Attempt to resurrect a Roland Space Echo RE-301

[beatnik]

Hello everybody,

I've recently acquired a Roland RE-301 tape echo in pretty bad shape and I'm trying to repair it. The unit suffered from being stored in a damp place.

I've cleaned it up and done a complete re-cap of power supply and main board and now I got dry signal from all the inputs to the outputs. Chorus section works fine as well and so does the spring reverb and the output bass/treble eq.

I still have a big problem with the echo section. The echo functions and controls work as expected, but the repeat sound is not clear and is more like a wobbly mess. I have made a short sample to explain better the thing

https://www.dropbox.com/s/3z82b3xl9r32oma/Audio%201-NORM_01-03.mp3?dl=0

I am afraid the record head could be damaged, and in that case  it would be hard to find a replacement

Do you have any suggestions on what to check to find the problem ?

 

[beatnik]

Here is the original service manual


http://www.interruptor.ch/Roland_RE-301_service_manual.pdf

 

[emrr]

New tape and pinch roller?  That's what you are describing, tape path issues. 

 

[beatnik]

i am using a fresh tape loop

the pinch roller i have not changed it, but it doesn't seem to be worn out that much

do you think the problem is purely mechanical, or maybe there is something else in the circuit ?

 

[mjrippe]

Clean and demag the heads and tape path.  Check pinch roller tension by gently pulling it away from the capstan while running.  If it starts to slip immediately you can adjust the tension as described in the manual.  Replacement parts are available from echofix.com

 

[beatnik]

i have made some adjustments to the pinch roller and tension arm and now it's getting better. before the tape wasn't running smoothly

i can actually hear delay sound, but it's not very strong

in this recording i have the echo volume and intensity controls at max

https://www.dropbox.com/s/qmfdqgt3bo0lzkv/Audio%201-NORM_02-02.mp3?dl=0

it seems to me the delay is not very strong

i've clean the heads but can't hear any improvement

do you think the demag process will help ?

 

[emrr]

It might help. 

I remember the 201 having an internal trimmer that limited the repeat amount, so you could tweak maximum feedback.  I might remember wrong!  The 301 may have something similar. 

 

[sodderboy]

It could still be a tension prob. Try gently pressing down on the tape crossing the heads- cover the finger with twill wipe, cotton glove, tissue even  It is gentle physics at some point.
Mike

 

[mjrippe]

You can also adjust the tension of the copper arm with the felt pad where the tape leaves the covered area.

 

[beatnik]

You guys were spot on, it was a matter of tape tension

I've had to mess around with the solenoid / pinch roller and tape arm to get the optimal tension

Now it's working very good

I notice a different frequency response between the three heads, the third (longest delay) has more high end whereas the other two are darker sounding

I wonder if it's still a matter of calibration. But actually I like having the two options !

Thanks everybody