Question about playback speed and uneven balance

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markoneswift

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Dec 11, 2015
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Hey everyone,

I've just put a new drive belt on my Toshiba RT-8097 and all seems well but I must admit I think the playback speed is a little slow. Is there any way to test this, any clever solutions ?

Also, when playing tape, the balance doesn't work properly. I get full sound from the left channel with the balance adjust set anywhere between full left and centre. Once slid to the right, the right channel is very quiet and crackles a fair bit when the slider is altered. Volume adjustment makes little difference.

I've tested the balance slider on CD and radio playback and it adjusts the channels fine. It's just the tape deck which is 'off'.

Any ideas why this would be ? Thanks :-)
 

goodman

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One of reason maybe is disbalance of tape head.
You must adjust azimuth of tape head with little screwdriver.
Try to play different tapes to make adjustment.
When you finish balance must be OK and high frequency - clear.

About tape speed, you must find little potentiometer and adjust him.
Listening song on tape and on youtube, must be with the same tempo and speed.
Good luck...
 

crazygamer

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Jul 31, 2015
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goodman said:
One of reason maybe is disbalance of tape head.
You must adjust azimuth of tape head with little screwdriver.
Try to play different tapes to make adjustment.
When you finish balance must be OK and high frequency - clear.

About tape speed, you must find little potentiometer and adjust him.
Listening song on tape and on youtube, must be with the same tempo and speed.
Good luck...
This potentiometer is in motor, small little hole is there, put very small Phillips screwdriver in, play cassette and listen to it. When you replace belt then speed may be little "off" as belts are with different tensions. Some motors don´t have that small potentiometer, like my small Sony CFS-45. All Toshibas i´ve worked on have had that small pot. :yes:
 

BoomboxLover48

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Dec 3, 2010
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crazygamer said:
This potentiometer is in motor, small little hole is there, put very small Phillips screwdriver in, play cassette and listen to it. When you replace belt then speed may be little "off" as belts are with different tensions. Some motors don´t have that small potentiometer, like my small Sony CFS-45. All Toshibas i´ve worked on have had that small pot. :yes:
Good recommendation!

Most tape speed issues can be corrected like this. I used plastic 2mm wide tip flat head screw driver for this use. You need to drop it straight in and gently turn it to feel it catching on the screw head. In some a small 45 degree tun and bring it back to original place rectified it. In other cases you might have to change it from the original set position.
 

markoneswift

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Dec 11, 2015
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Thanks guys, great tips. I'll have a look at the motor tonight. I have plenty of small screwdrivers as I also repair and modify digital cameras. Good tip about YouTube to compare the song speed.
 

crazygamer

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And also make sure it´s studio recorded, many self recorded cassettes tend to be little bit slower. By studio cassettes i mean original cassettes published by record company. :yes:
 

markoneswift

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Dec 11, 2015
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crazygamer said:
And also make sure it´s studio recorded, many self recorded cassettes tend to be little bit slower. By studio cassettes i mean original cassettes published by record company. :yes:
Yep, it's an original copy tape not a home made one.
 

markoneswift

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toshik said:
Do yourself a favor and keep the head adjustomnt as a last resorto!
Will do - any other ideas why the balance might be off but only on tape ?? It's not like I'm really bothered actually, as I have only a handful of tapes anyway. I just don't like things that don't work :-)
 

markoneswift

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Dec 11, 2015
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Aotearoa New Zealand
baddboybill said:
Here is what in in back of motor looks like. Has rubber type cover as well



Bad Boy Bill
Thanks mate, I had already found it :-) As instructed, inserted a small flat screwdriver and twisted around a little. I felt it drop into the pot adjuster so turned a wee bit which reduced the speed further. I then went back the opposite way and reached what felt like a 'stop', but the speed at that point seemed almost perfect so I'm happy to leave it there.

Now, about auto reverse. It doesn't work - the tape reverses or I can manually do it by hitting the other play direction but the tape immediately auto-stops. Any ideas on this ? I must just leave it alone as I won't even play tapes much, if ever lol.
 

crazygamer

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Jul 31, 2015
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markoneswift said:
Thanks mate, I had already found it :-) As instructed, inserted a small flat screwdriver and twisted around a little. I felt it drop into the pot adjuster so turned a wee bit which reduced the speed further. I then went back the opposite way and reached what felt like a 'stop', but the speed at that point seemed almost perfect so I'm happy to leave it there.

Now, about auto reverse. It doesn't work - the tape reverses or I can manually do it by hitting the other play direction but the tape immediately auto-stops. Any ideas on this ? I must just leave it alone as I won't even play tapes much, if ever lol.
When you screw it all the way back then it won´t stop, it just plays reeeeaaaaaaaallllly slowly. Glad you got it alright. That reverse play option is also present with my older Toshiba RT-170s too, but it works little bit different, audio head spins 180 degrees when you press reverse or forward play direction. Auto reverse doesn´t work on mine too, but that doesn´t bother me much, i can do it myself too. Even Auto Stop doesn´t work on many boomboxes i have, i know it´s actually easy fix, small tab that disengages the motor is just bit stuck. Good luck with your restoration job, it´s very rewarding once you´re done :-D :yes:
 

goodman

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Jun 14, 2011
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markoneswift said:
Also, when playing tape, the balance doesn't work properly. I get full sound from the left channel with the balance adjust set anywhere between full left and centre. Once slid to the right, the right channel is very quiet and crackles a fair bit when the slider is altered. Volume adjustment makes little difference.
One of reason maybe is disbalance of tape head.
You must adjust azimuth of tape head with little screwdriver.
Try to play different tapes to make adjustment.
When you finish balance must be OK and high frequency - clear.

Other reason for this problem maybe is bad contact:
You must clean function switch and playback/rec switch on board.

Here is a idea how to stop tape motor when you use line in jacks:
https://boomboxery.com/forum/index.php/topic/24579-sanyo-line-in-vs-aux-in-mt4290/?p=307003
 
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