RE-501 Chorus

[Gil]

Hi all !

I wonder what circuit the RE-501 uses for Chorus ? It doesn't sound like any other Roland or Boss Chorus I know of. Very lush and fat but not exactly similar to wither CE-1, CE-2 or CE-300.
As the CE-1 is supposed to be a replicate of JazzChorus, I guess the RE-501 design is a different ?

[Ice-9]

The Roland RE-501 is an old tape echo unit which uses a looped tape, I am not aware if they have made a modern version in a pedal format with electronics with the same name, I only know of the old tape machine RE-501

[Gil]

Sure, and a great Chorus unit as well

[dwmorrin]

Here's the chorus section of the RE-501's schematic.
You can see the full schematic here: http://www.proharmonic.com/images/schema/re-501/501-main.jpg

[Ice-9]

Excellent schematic, I had originally thought the 501 chorus was done using the tape taps with modulation. The schematic shows it is done with Bucket brigade chip (MN3007 +clock) nice find. Thanks for posting.

[wavley]

The lack of a speed control is really annoying.  I keep saying that I'm going to put one in and I haven't yet, I sold my Micro Chorus as soon as I bought my 501 and I've regretted it ever since.  I also had bought a Jaguar Custom Baritone around the same time and thought it would be instant Robert Smith, but I had a JC-160 at the time and there was no comparison at all.  It's not a bad chorus at all, but by the time you get it in that really lush territory it's like "Well, I guess the Space Echo decided what tempo the song is in."

Maybe this will be my motivation to put a rate control in.  Let me know if you need me to take any measurements or anything, the service manual is on the net and pretty comprehensive.

[noisette]

The lack of a speed control is really annoying.  I keep saying that I'm going to put one in and I haven't yet, I sold my Micro Chorus as soon as I bought my 501 and I've regretted it ever since.  I also had bought a Jaguar Custom Baritone around the same time and thought it would be instant Robert Smith, but I had a JC-160 at the time and there was no comparison at all.  It's not a bad chorus at all, but by the time you get it in that really lush territory it's like "Well, I guess the Space Echo decided what tempo the song is in."

Maybe this will be my motivation to put a rate control in.  Let me know if you need me to take any measurements or anything, the service manual is on the net and pretty comprehensive.

Would that be making R29 adjustable?

I happen to have a RE501 and I love the chorus on it, but what I also find annoying, is that the motor is always running,
unless you power the whole unit off.
During a lenghty recording session I always keep thinking of all those precious little wear parts...

[wavley]

The lack of a speed control is really annoying.  I keep saying that I'm going to put one in and I haven't yet, I sold my Micro Chorus as soon as I bought my 501 and I've regretted it ever since.  I also had bought a Jaguar Custom Baritone around the same time and thought it would be instant Robert Smith, but I had a JC-160 at the time and there was no comparison at all.  It's not a bad chorus at all, but by the time you get it in that really lush territory it's like "Well, I guess the Space Echo decided what tempo the song is in."

Maybe this will be my motivation to put a rate control in.  Let me know if you need me to take any measurements or anything, the service manual is on the net and pretty comprehensive.

Would that be making R29 adjustable?

I happen to have a RE501 and I love the chorus on it, but what I also find annoying, is that the motor is always running,
unless you power the whole unit off.
During a lenghty recording session I always keep thinking of all those precious little wear parts...

I'm not as up on LFO's as I should be, but that sounds right to me.  The always running was an answer to stop/start tangles that sometimes happen with the other models, plus the 501/555 have tails.  I mostly use the 501 for vocals these days because I prefer the grittier sound of my modded out 101 for guitar, plus I love to run the feedback and speed up, stop it turn the speed and intensity down, and start it again, so far I have not been able to find anything other than space echoes/Korg Stage Echoes that can make that sound.  With the wear thing, I wouldn't worry about that too much, the only things that currently can't be easily replaced are the heads and I have a feeling that if you really put your mind to it suitable heads could be modified to fit.  The bearings for the motor and new pinch rollers are easily had.  My 101 is easily as old as me and I've been using it for marathon sessions for over 20 years and I'm certainly showing more wear than it.