[Tom Alverson]

My guess is that the extra transformer is there to power the two added tubes, which could be cathode followers (buffers) for the audio stages.  The 12X4 tube socket is still visible in the picture, so it would not be too hard  to convert back.  I would say save your money for the Insight and use this preamp as it stands until then.  If you enjoy working on electronics, the doing the AVA PAS upgrade yourself can be a lot of fun.  In terms of what to best spend your dollars on for improvements in the sound quality the Insight preamp is the better investment.

[iclark]

Tom,
I made an inquiry to McAlister Audio about the mods made on my new preamp, this is the reply,

"A while since I was doing these.
Two extra tubes added- one to the phono, one to the line stage. Cathode follower outputs now on both with low impedance.
Upgraded output caps and removed the tone controls.
A number of other component changes.
 
The end result is a Pas3 much better than any stock unit regardless of parts. You now have much more linear frequency response, low output cathode followers and impedance."

You were spot on about the cathode followers, i'm impressed.

I think I'll give this preamp a shot as is until I get an Insight.

I am a little perplexed though, tonight, after all the weekend activities, I thought I would treat my self to a little quality time with my U70. I played 2 Lp's I got at the thrift store for 49 Cents each. U70, Omega III, Techniques Linear tracking turntable (found in the garbage) and a $50 Ortofon P mount cartidge. The records were, Swingle Singers Going Baroque and The Best of Leona Boyd.

Well you can't believe how good it sounded. I was blown away. I can't describe it but it was the best I have heard. Natural base, sustained notes on the guitar and silky smooth vocals. I attribute it to the U70 mods. (though there was some Scotch involved)
This is why I am perplexed, what  improvement can I expect from an Insight or T8. I can't imagine it getting better.

I listened to the same LP's on my Raysonic SP120 (KT88 Integrated) and a considerably better turntable/cartidge combo,(same Aurum Cantus speakers) and there was no comparison. The U70 was better!

Ian
 

[boycephoto]

Hey Ian,

I am sure the Scotch was really good!  but, have you done the latest U70 upgrade???  and it does and will get better, try a little tube rolling in you PAS.  I found NOS Telefunken 12ax7s made a difference over everything else I have tried.  ( Chineese, JAN Phillips, and Sovtek.) If that doesn't work then try just one more Scotch!!

Kalamzoo is pretty, in places.  The city is in a valley with small rolling hills surrounding.  It has its ups and downs just like most cities I have been to,  but no compairison to Ottawa. 

I lived in Montreal for a while when I was a kid.  My parents made many trips to Ottawa, and I have visted multiple times since then.  My wife and I enjoy the Toronto, Thousand Island, Ottawa treck, it's a great get away and not to far from home.

Happy Listening
Dave   
 

[boycephoto]

Ian,
If I would have read your post one more time before I sent mine, I would have realized that you have already made the U70 upgrade.   

When all is said and done, I will be surprised   if I like the Super Pas 3 over the Insight+, I just have that feelling.

Dave

[Dan Kolton]

I've learned over about 30 years that whenever I think Franks "latest" can't be improved, he does.  If he says it's better, it is.

[iclark]

This will be my last post extolling the virtues of the U70 with Frank's Mod.
Tonight, I listened to a new CD I got. Leonard Cohen Live in London. One of the best live recordings I have heard. A little bit of siblience here and there which I attribute to the recording, but all in all a really good recording.
For a source I am using a $25 Daytek DVD player. Just a red square box, no display, but it does decode HDCD. I am running it thru a Cambridge Audio Dac Majic. It works and sounds just great. An unusual feature of the Daytek is that it has a volume control and mute function, so I can match the levels to my phono setup.
No scotch tonight and It still sounds wonderful!
All you lovers of good sound out there who are contemplating puchasing a tube amp, go get a AVA Ultra 70 (is that correct?) as soon as it's released. You won't regret it.

Ian

[hotroady]

Have to reassess what I think what I think what was going on when I heard I first heard Frank's bridged prototype UltraValve 80's. Doing the math: 40w per channel times 3X factor of bridging= 120w per channel or 30w per tube. Problem here: EL34 types are rated to only 25w max. That's where I figured the extra 20% of the headroom of the JJ 34L's might help.                           The second time I heard his Saulk's was with the EH tubes were with a single U 80, which I believe was unbridged. Much different sound. In the full horsepower set up the midrange was not there. There was a smidge of mud in the bass, and a little piercing in the highs in some music passages. When I got my updated unit back in my system, none of these characteristics occurred. Later, when I heard the single amp with EH 6AC7's, they sounded like they ought to. Much lower volume, but sounded good.                           Frank and I agree that the JJ's are 'hotter' in the high freq. The EH is more boosted in the in the midrange, as is the GE 6AC7.

[hotroady]

 In applications where where you can't change crossover point like a sub, I can see why Frank prefers the EH's. I put my sub up crossover to around 80-100hz region, and turned back treble near flat. This tends to boost mids. I also use 8ga. welding cable and 4 ohm lead to 6ohm woofers on my Logans'. I think these helps track impedance swings of the 'stats, better. Getting real nice detail and transparency with JJ's and RCA short plates. The JJ 34L will sound leaner in the mids, tighter in the bass and extended in the highs. More extension than even the GE's. The JJ's seem to be losing briteness as I put more hours on them. They sound more towards Telefunkin long smooth plate 12AX7's with GE6AC7'S, though Teles still have nicer sparkle. Pre amps will of course add their own influence.