Altmann BYOB amp

[richidoo]

Got one used from Australia last week, been tinkering with it. Man it sounds awesome. I have never heard an amp sound like this. Despite the 12V battery power supply, the amp has more than enough volume gain and has built in volume control pot. Bass is stunningly fast and powerful. High freq is not quite as extended as the snappers, but plenty good enough, break in is supposed to improve HF response a lot. This amp only has a few hours on it before its intended project was abandoned. I will be experimenting with it to see if I can live with it as main amp, but my first attempt to insert it into the system failed. Putting the minimax between it and the DAC sounds like crap, thin and wimpy, so there are some impedance issues there. Altmann warned me about putting preamp between DAC and amp. The DAC has a monster output stage to drive the amp, so maybe that is the only way it sounds good, I dunno.... Also may have to biamp the speakers to keep the little chip's temperature under control with the Legacys 2ohm load in the bass. Great sound though. I encourage anyone to consider trying it on 4ohm speakers and up. Rated 20wpc at 4ohms, about 750 euros new.
Rich

[richidoo]

After a few days of playing it I heard some yukkies that I never heard before on this brass quartet recording. I thought I had played it too loud and fried the little amp. I recharged battery, swapped in another battery, added more heatsinking, no change. I kept using the same recording that first showed the distortion, thinking it was clean. Turns out that recording has digital clipping that I never noticed before, and playing on the BYOB showed it plain as day. Once I ditched that record, all is well. To his credit, Charles Altmann played along and provided good tech support while I chased my own tail.

Leave it to me to find something wrong when there is nothing. The amp sounds great, plays loud and clear, great bass, detail, harmonics dynamics. Good match for the Altmann DAC.
Rich

[rollo]

Sounds like one neutral son of a gun. As I always say garbage in garbage out. Bad recordings just suck . There is no excuse IMO. There was something wrong all right. The Engineer or processing plant. Maybe both.

rollo

[miklorsmith]

Hey Rich, after you've found a new toy to play with for a while, that Altmann amp would be real cozy over here for a bit!   

[richidoo]

rollo, the factory can't put overs on the disc, and the mastering engineer most definitely heard them and told the producer. He already had his money on the table so he threw the dice anyway. DG pulled it within a couple years, and now ArkiveMusiK is reprinting it to CD-R under license as part of their "bring back the lost classics" program. It is a great performance, real shame he didn't watch the levels. With digital you can leave 20dB headroom and normalize it later. There is no excuse for digital overs unless the person was still thinking analog tape and was unqualified to do the session. It happens. I wonder if there is a software plugin that can clean it up, like Soap.

Mike, definitely!