From: "Saved by Internet Explorer 11" Subject: avahifi - Ultimate 70 Vacuum Tube Amplifier Date: Fri, 10 Apr 2015 14:04:20 -0700 MIME-Version: 1.0 Content-Type: multipart/related; type="text/html"; boundary="----=_NextPart_000_0000_01D07397.3D80EDE0" X-MimeOLE: Produced By Microsoft MimeOLE V6.1.7601.17609 This is a multi-part message in MIME format. ------=_NextPart_000_0000_01D07397.3D80EDE0 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Location: http://www.avahifi.com/index.php?option=com_content&view=article&id=171&Itemid=221 =EF=BB=BF
=20 =20 =20 =20 =20 =20 =20 = Complete kit: $449
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Plans and bare PCB: $149
Circuits:=20
Ultimate 70
Chassis: Your Dyna =
St-70 =20
or AVA-furnished Dyna St-70 (subject to =
availability)
The AVA enhanced pure vacuum tube amplifier for your original = =20 Dyna St-70 chassis.
Over the years, we have gotten many calls and letters asking for = =20 service and upgrade help with the long-out-of-production Dynaco = =20 St-70 vacuum tube power amplifier. A thorough discussion = of the=20 basic operational parameters of vacuum tube power amplifiers = in=20 general and the Dynaco St-70 amplifier in particular was=20 presented in our July, 1982, issue of Audio=20 Basics. That issue also included directions to = correct=20 some of the amps worst problems within the context of its = original circuit board. You can =20 view it online for free from the AVA website.
The Ultimate 70 is a new AVA circuit set for the = Dyna=20 St-70 chassis that 2005 AVA circuit for the Dyna = St-70=20 chassis that goes far beyond what we describe above. It = consists=20 of a brand new motherboard incorporating significant = circuit=20 enhancements, all new modern parts, and an improved = layout. The=20 audio circuit has been carefully engineered for the = widest=20 controlled bandwidth and stability under all conditions. = Taking=20 advantage of what we have learned from our Transcendence = Seven=20 and Fet Valve R-series products, the Ultimate 70 = incorporates=20 five regulated power supplies, including an = isolated=20 regulated bias supply. The result is the purest musical=20 reproduction possible.
The Ultimate 70 replaces our highly regarded classic Super=20 70i rebuild that has had a production run of over = twenty=20 years. It was time now, with experience learned from = engineering=20 our acclaimed hybrid preamps and power amps, to see how = much=20 further we could push the envelope of pure vacuum tube = amplifier=20 design, and we have pushed it beyond our wildest = expectations. Do you = already own a=20 Super70i?
We think you will love the Ultimate 70 more than any other tube = =20 amp you have ever heard, price not an object. It is just simply = =20 lovely sounding. It takes every last bit of grain away from your = =20 records and CDs, but takes nothing else away at all. The highs just = =20 float. Transparency, detail, definition, range, and dynamics are = =20 wonderful. It's got a midrange to die for and bass extension and = =20 control you would not believe possible at this power and price. = =20 The sound stage is huge, the depth is pure reality, and the emotion = =20 of the music is all there, like you have never heard before.
With a good set of tubes, the Ultimate 70 will output about 33 = =20 watts per channel RMS up significantly from a stock St-70. = =20 (Dyna's original 35 watts per channel rating was rarely achieve = =20 under real-world conditions.) It sounds like much more power than = =20 that, driving our 87 dB efficient Biro L/1 speakers easily.
The Ultimate 70 can be delivered to you in three different ways:
You need a wired and working Dyna St-70 to start with, complete = =20 with functioning transformers, rectifier tube, and output tubes. = =20 (Replacement tubes are available from AVA, replacement transformers = =20 are not.) The rebuild replaces the entire audio circuit (including = =20 the small signal tubes), the quad filter capacitor, and the bias = =20 supply capacitors and resistors, and so most old problems will be = =20 thrown away along with the old circuits. Instructions for bias = adjustments =20 and basic troubleshooting are included in the manual. The PC = card =20 is solder masked and silk-screened on both sides to make it = easy =20 to build. Rebuild plans and a bare PC card are available alone = for =20 those who want to furnish their own parts.
An optional AVA Input-Output Jack Set provides heavy-duty 5-way = =20 binding posts for your speaker connections. The new gold-plated = =20 input jacks are spaced further apart than the originals, allowing = =20 modern cable ends to fit better.
The Ultimate 70 amplifier (like all tube amplifiers) runs hotter = =20 than a solid-state amp and will need ongoing maintenance, periodic = =20 bias adjustments and re-tubing. This is because power tubes, unlike = =20 the small signal tubes in our preamp and Fet Valve products work = =20 hard, operate at high voltage and high current, and thus don't = =20 last as long. Our small signal tubes run cool and tend to last for = =20 years and years.
Why the bother? Because a good working Ultimate 70 with a good = =20 tube set, properly adjusted, is a great little amplifier! Because = =20 it is faithful to the spirit of the music, absolutely pleasant, = =20 and rewarding to listen to on any rationally efficient loudspeaker. = =20 Because you will find this carefully engineered AVA project is simply = =20 fun to do.
The AVA-enhanced pure vacuum tube amplifier rebuild for your original = =20 Dyna St-70 chassis available as a kit or factory-wired.
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