Sure. The Buffalo is overall more transparent. Instrument tone is clearer. Extension is higher and lower. There is more treble detail and louder, I did not like that at first, not used to full treble power, I like it a little rolled compared to full blast solid state hifi treble. But after I got used to it I don't notice it anymore, which is a good sign that it is natural sounding. Bass volume at lowest frequencies is louder. Bass control is much firmer, more bass detail. Background is absolute dead silent, the Altmann was not as dead quiet, maybe due to battery PS or maybe 2134 opamps. The Buffalo uses 4562 which gives a lot of current and dead silent. The opamp twinge was very apparent before I cut 4 traces as recommended in the instructions. It made the soundstage depth very shallow and dynamics somewhat compressed. After I cut the traces, the DAC was very close to Shane's Oracle DAC1000. Only in direct AB comparison could be hear a difference, and then only on complex audiophile recordings of complex instruments like steel guitar, like Nils Lofgren. Others with enhanced hearing sensitivity said they could here a little more difference. The rest of us dull ears were satified good enough, or didn't hear much difference. On normal music like Sarah Vaughan record no difference could be heard.
A nice thing about the DAC is with such powerful output stage giving such full tone and strong bass, a preamp is not necessary to get the good satisfaction. I keep trying to put Sols Cary 6SN7 preamp in there, I like it at first, but after a while I can't stand it and it's a relief to go back to direct. The DAC has an optional volume control called Volumite which controls the DAC chip's internal digital volume control. Since it is 32 bit DAC, you can get 96dB of attenuation before losing any bits, so CDs don't suffer without a preamp VC. The volume control linearity is not great, it does nothing at the bottom and gets sensitive toward the top where I use it while connected to 26dB amp and 90dB speakers. But it's usable and sounds good, no preamp needed.
I was worried that the Buffalo would be just another OS DAC and waited to sell the Altmann before I could compare. The Buffalo has all of the natural high frequency that I loved about the Altmann, but adds in the power and extension. The Altmann has a bump in the presence region which is typical of the BB2134 opamp. Sol pointed this out to me many times, when I accused his amps of the flaw. It was obvious when compared to the Buffalo. It is part of the Altmann's intense charm. After a couple swaps on a few different records even before I cut the traces I liked it better than the Altmann. Cleaner, more detailed, more powerful, just all around better. I am happy with it. My wife likes the battery back in the garage. I am using a captive power cord that I pulled out of my computer parts box.
I use shit cheap home depot analog cable for digital. Don't ask me why. I hate the whole idea of wires. I suffer the speaker wires, but they make me crazy. The Sabre DAC chip doesn't seem to care. But I have not tried it with different digital cables yet. Even the Sonos which sounded horrible on the Altmann is clean and refined now, with same digital cable. The Sonos has a ugly looking switching power supply half inch away from the digital circuits. Output quality really suffers. But the Sabre chip straightens it out.
I'll be happy to build one for you Chris. I enjoyed building mine over a couple nights. They have a new even quieter power supply option now called Placid. You can try mine for a quickie if you want. It is pure stock with the cheap power supplies.
Rich
