Tascam 246 pinch roller question

famous beagle

Well-known member
Hey y'all,

So I got my re-conditioned roller back from Terry Witt and installed it tonight.

Check out these videos, which show the pinch roller while the machine is in play mode.





Is this wobble normal?

The main reason I inspected my roller in the first place was because I was getting a slight pitch wobble on play back. This seems to be mirroring that, but I admittedly don't have much experience with rollers. This is the first time I've replaced one.

By the way, when I shot this video, I had forgotten to add the E-type ring onto the pole that sticks up through the pinch roller assembly. I did add it, and the wobble is still there.

Any input is greatly appreciated!

Thanks
 
Never mind. I sent the video to Terry, and he confirmed that it was not right and asked me to send it back so he could fix it.
 
Terry is a standup guy who does quality work. I had an issue once when I got an Ampex pinch roller rebuilt. Honestly I'm not sure the issue was his fault, and he knew it too. But he was like "send it back...I'll make it right no charge." And he did. I will use Terry's services again and again.
 
That's good to know. I'm sending it back to him today, and he says he'll get to it right away. I can definitely say that his communication has been excellent thus far.
 
I seem to recall when I had my problem, and again we weren't even sure he was responsible, total turnaround was like 3 days including the shipping time both ways.
 
I am getting that same wobble with my 244 after replacing the roller with a plastic core AV1722 roller. I fitted another roller from the same supplier in my other 244 and it worked fine. I've tried another roller from the same supplier and it is the same - w&f coming up at a shocking 0.2% RMS. I've noticed that the rubber on these rollers seems to deform if you pinch it with your fingers and I wonder if some sort of deformation is happening. Can anyone recommend a supplier of good rollers in the UK by any chance?
 
I am getting that same wobble with my 244 after replacing the roller with a plastic core AV1722 roller. I fitted another roller from the same supplier in my other 244 and it worked fine. I've tried another roller from the same supplier and it is the same - w&f coming up at a shocking 0.2% RMS. I've noticed that the rubber on these rollers seems to deform if you pinch it with your fingers and I wonder if some sort of deformation is happening. Can anyone recommend a supplier of good rollers in the UK by any chance?

That sucks. Yeah I'm sure my W&F measurement would be spiking too if I knew how to measure it. :) I'm sorry you're having trouble finding a good second roller. Good luck!
 
That sucks. Yeah I'm sure my W&F measurement would be spiking too if I knew how to measure it. :) I'm sorry you're having trouble finding a good second roller. Good luck!
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I've used wfgui to measure W&F - you can download it here:

A.N.T. Audio :: Welcome :: Library

Just record a 3000 Hz tone (I downloaded a free signal generator app), digitise it and load it up into wfgui. I get around 0.024% RMS (DIN weighted) for one 244 I fixed with a new roller but an alarming 0.16% with the latest.
 
[/I]

I've used wfgui to measure W&F - you can download it here:

A.N.T. Audio :: Welcome :: Library

Just record a 3000 Hz tone (I downloaded a free signal generator app), digitise it and load it up into wfgui. I get around 0.024% RMS (DIN weighted) for one 244 I fixed with a new roller but an alarming 0.16% with the latest.

Thanks a lot for the tip; I'll give it a shot once I get my roller back and installed. :)

Just so I understand the process, you record a 3kHz tone on the 4-track, play that back and transfer it to your computer, and then import that file into the WFGUI program, correct?
 
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Yes that's right. Best just to record the 3 kHz tone on one track on the Tascam - I use track 1 and set the level to about -3dB. Then play that back in to the computer and record at a moderate level - say around -10 dB. Save as a mono .wav and let wfgui load this. I had to play around a bit getting the level of the recording right - it doesn't work if the level is too high. Hope you can get it to work! I'd be very interested in your results.
 
Yes that's right. Best just to record the 3 kHz tone on one track on the Tascam - I use track 1 and set the level to about -3dB. Then play that back in to the computer and record at a moderate level - say around -10 dB. Save as a mono .wav and let wfgui load this. I had to play around a bit getting the level of the recording right - it doesn't work if the level is too high. Hope you can get it to work! I'd be very interested in your results.

Cool, thanks! I'll let you know what I get.

Although, I don't know if I want to know! Ignorance is bliss, you know. :)
 
By the way, Findlay, can you hear artifacts on your unit with the really high W&F measurement?

The reason I checked out my pinch roller in the first place was that, after finally starting to track my first song on my 246 after getting the record/playback levels calibrated, I started hearing some pitch warble. Check it out. Are you hearing anything like that?
 

Attachments

  • 246 pitch issue - 2 minutes in.mp3
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Famous Beagle - I just listened to your track and I had something similar when I fitted the first roller on my other 244. It settled down after an an hour or so running to a just noticeable amount of W&F without any of these artifacts. (measured at 0.14% RMS or about 3x the spec). I think it may be due to a slight looseness of the rubber on the roller. I fitted another roller and this also had a lot of wobble - thinking it might be something wrong with the spring tension I gently applied some pressure to the roller arm during play. This produced the effect in your track, with pronounced wobble and W&F. I could see the rubber on the roller was becoming slightly ovoid. Again it settled after an hour or so - no artifacts but W&F about 4x spec.
 
Famous Beagle - I just listened to your track and I had something similar when I fitted the first roller on my other 244. It settled down after an an hour or so running to a just noticeable amount of W&F without any of these artifacts. (measured at 0.14% RMS or about 3x the spec). I think it may be due to a slight looseness of the rubber on the roller. I fitted another roller and this also had a lot of wobble - thinking it might be something wrong with the spring tension I gently applied some pressure to the roller arm during play. This produced the effect in your track, with pronounced wobble and W&F. I could see the rubber on the roller was becoming slightly ovoid. Again it settled after an hour or so - no artifacts but W&F about 4x spec.

Interesting. Thanks for the info.

I'm just hoping when I get my roller back this time, that it's all good. I've had this 246 in my possession for about 3 years so far, and between the repairs (the unit spent about 11 months at a repair shop because it had to be sent back three times for them to finally get it right), a huge work project, and moving, I have still not been able to record anything on it! I feel as though I'm so close if this pinch roller issue is resolved.

The idler tires looked fine, but I went ahead and replaced them as well. I replaced the belts after I got it, so it'll have all new rubber in it.
 
Good idea to replace the belts and idler tyres. Did you use the proper spares for the idlers, faucet washers or "O" rings? I cheated and used "O" rings - it was much easier and they have worked well for over 50 hours play.

I hope you can get the 246 going ok after all this effort. I'm still amazed how good they can sound. My 244 has improved W&F since running a while. I can still see some wobble but it returned a figure of 0.025% RMS this morning and is sounding really good.
 
Good idea to replace the belts and idler tyres. Did you use the proper spares for the idlers, faucet washers or "O" rings? I cheated and used "O" rings - it was much easier and they have worked well for over 50 hours play.

I hope you can get the 246 going ok after all this effort. I'm still amazed how good they can sound. My 244 has improved W&F since running a while. I can still see some wobble but it returned a figure of 0.025% RMS this morning and is sounding really good.

Good news on your 244.

I used (what I assume are) proper spares for the tires. That's what the auction said they were, anyway. And they looked indistinguishable from the ones that were in the machine (which were original as far as I know). In fact, they looked so much alike that I immediately put the old ones in a bag after removing them and labeled as "old" just so I wouldn't mistake for the new ones in case I got distracted/called way before I could install the new ones.

But, like I've heard/read many times, just because the old ones look new doesn't mean they haven't hardened inside, etc.
 
Was it easy to fit the tyres? I was put off a bit by comments that they were difficult to fit and get to run evenly, so I opted for the "O" rings instead.
By the way, if you use wfgui to check W&F when you get your roller back, look for the old version where you let it run from a .wav. The new version uses the microphone to sample audio output and I can't get levels high enough to get it to work.
 
Hmmm ... it seemed very easy to fit them. I haven't run the machine yet since then to see if they look smooth or not (I was waiting until I got my pinch roller back), but it seemed like a very cut-and-dried procedure.

Thanks for the tip on the program. I'm pretty sure I got the latest version, so I'll have to check that out.
 
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