Hello I've thankfully recieved quite a bit of help in the past from this forum; through this help I've gotten my D6C almost fully functional. I did a whole lot of fixing and testing earlier this year but havn't been able to work on it much until recent. Basically all of this past work can be found in the thread here: https://stereo2go.com/forums/threads/wm-d6c-record-issue.11100/#post-90784 My issue now is after playing many tapes (all sounding flawless) I decided to look at the physical tape expecting nothing. Unfortunately I found what appears to be permanent damage on all the tapes I've fed through my D6C. The best way I can describe it is if I play a brand new tape once, you will find small precise crimps equally spaced from eachother. If I play the tape two, three, or more times you will find those crimps from each time the tape was played. Luckily I don't hear much damage from these crimps but it's still unsettling especially for my more sentimental cassettes. I'll include pictures of the damage across a couple tapes. I can't have my WM D6C cause damage to any more tapes of mine. Some advice would be incredibly appreciated. Please refer to my other thread included above so you understand what has been fixed and what hasn't. A lot has already been fixed and tested! All the best, Trey
That's wild looking, I'm not an expert at these issues but it looks like the pinch roller is pinching maybe too tight and embossing the tape. Like Valentine said, if that roller is off center, maybe it's applying too much pressure on one side? Again, I have very little experience with this. Good luck with fixing it.
How does the pinch roller and capstan look ? Seems at first glance that the roller is pulling the tape up/down, although the damage in the picture is not very clearly visible from this angle.
Hello Valentin! It was difficult to capture in the above pictures so I apologize if the damage is not clear. You can sort of see how the light reflects off of the crimps/dents. The capstan is very straight but the pinch roller does seem somewhat problematic now that I'm looking closer. When I recieved it from FixYourAudio I had to sand down the sides because it was very tight in the frame. I'm noticing the tape path on the pinch roller is not perfectly centered which I'm guessing is a problem? There's many things I've fixed in this D6C, but one thing I havn't done is adjust anything in the tape path such as the heads. If you believe this is causing the crimps/dents in the tapes do you have a guide to fix this? I will include a picture and video so you can have a closer look. https://drive.google.com/file/d/19_XKuXU4n1eIlOxYTsbLOaLJ_CF0QWTB/view?usp=drivesdk Thank you so much for the reply!!
For a problem like that I would immediately change the pinch roller without questions then proceed to the troubleshooting, But highly likely rubber is the one to blame for a problem like that. For pinch rollers I feel comfortable with this seller, not sure why but seems he know what he is selling.
Pinch roller is brand new and was replaced with the rest of the rubber so I don't believe that's the issue. All rubber is still supple.
Sorry I did not find the time to read your linked thread, but if this problem appears after replacing the roller this means the new roller is not up to spec, Put in the old one back and see if the problem goes away.
@treynava1 Don't notice anything abnormal apart from something wet at the bottom of the roller (oil ?). The ebay link in post #5 is from FixYourAudio, so rollers are the same as what you already have. However have seen rollers from FYA to cause problems, so this alone is not a 100% guarantee the roller cannot be the problem. I suggest as it was said already to replace the roller with original one and see what happens. If the original proves to be ok, clean that thoroughly and leave that one in place.
You're right, it is the same seller, I just looked at the business card he sent me with the kit. Maybe the OP messed with the pinch roller or modified something, I will find out on my own D6C this weekend when I put in the rubber kit, I'll let you all know, Note that this Walkman works perfectly, the only problem it has is no FFW or REW so I decided to order every piece of rubber on it even if it doesn't need them all.
The pinch roller it usually doesn't need, but the other rubber yes. All D6Cs I serviced are pretty noise due to hardened capstan ring and tend to have low takeup torque due to small idler and loose belt. Generally speaking what needs to be done on these is replace the idlers, belts and capstan ring, re-lube the main rotating parts, adjust flywheel thrust play, motor position and depot/replace the 3 hybrid modules if you have the THT board (most of them have this PCB). Additionally Dolby levels should be checked/adjusted and if one intends to record, level and bias are also to be adjusted on specific tape one wants to record on.
The lack of test tapes makes me hesitate from attempting such adjustments, The best test/calibration cassettes sold today are made on good home decks, better than nothing but not close to a factory made test cassette.
Have to disagree on that. While it is true that the best calibration cassettes sold today are made on good home decks, that in and of itself does not make the tapes trash. It all comes down to how that deck is calibrated, its head, mechanism: - for a speed/W&F test tape, using a quartz lock DD deck gives the best result as aging and drift of a crystal is minimal. - for azimuth, it's important to be full-track (mono head), have a stable tape path and be correctly adjusted itself. etc. Calibrated enough D6Cs to say many of them are poorly adjusted from factory, having audible imbalance. Using a commercially available tape to adjust them fixed the problem. Also Dolby decoding works perfectly after such adjustments. If we were to rely only on factory tapes, that simply means we cannot check or adjust any of our decks and walkmans nowadays.
I didn't say modern test tapes are trash, I said they are not as good as the factory ones, These home decks making those tapes also are aging making them reference decks is not a reliable and sustainable way of maintaining vintage gear, Someone has to come up with a new process of making such adjustment tapes.
I would trust a fresh tape recorded correctly way more than a factory one made 40+ years ago. All tapes have some tolerance, including the factory ones. For example, Dolby level tapes vary between +/-0.4dB (HPR tapes) and +/-0.2dB (test-tape.com). Based on info available, the original P-4-L300 isn't better than any of these tapes in this regard. As far as decks aging, those can be serviced, heads can be lapped I don't see a particular problem in using those decks as long as they are in perfect order. You say one has to come up with a new process. What is wrong with current process and what should be changed in your view ?
I don't want to drag this thread into the wrong directions, In short, a year or so ago I was discussing with a fella who's also a mechanical engineer like me to come up with a process to make new calibration tapes at least for Azimuth and speed adjustment by using a full track 1/2" head to cover a wide range of 1/8" and 1/4" tapes by using an adjustable head mount by a microscope for a near zero tolerance 90 degree head gap to set the azimuth. and a tone generator wheel directly built into the capstan that drives the tape for zero drift to record 3000 KHz (we called it zero drift because the tone generated and recorded on the tape does not depend on the motor's W&F laying it down, no gears or belts), There are several tone rings on the tone generator wheel with different diameters for different tape speeds, Whole pancakes are recorded on a rig and distributed for different formats. We could not find an appropriate head that accomplishes the project in terms of the head gap so we sortta gave up.
Interesting idea, if you can find the right head worth pursuing the project. Maybe worth asking some head manufacturers if they can make a custom one based on your specs. Likely better tapes than what exists on the market can be made, think it comes down to cost at the end of day. My main point was for calibrating a D6C (and pretty much everything else) the best tapes we have are more than good enough to restore them. If in the future we'll have better, by all means we should use better.
Building a new head from scratches would cost thousands of dollars, We were just looking to see if we can find a NOS 1/2" full track head with a suitable head gap, The wider the head, the precise setting the azimuth angle is. It is doable with 1/4" full track head but we lose 50% the tolerance, unless we come up with a better setup using a laser guide rather than relying on an optical magnification and a vertical reference line. Anyway, enough of derailing the thread.
