Good luck on the fix. Hope it's nothing major. lolbou's tip was right on the money. I removed the cables, cleaned the connector pins, cleaned the switching jack contacts, re-connected and success.....beautiful rich Univibe chorus and vibrato. Excellent. Glad it wasn't a serious problem. :thumbsup F...

rocklander wrote:and in response.. turns out it's an LM301a
the board clearly states it as IC1 so I'm a happy camper

Glad you were able to find that schematic... and between The Rat and the RM pedals, it sound like they'll most likely find a good home...

greenskull wrote:Thanks everybody. I went ahead just ordered another board and will try again this time with sockets.

Are there still boards available from the original buy? If so, I'd love to grab a couple...

Cheers...
Steve

Hey everyone... I saw a mention of the MXR Sustain pedal in the thread about the Marshall ED-1 Compressor. I just happened to get one I bought a few days ago on eBay in the mail tonight, so I thought I'd take a few quick gutshots since there didn't seem to be much info available on it. SAM_0170a.jpg...

Apologies... I accidentally posted the first schematic inline twice, and then attached the Vol/Compressor as a separate attachment at the end, but they're both there for reference.

Also have a look at the (somewhat rare) MXR Sustain Unit - not the Dynacomp. Again, the OTA provides the negative feedback for a TL072 op-amp. MXR's transistorised rectifier was a bit "over the top" in the Sustain Unit, but it worked really well. Hello Mic, Thankyou heaps all very helpful...

1N916 - Supposedly* the stock SD-1 diodes. Pretty smooth and dynamic (it's the rest of the circuit that sounds like junk) Here's a schematic I had for the SD-1. Not sure where I got it, though, so I can't say for sure it's 100% accurate... It has some 1N916s in the drive section of the circuit. Bos...

Good tip, thanks. I just put mine back together and for the first time ever it doesn't 'vibe. Sorry to hear that, BB. Despite being a trained technician, I always get a little case of nerves when I pull one of these things apart, for just that reason. Perhaps I'd feel a bit more at ease about it if...

This one ... MXR Phaser. See the talk about the phasing circuitry in this thread ... :wink: Much appreciated, lolbou... I knew it looked interesting, but I didn't have any idea what particular model I was looking at ... I guess the "161-4001" code at the bottom right should have been a ti...

As this "univibe" seems to be a standard 4 stage phase with FET's it would be interesting to see in which extend it is following the concept of a phase90 with altered coupling cap values. Which is more or less what people tend to call "univibing" when they rape a phase90 with al...

Hey all... I was just rummaging through my ever-growing archive of poorly-labeled schematics and came across this MXR factory schem sheet... MXR-Phaser.gif Does anybody know which version of the MXR Phase this is? It appears to carry a date code from '81, but other than that, it doesn't really tell ...

Yep. JFETs. All four are Fairchild 2N5952. Expect something looking like the Phase 90 4-stage circuitry... :wink: That would certainly explain the swirly quality... :lol: I'm nowhere near familiar enough with these circuits to recognize close parallels to other effects. I'll have to dig up a schema...

No bulb/LDRs in this one. Opamp phase stages. I guess it's all around the TL074, on the right of the switch... By golly, I think you're right....no lamps or LDR's. Completely different design to our "vintage" UV-1's. How does it make that nice lush stereo chorus that Tonetweaker likes so ...

For those prices, I would have just paid Mr. Trower to play a gig at my house. :lol: Oh yeah, and they're even more expensive here in Australia. Late last year there were some large online stores listing UV-1 & footcontroller pair for around $950, without mentioning that they were clearance sto...

I stand corrected. Musician's Friend shows the UV1 as discontinued, but both the UV1 and the expression pedal are still available on the Dunlop site... for a small fee. :shock: UV1-US UNIVIBE EFFECT UV1FC UNIVIBE FOOT CONTROL For those prices, I would have just paid Mr. Trower to play a gig at my ho...

lolbou ~ No hijack intended... but I wanted to let you know that I took the UV1SC apart tonight and created a thread for the gutshots. Enjoy! I haven't actually taken my UV1 apart, but I'd suspect the two units share a bit of common circuitry. Nice shots. It looks like there may be a little less ci...

After a fairly long wait, this pedal arrived... broken. It passes clean tone, but the signal is still dry when the footswitch in pushed. There's also no LED to indicate whether or not the effect is engaged. I'm going to have to do a little desoldering on this one to get the board out. The leads for ...

Sorry about the stray shot at the end. It got separated from the herd somehow, and there's no edit function available in this section.

I loved it so much in fact that I also bought the UV1SC too. Time to open it and take pictures! :wink: lolbou ~ No hijack intended... but I wanted to let you know that I took the UV1SC apart tonight and created a thread for the gutshots. Enjoy! :) I haven't actually taken my UV1 apart, but I'd susp...

More... SAM_0149a.jpg SAM_0150a.jpg SAM_0151a.jpg SAM_0153a.jpg SAM_0154a.jpg SAM_0157a.jpg I tried to take some close in shots, since the board is pretty tightly spaced. Please excuse the "jittery hand" quality though. :P The board is pretty tightly held in by the pots, switch and jacks.....