SET amplifier (for AvantGarde Duo's-original) recommendations


Hello all,
I inherited the above speaker and I have been really enjoying them.  I also have a pair of Thiel 3.7s- paired with pass labs xa60.5's (and it works!) which I also love albeit they are very different animals from the DUO's as you can imagine.

Right now I am focusing on the Duo's and have used them both with Pass Labs and a Mastersound Compact 845- both are great but there is something about the DUO's driven by this 845 SET that is magical.   The problem is that the 845 was dropped and developed a hum.  A technician went through it and managed to reduce the hum but it is still there and it bugs me- I am not sure if one of the transformers itself may have been damaged and that isn't really repairable at reasonable cost, though I will speak to Mastersound to hear their thoughts. I should add that the amp used to be dead quiet and generally Masetrsound makes superb amps- and are renown for their transformers.

So I am now starting to think about alternatives solutions- I would like to either stick to a SET of comparable quality (that is known to be relatively quiet with efficient speakers)- maybe a 300b type just for a change, or even an OTL.

There's a lot of stuff out there at the moment, take the Line Magnetics that are floating around (but would they compare to Mastersound in terms of build quality etc?) and I was hoping to get some insights on what you think would work well.  I have read a lot of reviews and while helpful at times I feel they are almost always positive and a little too generic  when comparing similar products.  I'd like to stick to a $5k or so budget (therefore I would look for something used).

pgastone

With the Avantgarde soeakers what really matters is speed. I suggest you llokmat Atmasphere or Wavac. alternatively Ken Shindo’s higher end offering might get you there. No need to bother with Audionote or Kendo

Have you looked at Whammerdyne? I have their DGA-1 (2a3s) driving a pair of Spatial X5s. Obviously the Spatials (open baffle, 97 dB) are very different from the AvantGardes, but wow that Whammer is special ... and absolutely quiet ... and in your price range.

@pgastone I’m a huge fan of SET amps and Avantgarde. What a wonderful direction you’re going in. While 300B are amongst my favorite tube type, I agree with others that speed and resolution are equally important to the bloom that you seek.

In this type of application, my favorite amps are custom built by an engineer out of Brooklyn named Oliver Sayes. I have a Korneff 45 clone from him that uses Hashimoto transformers and upgraded capacitors with Russian PIO, Audience Auricap XO and Mundorf. The amp uses a tube compliment of a pair of EML 45 Mesh, a single 6SN7 where I employed a Shuguang Black Treasure (the only place I’ve ever permanently lived with this tube), and a Philips 5R4GYS rectifier. All in all this build and configuration with tubes can probably be had for less that $3500, with tubes costing almost half that. 

While I didn’t own Avantgarde, I did use this amp with Oris 200 horns using AER drivers and they were lovely. I unfortunately no longer have the horns as we had to repurpose the room for that system for something else, but I still do own the amplifier and now use it as a headphone amp to drive my Audeze LCD-4, and it is killer!

I have AG Trios and have demoed many amplifiers on these high efficiency speakers.  The good news is you do not have to spend a lot of money on amplification to get really excellent sound.

I have two integrated amplifiers that I alternate with as they have rather different sonic attributes. My favorite is the Elekit  TU-8600 with the Lundahl transformers.  Herb Reichert has reviewed these and are in his reference system.  They sell for around $2200. My second amplifier is a Sophia MC-300 A which has a more full sound and bigger image. This amplifier is a little more expensive at $4000.

On the downside, the efficiency of these speakers makes mitigating hum a top priority so be sure to demo before you buy.

Once you become accustomed to the dynamics, both micro and macro, of high efficiency horns you will find it hard to go back to conventional drivers.