10k 300B single ended amp, what should I choose?

Hey Linkoping,

Have you considered going after the Art Audio Adagio monoblocks being auctioned here right now?

The Adagio are the most powerful amps AA makes. Depending on the output tubes used, they are 40 or 60 wpc. The bass output is supposed to be stunning. Don't know aboutt he rest of the audio spectrum.

They are currently at $7,400 with 2 days left. Maybe you could lucky and get them for $10k, though biamping with a PX-25 on mids/highs and your 845's on bass is probably the best of all worlds.

Hi Linkoping,

It's great to hear you've already used a Jota because it is very hard to describe how AA amps.

You might want to talk to Joe about their high powered Jota which uses the KR52BX tube. It puts out 40-50% more current than the Jota you used. That might be enough to handle big orchestral works that you like.

If not, you can always have Joe make you Jota 300B monoblocks.

After that, I don't think there are many other 300B amps under $10k that have greater drive. No wonder you have that parallel 845 amp!

I suppose you are considering bi-amping with the PX-25 for mids/highs and your Matersound 845 on the woofers?

Have a close look and listen at the Tron 300B Jubilate (www.tron-electric.com) distributed in the US by Highwater Sound. Tron is a tiny UK based manufacturer; the amps are designed and made by Graham Tricker, who is rated as one of the world's best valve amp designers. All his amps are made to order by him and no-one else. I have his Tron Meteor preamp (new model is the Syren, which has had rave reviews) , which is Very Very good. I'm looking to buy some 300Bs as well. Just beware that many 'new' PX25 amps use 'new' PX25 valves, which are more like modern 300Bs than the original M-O PX25 valves. More importantly many modern PX25 amps have modern valve bases and will not accept NOS M-O PX25 valves, which sound stunning.

Kevin & Darkmoebius,
Thanks for the recommendation. I'm actually thinking about the PX25 as well. In the past, I owned the wonderful Jota BX with KR300BLX tubes. Sure, this is a wonderful amp, however I found lack of dynamic when playing big orchestra. The high/mid on this beauty is wonderful, but the bass is not enough for my orchestra piece.
The SAP speakers I have is actually a J2001 mkII, new model which better woofer than the original J2001. The new specs for the mkII is 97db, not 102db.

I also have 97dB fullrange speakers , Cain & Cain IM-Bens.

I've got Welborne DRD 300B monoblocks and the above mentioned 6 wpc Art Audio PX-25. The PX-25 is a far superior amp in term of drive, tonal richness/density, control, finesse, detail, soundstaging, depth, etc. Of course, it should be at 3x the price.

The PX-25's power supply is phenominal and provides massive amounts of current for complex passages. It really performs like something 5x the power. It seems like I have never gotten close to running out of steam. I'm not talking sheer volume, any amp can get the Bens to painful levels - in terms of grip and control of music. Although, my speakers have Fostex FE-E Sigma 168 6.5" fullrange single drivers.

Having said that....

Large scale classical/orchestra pieces really make unusual demands on any amp. You SAP speakers have that big 12" woofer and you have gotten used to the drive/reserve power of a 40 wpc parallel 845 amp. I'm not sure the PX is going equal that kind of power. It may outshine the Mastersound in all the other important sonic traits, but in sheer power - I dunno. (possible, though)

My guess would be the Art Audio 300B amps - Diavolvo(13 wpc), Jota(20 wpc), or high power Jota (30wpc and 40% more current drive) would be more comparable.

I talked to Joe fratus, the owner of Art Audio, about exactly this before getting the PX-25 and he told me that PX is his favorite amp for overall sound (he has the same speakers as I do) and the amp he uses at home even though he has far more expensive models. His advice was to go with the PX first and if I found that didn't have enough drive, then go to the Diavolo.

I would definetly call Joe and get his input. He's very, very, easy going and knowledgable. Loves to talk audio and isn't the type to try and force his most expensive product(or any) on you. His office # (401)825-8626. If he's not there, they are usually at the assembly shop (401)265-6765.

Art Audio

Be sure to read the reviews section.

BTW, are your speakers really only 97dB?

SAP J2001

The 12" woofers are 99dB, the mids 102dB, and tweets 105dB. I guess there's some efficiency loss for the crossover, but it seems to me those puppies should be around 99/100dB.

Hope some of this is of help.

Not that I'm trying to change your mind on getting a 300B amp . . . but have you considered a SET amp that uses the PX25 tube from Art Audio or Audion? I too was thinking 300B, did some listening and finally spoke with Joe Fratus who is the owner of Art Audio on USA as he makes/sells both the 300B and PX25 amps. In his opinion the PX25 amp was the better of the two so I bought it and have been extrememly happy with it. It is a very strong sounding 6watts/ch. but with my 97dB efficient speakers and high gain preamp I can only turn the volume up a few notches before getting too loud for the wife.

Give Joe a call - he's a great person to chat with and not pushy at all. Very customer focused. And the price of the Art Audio PX25 is US$6,500 so it's within your $10K budget with bucks to spare for music presumably . . .

Kevin

Thanks for the suggestion. I'm thinking bi-amp using the Mastersound for the bass and some 300B for the mid and high. I never knew about jeffery but will sure give it a try.

Indeed, you'll need a very hefty 300B to reproduce large orchestral works with ease especially if you want one amp to drive the spkrs full-range (I would suggest you use another amp for the bass).
DIYing is an excellent option, as suggested above. Also check out a refined classic designed at goodsoundclub.com.
IMO this investigating is well worth doing BEFORE you invest 10k in a commercial product!

I 2nd Hermans recommendation of Jeffery. AND he's a great guy too!
Good Listening!

Check this guy out. http://www.experiencemusic.net

You will get much more for your money with a custom built amp from a guy like Jeffrey. The quality of parts will be higher than a commercial amp and the sound will be incredible. He can build it to suit your tastes and other equipment.