Tascam TSR-8 Tension issue

[soul]

Hey all,
My first post here. I have a TSR8 that I am all of a sudden having playback speed issues with. I read the manual and found the adjustment pots for the two reels. I don't have a tentalometer, but I got them to feel pretty balanced. The playback is normal for a few seconds, then all of a sudden it starts speeding up, or maybe even slowing down. Is this because I don't have the tension set right? or is there some control board part that might be faulty? Thanks for any advice you can offer

 

[SkywaveTDR]

I had to go look but the TSR8 is a belt drive deck and like all other decks has a capstan bearing that requires yearly oiling and is also known on occasion to need a new Pinch Roller rebuild as they get sticky and will affect the speed as well. So which one is wrong? I can only say if it is in my shop. Adjustments of tension by a person that has no measuring device is a sure fire way to have the tensions off. I see local shops do X1000 and X2000 servo tension decks all the time and do they get them even close? NO not at all. I keep on turning then down from 190 to 200 g/cm when they are suppose to be at 50g/cm.
If you are going to work on the product then get the right tools, with MRL alignment tape and Tentelometer you can easily be into $550 just for those two if not more. You can never work on the deck correctly with out these tools and tapes. That is just the way it is. Then on top of that guessing that the tension is the problem complicates the analysis and is not at all a good guess.

 

[soul]

Thanks @SkywaveTDR ! I think the parts you mentioned, like the rollers, are good. It was fully serviced by well-known tech in NC before i bought it from a very respected owner! Then I only used it for several hours since over the past few years and it ran perfectly until recently. Could it have been changing speed because I was at the end of the tape roll? I definitely messed up the tension now by guessing and tweaking blindly.The equip needed to properly diagnose is gonna be cost prohibitive, so either I hack away at it or send it to a pro. What would it cost to have a pro tweak it? thanks, steve

 

[wkrbee]

Verify the capstan belt is not slipping.

 

[SkywaveTDR]

Cost can not be stated based on a symptom that we do not know what is the cause.
Right now I have so many unit here that I can not take more in maybe for at least a few months.

 

[soul]

@wkrbee Can you point me in the right direction toward checking the capstan belt? I looked through the manual, cant find it anywhere. The playback is fine for a few minutes, and then it speeds up sometimes significantly, sometimes slightly. If I stop playback and restart, then it plays at normal speed again

 

[SkywaveTDR]

On the manual page 6 is shows the unit with top front panel removed and the motor pulley and belt are clearly visible plus it notes the capstan shaft which is all cases links to the flywheel that usually has the belt around it to the motor pulley.
Also in many decks there is a switch and a Pitch control that is a pot that can get dirty. Otari MX5050 is very well known for this. The TSR8 also makes use of U5 4066 IC which is a Cmos bilateral gate and these are parts that in other equipment are known to fail. These are the switches of the three modes of operation of the capstan servo and these are all possibles but start with oiling the top motor bearing, Capstan bearing by taking the capstan shaft out and I use AMS Signature series motor oil that is a synthetic and has given me wow and flutter as low as .0135% in a BR20. The head base needs to be removed to get to the flywheel and belt- doing it the other way is more amateur and does not oil the deck correctly.

 

[soul]

@SkywaveTDR @wkrbee I bought a new capstan belt, got the TSR8 on the bench, gonna replace it tomorrow. fingers crossed. Thanks for the advice!!

 

[SkywaveTDR]

Remember to oil the capstan bearing- too many people skip this and then never get good results.
Why put new spark plugs in a car if you are not going to put gas in it?

 

[soul]

Is that underneath the capstan motor?? I got the belt swapped out, and seems to have solved the problem!! thanks again!

 

[SkywaveTDR]

The capstan bearing is the thing the capstan shaft goes into and takes all the load of the pressure from pinch roller. This is in front of the flywheel.

 

[soul]

just getting back to this. I did swap out the capstan belt (thanks!) Unfortunately, I tweaked the tension pots before that, and still have a little bit of a speed issue. The good news is I just bought a Tentalometer! So, once I get it in the mail, I can get back to work and hopefully be working 100% thanks for all your help and guidance

 

[SkywaveTDR]

Yes, That tool is a very much used tool on some machines. Especially on those machines that are easy to get off the reference and the TSR8 usually does not have that problem.

 

[soul]

I inadvertently went in and tweaked the pots that control the tension (before I changed the capstan belt). So now I gotta get them calibrated, cause the tape playback slows down very slightly, noticeable after a few minutes of play

 

[SkywaveTDR]

Tension usually does not cause that but lack of oil in bearings or a decaying power supply. If back tension is way out of specs then it should be there all the time.

 

[soul]

Ill oil the capstan bearings too. I know you told me to do that before, and I forgot. Thanks again for your advice!

 

[SkywaveTDR]

Well are we fixed yet? I am working on a deck from this Spencer guy with yellow paint all over head screws and from SC and it was a mess including missing screws. I can sometimes tell from the start when I take case screws out and already see that they are damaged due to a impact wrench drill that numskulls use. He had the wrong belt in this deck too. When people ask me who is a good Technician in SC, NC or Georgia I have NO recommendations and I can tell you some places not to take equipment to for sure as I have seen their messes. I usually send them to
Gerhard in Florida one of my trainees. He is doing well in the short time I have trained him. Some guys were meant for this kind of job and so they catch on very fast- I think he is one of them.

 

[SkywaveTDR]

You know in the Tascam 48 there are tension adjustment pots under the splice block. I wish they would never tell people that they are there. Every idiot and his brother has to go adjusting these pots and then the deck does not work correctly almost 100% of the time. It is not hard to correct unless they wreck the pots and I have had some of those. But why mess with stuff you do not have the right tools to set again? The idiot mind forges ahead regardless of any reason or resultant cost to fix it afterwards. Why do I get pissed? These are things that I should never have to deal with but if there is a screw on a head block the idiot will turn it to make the deck better.
How many decks do I see that have heads pointed to ever constellation in the sky? I just have no sympathy for idiot people. They cause their own high repair bills and me a lot of headaches.

 

[Arjan P]

Every idiot and his brother has to go adjusting these pots and then the deck does not work correctly almost 100% of the time.

Skywave, lighten up!
These are the people bringing you business - money in the bank. If every idiot and his brother knew what they were doing there would be no need for skilled technicians like yourself, right? Enjoy their ignorance!

 

[-mjk-]

I got rich off of idiots.