|
Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc. |
|
Thread Tools |
7th Jan 2019, 4:10 pm | #1 |
Retired Dormant Member
Join Date: Jan 2019
Location: Bournville, West Midlands, UK.
Posts: 2
|
Akai 4000D speeding replay
I have a reel to reel AKAI 4000D which has developed a reel odd fault !
It plays back faster than it records , this happens on both speeds I dont understand how this can happen as what ever controls the capstan speed must be common to both record and play I have owned the machine for many years and the fault has just happened ,this has encouraged my wife to speak against the machine and get rid !, I have no intention of doing this it if can be repaired at reasonable cost Any ideas ? Chocolatetony |
7th Jan 2019, 6:53 pm | #2 |
Heptode
Join Date: May 2006
Location: Accrington, Lancashire, UK.
Posts: 978
|
Re: akai 4000D speeding replay
I'll tell you what, Tony, this is an odd one. And yes, as far as I am aware, there can be no difference in speeds between record or play. I will look at the manual when I get home. You need to ascertain which is out, what is it like on previous recordings made on this machine?
|
7th Jan 2019, 10:13 pm | #3 |
Retired Dormant Member
Join Date: Jan 2019
Location: Bournville, West Midlands, UK.
Posts: 2
|
Re: Akai 4000D speeding replay
Yes, will do this. That will tell me if the 'record mode' is slow or the 'play mode' is fast. Logic tells me this problem should not exist, but it does.
|
8th Jan 2019, 7:29 am | #4 |
Dekatron
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
Posts: 7,662
|
Re: Akai 4000D speeding replay
After reading this yesterday I got to thinking, how do you know it is faster on PB than record? Do you have a tacho or speed app or something to track speed on the two function's, or is a gross difference? Or do you mean something else, on PB the track is too fast?
Tony's post is about essentially the same thing. Whenever you have a fault like this on a R2R, change the tape after a good clean of the tape path, especially the capstan roller. Andy.
__________________
Curiosity hasn't killed this cat...so far. |
8th Jan 2019, 9:33 am | #5 |
Heptode
Join Date: May 2006
Location: Accrington, Lancashire, UK.
Posts: 978
|
Re: Akai 4000D speeding replay
Andy and Tony, briefly perused the service manual, nothing yet!
|
8th Jan 2019, 9:51 am | #6 |
Dekatron
Join Date: May 2008
Location: Derby, UK.
Posts: 7,735
|
Re: Akai 4000D speeding replay
Measure 1.9 metres of tape, and time how long it takes to pass through the machine in both play and record (should be 20" without capstan sleeve fitted, or 10" with).
It's difficult to think what could be at fault here, except the motor and its associated capacitor.
__________________
If I have seen further than others, it is because I was standing on a pile of failed experiments. |
8th Jan 2019, 12:50 pm | #7 |
Dekatron
Join Date: Jul 2008
Location: Kington, Herefordshire, UK.
Posts: 3,670
|
Re: Akai 4000D speeding replay
Could this be a fault which has developed recently, so making all pre-recorded material sound fast? I'd be inclined to look at the take-up tension - tensions are high on these machines to start with and if the clutch is binding it could compete with the pinch.
|
10th Jan 2019, 4:27 am | #8 |
Octode
Join Date: Jul 2006
Location: Perth, Western Australia
Posts: 1,969
|
Re: Akai 4000D speeding replay
Not sure if already covered but many Akai machines have a stepped motor pulley for either 50 Hz or 60hz mains operation. Could the 50/60 setting have been accidentally changed?
I have also had Akai machines where the capstan belt stretches enough to ride up on the flange between the two pulleys. Also what degree of speed change between record and playback are we talking about? 1%? 5%? In musical terms, a tone? A semi tone? |
10th Jan 2019, 7:32 am | #9 |
Dekatron
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
Posts: 7,662
|
Re: Akai 4000D speeding replay
"Akai machines have a stepped motor pulley for either 50 Hz or 60hz mains operation" good point Tim.
Andy.
__________________
Curiosity hasn't killed this cat...so far. |