[martyo]

  got it.   

[Art_Chicago]

Oh. flagged as in a bit tippled. Irrigated, you understand. Listing a few degrees to port. Out of plumb. I was in my cups, you see.

How is it going, Brian? no pressure, just cuuurious

[avahifi]

I suspect it has a Triode power transformer if the power transformer is almost the same height as the two output transformers (the stock power transformer is a bit shorter).

It might have Magnequest output transformers which are very nice indeed.  Tell me what the output transformer wires look like (thickness, insulation type, whatever).

Regards,

Frank

[oneinthepipe]

Nice review.  I just received my U70 a couple of weeks ago, and I am amazed by the little amp in comparison the Insight 440.

I am also interested in tube selection.  My amp has a matched quad of JJ EL34, and I suspect that there are better choices.  Additionally, I am also interested in other owners' methods for testing tubes.  Does everyone own or have access to a tube tester?  Years ago, I owned two ST-70 amps and a PAS preamp, and I don't think that I ever tested the tubes.  Now, I have two pieces of AVA tube equipment,and I need to pay more attention to my tubes. 

[boycephoto]

Hi Brian,

I think your review of the U70 is right on.  I moved my U70 into my large room a few days ago.  I put it in place of my OmegaStar EX 440H.  I was amazed at how well it drove my Magnepan 3.6's. On everything except the loudest settings the little U70 sounded very big and strong and very clean.  Excellent detail at lower volumes too. I noticed how quiet it is compared to the 440H, I like the U70 better than my 440H in many ways.  My U70 has a new Triode electronics power transformer & Magnequest MQ 470 output transformers. That might give it just a little edge over the stock Dyna transformers.  Then I moved in my Rogers LS3/5a's.  I was amazed.  They totally dissapeared, I couldn't hear them.  The image was wider and deeper and just as big as the Magnepans! When I closed my eyes I could not hear the position of the speakers at all.   The Rogers have no bottom end to speak of and need a woofer to complete the system.  I hooked up a little Velodyne Mini Vee and finished listening at 2AM, if figured I better quit, I had to be at work at 8 in the morning.  Well I am going to the man cave right now and warm my toes next to the tubes. Enjoy. 

Dave 
 

[boycephoto]

Good morning Brian,

You said you put in new power tubes, what tubes did you use?  Sounds like your in love.    

Dave

[Art_Chicago]

Late, post-tube-break-in update!

New power tubes have had the weekend to cook and, man oh man the music this amp is making. What you've heard about the 3D imaging, the depth, the delicate, precise delineation of instruments onto a wonderfully silent background, it's all true and adds up to I think the most satisfying musical experience I've yet had in front of my stereo. Brilliant piece of engineering. Frank has, in his unassuming way, suggested that it's possibly the best tube amp you'll find at any price. I certainly haven't heard every tube amp out there, as there are currently one billion, but I have heard a number of them including some quite expensive ones, and I certainly don't disbelieve him. And if plain-old musicality is your end-all, I would rephrase the above without the word 'tube'. It's not good 'for a tube amp' it's simply a great, music-revealing amp, period.

Come to think of it, I believe I'm gaga over it.

If you have a reasonable pair of speakers and a reasonably sized listening room, you should be considering this amp. The bass from my 1801s is making the room pulse; cello and bass notes dig deep and have very satisfying bite and richness. And everything else takes care of itself.

If you have less reasonable speakers, you should seriously consider getting a pair and bridging them. IMHO.


p.s. Played some for my wife and she said, It's better than the other amp.    I shan't be parting with it.

That is why we like your reviews 
You have even removed FetValve Ultra from the Signature pane...

[ArthurDent]

Nice review Brian. Will have to put the U70 on the wish list for when I win the lottery.

Thanks 

[simon wagstaff]

Why would you need to win the lottery?  A U70 is not that pricey and near as I can tell one of the best bargains in audio. I have my system moved into a new room, Infinity IM4.1, Pioneer TSX59i, Pioneer 79i connected via firewire and a pair of VMPS subs to supplement the bottom end. Volume is not an issue at all, I am sitting a little closer so am more in the nearfield. Got a black mamba II interconnect and some anticable speaker wire and the detail is kicked up a notch.

I am in the next level of audio heaven, who knew that it could get any better?

I think the U70 would be ideal in a sat sub set up where you can crossover at 80 hz or an excellent match with one of those speakers with built in subs like the Infinity or the Mythos.

Yep, I am gaga as well!

[carusoracer]

Brian,

Need to put the U70 on the must hear list aa  I'm glad I swayed you towards tubes, although I'm sure you have been thinking about it for quite sometime.

Let me know your schedule, I'm in town this weekend. I have an assortment of tubes we can roll

[carusoracer]

No you can't hear it, I've already built it up too much.

It's probably not that good an amp, really.

Though if you have the right tubes, that could tip the scales...

[Wayner]

I was just out to Franks on Sunday, we went out for breakfast at the "Little Oven" and the U70 topic came up at some point. It certainly is a great tube amp in it's current revision and I personally can't wait till the new chassis is done. I do hope some of you folks are lining up for this amp. I know Frank is excited about it and so is the rest of the crew at AVA.

It is going to have a very high "cool" factor when you see the new polished stainless steel chassis with natural aluminum faceplate (black silkscreening) and a tad more power. I think it will actually boast 40 watts RMS per channel as Frank has chosen the higher power output trannies.

Wayner 

[Wayner]

[boycephoto]

Hey Otis,

You forgot a couple of things,

Curb feelers, so nothing else cramps it's space!
a TV antenna mounted on the back with lots of RFI, of course. 
How about tinted valves.
Don't forget a place for a spare EL34, never know when your going to sound flat.   

The first upgrade after the UltraValve is released will be "Pimp my UltraVale".

Oh. It's Saturday night and the beer is really good!

[boycephoto]

Good morning Otis,

It's amazing how our minds can see the possibilities and dream the "what if " when it comes to a piece of equipment. 

Franks products have always been more to the utilitarian side of appearance.  Keeping the frills to a minimum keeps the costs down and adds to the value of an AVA product. 

I do like your ideas, and the new UltraValve does needs to have a look of its own, it's identity, drifting away from the Dynaco 70.  If its on a shiney chrome chassis with black transformers some people may mistake for  "just another ST70 mod" and not realize that it is a totally new amplifier.  I like your idea of gold endbells, a black chassis, wood end picecs and large feet, that would help set it apart and help created more intrest, get it the attention it should have!       

I do think a lot of audiophools are as concerned about the looks of their equipement as much or more than the sound. I was talking to a guy last week(I have known him for 30+ years), he told me that he is thinking about getting the $34K pair of 200w/ch class A Pass amplifiers.  He has never heard them, but he did say "and they really look great" to help justify the price. He is willing to spend that kind of money on a reputation and looks???  I told him before he opens his wallet maybe he sould listen to my AVA Ultimate 70, I even offered to loan him my OmegaStar EX 440H to try in his system.  When I mentioned Audio by Van Alstine he said "oh I heard that stuff is really good too"  and eagarly accepted my offer.  He is going to pick up the amp next week.  I know how looks and a sexy picture in a national magazine can play a big part in a buying decision, and yet how wrong it could be.  We all are attracted to pretty things!  I am sure the AVA design team has thought about these kind of ideas a long time ago. 

Anyway, I like your ideas. 

Dave