The ones I made are pretty stable, but cold they does drift. You have to let them warm up for a while before they start to settle in. The drifting gets slower and slower over time as the circuit reach its workingpoint/temparature. Try to let them cook for a while.
Is your PSU stable and regulated? The D1's must be adjusted with the excact final PSU volatege's. Just a little deviation on the rails, calls for a re-adjustment.
Is your PSU stable and regulated? The D1's must be adjusted with the excact final PSU volatege's. Just a little deviation on the rails, calls for a re-adjustment.
Godmorning Steenoe,
Thanks for your answer.
My PSU are textbook LM317/337. The few times I have measured it it have been stable.. I have heatsinks on the LM's so temperature shouldn't be and issue.
I did find that a few more have had similar problems as I do. Actually Spencers description is pretty much the same as I experience..
Also Promethius have the same experience +/-10mV. Taken from his thread..
Steenoe, the temperature drift you talk about is very present! as I move my hand over the circuit, the offset can be as big as 50mV just from the vind of my hand..
Maybe I'm just overly careful.. Or to impatient when letting it warm up.
Thanks for your answer.
My PSU are textbook LM317/337. The few times I have measured it it have been stable.. I have heatsinks on the LM's so temperature shouldn't be and issue.
I did find that a few more have had similar problems as I do. Actually Spencers description is pretty much the same as I experience..
Also Promethius have the same experience +/-10mV. Taken from his thread..
Steenoe, the temperature drift you talk about is very present! as I move my hand over the circuit, the offset can be as big as 50mV just from the vind of my hand..
Maybe I'm just overly careful.. Or to impatient when letting it warm up.
In that case; I suspect that you are good to go then I did notice that the adjustment wanders when fiddling with the pot's.
50mV is not a lot, so just trim as close to zero as possible when the circuit is left alone, with no hands nearby (or breathing on it).
As far as I recall, I let them cook for just over an hour. Anyway, when the circuit is build into a case, it will be protected from windy conditions
I did notice that the adjustment wanders when fiddling with the pot's.50mV is not a lot, so just trim as close to zero as possible when the circuit is left alone, with no hands nearby (or breathing on it).
As far as I recall, I let them cook for just over an hour. Anyway, when the circuit is build into a case, it will be protected from windy conditions
Hehe
Thanks guys for the encouragement!
Steenoe, thats good to hear!
I'll wait an hour, hold my breath, and adjust as close as possible then.
The new parts (2700pf and 10nf) will arrive tomorrow so I'll change those parts, readjust and report back here.
My plan is to connect the D1 to Twistedpairs "buffalo" DAC in balanced mode. The buffalo will be feed by a squeezebox..
Thanks alot guys for your help!
Thanks guys for the encouragement!
Steenoe, thats good to hear!
I'll wait an hour, hold my breath, and adjust as close as possible then.
The new parts (2700pf and 10nf) will arrive tomorrow so I'll change those parts, readjust and report back here.
My plan is to connect the D1 to Twistedpairs "buffalo" DAC in balanced mode. The buffalo will be feed by a squeezebox..
Thanks alot guys for your help!
Thanks for being the pioneer Yunick. I'll be very interested to hear your findings as well, since I have a buffalo module and was planning on connecting it to the D1 I/V as well.
Russ mentions something in another thread about tuning the I/V stage for optimal performance. Please let us know what voltages you settle on.
And just because it's so cold here today
Russ mentions something in another thread about tuning the I/V stage for optimal performance. Please let us know what voltages you settle on.
And just because it's so cold here today
Thanks guys!
I'll report my findings as I go along. Hopefully I can try it all tonight..
I have limited skills in electronics so I may need some help adjusting the circuit to optimal performance with the buffalo.
Twitchie, Do you remeber what Russ said? Could it be that the buffalo have a higher Iout then PCM63, so it's a gain adjustment?
Best Regards
I'll report my findings as I go along. Hopefully I can try it all tonight..
I have limited skills in electronics so I may need some help adjusting the circuit to optimal performance with the buffalo.
Twitchie, Do you remeber what Russ said? Could it be that the buffalo have a higher Iout then PCM63, so it's a gain adjustment?
Best Regards
I did as told and took my time while adjusting.. I let the circuits cook for 1.5-2hours before attempting any adjustments.. One's warmed up, there where no problem adjusting for +/- 0.005V.
After another hour cooking I rechecked everything and it was stable. Connected the D1 to the buffalo, used my CD players S/PDIF and the buffalo showed a lock! Sweet! Hooked it all up and it worked!
Well.. It was only one channel (balanced) at low volume, but it played music. So there is hope!
After another hour cooking I rechecked everything and it was stable.
Connected the D1 to the buffalo, used my CD players S/PDIF and the buffalo showed a lock! Sweet! Hooked it all up and it worked!Well.. It was only one channel (balanced) at low volume, but it played music. So there is hope!
Sorry Yunick, I searched through the day, but I can't find that post again. In any case, I'm glad to hear you have good results
In the post I was trying to find, Russ was talking about the different values he uses in the IVY for the Buffalo and for the OPUS, or maybe it was the COD. If I can find it again, I'll definitely post it.
In the post I was trying to find, Russ was talking about the different values he uses in the IVY for the Buffalo and for the OPUS, or maybe it was the COD. If I can find it again, I'll definitely post it.
Hi,
I have played the D1 for a while now and I have a few question's.
I'm feeding the D1 with the Buffalo from twisteadpearaudio based on the ESS9008 chip. This chip (according to Russ White) is most happy if the input bias of the I/V stage is at 1.65V.
Problem1, I can't reach that far with my D1. When adjusting I reach 0.9-1V.
Problem 2. There seems to be to much gain. I use two D1 as balanced in to UGS moduls. The buffalo is feed by a squeezebox. If the SB is at full volume there is some distortion, if I lower the SB's internal volume the sound is crystal clear. Is there a way to lower the gain of the D1?
Best Regards
David
I have played the D1 for a while now and I have a few question's.
I'm feeding the D1 with the Buffalo from twisteadpearaudio based on the ESS9008 chip. This chip (according to Russ White) is most happy if the input bias of the I/V stage is at 1.65V.
Problem1, I can't reach that far with my D1. When adjusting I reach 0.9-1V.
Problem 2. There seems to be to much gain. I use two D1 as balanced in to UGS moduls. The buffalo is feed by a squeezebox. If the SB is at full volume there is some distortion, if I lower the SB's internal volume the sound is crystal clear. Is there a way to lower the gain of the D1?
Best Regards
David
Hi Yunick.
You must adjust the input to 0V, and leave it there! . It is not input bias you are adjusting, but offset. Offset does result in distortion. ( I am assuming you are trying to adjust the thing you call input bias with the trimpots?)
Regarding the gain, I dont think it is the D1 that has too much gain. One fet in the D1 is the I/V converter, the other is setup as a buffer.
Did you try it with a CD player?
You must adjust the input to 0V, and leave it there! . It is not input bias you are adjusting, but offset. Offset does result in distortion. ( I am assuming you are trying to adjust the thing you call input bias with the trimpots?)
Regarding the gain, I dont think it is the D1 that has too much gain. One fet in the D1 is the I/V converter, the other is setup as a buffer.
Did you try it with a CD player?
Hi Steenoe,
As usual I don't know what I'm doing.
Yes the pots are at 0V or as close as I could get. I'll leave them alone. I tried now after your reply with a CD player, The distortion was still there, but the gain was the same so your right
I'll try and readjust for closer to 0V and hope the distortion goes away.
Btw, What's the input bias?
Thanks for clearing this upp
As usual I don't know what I'm doing.
Yes the pots are at 0V or as close as I could get. I'll leave them alone. I tried now after your reply with a CD player, The distortion was still there, but the gain was the same so your right
I'll try and readjust for closer to 0V and hope the distortion goes away.
Btw, What's the input bias?
Thanks for clearing this upp
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