I noticed that when my BR-20's speed is in the "FIX" position, it runs a full semi-tone fast, and so I've had to manually keep it in "VARI" position, carefully detuned. Unfortunately, the BR-20 "forgets" this switch selection after a couple days of being powered-down, and sometimes I forget to punch the "VARI" button. I'd like to properly calibrate the BR-20 so that the "FIX" switch gives a true read (I've got MRL tapes). The manual doesn't indicate where such a master pitch/speed control trim pot might reside - it isn't obvious if it does live under the meter panel. Where is the pitch trim pot?