Author Topic: MXR 117 Flanger - Ten Foot Pole Test  (Read 242 times)

Bio77

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MXR 117 Flanger - Ten Foot Pole Test
« on: November 19, 2019, 03:13:05 PM »
I'm looking for some advice from anyone who has done repairs on these.  A friend of mine asked me to take a look at his friends vintage MXR 117 (so, friend of a friend to me  :o).  I told him no, because I didn't feel comfortable working on and potential breaking something that valuable.

Today I got an email from my friend asking if I had a spare Reticon 1024A lying around(!), which has me worried they are planning to start pulling parts.

So, should I keep my original inclination and not get involved, or try to save this pedal from certain destruction?  I have a scope and could at least trace the signal out for them.  What do you guys think?

Here is the description of the problem:
"signal is not being bypassed when the pedal is off, so no sound comes out...  when it's activated, the signal comes through but none of the effect is present, so, no effect, only clean"

somnif

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Re: MXR 117 Flanger - Ten Foot Pole Test
« Reply #1 on: November 19, 2019, 04:53:45 PM »
I'd be willing to at least open it and give a visual inspecton, maybe give the switch a poke with a dmm. As long as you make sure everyone involved is aware of the possibility of paint scratches around the screws, And that you aren't guranteed miraculous results.

gordo

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Re: MXR 117 Flanger - Ten Foot Pole Test
« Reply #2 on: November 19, 2019, 06:06:51 PM »
When I was still doing repair work I got to do some seasonal maintenance on a 1961 cherry red Trini Lopez.  To this day the best guitar I've ever played.  Tweaked the neck, cleaned and oiled the board and polished the frets.  This thing was a player so had the bruises to show for it.

It was the most terrifying/thrilling repair I've done and I'm SO glad I got exposed to that instrument.  As above, as long as all parties are aware that things can always go wrong.  I'd say jump on it.

Bio77

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Re: MXR 117 Flanger - Ten Foot Pole Test
« Reply #3 on: November 19, 2019, 08:30:22 PM »
Thanks guys, think I'll give it a go

Govmnt_Lacky

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Re: MXR 117 Flanger - Ten Foot Pole Test
« Reply #4 on: November 20, 2019, 07:11:47 AM »
Looking at the schematic, it appears to be a buffered bypass. If they are not getting any signal out while bypassed it is most likely the switch itself, a misplaced wire, or something grounding out the signal in the circuit.

Did you ever ask whether this pedal has been "worked on" before?

lars

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Re: MXR 117 Flanger - Ten Foot Pole Test
« Reply #5 on: November 20, 2019, 09:26:57 AM »
Thankfully MXR was smart and they originally put the SAD1024 in a socket. It's really the only part in there that makes the pedal "valuable". If you're really worried about messing it up, you can always pull the 1024 and sub in another BBD with a daughter board, so you can run all the diagnostics with no chance of damage to the 1024. There are a million schematics of how to make an MN3007 daughter board for use in SAD1024 circuits. It's a good diagnostic tool to have.
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