Alesis Microverb III Internals

[BoomOperator]

-Tried to move to Geekslutz forum, doesn't look possible from user side-

Hi slutz, long-time fan and first-time poster. I've included decent pictures of the board and I/O configuration for this pervasive piece of gear, so hopefully this thread can become a useful piece of archive on the Alesis Microverb III.

I recently came upon one of these that might have some issues. After not finding much detailed info I decided to open it up and snapped some pics and hoped someone with more experience could tell me any of three things:


1) What happened to two of these 1/4 connectors???






One channel on the input and output looks like it has literally burned up. Is this a common occurrence? Do they need to be replaced? I already had to bend that input jack prong down to make contact with the 1/4 plug. I got the unit for $20 because one channel didn't output in bypass mode. It turned out that input jack wasn't properly making contact with the 1/4" plug. I got it to make contact with just a little push, but the jack prongs still look like they've been mangled somehow.

Even before the fix the unit had played out in stereo when the mix was wet because the left mono input is bridged to both output channels when only a mono signal is received. That brings me to my second question:


2) Does this I/O wiring look alright, or is one wire out of place?

Outputs are on the left. Inputs on the right. Notice that the input wiring is: ground to shield, pink to +, black to -, but the output wiring is green to (+), but instead of going to the (-) the black wire is (sloppily) soldered to the ground shield along with the ground wire...maybe this is part of the bridging process but I can't find any schematics or precedent for how this should look.





Input wiring (looks as I'd expect):



Output wiring (looks funky to my untrained eye; the black wire does not make contact with the - terminal, only with the grounding shield...there is nothing connected to the - terminal at all):




And finally, the third little issue:

3) Light chalky residue on circuit board...cause for concern? Anything I can do about it?





Other pics for future reference:






I appreciate any help. I contribute a lot to boards where I have expertise...A/V circuitry is just not one of them. If you want to mod a Jeep TJ or hack your Wii to play old school NES games look me up! Thanks again for any insight!

[BoomOperator]

OK maybe this isn't the best place to ask, I'm going to try a more vintage dedicated forum. If this needs to come down feel free to delete or I can edit it out, I'll just leave it for now in case the pictures prove useful to someone tinkering with one of these units. Thanks!

[projektk]

Geekslutz section might be better for this.

Sent from my LG-P925 using Gearslutz.com

[BoomOperator]

Thanks for the heads up, it doesn't look like I can edit to change forums, maybe a mod could help if it's appropriate...?

[Big_Bang]

Probably best to drop them a mod a nice PM.

So much stuff going on, either they jump in, or a post gets reported...or a PM

Welcome aboard!

[BoomOperator]

Thanks, PM sent to Jules. See ya in Geekslutz!

[explorer]

Looks like someone who is really bad at soldering has made a bit of a mess there! The chalky residue could be from the capacitors or the battery (both of which may be getting a bit old now)?

[audiotech]

From what I can see from the photographs, it looks like someone "adjusted" the 1/4" connector contacts for better conductivity with the 1/3" phone plug. To me the soldering of the cables look atrocious with massive overheating of the insulation on the conductors. I would guess that they re-heated the wires for the same reason they dented the contacts on the 1/4" connectors, to find out why they were getting intermittents. I can't see the chalky substance very well, but it could just be the remnants of something they tried to use to clean the circuit board, such as alcohol or contact cleaner that oversprayed and hit the board, I don't really know. I looks as if they just wiped it off haphazardly around the components.

Sorry to say it just looks like an amateur technicians attempt to correct an intermittent signal problem.

Dennis

[BoomOperator]

That was my suspicion as well. Not a big deal, it still works well enough for me to have fun with and I don't know any better to say that it doesn't still sound optimal. I was just wondering if there was anything I needed to do to ensure at least safe performance - mainly regarding that I/O wiring which I wasn't convinced was bridged properly.

Thanks for taking a look, if anyone else cares to add to that I'd appreciate any further comments. Thanks again!

[Mixermend]

What does the cable connect to?

I would suspect that somebody has tried to extend the sockets to an external device - or patch bay perhaps - and has 'lifted' the existing jack socket contacts.

This would be necessary because when there is no plug inserted, they usually maintain a short circuit to earth (or ground).

I wonder why it was done in such an ugly way though?

[BoomOperator]

The cable running off the inputs is connected to somewhere on the board or faceplate, I can't recall exactly where and I don't have the unit opened up at the moment. In any case - the condition of that board didn't look factory so I just wanted a fresh perspective to make sure I'm not going to blow my rack through the roof when I patch the Microverb into the loop.

After bending the inputs back into place the unit can bypasses and process sounds as I'd expect. I'm not sure if the occasional crackle and muddiness is endemic to these units or if it's a function of a poor repair job, but for $20 it's fun to have just for using the reverse effect when I'm watching Netflix to put that creepy Poltergeist effect on people's lines. I appreciate the support guys - I guess I'll just roll with it until something catches on fire! Thanks again.

[Jidis]

Make sure you spray out and exercise those pots too. All the Alesis MIDI/Micro gear I've had around here has ended up with gummy crackly pots.