Amp advice for Avantegarde HELP

Hi guy's,

I am entering new and unchartered territory and need some real help. I had been running high powered tube amps into panels (see system) but have recently decided to try the high efficiency side of life. I had really good ideas about what worked well with my Logans but am quite a newbe on the horn thing.

At the moment I have a pair of Avantgarde Duo 2.2's upgraded with Cardas internal wiring in my room. I am using my Aesthetix Callisto signature (which seems to work very well) as a pre into a pair of Nagra VPA's. The Nagra's sound really good but are a little too noisy. I don't think I need 50 watts either. In addition, the gain structure of my system is messed up; I can only crack my preamp volume open about 3-4 notches (for full volume).

Help me with some good choices for amplifiers in the 3-4k used range? I am thinking low wattage SET is probably the way to go but don't really know the differing characteristics between 300B, 845, PX25, etc. I have always run my system balanced; are there any good sounding amps out there that fit the low power mold and are a balanced design? I obviously need something that is quiet. Also, I am not sure about what to look for to correct the gain structure (lower gain amps?, but what numbers?).

Some items on my radar right now are Wavelength Cardinal, Dehavilland 845, Art Audio Diavalo (sp?). Are these good choices? (BTW, I really like the looks/design of the Dehavilland).

Thanks for your help in advance everyone.

Art Audio is a great value on the second hand market here. Joe Fratus is a great guy and continues to support his amps no matter how old they might be. I think this is the best value and quality set amp out there for the dollar.
Get a 2a3 or 45 amp, with your sensitivity you don't need many watts and both of these tubes sound awesome! I love 2a3's but many people seem to prefer 45's. The Art Audio suggestion is a good one, as is Cary, Wavelength, and Audio Note. It sounds like you're about to get started on a fantastic journey, just remember to enjoy it!
Art audio is a good choice. Another you may want to consider is the Audiopax 88. It is a very innovative design using KT88's. Supposedly they are an excellent match with the Avantgardes.
The cost for a used Art Audio PX-25 should be within the ball park. The s/n ratio, the quietness is astounding, as is the fidelity. Rumored to be Art Audio's finest amp. The quietest amp I've ever hear. Perfect on my Duos. With this amp, you can hear every scrap of music as songs fade out into blackness at the end of a cut. Hearing into the music in that manner really adds to the realism of your listening experience. (Lacking this level of quietness, most other amps/systems cannot capture this low level content.) Note, that your preamp, if it is super sensitive, may be contributing to the inablity to turn up the volume.

You'd be surprised that in many cases, AG's do like power. Though the "little" PX-25 works exceptionally well, able to provide both micro and macro dynamics. And they can boogie too.
There is an Air Tight 300B amp for sale right now for $4000. It would be a superb match. I have owned AG's for awhile and used them with Sun Audio 2A3, Fi Super X with 2A3 or 45's, Welborne Apollo's, and now Audio NOte Neiro. You really should go the single ended route.
I had a pair of Uno's. Tried many tube amps. Finally settled on a Pass Aleph 3. I know it sounds crazy, but it sounded incredible.
Forgot to mention per the Art Audio PX-25s. They are available either with a low voltage input or the std input. For your AGs, you want the low voltage input option.
Thanks for all of the input so far. I am wondering, can anyone share experience on the sonic traits of various power tubes? 300B vs. 845 vs. 2a3 etc.? Or, is there more in the design of the amplifier than the tube per se?

Dear Chris,

I suggest looking at the Yamamoto A-08 SET based on the 45 output tube that got a rave review from 6moons. The reviewer has a pair of Duos and the sound is said to be heavenly! Brian of VenusHiFi is the US distributor.

Good luck. Welcome to the world of horn speakers in general and Avantgarde speakers in particular. There is no turning back!
I believe I have the simple solution for your problem. I have been runnung Duo 2.2s partnered with Atmasphere M60s for 5 years now. M60s are 60 watt monblocks (obviously) and I experienced the same noisiness and gain problem that you are. If you pull out the 6SN7 in V2 and replace it with a shorted 6SN7 tube socket that Ralph will make you for a nominal fee, your noise floor will be lowered by 12db and the gain profile on your preamp will benefit accordingly. V2 is the right front 6SN7 as you face the amplifier. ABout $30. and your done. I feelcertain this will solve your problem entirely. Good luck!
Has anyone heard the Dehavilland 845's? These amps seem like they might be a good match with the Avantgardes, but I'm unsure of the 845 tube's sonic signature. Would they be quiet enough?

As for the Atma-Sphere's; how might their sound compare to a single ended design?

Thanks for the feedback so far, it's very helpful.

I heard a pair of Audionote Quest 8W 300B mono SETs with the Avantgarde duos sounding absolutely fabulous - who needs more watts?!
If you can find one, a used Audiopax Stereo 88 is ideal and a synergistic match to the Avantgardes. I've seen Stereo 88s used on Audiogon for $3500 - $4000. 15/15 watts per channel using a KT88 each side in an innovative circuit that models triode behavior from a commodity tube. You need a preamp or source with robust gain to drive it.

The deHavilland 845s are good amps and should be quiet enough for you. Sound is quite tunable depending on which 845 tube you choose to use. The Audion PX25 amp is exceptional, with the Art Audio PX25 close behind and recommended.

PX25 all the way. The original version of the Audion Silver Night PX25 was what convinced me to move away from 300B amps. I have no experience with 2A3 or 45 amps, but I know that I much prefer the Audion PX25 to my Wavelength Triton 300B amps driving Fab Model 1 speakers (97dB dynamics).

If you have the money down the road, though, consider a Tom Evans Linear A. Check out Jeff Day's review of the amp in the archives at 6moons. He has Duos, and my reaction to the amp on my Fabs was identical to his. This is one insanely good amp for SET lovers.
Hello everyone,

I want to thank all of you who answered my thread and have exchanged emails with me to further discuss my ampquest. It was really nice to have input from others who have more experience in SET thing provide some guidance. To make a long story short, I bit the bullet and ordered an Art Audio PX25 from Joe Fratus............. Man, what a nice guy to talk to and deal with.

The amp should be here (or should I say "hear") early in the week. I'll post thoughts on this thread for anyone interested.

Thanks again,

Congrats on a good choice, Chris. From what I've heard, I suspect you are going to love that amp. Let us know.

I am not sure where you reside, but Deja Vu Audio specializes in high efficiency systems! Also, The Cardas upgrade I am not familiar with. However, go to and see what they have. Also, call them and chat with Vu. With your speakers you need between 1 and 10 watts to really appreciate what they can do! I currently run a homemade 1 watt SET on 93db Klipsch speakers. No, I can't rattle windows with it - but I can have instruments and voices delivered to my listening space that makes me smile.

Studio 1
Chris: At this stage, I have 0 advice but instead, a question.
I am moving in a similar direction to you- from Crosby-Quads and ARC tube electronics to an Avantgarde Duo with Audiopax Monoblock tube amplifiers. (I understand that these are quite a good match for the Avantgardes). Here's my question:
I contemplate having to change preamps sooner if not later, because my trusty ARC SP-10 is likely to be too noisy over such an efficient system. I am seriously considering the Aesthetix Janus and would like your impressions, as well as those of others here, on the Aesthetix preamp in this type of system.
I recognize that the relationship between the preamp and amp may be a big variable here, so perhaps the question is not quite valid. But, I'd appreciate your insight, and that of others, on the 'sound' of this preamp with those speakers, and given what I have read about the tube sensitivity of the preamp, what experience you have had in that regard, as well.
(BTW, i like the look of your listening room- nice and airy). Regards, and congrats on your newest purchase.

I had just purchased my Aesthetix Callisto signature when I heard the Duo's. I was a bit worried about the combination as I wasn't seeing too many people use this pre-amp in this kind of system........... to make a long story short; the Callisto has to be one of the quietest preamps there is. It is big (make that HUGE), vivid, and works very well in my system. I don't know if it's smaller siblings are in the same ballpark but I can't imagine they would be too far off. Maybe someone else with more experience in this context can provide additional guidance, but I myself cannot imagine using a different preamp. I don't know if your budget will allow but a Callisto is mighty fine indeed.

Hello everyone (anyone) still tuned into this thread. It's been a couple of weeks now with the Art Audio PX25 and my Duos........... All I can say is WOW. I am loving it. The only drawback so far is I'm exhusted when I go to work from being up so late the night before listening to music.

I would still love to hear a nice 2A3 or 45 amp, just to hear what it is like. Things are a lot different from the Martin Logans and I do miss some aspects of their sound. I guess the trick would be able to afford both.

Thanks again everyone for the amp guidance

Just got my Duos set up this weekend, with the Audiopax 88's.
Right out of the box, even without all the proper cords and cables yet, the combo is amazing. Remember, I am used to Quads, so I also come from the electrostat school- but despite the ability of the Quads to famously render detail and nuance, the horn/amp combo does it quite well, and adds a bigger, much more dynamic stage, realistic listening levels for bigger musical pieces, and a certain 'aliveness' that must have to do with dynamics.
I'm also exhausted, because while the set up was a cinch, I'm now going through my thousands of LPs to listen to stuff I haven't heard in years, and those suckers are heavy!