I don't remember either deck having an external pitch control. How much variation do you require and are you asking for an internal adjustment?

None. I let the techs do those things. If you have the know how and the tools, you should be able to find the schematics on line for the TEAC and possibly for both decks. I don't remember the best web sites for schematics. Possibly someone else will post it here. Otherwise, do a search engine with "TEAC/TASCAM schematics". You can probably still find the shop manual for the TEAC/TASCAM on line but certainly you should be able to order it from TASCAM. Any shop that services the current TASCAM line can probably do the adjustment for you.

I have no idea how to go about getting any information on the Tandberg. They haven't been represented in the US for a long time and I don't think most Tandberg dealers left anything behind to remind them of their departure from the US market. Check a few of the vintage audio web sites.

Quote:
Can anyone help me on how to adjust the playbackRecording speed on a TEAC X-2000M reel-to-reel? The same question goes for a Tandberg TD20 A(L), log recorder.

Back in the 1970s I had a Bogen PA amplifier with a 115 VAC tap on its output transformer. I built a sine wave oscillator that varied from 30 to 120 Hz, and used the output of the amplifier to drive the capstan motor on my Ampex AG-440 recorder when I wanted to change the playback (or record) speed. But more modern recorders use a DC servo controlled motor so this approach won't work with that type of tape deck.

The short answer is this is very easy to do today using an audio editor such as Sound Forge. Record the tape recorder output into a computer at its native speed, then change the playback "speed" in software.

--Ethan