Rolls has it right.
the edge of C11/C12 closest to the Sabre chip carries AVCC. I just tagged a thin wire to C11 on that side and ran it to the Counterpoints, tying them together with another short wire AVCC - AVCC. I checked that C11 and C12 carried exactly the same voltage before doing it this (simpler) way.
Just got my Counterpoint boards installed and listened to a few tracks.
I can hear better separation, transients seem more dynamic. No idea if they are going to improve with time, but a positive step up from the IVY, I do believe.
If I can squeeze just a bit more voltage swing out of these i/v boards, I can do away with a preamp and utilise the Volumite.
Thanks to Brian for the kits (not the glamourous job) and to Russ for the design.
(now, about that voltage...?)
Mark
the edge of C11/C12 closest to the Sabre chip carries AVCC. I just tagged a thin wire to C11 on that side and ran it to the Counterpoints, tying them together with another short wire AVCC - AVCC. I checked that C11 and C12 carried exactly the same voltage before doing it this (simpler) way.
Just got my Counterpoint boards installed and listened to a few tracks.
I can hear better separation, transients seem more dynamic. No idea if they are going to improve with time, but a positive step up from the IVY, I do believe.
If I can squeeze just a bit more voltage swing out of these i/v boards, I can do away with a preamp and utilise the Volumite.
Thanks to Brian for the kits (not the glamourous job) and to Russ for the design.
(now, about that voltage...?)
Mark
Russ White said:
I am glad you got it going.
Adjusting the output swing is pretty simple to do, just increase RG1 and RG2.
Try 357(or soemthing around that) and you will get about 4VRMS. You should be able to go up to about 470R.
Cheers!
Russ
Russ
Thanks for the speedy reply. I'l give it a few days, then swap in a couple of resistors as per your suggestion.
Mark
OT, sorry
Russ/Brian, what's going on at http://www.twistedpearaudio.com
Haven't been able to reach it for the past 3 days.
Russ/Brian, what's going on at http://www.twistedpearaudio.com
Haven't been able to reach it for the past 3 days.
Progress report
Hi Guys,
I got everything singing sweetly yesterday - LCDBP, LCBPS, Buffalo, IVY, TorX. To this I added a robust mains filter and used caps of higher values:
LCDPS & LCBPS -
C3-C4 - 1500 mfd
C5-C6 - 1200 mfd
Added additional bypass to C5 & C6, and at entry points on IVY & Buffalo. 1000pf snubbers on all bridges.
I had been using a Zhaolu 2.5C with output caps shorted. The impressions are based on a comparison of this DAC. Granted, this DAC is not the greatest DAC on earth, but that is the best I can compare with any authority.
After getting the LCDPS & LCBPS working with the right voltage, hooked up the rest, set the DIP switches and connected my laptop. I was happy to see the system come on pleasantly. Right away the most obvious thing I noticed was marked improvement in the image. Zhaolu used to image OK, nothing spectacular, just that there were some integration issues. The image now just seems to integrate nicely, just seems to fit together. Then I started to notice that the Bass had deepened quite a bit. The mids had a new richness, making male voices far more sweeter. The level of details is now much more improved, specially treble. The notes now seem to hang in the air delicately just a tad longer.
A friend of mine remarked how much more clear the sound is. She could not describe things better, except to say the sound is much much better. She wanted me to build her one and said it is not fair that I have the best system
All this with practically nothing on the meter, I just can't wait to see 200-300 hours on it.
Now to figure out what case to get. This time I will also do the AVCC/VRef mod. What's better, a FET driven CCS or LED based as Russ suggests.
Russ, Brian,
Thanks for making such a nice DIY offering.
Carl,
Thanks for selling to me.
For somebody local to Metro DC area, I would love to compare this implementation with other Buffalo implementations just to see if the power supply improvements are actually audible. Come over for an evening, I will throw in drinks and eats too.
Tried to upload an image, but could not. Or else you could have seen the hightect and expensive case it is in. Paid a princely sum of $0.99 for it. I will edit the pic to the right size and upload it later.
Regards,
Dinesh
Hi Guys,
I got everything singing sweetly yesterday
- LCDBP, LCBPS, Buffalo, IVY, TorX. To this I added a robust mains filter and used caps of higher values:LCDPS & LCBPS -
C3-C4 - 1500 mfd
C5-C6 - 1200 mfd
Added additional bypass to C5 & C6, and at entry points on IVY & Buffalo. 1000pf snubbers on all bridges.
I had been using a Zhaolu 2.5C with output caps shorted. The impressions are based on a comparison of this DAC. Granted, this DAC is not the greatest DAC on earth, but that is the best I can compare with any authority.
After getting the LCDPS & LCBPS working with the right voltage, hooked up the rest, set the DIP switches and connected my laptop. I was happy to see the system come on pleasantly. Right away the most obvious thing I noticed was marked improvement in the image. Zhaolu used to image OK, nothing spectacular, just that there were some integration issues. The image now just seems to integrate nicely, just seems to fit together. Then I started to notice that the Bass had deepened quite a bit. The mids had a new richness, making male voices far more sweeter. The level of details is now much more improved, specially treble. The notes now seem to hang in the air delicately just a tad longer.
A friend of mine remarked how much more clear the sound is. She could not describe things better, except to say the sound is much much better. She wanted me to build her one and said it is not fair that I have the best system
All this with practically nothing on the meter, I just can't wait to see 200-300 hours on it.
Now to figure out what case to get. This time I will also do the AVCC/VRef mod. What's better, a FET driven CCS or LED based as Russ suggests.
Russ, Brian,
Thanks for making such a nice DIY offering.
Carl,
Thanks for selling to me.
For somebody local to Metro DC area, I would love to compare this implementation with other Buffalo implementations just to see if the power supply improvements are actually audible. Come over for an evening, I will throw in drinks and eats too.
Tried to upload an image, but could not. Or else you could have seen the hightect and expensive case it is in. Paid a princely sum of $0.99 for it.
I will edit the pic to the right size and upload it later.Regards,
Dinesh
I have got to stop shopping at Twisted Pear
An externally hosted image should be here but it was not working when we last tested it.
Re: Progress report
Hi Dinesh,
I am very glad you are enjoying the DAC.
I have posted the findings below on our forum, and I figured I would share it here as well.
I have found that I get the best distortion measurements and sound out of the IVY when I omit C1-4 and use 1-10nf at C13-16.
Dustin reported similar findings to me early on. I am not sure why it took me so long to try it out for myself. Probably because I was preoccupied.
Some of you may also want to try it for yourselves and report back.
I also found that increasing the output swing helped with DNR. So you may want to try 357R or 392R(anything in that range seems to work very well) at R1-4. This change is not as dramatic as removing the feedback caps, so if you absolutely do not want to increase the output swing stick with 187-221R.
Cheers!
Russ
dviswa said:
Hi Dinesh,
I am very glad you are enjoying the DAC.
I have posted the findings below on our forum, and I figured I would share it here as well.
I have found that I get the best distortion measurements and sound out of the IVY when I omit C1-4 and use 1-10nf at C13-16.
Dustin reported similar findings to me early on. I am not sure why it took me so long to try it out for myself. Probably because I was preoccupied.
Some of you may also want to try it for yourselves and report back.
I also found that increasing the output swing helped with DNR. So you may want to try 357R or 392R(anything in that range seems to work very well) at R1-4. This change is not as dramatic as removing the feedback caps, so if you absolutely do not want to increase the output swing stick with 187-221R.
Cheers!
Russ
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