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

Oh, I should add that the rest of the equipment consists of:
Vinnie Rossi LIO AVC preamp (passive or tube buffer)
Primaluna Dialogue Premium preamp
Analog- VPI Aries 1 + Lyra Etna+ ps audio stellar phono
Digitial- Mac mini, Moon 280d Mind 2
Cabling- Nordost Heimdall II

 

There is an Audion 300B DH/SET "integrated" amp listed on A'Gon now that was previously used with AvantGarde speakers.

It can use 2A3 tubes as well (2A3 and WE 300B tubes are included).

I owned an Audion 300B DH/SET years ago and liked it.

 

DeKay

I have the line magnetic class a  845 ia, have 

Upgraded all the tubes, and every time I listen 

It puts a smile on my face. Best of luck on your 

Journey.

The Avantgarde Duo is magical with the Lamm ML2. There are a few things I did to bring up the bass to the level of the mid-horn, both in terms of quantity and quality. But the Lamm adds an extra dimension to the sound that makes the combination sound more like real instruments, especially on small combo jazz. I have lived with variations on this system for about 15 years in a couple different rooms. The speaker definitely benefits from a large room.

I don’t typically play "audiophile" records-- most are standard issue pressings from back in the day. I had a visitor today for whom I played "I Ain’t Superstitious" from a UK EMI/Columbia first press of Truth. He said it made him want to go home and throw away his copy (probably an Epic). With bass supplementation, you can get the texture and tonality of the bass to play like the mid-horns. The other ingredient for me was a change of cartridge- I had the usual suspects over the years- top line Lyra, Airtight. The Koetsu stone bodies add a level of gravitas and dimension to the bass that I have not heard with other cartridges on this system. So, it is more than just the amp-- but I consider the Lamm a necessary, if not sufficient, element of the combination. The bass was, to me, always the issue with the Duo-- in stock form it either sounds anemic or discontinuous. Now, it is all of a piece. And extremely enjoyable, top to bottom.

PS: Sorry, you won't find the Lamm at 5k, but perhaps double that, used. 

Check my system out at AGon or AA inmate systems. Been using Duos and Atma-sphere M 60s for 20 years. M60s used would definitely fit within the prescribed budget.

I can suggest the Erhard Ray. Listening to it right now. Will come in under way under budget. Dead quiet. Premium transformers. Suggest you wear Depends as you may lose control of bodily functions.

What a cool set of speakers. at 110dB, you need one watt or less in most listening situations.

I have a Tektron (italian maker) Amp that uses 45, 2A3, or 300b and the 45’s are less than 2 watts and more than enough with my 96dB speakers. The 845s are actully way more than you need. Mastersound makes great amps. Sorry this one isn’t doing well.

Decware makes a magical 2 watt amp, the SE84UFO2. You’ll have to find one on the used market since there is a 2 yr wait. If you go on the Decware forum and post that you have an utracool set of speakers that you’d like to listen to with a decware amp, a local owner will likely bring his amp over for a listen. I would.

The new Aric audio 2A3 looks interesting but I haven’t heard it.

Or have an amp custom built. that would be the way to go.

Jerry

SET is the way, in general, but they are made for your speakers. A 2a3 would be a very good combination. I own a company called Apollo Audio Systems that focuses on this topology at the highest standard. Proprietary/domestic/hand wound iron, the finest audio path components in the world, lifetime limited warranty, personal support, ease and low cost of ownership and full customization options to match your other gear, the color of the horns, etc. The list goes on but I will put my gear up against any of the big boys. I have yet to find anything on the planet that will outperform Apollo gear at any discernible level or cost. I'll send you some pics if you're interested. End game gear is what I do and those speakers def deserve more than Line Magnetic or Willsenton. 

 

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.

I have been running Duo’s since 2006 with Atma-Sphere S30 Mk3 OTL stereo amp. The amp is dead quiet and produces a wonderful sound. At ear-splitting levels it wasn’t even showing 1W on the meter.

 

I’ve recently changed to AGD Audions and these are also a terrific match with the Avantgardes. You could also have a look at Atma-Sphere Class D monoblocks which are getting great feedback.

 

I agree with @lubachi that you don’t necessarily need to spend a lot on an amp for these speakers as they are so easy to drive with their high impedance/efficiency.

Oh boy! there is a wealth of information here- I cant thank you enough for all the suggestions.  There's a lot to ponder.  One thing that surprised me is that in some cases we are talking about very low wattage amps and I was always a little concerned that while the speakers are very sensitive as some 100db, the nominal 8Ohms impedance, albeit good, would require a little more power  (that said, the Mastersound Compact 845 is overkill in the other direction).  It sounds like I should reconsider my assumption.

@rocketiii
I have been intrigued by Atma's- at the risk forcing you into worn out cliche's how does the sound these compare to a SET or Audion's.  Good to know they are quiet which brings me to

@lubachi
Hum is one indeed one of my biggest concerns.  The problem is that auditioning is not always easy.  Someone had indeed suggested Sophia electric to me (the 300b mono's) and it sounds like noise is unlikely to be an issue assuming these are as quiet as the MC300 you mention.  I'll look into the Elekit as well- it is interesting you prefer this to the Sophia.
As for the addictive nature of the immediacy of horns it is indeed very hard to go back (though I am still very impressed by the Thiels when I get a chance to hook them up).

@blisshifi
I have heard about Oliver Sayes and seen some of his amps pop up for sale.  And since I live in Westchester and work in NYC this sound very intriguing. How does one get in touch with him?

@jaybarnett 
I had not heard of these.  I'll take a look

@dishawasha 
I have looked at these, but as I mentioned above I simply thought that the DUO's needed a few more watts,  I have to say the Triode Labs look ver impressive in terms of fit and finish.

@antigrunge2  and @acresverde 

Yes, Atma sphere keeps coming up- and I have never tried OTL so I would love to audition (and it would like not to have to deal with 75lbs beast- thus the acceidnt with the Mastersound).

@carlsbad 
Those Decware amps look amazing- not familiar with them and it sounds like I should be.  So really?  I can get away with 2 watts?
Just by everything that has been written so far seems like I was dead wrong about the required wattage- if this is indeed the case this opens a whole new other world of possibilities.

@brandonw 
I would indeed be interested. Please tell me more- email is pgastone@
aol.com.

@corelli 
Another one I was not aware of!  And I thought I was generally well versed in the possible alternatives.

@needfreestuff 
A lot of good press for the LM's- my only concern is that a couple of times I have heard they aren't always super quiet.

@vinylvalet 
Yes, I saw that Audion- thanks for the heads-up.  My budget is $5k but I wouldn't mind going a tad lower if possible.  YTha said, the unit in question has a great reputation- a similar version is listed on the Music Room website.


@dekay 
Wavelength make great products but they are  out of my price range.

So it sounds like
a. I should castt a wider net to include lower powered SETs
b. 300b might not necessarily be the only choice.

There is a seller that has a Mastersound 300b for a little over $4k but then of course there is the shipping and a tube upgrade (they are all stock- they are ok but there is scope to upgrade).  And with everything I have read here I am staring to lean towards exploring some of these great suggestions.

I owned & very much enjoyed first the Uno's purchased in about 2001 & then upgraded to the Duo's in 2003 which I kept for about another 6 years until I decided to try a pretty high end surround sound system based on Dynaudio Contour line of speakers.  I was watching a lot of movies at that time as well as listening to music & only had room for one system.  I know the Avant Gardes pretty well & they are very special & great in many ways. 

I used an Art Audio PX25 SET power amp & an Aesthetix Calypso preamp w/ excellent results w/ a very good Basis table/ arm & a nice Naim CD player. The amp is 5 watts per side & more than enough power to drive the Duo's to loud volumes in a big room & sound great!  It uses a special tube that not many have heard of (the PX25) which has a beautiful midrange & high end & w/ the powered subs of the Duo's, I don't really know about the bass. I think they are now very expensive ($17K) but might be in your price range for a used one? I would suggest that whatever amp you get, try to find one that is fully point to point wired so it can repaired by any good tech w/ a schematic years from now if needed. 

Here's a few thoughts on the Duo's that might help regardless of what amp you wind up with:

1 - They are not easy to set up & get dialed in & expect this to take a while. Distances form boundaries, from each other, from you, toe in angle etc. all can have enormous effects on the sound!

2 - Getting the subs dialed in also takes patience w/ both volume & frequency selections. I sub's amps are very susceptible to hum & ground loops as I don't think the power supplies in them were that great. The original versions of these speakers had different subs which got improved after a few years, not sure which you have & I don't recall what the different sub models were called. I didn't have a power conditioner back then but one might help if this is an issue. 

3 - The stock jumper speaker wires that go to the different drivers aren't great that came w/ the speakers & I had some custom ones made by a wire maker friend of mine that greatly improved the overall sound. I think even a decent wire from Audioquest would help out a lot.

BTW, I have since realizedI can't live w/o horn loaded speakers if I really want to enjoy music that sounds close to live as opposed to good "hifi" sound so I sold my surround sound system & got back into horns & tubes w/ Volti Audio Rivals & a Rogers High Fidelity integrated amp. Both are really good! Still have my Basis turntable set up (new cartridge) & now stream w/ an Innuos Zenith. Music is fun again!!

 

@pgastone Your locale feels really familiar. I used to live in Valhalla and commute into midtown daily until I moved into NYC for 12 years, though I’ve now been in Minnesota for about 5 years. 

I’ll PM you directly on Oliver’s amp as well as more details on mine. 

@pgastone I also used Atma-Sphere S-30 Mk 3.3 with Oris 200 horns with AER drivers. I swapped the Oliver Sayes amp and the Atma interchangeably, and both were excellent. I ended up pouring way more $$ into the Atma, but both were excellent. I would still have them both if I didn’t have to get rid of that system and convert the room for other purposes. 

pgastone:

The amp I mentioned was an Audion amp (under budget if both sets of power tubes test well - no need to upgrade).

DeKay

Thank you again!
@jonwolfpell 
Yes the AG's took ages to get right- particularly in getting the drivers to integrate properly.  And yes the jumpers have been upgraded.

@blisshifi 
Thanks again for all your help- I am now looking at all the options I had never really considered.

I am also having a conversation with a Decware owner and I will definitely contact Oliver Sayes,

Dennis Had designs and builds some astonishingly great sounding SET stuff...I own a 2016 built SEP (Pentode) that's amazingly well made. More recently he's done 300B amps and other stuff, but it's hit or miss when he might list new amps on Ebay...utterly worth finding one. You contact him through Ebay.

SET for sure.

The lower the power, the more the magic.

So, the 45 tube is the way to go.

Yamamoto makes a very good 45 amp. And they are very affordable.

Unless, you get a $5400 pair of the new Atma Class D.

Ralph uses them with his very efficient Class Audio  speakers.

They are very transparent, detailed with great bass.

I like the Duo a lot.  It IS somewhat difficult to set up and get the bass to integrate well with the horns.  I don't think one ever can get great integration, but, there is no speaker system that is perfect in all respects.  While I do think the Duo would work well with a wide range of amps, they are worthy of the best.  There are plenty of good suggestions made above.  Everyone has their own taste, so you need to figure that part out for yourself.  In SET amps, I like 2a3 and 45 tubes myself.   Although power is not really an issue, I think you should also explore some lower-powered pushpull amps.  I like many 6L6 and KT 66 pushpull amps myself.  

While the Duo is extremely dynamic and lively so they don't need "help" in that aspect of their performance, I have heard them with OTL amps and they sounded quite amazing with such amps.  There aren't too many commercial OTL amps out there, but perhaps something from Atmasphere would be worthy of consideration.  I've heard a few of their amps that were a bit noisy with very high efficiency speakers, but, they are still good candidates.