Hello alltogether,
since the Twisted Pear forum isn't really well attended anymore, I try to get some help here. I ran into a problem with a "vintage" Buffalo v 1.2 which still sounds really good. Maybe someone can help me:
My Buffalo 1.2 ist supplied via i2s from a css8416mux. All settings on the Buffalo are set for i2s. The output of the Buffalo goes straight into an IVY v 2.01. The combination plays music when the Mux is fed from the s/pdif in.
But
At my Buffalo 1.2 I measure a voltage offset on one channel when it is connected to the IVY (Out+=1.7V, Out-=0.7V, i2s connected no signal applied) and the same at the output of the IVY. I measure a DC offset of approx. 1V at the SE output. The signal at this output is then significantly quieter. For comparsion: At the other channel I measure Out+ = Out- = 1,56V
Without IVY connected, I get Out+ = Out- = 1.54V at the output of the strange channel.
Even if I connect a Ballsie Lite directly to the output, everything works without DC offset. Accordingly, the level on both channels is the same.
The IVY alone has no DC offset (all inputs on ground). I measure the input resistances In+ -> Ground 3.78 kOhm on both channels and In- -> Ground approx. 20 MOhm. This cannot be the reason for the difference between the channels.
Somehow this seems to be a bug (on the Buffalo?) that only occurs when it is operated as current-out.
I'm a bit at a loss, does anyone know how to help?
Best regards
Flo
since the Twisted Pear forum isn't really well attended anymore, I try to get some help here. I ran into a problem with a "vintage" Buffalo v 1.2 which still sounds really good. Maybe someone can help me:
My Buffalo 1.2 ist supplied via i2s from a css8416mux. All settings on the Buffalo are set for i2s. The output of the Buffalo goes straight into an IVY v 2.01. The combination plays music when the Mux is fed from the s/pdif in.
But
At my Buffalo 1.2 I measure a voltage offset on one channel when it is connected to the IVY (Out+=1.7V, Out-=0.7V, i2s connected no signal applied) and the same at the output of the IVY. I measure a DC offset of approx. 1V at the SE output. The signal at this output is then significantly quieter. For comparsion: At the other channel I measure Out+ = Out- = 1,56V
Without IVY connected, I get Out+ = Out- = 1.54V at the output of the strange channel.
Even if I connect a Ballsie Lite directly to the output, everything works without DC offset. Accordingly, the level on both channels is the same.
The IVY alone has no DC offset (all inputs on ground). I measure the input resistances In+ -> Ground 3.78 kOhm on both channels and In- -> Ground approx. 20 MOhm. This cannot be the reason for the difference between the channels.
Somehow this seems to be a bug (on the Buffalo?) that only occurs when it is operated as current-out.
I'm a bit at a loss, does anyone know how to help?
Best regards
Flo
Sorry that I can’t spend much time to help, but the most likely sources of the problem would seem to be either several of the 8 individual channel volumes in the ESS chip (as opposed to master volume), or the alignment by which the channels are summed for stereo output. It could be a damaged chip, or perhaps a problem with the Buffalo’s firmware program. I would start by refreshing the firmware’s memory.
IMPORTANTLY! Do not use this DAC with any balanced amplification until the offset is cured! You run the risk of immediate speaker damage from direct current sent to the voice coils.
IMPORTANTLY! Do not use this DAC with any balanced amplification until the offset is cured! You run the risk of immediate speaker damage from direct current sent to the voice coils.
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Thank you for the quick answer.
Unfortunately Twisted Pear has not published the firmware of the 1.x versions of the buffalo so there is no way (that I see) to refresh ist.
Don't worry - the preamp where the buffalo resides and the power amt are strictly dc-coupled. When I use the Buffalo in voltage-out mode, there is no offset.
Unfortunately Twisted Pear has not published the firmware of the 1.x versions of the buffalo so there is no way (that I see) to refresh ist.
Don't worry - the preamp where the buffalo resides and the power amt are strictly dc-coupled. When I use the Buffalo in voltage-out mode, there is no offset.
I looked at your post again and it makes me suspect the IVY equally to the Buffalo 1.2. Without needing fresh Buffalo firmware, you could try sending the defective side of the DAC into the opposite side of the IVY. Is the output normal? If so, then you have a good reason to upgrade to the Mercury I/V! 
If not,
If not,