Uploaded November 2024 | Updated September 2026, 2 weeks ago
OK, everyone I’m looking for your input. I have a Pioneer RT-707 reel to reel that I believe has a reasonable number of hours on it, I got it really cheap, and the performance has been absolutely terrible to date. Recording remains to be an issue with fluctuations and dropouts on multiple new blank tapes.
By using a high-quality tape and recording a 1K test tone on a decent Akai GX-4000D with a AC governed motor, I was able to follow the service manual and make all sorts of improvement adjustments to the 707.
To date here’s what’s been accomplished:
-New meter bulbs (one was actually burned out. The lead was still attached)
-New auto reverse bulbs one was burned out. Presence of two burned out bulbs tells me this has some hours.
-Lubrication of all items below the face plate
-Rubber restore rejuvenation of pinch roller, which appears to be in good shape
-Speed adjustment from tape recorded on different deck that uses AC governed motor
-Tape playback output levels adjusted to be proper at zero and I believe that they’re pretty close to being perfect
-VU major adjustment not only from the O adjust on the face plate, but also the two internal potentiometers
-Supply and take up real tension non-scientific adjustments, tape was originally pulling too hard and tape and kept falling off of the capstain. Used to fall off all the time at different spots of the tape haven’t had a problem since.
-Playback azimuth forward and reverse adjusted.
-Record Azimuth adjusted, but seems to be a little temperamental even with tilt adjustments.
-4 EQ pot settings (not scientifically) set to the same millivolt number on output, I could not get accurate decibel voltages but they’re all equal at around 140mv and they were all off by about 20 mV from each other
-No bias adjustments or record potentiometer adjustments made (need to bring out the oscilloscope for this)
-Tape heads have been thoroughly cleaned and demagnetized. I do see where and it does seem to be a little uneven, but the heads generally in OK shape in my opinion.
The unit performs exceptionally well on playback, foreign tapes sound great. Really no noticeable wow or flutter.
This unit does not record right though - I hear dropouts, and the high frequencies sound a little harsh and raspy.
Before I invest on anything further, I would like your feedback.
Should this be recapped and re-transistorized? Should I invest on a test tape and also proper decibel meter? Should I re-bias this properly using a scope per the manual instructions?
Of course the answer is yes to all, but I’m a hobbiest and while there’s so many videos and problematic issues with these, I just wanted opinion before making the next move.
Video is a verbal walk-through.
Also posted two pictures below. I have reason to believe the record head might have uneven wear. That’s my remaining problem.
OK, everyone I’m looking for your input. I have a Pioneer RT-707 reel to reel that I believe has a reasonable number of hours on it, I got it really cheap, and the performance has been absolutely terrible to date. Recording remains to be an issue with fluctuations and dropouts on multiple new blank tapes.
By using a high-quality tape and recording a 1K test tone on a decent Akai GX-4000D with a AC governed motor, I was able to follow the service manual and make all sorts of improvement adjustments to the 707.
To date here’s what’s been accomplished:
-New meter bulbs (one was actually burned out. The lead was still attached)
-New auto reverse bulbs one was burned out. Presence of two burned out bulbs tells me this has some hours.
-Lubrication of all items below the face plate
-Rubber restore rejuvenation of pinch roller, which appears to be in good shape
-Speed adjustment from tape recorded on different deck that uses AC governed motor
-Tape playback output levels adjusted to be proper at zero and I believe that they’re pretty close to being perfect
-VU major adjustment not only from the O adjust on the face plate, but also the two internal potentiometers
-Supply and take up real tension non-scientific adjustments, tape was originally pulling too hard and tape and kept falling off of the capstain. Used to fall off all the time at different spots of the tape haven’t had a problem since.
-Playback azimuth forward and reverse adjusted.
-Record Azimuth adjusted, but seems to be a little temperamental even with tilt adjustments.
-4 EQ pot settings (not scientifically) set to the same millivolt number on output, I could not get accurate decibel voltages but they’re all equal at around 140mv and they were all off by about 20 mV from each other
-No bias adjustments or record potentiometer adjustments made (need to bring out the oscilloscope for this)
-Tape heads have been thoroughly cleaned and demagnetized. I do see where and it does seem to be a little uneven, but the heads generally in OK shape in my opinion.
The unit performs exceptionally well on playback, foreign tapes sound great. Really no noticeable wow or flutter.
This unit does not record right though - I hear dropouts, and the high frequencies sound a little harsh and raspy.
Before I invest on anything further, I would like your feedback.
Should this be recapped and re-transistorized? Should I invest on a test tape and also proper decibel meter? Should I re-bias this properly using a scope per the manual instructions?
Of course the answer is yes to all, but I’m a hobbiest and while there’s so many videos and problematic issues with these, I just wanted opinion before making the next move.
Video is a verbal walk-through.
Also posted two pictures below. I have reason to believe the record head might have uneven wear. That’s my remaining problem.
