Avantgarde Trios, SETs, and Impedance Curves

The Trio is tricky to set up because the impedance curve is very unusual for a horn- high in the bass and low in the highs, due to the design of the crossover, which is mostly capacitors. A lot of SETs have difficulty with the speaker as a result.

FWIW It is very easy to set up the M-60 to work with the speaker, by using the same technique that the designer used: negative feedback. The speaker is so sensitive that about 6 db of feedback can be employed in the M-60, solving any rolloff issues. This is easy to set up with an external jumper arrangement.

We don't regard the arrangement as ideal, but since the designer's amps used feedback, that's what you have to use. Neither the Duo or the Uno seem to have this requirement.

Why not solid state class A amplification, like Accuphase A-20, 20 class A. You can biamp or triamp the Trio's.

Chris

The problem is that really low output impedance amplifiers don't sound right on highly reactive/high efficiency speakers (like most horns). There are interactions that result in shrillness. So a tube amp is indicated...

I was using my Trios with Audio Note Kageki (really beatiful combination) then with EAR 834T, not as smooth as the Kageki, but no shrill and dynamic like hell then I am using an Altmann BYOB amp with the Trio and my REL Stentor II sub. The most musical combination I have ever heard, period. The battery driven Altmann amp is perfectly quiet absolutely no noise through the speakers at all, which makes all kind of music detailed, rythmic, smooth and flowing, quiteness is an important aspect when the speaker sensitivity is above 108 dB/W/m.

I guess I should check in here more often. I thought my thread was done in September. Thanks to all of you have responded here in November with some really helpful information and suggestions.

Ferenc, your comment on the Altmann amp is truly interesting. You're the first person I've seen report using the Altmann, and that you like it with the Trio tells me you are a man who listens and doesn't give one whit about the cosmetics of your amplification devices. I am also curious about your use of the REL Stentor II sub. I assume you have replaced the AG woofers, is that correct? Are you using one or two RELs? If so, at what frequency are you crossing into the REL? I didn't think the REL was able to go up high enough in frequency to mate with the Trio's lower mid horn.

711 smilin, the Mactone sounds very interesting as well, but given the inability to audition one with the Trios along with their cost, it probably isn't going to happen.

Atmasphere, it seems to me that you are saying that neither SETs nor solid state amps work properly with the AG Trios due to the Capacitors in the crossovers. Don't most speakers with crossovers use capacitors? Your comments seem to conflict with all the results of others who report very fine results with SETs and now Ferenc stating he is getting fabulous results with the Altmann amp, which to my knowledge (correct me if I am wrong) doesn't use any feedback just like most of the SETs that others have found favor with. Yet you claim that an amplifier with feedback is required in order to achieve proper results. It does make one wonder.