that the crossing frequencies don't always sound natural when bypassing, maybe Ill try taking a couple out the next time I'm in there. I do like how more room is created by removing the small ones to make way for some decent parts.
The os-cons sound very good on the clock, and on the dac chip also.
I think it would be very cool if better parts were offered from the start, with some specs to back it up, would save on shipping charges. But it wouldn't be nearly as much fun however.
philips do have a few 40v capacitors that fit on this board.
New components finally arrived, testing right now