[sdiy] Teac Trivia

[Gene Stopp]

Hi Magnus!

Well I haven't pulled apart the deck to check, I've just pulled off the rear
cover which I like to do every once in a while anyway. It's a mint condition
machine, so I'd rather keep it that way if the motor is just a sync motor.
However the 3340 has a pitch control so it makes me wonder...

I work very slowly these days with hobby projects, mainly scanning the
internet for tidbits of information beforehand. The kids keep me busy so I
don't want to do anything without some kind of plan of attack. My workbench
philosophy is "get in, get it done, get out, before my wife notices".

An inverter sounds fun anyway. Since it involves HEXFETs and a power
transformer wired backwards, there's probably going to be some rather large
currents which could be exciting. I do like to mess around sometimes with
slightly dangerous stuff - not so much because of the potential fireworks,
but more because it's outside of my normal habits and I get to have some
mental challenge where I have to actually think and discover things. I like
that for some reason! Besides, a small sine wave inverter would be nice to
have around to vary other line-frequency machines like telescope drives and
Hammond organs. I've been doing some casual searches and most compact
inverters these days seem to be square-wave or "modified sine wave" which
seems like cheating to me. And they certainly aren't tunable.

Best Regards,

- Gene

-----Original Message-----
From: Magnus Danielson [mailto:cfmd at swipnet.se]
Sent: Wednesday, April 03, 2002 10:29 AM
To: gene at ixiacom.com
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] Teac Trivia


From: Gene Stopp <gene at ixiacom.com>
Subject: [sdiy] Teac Trivia
Date: Tue, 2 Apr 2002 16:54:03 -0800 

> Hi DIY,

Hi Gene!

> Sometimes I get strange ideas... I want to do some tape flanging
experiments
> so I was wondering if anybody out there knows whether or not a Teac 2340
> reel-to-reel uses a crystal oscillator for the capstan motor, or the
> 60-cycle power line. Anybody got that page from the service manual? Mark
> Glinsky's page 404'd me when I tried it. If it's the power line I was
> thinking of building a little sine wave inverter with:
> 
> a tuneable EXAR 2206
> some IRF HEXFETs
> a big 12v filament transmformer wired backwards
> 
> Pretty goofy, huh. I should have all these parts laying around. At least I
> feel at home with you guys :)

Have you looked for a crystal oscillator on any of the PCBs?

You should be able to fairly quickly find the relevant PCB since it
should be hooked up to the tacho-sense of the capstan wheel.

I fortunately have Tacho-drive on my Studer B67, but sadly enought I
only have one of them, so I can not run them in parallel for such
experiments.

Cheers,
Magnus