MXR 130

[waybomb]

I recently purchased a MXR 130 with a bunch of other Carver items. This receiver does not work. It powers up, the two red meter indicators light up, the display lights up "CARVER" only. Pressing any button results in nothing. Turning the gain stop to stop does nothing.

I found another site that has a service manual for this unit. At the end of the manual, there are tech-bulletin type notes. One of them indicates simply taking the cover off and cleaning the back of the display ic with contact cleaner.

Before I do this, I'd like a real tech here to tell me that this is an acceptable thing to do or not.

If you don't believe the problem to be dirty components on the back side of the display, what else could be wrong?

[BillD]

There are several service bulletins that deal with all sorts of problems with the MXR-130, none of which will harm your unit if done properly. Take a copy of the service manual and follow it carefully.

[cring08]

Welcome!!!!!!!!

I have recently joined this group, and everyone is a lot of help!!

I also have the MXR-130. It had a similar problem.

I let my local high-end audio guys clean it, and now it's like new.

I also bought a new set of knobs from Beemers(on here).

You will find great advice here!

[kingman]

As long as you do not get contact cleaner on the front flourscent side of the display...spray away...it can't hurt!!!

[TNRabbit]

Make sure you only use something like DeOxit contact cleaner; you can get a spray can from www.sweetwater.com (ask for Paul); they are a LOT cheaper than most retail outlets.

[duplonge]

A more permanent fix than spraying is to replace the trim cap TC251.

Here's where to get it:

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... RK:MESE:IT

[palmfish]

I'd like to revive this thread with a question...

I am the original owner of a MXR-130 that I recently put it back into service after storing it for 12 or so years. Except for a little scratchiness in the L/R balance control, all seemed to be good. I've been listening to radio and CD's for a few weeks and the sound quality is as good as I remember.

More recently however, I got a new turntable and some LP's to start getting back into vinyl and encountered an issue. When listening to LP's, the sound quality is muddy and dull with very little high frequency information. I am able to turn the treble knob all the way up and "improve" the sound, but it's definitely not normal. To see what might be wrong, I hooked my turntable up to my very new theater system and it sounds very good, so I'm thinking the phono preamp stage in my Carver has deteriorated.

Is this something that happens with disuse? Can I fix this with a contact cleaner and q-tips or is a service visit in order? I appreciate any advice/opinions you might have. Thanks!

[elgrau]

I have a "parts only" 130. If you could describe (location wise) and/or post a pic of the board that as the phono stage amp, I'd be willing to sell you the one from mine (cheaply...cover shipping plus a bit for my trouble). PM me if interested...Ed

[palmfish]

I have a "parts only" 130. If you could describe (location wise) and/or post a pic of the board that as the phono stage amp, I'd be willing to sell you the one from mine (cheaply...cover shipping plus a bit for my trouble). PM me if interested...Ed

Thanks for the offer Ed, I really appreciate it and will definitely let you know. Would you believe my 25 year old receiver has never been opened up? I've never cleaned it or anything so I have no idea where the board is or what it looks like - but that's going to change very soon! I'll check it out and send you some pictures in the next few days.

I'm going to research whether it's an age problem or something else and then decide whether or not a $150 entry-level external preamp is a better choice than repairing/replacing the internal Carver unit. Hopefully somebody on the forums here has some experience with this and will give me an idea about what I'm facing.

BTW, do you live in HB? I'm a CSULB alum from Redondo.

Regards,

Brian

[elgrau]

Yep...in HB. But still probably cheaper to ship then drive down here and pick it up (what with gas at over $3 per gallon!. But we can worry about that later if you decide you want to try a "new" board.

[BillD]

your problem sounds a little like having the RIAA equalization curve applied twice, or not at all. If you are using the phono input, that clears up the second possibility. What kind of turntable/cartridge are you using?

[palmfish]

Bill: It's a Pioneer PL-707 (mid-80's direct drive) with a brand new Shure M97.

Ed: I'm a pilot and come down to OC every March for recurrent training, but you're right - shipping is only a few bucks. I'll take a picture and send it to you with my address in a few days.

[elgrau]

Whichever way...but always glad to meet (in person) another "Carver Crazy" like myself. If you can wait 'till march, it'll still be here! Ed

[BillD]

Hmmm. That combo should be OK. Has the MXR ever had a turntable attached to it before? Are you sure you're using the Phono inputs, not some other input, to the MXR?

[palmfish]

Ed, I opened the top today and sprayed DeoxIT on all the contacts, terminals, and controls. I noted that the phono stage appears to be built onto the board that all the input plugs share. It's mounted onto the rear panel burried behind 2 other larger boards and metal framing. I don't think I'll be the one to go in there and swap it out after all. On the other hand, after further research, I don't think the phono stage is the problem...

Bill, I'm pretty sure it's not the turntable. I had a Denon turntable back in the 90's that sounded fine the last time I had it hooked up to the Carver. My Pioneer turntable also sounds just fine when hooked up to my home theater system. But here's the interesting part...

After the DeoxIT treatment, I did some critical listening on headphones with a few different LP's and some of my "reference CD's." I observed that the high frequencies through the phono stage were basically consistent with that of the other inputs (DAD and AUX). I also found that bass bloat was present with all inputs (Phono, DAD, and AUX). When I turned the bass control all the way down to the left, it sounded pretty OK. That's why I think your idea about the equalization is right on. When I was cleaning it today, I noticed that there was a nice silver dollar sized scorched area on the underside of the metal cover, and on the board beneath that spot, there are 4 blue resistors (2W, 68 Ω HONDA) all in a row that appear to be the cause - the board immediately around these resistors and a neighboring connector look a little discolored too. I don't know if this is normal or not, or whether it's even a contributing factor. But what I do believe now is that in general, heat and time have simply taken their toll on the amp - resistances have changed and as a result, so has the sound.

I'm thinking now that if I want to continue using and enjoying my Receiver for years to come (which I do - it has a lot of sentimental value), I will need to take it to a proper service facility and have the whole unit gone over and refreshed. I've found a couple of shops within my reach that service Carver equipment and I'll take her in for a much deserved spa treatment before the end of the month.

Thanks to both of you for the time and thought you've put into helping me out - I do appreciate it!

Brian