Restoration Project: Roland RE-201 Space Echo - #2

[culturejam]

Its seems crazy to think that but I thought the same way when I was reading your post. lol

I emailed EchoFix to see if they had any spare switches from their boneyard. If I can get an exact replacement, I can use my good Space Echo as a guide to rewire it.

Failing that, this should work:
http://www.mouser.com/ProductDetail/Grayhill/71C30-1BC-1AL/?qs=sGAEpiMZZMvNbjZ2WlReYhndqMY8foDI6mKDBctiJLI%3d

But it will take some head-scratching to figure out what goes where. I'm dangerously "slow" at understanding switches.

[culturejam]

One thing I forgot to mention:

When changing modes, there is an audible pop in the audio. Kind of like bypass switch pop.

[peAk]

nothing to add but definitely excited to see your progress!

[atreidesheir]

That VU looks like electric sex in the little window.
I like that the reverb tank is manufactured by beautiful girls in Milton.

[culturejam]

More test results:

• Can confirm that the reverb tank on SE #2 is functional. It worked fine plugged into SE #1.
• I unmounted the Mode rotary from the panel and hit it with more contact cleaner and inspected it. It seems to be functioning properly in the mechanical sense.
• The wire from the rotary's terminal that connects the reverb and delay output back to the main board mixer is intact and has full continuity.
• Audio probe indicated no singal on that wire

Next steps:

– Audio probe the output of the reverb tank directly
– Probe SE #1 to see where wet signal shows up and then compare with SE #2

[TNblueshawk]

More test results:

• Can confirm that the reverb tank on SE #2 is functional. It worked fine plugged into SE #1.
• I unmounted the Mode rotary from the panel and hit it with more contact cleaner and inspected it. It seems to be functioning properly in the mechanical sense.
• The wire from the rotary's terminal that connects the reverb and delay output back to the main board mixer is intact and has full continuity.
• Audio probe indicated no singal on that wire

Next steps:

– Audio probe the output of the reverb tank directly
– Probe SE #1 to see where wet signal shows up and then compare with SE #2

You are dug in like a tick on a hound dog. Great read on troubleshooting.

[culturejam]

You are dug in like a tick on a hound dog. Great read on troubleshooting.

It's kind of fun to run down the list of tests to narrow in on the problem. Hopefully I get to the root of the issue soon. It's fun for a while, and then it just becomes depressing.

[gtr2]

Resurrecting this thread from the dead...carrying on the torch

The RE-201 continues its journey...

I met up with CJ to buy the unit in this thread.  It was great meeting CJ and buying the RE-201 was a bonus

I did get a chance to pull the unit apart and continue some troubleshooting on it.

I checked some things like making sure the tape head oscillator circuit was working, checking some voltages through the circuit, and running a square wave through it and oscilloscope probing.

I then used the mic input to do the audio probing as the instrument input wasn't strong enough.  When listening with an audio probe I do have some wet signal on the echo volume pot.  The most I get is a weak reverby/slight slapback delay that you can get to warble by adjusting the repeat rate pot. (probing the echo volume pot lug)  The signal is then reduced to nothing as it works through the rest of the circuit.
There is absolutely no feedback and it can't self-oscillate.

I'm not sure that all the replay heads/switch are actually working but that's something to figure out later.  Unfortunately, all the heads are fairly worn from years of use, but they may still be functional and it is encouraging that there is some recorded wet signal at all.

I'd like to do some more testing but I'm fairly certain the next step is a full recap and pot cleaning/checkup. There are many electrolytic caps in the signal line on these.  I haven't looked up when this one was built but I'm sure it is older than my other RE-201.  The service manuals are pretty hard to read for the component layout etc from years of photocopied copies so I will do my best to document the recap as the info on the net is absent.

It's a bit of a project so I'm sure progress will be slow as I have actual "work" to take care of

Josh

[culturejam]

Unfortunately, all the heads are fairly worn from years of use, but they may still be functional and it is encouraging that there is some recorded wet signal at all.

Huh. I guess I was wrong about that detail. My recollection from last year is that they looked very similar to my other unit, which sounded amazing. But, there's a lot of sleepless toddler nights (and a lot of beer) between then and now. Sorry about that. 

[gtr2]

Haha, no worries! It was more just trying to make an observation.  I've seen worse and my comparison is against ones I have, so I got lucky on those I think, which look practically new.

[mofuzz]

I'm following this resurrected thread closely as my RE-201 has the same problem - only dry output, no reverb or echo. I cleaned the heads, relubed the roller shaft, and loaded a new tape but haven't had the chance to dig into the electronics yet. I'm really hoping it's something as simple as a bad connection...

Please keep us posted on what you find with yours!