[avahifi]

Our Super 70i circuit for the Dyna St-70 chassis has been a tube classic for the last twenty years, but the time has finally come to welcome the next-generation classic: The Audio by Van Alstine Ultimate 70 Amplifier.

If you love vacuum tube sound, you likely will love the Ultimate 70 more than any other tube amp you have ever heard, price not an object. It is just simply lovely sounding. It takes every last bit of grain away from your records and CDs, but takes nothing else away at all. The highs just float. Transparency, detail, definition, range, and dynamics are wonderful. It’s got a midrange to die for and bass extension and control you would not believe possible at this power and price. The sound stage is huge, the depth is pure reality, and the emotion of the music is all there, likely like you have never heard before.

Taking advantage of what we have learned from our Transcendence Seven and Fet Valve R-series products, the Ultimate 70 incorporates five regulated power supplies, including an isolated regulated bias supply. The audio circuit has been carefully reexamined and reoptimized for wider bandwidth and greater stability under all conditions. The result is the purest musical reproduction possible.

The Ultimate 70 consists of a brand new circuit board for the Dyna St-70 vacuum tube amplifier and all associated parts. Output power is about 33 watts per channel RMS (up significantly from the Super 70i and the stock St-70), and it sounds like much more power than that, driving our 87 dB efficient Biro L/1 speakers easily.

The price is $449 for the easy to build kit version, or $749 factory installed (including all new tubes and a new input/output jack set). You need a wired and working original Dynaco St-70 or AVA Super 70i amplifier to start with. The new motherboard has a silk-screened top layer and solder masked and silk-screened bottom layer also to make kit assembly easier. No metal cutting or hole drilling is required.

Note for our many Super 70i amplifier owners: Sorry, but there are almost no salvageable parts from you existing AVA Super 70i mother board, so we cannot offer you a cost savings on the rebuild kit. However, the Ultimate 70 kit will be an easier project for you, as much of the internal wiring you have already done can be saved and reused.  Also, installing the Ultimate 70 board in a Super 70i will save us some time too, so we can offer a $50 discount on the factory rebuild or $150 if all your existing tubes are good and do not need replacing.

The Ultimate 70 rebuild is in stock now, and we are accepting orders. This is one amplifier you are going to enjoy.

Call us at 651-330-9871 about this little beauty, and Happy New Year!

Frank Van Alstine

[WEEZ]

Sounds like a winner!

I've often wondered why AVA doesn't just come out with a complete amp based on all the circuit work you've over the years. Seems like all you would need is to source some good transformers and build a chassis.

Good luck with the Ultimate 70!

WEEZ

[avahifi]

The obvious difference is that the Fet Valve amps are ten times as powerful which is very useful in many applications.

However, a die hard "tube lover" is going to like the U70 better, just because of the intangible "vacuum tube" presentation (without the normal vacuum tube fuzz and obvious colorations).

The U70 does not match the dynamic range or extension of the Fet Valve amps, and probably not quite the same transparency (a bit different kind of transparency?) but it does have this sense of "musical rightness" that some will love, others will not observe, depending upon what they think is "right".

The Fet Valve amps are a better musical photograph right out of Arizona Highways, the U70 maybe a better musical painting hung on an art gallery wall.  In other words, I sense that the U70 is providing an exquisite interpretation of the music, but a very human and likeable interpretation indeed.

Its all in what you want.  I love them both.

Frank Van Alstine

[avahifi]

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=370

Got a photo posted in the gallery here.  One of these days I will figure out how to just put it directly in a message.  Could use some help regarding that.

Frank Van Alstine

[jackman]

[Gvt1911]

I am new to this group but must give credit where credit is due...I just finished and installed one of the new U70 boards in a tired ST70...I rebuild tube audio as a hobby and have done many a mod,mostly use VanAlstine's 70i boards,mainly because they are more user friendly to the older crowd I deal with (over 60+)...
Well I do not know where to begin...This mod is like Viagra for these old Dyna's!!! It is a total transformation...Every work Mr.V has said is true and then some...I have owned and modded MANY a tube amp in my day,it is very difficult to find an amp that does things right...I mean play MUSIC and all of it!! Some amps are lacking in certain areas,while other overdue certain things...The U70 board is just "right"...I'am so impressed with the detail,clarity,warmth and strength of this little amp... Very simple to build and very easy to maintain and OHHH the sound!!!
I am in shock on how this amp can play my big old VSA VR4 modded speakers so loudly with such air and freedom...This is definetly a must have mod for anyone with an ST70!!! You will not believe it until you hear it for yourself...Many Thanks to Mr Van Alstine for bringing the music back!!!

[audiojerry]

Frank, do you have a demo model that one could audition before committing to the mod? Maybe even charging a nominal fee for a couple of weeks usage.

Would you be interested in setting up a demo with the Northeast Wisconsin Audio Society? We could set something up in the Milwaukee area.

[avahifi]

Yes I would indeed be interesting in a demo for the NE Wisc Audio Society.

Thank you for the inquiry.

I would bring the U70, along with a Transcendence DAC, Transcendence Preamp (with the new remote control) and a Fet Valve amplifier too.

I would need a CD transport with coax digital output, and speakers that can be driven well on the 30 watt per channel tube amp.  Note that speakers specifically designed for a SET amp likely will not work well as these designs are usually done to provide matching non-linearities with the SET amplifiers.  The Society can furnish whatever it wants in the way of interconnect cables and speaker wires.  Hopeful the demo can be done in a reasonably good listening envoirnment.

I will need at least a couple weeks notice to plan on being there.  Let me know if you want to make plans.

Thank you.

Frank Van Alstine

[jonwb]

Jerry, please let me know if you are able to work out a get together w/ Frank and his U70.  I'd love to hear that amp!  Unfortunately, I don't think I'll be able to bring the Alphas over  

[avahifi]

The U70 is going to sound amazing on your 801s but only at modest levels (it is after all just 30W+ per channel).  Now a pair of them bridged would be a different story.

Frank Van Alstine

[audiojerry]

Hi Frank, I'm currently in Arizona, and I'm sorry I haven't been able to reply until now. When I get back into town, I'll bring up this topic with the members. I think it would be great if we could make it happen. Currently there is a gathering and demo set for the 26th of Feb. I'll bring it up with the members at that time. Thanks for responding.

[randog]

Say, what would one expect to pay for an original Dynaco St-70 in excellent condition (no mods)?

[doug s.]

Say, what would one expect to pay for an original Dynaco St-70 in excellent condition (no mods)?

this is likely typical, for a stock iteration:
http://cls.audiogon.com/cgi-bin/cls.pl?ampstube&1113944371
here's what an ebay search for "st-70" comes up with:
http://search.ebay.com/st-70_W0QQsojsZ1QQfromZR40QQsatitleZst-70
and what's recently sold:
http://search-completed.ebay.com/st-70_W0QQcatrefZC6QQcoactionZcompareQQcoentrypageZsearchQQcopagenumZ1QQfisZ2QQfposZ20892QQfromZR10QQfsooZ1QQfsopZ1QQftrtZ1QQftrvZ1QQsadisZ200QQsatitleZstQ2d70QQsbrftogZ1QQsofocusZsoQQsojsZ1

doug s.

[randog]

Looks like anywhere between $300-450, eh?

Thanks Doug

[randog]

I was entertaining going to tube amp(s) for my vintage rig and the price of an ST-70 used plus these mods are right in the ballpark of a pair of McIntosh MC-30's (my preamp is a McIntosh MX-110) and at the same power output to boot.

I'd be interested in hearing comments of comparisons. Would the new U70 blow away the vintage Mc's?

[beatgr]

For the Ultimte 70 driver board, whose blue box capacitors are you using?  They don't look like Wima.

g. beat

[avahifi]

It makes me sad to get questions "what brand of parts are you using?" as if that was anything important.

Nobody asks "tell us about the circuit topography and why it works so well?"

Do you question the brand of electronic parts used in an airliner before you take off, or in your BMW or Mercedes?  The only thing I question about the parts brand in my Audi S6 is the radio, a manditory Bose system, it sucks, but oh well, all car radios suck.

I could build the amplifier with all 20 percent tolerence carbon comp resistors, but it would be very very very expensive, as I would have to sort through thousands of parts to find ones that were both quiet and within 1 percent of the needed values.

The capacitors are Seimons 2.2uF 400V flim units for your information, selected and matched and installed in parallel to provide the correct critically damped low frequency pole and to reduce series inductance to an appropriate level.

Remember boys and girls, if military grade parts and the ilk sound so wonderful, why does the radio in an army Humvee sound so bad?  Its built completely with military grade parts.

If you want to learn something about the reality of good audio circuit design, pick up a copy of Fundamentals of Transistors or similar and start learning a little engineering math.  Of course thats nowhere near as much fun as dinking around with wonder parts.

The secret to the Ultimate 70 (which is probably day and night more musical sounding than anything you have ever experienced) is the layout (nearly zero path lenghts for supply feeds and grounds), the multiple active analog regulated power supplies for the small signal tubes, and a very carefully engineered critically damped circuit design.

It is not the parts brands, boys and girls, its the design quality.  I wish more of you would sometime understand and care about that.

Frank Van Alstine

[beatgr]

Frank -

The query was concerning a ST-70 restoration that I am assisting my brother with (remotely).  Modern capacitors continue to decrease in size and change lead spacing - fine for new deisgns - but for repairs (when the requriement is Smithsonian restoration) - "no an orange cap will NOT do" - takes much more time / research.  So in this case a capacitor brand CAN make a difference.

I have 2 broadcast mixing consoles of this same era that use radial paper capacitors on phenolic PC boards  - trying to find a axial cap that has sufficent lead length (to fit - mounted on its end) is a challenge without hacking the board up.

Sorry to trouble you with such a question.
I'll just advise him to take out the AVA driver board.

g. beat

[rosconey]

quote-
It is not the parts brands, boys and girls, its the design quality. I wish more of you would sometime understand and care about that.



frank you are sooooooooo fuuuuuuuuuunnnnnny-its about the name  and how much more the fancy name costs man-
i some times think audiofools are the stupidest consumers there are-phantom chips that make your cd's sound better,120$ caps,600$ power cords-ect ect.solid fundimentals are worth squat

the market is so over saturated that the idiots with the most time and money to waste keep looking for the holy grail in audio gear-

they dont realise one must be content with what they have and enjoy instead of thinking i'm one part away from making this the best(insert equipment)in the world-thats why modded pieces are so popular right now-

3 basic kinds of audiofools

the cheap ass-he hunts for bargains that sound good to him no one else-

the changer-he replaces a piece does a mod or changes cables at least  once a month ,in a year his system will be totally changed-he also knows more than everyone because of changing so much equipment

the moocho denero-he buys on price,if it aint more expensive than what his friend has he keeps looking-prone to system changes more than the cheap ass but not near as much as the changer-also many consider themselfs to be know it alls

thats not to say there are only 3 types because they can morf together-
 like a cheap ass changer-

[boead]

quote-
3 basic kinds of audiofools

the cheap ass-he hunts for bargains that sound good to him no one else-

the changer-he replaces a piece does a mod or changes cables at least once a month ,in a year his system will be totally changed-he also knows more than everyone because of changing so much equipment sm_lyellow.gif

the moocho denero-he buys on price,if it aint more expensive than what his friend has he keeps looking-prone to system changes more than the cheap ass but not near as much as the changer-also many consider themselfs to be know it alls

thats not to say there are only 3 types because they can morf together-
like a cheap ass changer-

Which one are you?