Tascam 234 slow playback??

[GetReel]

So I relpaced the belts on my 234 and last night finally was able to go through my old Porta 02 cassetts. However the playback seems kinda slow, OK it is slow. Its not that far off from the original tape speed, but even with the tape speed adjustment is still off in speed. Most of my old tapes were recorded on 90min CD IT type tapes. I know now those are too long, but if the cheaper Porta 02 could handle it, hmm....Any thoughts, maybe the belt is slipping or the play motors pressure wheel is slipping?

[scotchtape]

You can adjust speed on most tape players at the motor.
Experts on Tascam will tell you more, I am sure.

[Skywavebe]

Hi Get Reel,
Many years have passed since the unit was new. Therefore, it is wise to reduce the drag on the old motor which can still be working well except there are other factors now at this late date to take care of. When a Technician changes a belt- that is NOT all that he does. The standard practice is to remove the Flywheel from the deck and place oil into the dry oil bearing. If you check from before and after you will see a big difference. It is suppose to be the way it is after you oil it. The Capstan motor is old and the oil that may have been in the bearings has long dried up. If one is not to take the motor apart for a reconditioning and oil placement front and back then at least place a drop of oil at the front bearing and work it in. This means with the oil on the bearing pull the motor shaft front and back with a little pressure and spin the shaft. This will also remove drag from the motor. Then once the unit is back together again- and BEFORE you play any tapes clean the Capstan shaft from the front with alcohol to remove oil from in the bearing as it was inserted. Look for an oil retaining clip that fell off it is usually a black plastic washer that keeps oil from creeping out onto the shaft and onto your tapes and place that back on back to the bearing front. After all these things are done and the correct belt is on as in the right size then a speed adjustment can be done with a frequency counter and MTT111 tape or you can use the tape with a Wow and Flutter meter. Speed is set to values as 3009 to 3012 for a regular speed deck with a 234 the speed is at 3.75 IPS so you would set it for 6008 Hz. If the speed will not adjust to the correct speed then the belt is either too tight, there are other friction components or the motor needs to be taken apart and reconditioned or replaced. The capstan speed control requires a long screw driver and it is a center speed adjustment at the lower left side of the deck which should be accessed with the cover off and the Pitch control switch to off. There is a modification that was done to this board for speed control- I can do it at my shop.

[GetReel]

Wow thanks, thats alot to consider. So I may just consider sending it to you. I am pretty handy when it comes to this stuff, but I'll have to look into it further. I know that there are also trim pots on the transports circuit board corresponding to play FF, RWD etc. I'll look into them as well.

[bgates1983]

Hello!

I recently inherited one of these machines and it seems to be having some trouble with the play/record drive system. The unit had been sitting in an attic for some time when it was given to me so the heads are naturally very dirty but surprisingly, the belts look brand new! The deck can fast forward and rewind without issue but whenever I try to play, the speed begins to play at ALMOST full speed, but gradually slows further until it stops. Of note is that when it stops, it also shuts off the record function, if active. It’s just like pressing stop, but without actually doing so. Is this likely to be a motor? What am I looking at in terms of difficulty and cost to repair a problem such as this? I’m really looking forward to getting this running, albeit as cheaply as possible.

Any input is appreciated! Feel free to email me at bgates1983@gmail.com. Thanks!

[Audiomayvin]

Hi Sam!
Concerning the "oil retaining clip", I thought that it is for the exact opposite!-that is that when the capstan shaft is cleaned with a moist Q-tip, the liquid of the cleaner should not run down into the the bearing and dry out the oil.
All the best,
Leon(The Audiomayvin, Montreal(514)739-5403)

[Skywavebe]

Hello Leon,
Good to see you posting again!
The oil retention clip and sometimes just a nylon washer around the capstan shaft can have a two fold purpose and one may not cancel out the other. Being good technicians know not to work the alcohol or cleaner into the capstan bearing and those who clean this part are mostly us guys and not the users to the greatest extent, I just stated the simple comment that does not go far into details to also outline what you think about it.
The symptom to this 234 is either a belt issue, a dirty pot or even a lack of oil in the motor itself but also sound like a power supply problem where the power is there at start up but diminishes due to poor filtering or failed semiconductor. These people want the answer like a sniper but as you know we can't give them the exact cause as there can be very many things to contribute to this problem and the first 10 items that we think of may not even hit on the one thing that we see if we examine it. The responsibility still lies with the fixer who is sometimes a user that has little to no knowledge of the product or electronics. That is why in many of the cases we see here it is best to just send it to a qualified
Tape Technician!