Thanks for the hint.
I don't know if there is a simple (and reversible) way to bypass the onboard iv converter on the Buffalo32 and get the + and - DAC output out of the board (Brian and Russ can say this). In this case you could try the transformer out solution with little investment: the Monacor LTR-110 cost 9.2 euro and give a really good sound (to my ears). When i will try the IVY if i like more the Monacor i will invest in some more expensive and better transformer (lundahl LL1690).
Ciao
Andrea
I do not plan to dig in to the Buff32 PCB, I am not that brave. When I used lundahl (there is a great rep here in the states that gives lots of help)trannys for my MC step up device I had hum until I put them in a metal case which was well grounded. My gut feeling that most of the differences that folks are hearing between DACs is how the audio out is handled and Russ and Brian did a great job on the Buff32 audio on board. cant get much simpler that what you are doing and sometimes simple is better.
If you're using it for balanced out, I guess you should ground the secondary CT. Of course this does not apply if you're using unbalanced out (one end is already grounded).
Hi Brian,
i had the time to look at the comparator on my buffalo it has C14A on it.
Is this the faster or slower version?
Thanks
Andrea
With the same source and same toslink receiver i have no problem feeding a chinese DAC with DIR9001 and spdif coax input with the same 96/24 flac files.
When i have time i will see with my scope the signal at the output of my toslink receiver and after the comparator and i will report the results.
Ciao
Andrea
The hint by Brian was in the right direction, the problem was in my toslink receiver, the dir9001 had no problem because it has a larger pll bandwidth.
I changed the 74HCT04 used as buffer and line driver (a "classical" implementation taken from Elektor) with a 74ACT04 and the buffalo lock till 192KHz but strangely not on 88.2 and 176.4.
Then i changed the 'ACT04 with a wire (TORX -> 100nF capacitor and resistors to have 0.5v pp without DC) and i have no problem on all the frequencies.
Ciao
Andrea
Anyone using a Roku SB M1000 with Buffalo/IVY?
I have a weird phenomenon where I get varying levels of DC (all the way to almost 1V) on SE as well as XLR output from my Buffalo/IVY when hooking it up to a Roku. Other sources are fine. I tried switching cables to no avail.
The thing is that the bits are good. The sound is fabulous, so it doesn't seem like the bitstream is corrupted. I have also tried a different Roku unit. Same thing.
Is anyone using Roku Soundbridge with their Buffalo? Has anyone seen this sort of problem? I don't know what this could be...
Puzzled in Altadena...
Peter
I have a weird phenomenon where I get varying levels of DC (all the way to almost 1V) on SE as well as XLR output from my Buffalo/IVY when hooking it up to a Roku. Other sources are fine. I tried switching cables to no avail.
The thing is that the bits are good. The sound is fabulous, so it doesn't seem like the bitstream is corrupted. I have also tried a different Roku unit. Same thing.
Is anyone using Roku Soundbridge with their Buffalo? Has anyone seen this sort of problem? I don't know what this could be...
Puzzled in Altadena...
Peter
Russ and Brian,
I have a Denon VD-1930 that I modded to get the DSD signal. I am getting some serious noise when I plug the Denon in. The system is quiet and then it sounds like a ground hum with static pops when I plug in the Denon. I am ready to scrap the project due to frustration. Any ideas? It looks like the solder joints are clean. It sounds good except for the noise.
I have a Denon VD-1930 that I modded to get the DSD signal. I am getting some serious noise when I plug the Denon in. The system is quiet and then it sounds like a ground hum with static pops when I plug in the Denon. I am ready to scrap the project due to frustration. Any ideas? It looks like the solder joints are clean. It sounds good except for the noise.
I figured it out. I had to add a earth ground to the Denon and it is as quiet as a mouse now.
Peter,
Sometimes DSP people make assumptions about the DACs downstream. One that unfortunately is not all that uncommon is that the DAC will be AC coupled to the output. So the DSP may not be filtering subsonic and DC signals. The Buffalo is DC coupled (unless you add your own caps at the output) so if there is any DC in the digital signal it will happily pass it.
The only suggestion the comes to mind would be that if you plan on using that DSP then install output caps. Otherwise just use a different source.
Cheers!
Russ
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Where to connect earth mains for Buffalo/IVY combo?
Dear Friends,
I may be having a ground problem (not clear, but I need to test hypotheses...). I have the stock Buffalo DAC with the IVY and the two power supplies. They are fed by the same r-core xformer (2x15V and 2x9V respectively). Earth mains is not connected at this time (Yes, I am aware of the safety implications and have taken proper steps).
For starters if I use doubly insulated techniques I should not need earth mains anywhere (and that is my preferred approach). But I have mysterious problems that may have to do with ground potentials between devices. To test this hypothesis I want to engage mains earth. But I am unclear on where the recommended point in thes dual supply Buffalo/IVY combo would be. There doesn't seem to be an obvious star ground... Am I just not looking in the right places?
What sorts of configurations have people experience with? Anyone use doubly insulated technique to avoid any mains earth?
peter
Dear Friends,
I may be having a ground problem (not clear, but I need to test hypotheses...). I have the stock Buffalo DAC with the IVY and the two power supplies. They are fed by the same r-core xformer (2x15V and 2x9V respectively). Earth mains is not connected at this time (Yes, I am aware of the safety implications and have taken proper steps).
For starters if I use doubly insulated techniques I should not need earth mains anywhere (and that is my preferred approach). But I have mysterious problems that may have to do with ground potentials between devices. To test this hypothesis I want to engage mains earth. But I am unclear on where the recommended point in thes dual supply Buffalo/IVY combo would be. There doesn't seem to be an obvious star ground... Am I just not looking in the right places?
What sorts of configurations have people experience with? Anyone use doubly insulated technique to avoid any mains earth?
peter
Typically mains earth would be connected to the chassis. You can connect your various grounds to that as well, but I would do so through a "ground breaker," which is typically something like a pair of diodes connected back to back, so there has to be a couple volts of differential before current will flow through it.
I do not think adding earth ground to this circuit will prevent an existing ground loop, if that is the issue.
If you have you Roku's S/PDIF attached along with it's ground and you suspect a ground issue between the devices, try transformer-isolating them (with a pulse transformer).
I do not think adding earth ground to this circuit will prevent an existing ground loop, if that is the issue.
If you have you Roku's S/PDIF attached along with it's ground and you suspect a ground issue between the devices, try transformer-isolating them (with a pulse transformer).
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