My interpretation of the Quickie (see photo!)

Dr. Toobz · 12192

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Offline Dr. Toobz

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on: October 25, 2009, 04:50:06 PM
Here's my take on the Quickie. I received a black plate, so I stained an extra Seduction alderwood base a deep mahogony. Then I sealed it with two coats of ployurethane, and sanded it in between, so it has a glassy, shiny look (easy to tell in the photo by looking at the reflection of the headphone pulg). Under the hood, I snuck in two Specos as OPT's and a pair of Hammond chokes in place of the plate resistors. Then, I chiseled out a crater in the front to fit a headphone jack, which was leftover from my S.E.X. amp. I got down to about .20" thickness before drilling a hole for the jack to poke out through.

All in all, a wonderful new friend for my 2009 iMac! I may eventually play around with - gasp! - wiring the pentodes in UL mode if I can find good OPT's for serial feed, which would allow me to take a primary tap back to the screen. Probably wouldn't get me much more power, though. Too bad I don't have a pair of ~120dB or so sensitive speakers! Some Jupiters or other warm-sounding cap might be interesting if I stick with parafeed.

Offline Paul Birkeland

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Reply #1 on: October 25, 2009, 05:10:18 PM
If you change the operation to UL, the output impedance will go sky high.  It would be a fun experiment, but if you get a lot of gain and really thin sound, you will at least understand why.

The project looks great!  Not too many black plates have gone out so far!

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Dr. Toobz

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Reply #2 on: October 25, 2009, 05:28:38 PM
You know, that's exactly what I thought, but I wasn't sure - my understanding of tubes and different circuits is pretty basic at this point. I had figured that feedback would raise the output impedance, which, as I've talked about in other threads, seems to be one of my pet peeves (leading to poor damping factors and odd interactions with my headphones and speakers).

Maybe I'll just stick to wiring these as triodes - gain is not a problem as it is! The amp drives my Beyers quite loudly following the addition of some plate chokes.