That made a pretty substantial difference as both channels now sound "ok" when listening to what is being recorded using the "tape" position. As a result I replaced the C1344 Hitachi transistors on the board that supplies signal to the tape heads (RWR-053). Both channels sounded great in "source" position. The right channel worked better but also has some odd amplitude variations and it sounded slightly distorted when listening to what I was recording in "tape" position. I tried to record the other night and the left channel was barely working (intermittent) and highly distorted in "tape" listen position. Test tones sound very solid and very steady when listening in "source" mode. This seemed to make the inputs nice and quite and stable with no crackles. So, I also replaced the A672 transistors. This made a difference, but there was still some noise. My inputs were pretty noisy and a bit crackled sounding, so as other's on AK have suggested, I replaced the C1344 Hitachi transistors on the mic/line board. This seems to have remedied that situation. I did have some speed wobbles here and there, so I cleaned the white multi-pin connectors as described in another AK thread on speed issues. Playback sounds very good for the most part. I am awaiting arrival of an alignment tape to tweak these further and to get them to specification. I've also adjusted the meter level pots (as per service manual) as well as the playback levels for both FWD and REV playback heads. Additionally, I have air blasted (gently) the boards to clean them up and vacuumed out the chassis. I also have cleaned all of the top row of switches and the speed control pot. I replaced the tape counter belt as we probably all do. I've been working on my RT-707 the past few weeks.
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