[avahifi]

Ultimate 70 chassis back to the metal bender for one more prototype revision.  We figured out we could take 3/4" inch out of the chassis height to make it look less "chubby" looking, are relocating the bias test points a bit  to provide better access further from hot power tubes, and figured out how to configure the output terminals so that each of the 4, 8, and 16 ohm taps can be accessed with standard double banana plug speaker wire terminations (strongly recommended).

We also have proto output transformers coming from Magnaquest.  More expensive but really, really good.

Frank Van Alstine

[guest1632]

Ultimate 70 chassis back to the metal bender for one more prototype revision.  We figured out we could take 3/4" inch out of the chassis height to make it look less "chubby" looking, are relocating the bias test points a bit  to provide better access further from hot power tubes, and figured out how to configure the output terminals so that each of the 4, 8, and 16 ohm taps can be accessed with standard double banana plug speaker wire terminations (strongly recommended).

We also have proto output transformers ...

Hi Frank,

Are these new transformers the standard E Bar typee? What makes them better than whatever else you would have used.

Ray

[scato345]

frank,

just some thoughts.

ultimate is a relevant term - and i would suggest that "ultimate" refer to value and utility.

consider me an old fuddy duddy, but i'm very much into "industrial" right now, and have been buying a bunch of old amps once again, as much for their style as their potenetial.

i'm very select in my equipment, and fairly well versed in what's out there and been out there.

i would suggest a basic chasis, with no paint. if you want to go beyond aluminum, go for copper.

etch the tube notations on the deck and the amp info on the sides, don't just silkscreen them on. this alllows for good cleaning of the bare metal for many years to come. (the way that an eico facplate can be "restored" with a good metal polish)

use a rectangular chasis, 17 X 5 or 6 and three high for effect. have an optional cage for those who want it - ala fisher, eico, marantz, etc.

have an old fashioned  pilot light, a good quality on/off toggle on the front transom - and lay out the tubes symetrically and logically -   so that the amps (if used as monoblocks)  can be mirrored l&r, if only because they have the same layout; have two removable power cord outlets, one on each side.  put the fuse on the deck. put the inputs and high quality binding posts on the rear transom.


as far as power goes, why limit it to 32 watts? you could easily move from 32 to 60 watts by adapting the design to allow for different tubes : 6l6, el34 , kt88 - etc. (64 to 120 bridged) - quicksilver and vac and many other high quality companies offer this. have a built in meter, and easy to use bias pots.

it is the original sound that you are recreating, and the spirit of the original design in which  form  followed function in a very cost effective manner. The goal should be the same, but now changing some of the design parameters and improving the quality.



respectfully,

dorian jones

[Wayner]

Copper? The customer should be isolated from electrical hazards right? Raw copper will turn green after awhile in some parts of the country. Etching the metal surface is a very expensive process called photo-etching (can also be done chemically) both are very expensive. The reason most amps aren't made that way anymore is that the design costs too much. Good engineering requires knowledge of materials and operations (forming, finishing and assembly). That way, the true engineering can be put into the electronics, where it counts.

Wayner

[lazydays]

One thing to keep in mind, you can successfully use a 32 watt very good vacuum tube amplifier where you would normally use a 100 watt solid state amplifier.  Heck if I know why.  But one of them drives a set of B&W 802 Series II speakers quiet well indeed and those speakers were the downfall of lots of 200 watt per channel solid state designs.  A pair of Ultimate 70 amps bridged into the 801s is more spectacular than you would ever believe.

Frank Van Alstine

I used to know a lady in Ohio that had two bridged Dynaco ST70's driving a pair of Maggies (1.6's or 1.4's). Sound was great.
gary