Hey all! Any advice on this recording issue I have with my Walkman would be greatly appreciated This is a first generation near-mint walkman that has had all the belts, tires, roller, muting module, and eq switching modules replaced. All functions of the walkman appear perfect except for specifically recording mode. I've confirmed with a 3000hz test tape (as well as with pre-recorded albums that sound great to my ear) that the walkman functions properly in playback, rw, ff, and pause. But, when I attempt to record a 3000hz tone onto a blank tape and play it back I get awful results! I first learned about this issue when I recorded my own mixtape and played it back to immediate dissatisfaction. I've included a video of the issue below (uploaded to Google Drive): https://drive.google.com/file/d/10l7pJ8813IHCf32ZsxCYlxc83Srih-2L/view?usp=drivesdk If more information is required please feel free to let me know and I'll do my best to provide it! My ultimate goal with this Walkman is to record my brother's jazz concerts onto cassette, but of course I can't do this if the record function doesn't work. Thanks for the help!! Best regards, Trey
Can you do a WFGUI reading of the W&F for both PB (with a known-good 3kHz tape) and this tape recorded on the unit ? It does sound like W&F and I think there's also a periodic mechanical noise I hear in the video. Is that correct ? If so, is this sound present without a tape inserted ?
Here's a few more videos for reference. Hope this helps! Operation without a tape: https://drive.google.com/file/d/12_4EPaXzcMsso8rcByT6-ycVC3XQMmQ8/view?usp=drivesdk Testing real 3000 Hz tape with WFGUI: https://drive.google.com/file/d/1juuTAP23s3ZOuqp3wGMAA4wO2kmE8Lao/view?usp=drivesdk Testing self-recorded 3000 Hz tape with WFGUI: https://drive.google.com/file/d/1wM4iMg5nNkJ4XJ5BYUQpI4RfitLLhHy4/view?usp=drivesdk The software helped me notice as the minutes pass the machine gets slightly slower. I also noticed that when a tape isn't loaded the paused machine will inch forward and while rewinding the right will continue moving. But neither happen when a tape is loaded.
Interesting. There is no abnormal mechanical sound without a tape. With FixYourAudio test tape W&F is jumping quite a bit, with peaks reaching 0.15% WRMS. Even this suggests a problem, but with music it may not be very obvious. Real issue is with tape recorded by itself, W&F jumping to 1%. Don't see how this could be a mechanical problem, but it's worth testing if pressing the back side of the motor (to put more pressure on the rubber disc) changes anything in this behavior. In terms of the electronics, what can be checked is if the problem is the same with speed tune on. Also, do the main 6V rail and the +11.2V rail drop significanly during recording ? While the +11.2V rail is not related directly to the servo, loading it down too much may cause issues on its input.
When pressing on the motor as you mentioned it seems to make the W&F worse, I believe the motor already has a good connection with the new capstan ring so further pressure causes more harm than good. When testing with the speed tuner on, the same issue with the FixYourAudio test tape still persists but is marginally better, going ever so slightly lower in Hz as the tape progresses. As for testing the rails, what is the best way to perform this test with the lowest risk? I did a small amount of research on this specific test and it sounds like a mistake could damage the irreplaceable CX20084 chip, so I need to make sure I test these correctly. I do have a multimeter for this. Thanks so much for all the help Valentin! This is seriously appreciated. I'm hoping I can get to the bottom of this without sending my D6C to a professional across the world considering I don't know of anybody in Portland, OR or the surrounding area.
There is no risk in measuring these 2 voltage rails. You don't need to touch the CX20084 to do these measurements. See picture attached for points of measurement.
Measuring 6v rail with the negative on GND and positive on 6v (Eneloop Pro batteries only): Machine not in operation: ~5.2V Machine in Play: ~5.09V Machine in Record: ~5.07V Measuring 11.2V rail with the negative on GND and positive on 11.2V: Machine not in operation: Undefined Machine in Play: ~11.64V Machine in Record: ~11.57V
There's nothing obvious so far, the voltage drop in REC is normal given there's more current draw in this mode. I would assume you don't have an oscilloscope, so my next suggestion would be to check some DC voltages around CX20084. In particular the voltage reference at pin 5. Is it stable ? Does it change in REC mode ? This voltage should be very stable, even with some minor changes in the 6V rail. Then I would also check pin 4, 7, 8 and 15. Are these the same in PLAY and REC ? And of course be careful when measuring, not to short out 2 pins of the IC together. For ground probe use the same ground as before.
Each of these voltage readings appear to be relatively stable.. Pin 5 Play: ~1.59V Record: ~1.59V Pin 4 Play: ~0.76V Record: ~0.77V Pin 7 Play: ~3.655V Record: ~3.627V Pin 8 Play: ~5.01V Record: ~4.98V Pin 15 Play: ~4.345V Record: ~4.3V I do notice these readings are lower than what's on the PNG you provided. Is this simply because I'm not using a steady 6v current and each Eneloop Pro battery rests below 1.5V? If so, is this bad the readings are lower? Is this normal? Thanks
I believe this may be a mechanical issue because I just observed a tape stopping extremely briefly (maybe a quarter of a second) right when the end of the leader tape reached the pinch roller. I remember when replacing the pinch roller the new one from FixYourAudio fit tighter than the stock pinch roller, but I thought nothing of it. Maybe this W&F is being caused by friction? Would this track with the information I've provided you? I read a thread including a response from Deb64 about sanding the pinch roller hub to prevent this; I will try tomorrow and update with my findings.
Yes it does look like a mechanical problem, what's curious is how it gets triggered only in record mode. A hard to turn roller can increase the W&F, but then again why that happens only in REC ? When installing these rollers, the pin must be centered in the hole when pressing it, otherwise you risk pinching the plastic hub and roller will turn hard. If that's the case you can use a drillit of higher size than the hole to create a small chamfer.
It turns out the tight pinch roller was the issue and so far everything seems in order! The FixYourAudio 3000 Hz tape is stable throughout all 15 minutes now, and I did a test recording that also sounds near-perfect Thanks again for all the help Valentin!!
The only other issue I know of currently is the record level knob creates static noise when I bump it, but this doesn't effect operation enough for any immediate fixes. I did attempt to clean the potentiometer with CRC electronic cleaner and DeoxIT Fader but the same static persists only when bumping the knob, not when turning it as intended.
