Rane SM82 tech question

[frog.jr]

Hi, I just purchased a handful of old SM82's, and am puzzled to find that they are all only working as mono units. I've opened the box and I see no jumpers or anything. I'm just grasping at straws hoping somebody recognizes this problem. Any ideas?

[dwire]

Here are the link from RANE to their discontinued manual, datasheet and schematic if that helps...
http://http://www.rane.com/pdf/old/sm82man.pdf (MANUAL)
http://www.rane.com/pdf/old/sm82dat.pdf (DATASHEET)
http://www.rane.com/pdf/old/sm82sch.pdf (SCHEMATIC)

If you had one apart and it has not been modified, and they all act like that, AND you have already read the above data, I don't know what to say. I believe I have used those in the past and never had a problem. I think I had to fix one at one point, but that would have been back when I was performing, and I have no records of the favors going on then...

None of this is meant in an offensive manner, but you know that you have an unbalanced input machine there, and it takes two inputs for each "channel" for a stereo output at the end which can be run balanced or unbalanced, BUT IT DOES TAKE TWO CABLES, A LEFT AND A RIGHT FOR STEREO OPERATION. If these are indeed the same thing I used before of a buddy's you want to plug in a balanced TRS cable (stereo type) into each of the outputs, as I think they had some kind of distortion problems if one used TS (mono) plugs instead; you would want to use the TRS, and wire it for unbalanced in order to avoid this if you want to have unbalanced outputs.

You should be able to put the slider "thingy" on a channel in the center between L and R or what have you, and then I think the knob for that pair was how much was assigned to the output stereo pair. (Sorry I have not even opened those .pdf links as you are the one that should if you already have not; so I am going on memories that could be wrong...)

Anyhow, if you have already read this manual, and gone from there and you still have a monaural output, I would not know what to tell you. It seems unlikely that a whole bunch of them would fail exactly the same way, but always possible I suppose. And as mentioned you did open it up and I suppose you would have seen if things had been seriously yanked around to cause them to loose a channel. Is it possible that you looked at the balanced plugs that are TRS in the output, and since they are TRS (stereo) type plugs you thought that they were supposed to each be feeding you stereo? Heck I don't know! Don't trust me either, as that has been well over 10 years ago for me. That is why if you do not have or haven't read the manual and other data linked to above, you should!

Let us know what you find out, or if you have already solved it (or since I am gong off of my burned out memory here, if I am leading you astray; but in that regard, I doubt RANE's manual datasheet or schematics from their archives will do that to you.) If I HAVE helped you here, how about sending me a RANE PI 14 Pseudoacoustic Infector, as that is the one piece of gear the studio will NEVER make it without. If you can't do that, and you units are still screwed up, PM me, maybe I'll buy one of the "screwed up" SM82's from you and throw it in my old MESA guitar rack.

Best of luck, and trust the RANE stuff and not me, as I am way too tired, and burnt out to even know if the RANE unit I used and am talking about here is actually what you have...

Good luck,
dwire

[frog.jr]

Hey, thanks for all the infos. Extremely helpful. And no, I'm actually going to repair my muffler before doing this so I haven't read the manuals yet, but I shall.

My rudimentary testing with this stack of mixers has been just using unbalanced cables. I'll next try using proper balanced-unbalanced adapters as you suggest. That will be easy enough.

But thanks for the links and I am downloading them presently. I'll get back to you after I make my car stop sounding like an airplane. Cheers, frog

[Jay-]

weird, there not mono.

Is it as simple as the output is out?
The out fader dead?

Have you used the TRS out to test or headphone out?
Try one of the many many outs for a test..

I cant believe I have mine after 10 years.
Such a fantastic device. A real swiss army knife in the studio.


EDIT: If I remember its auto mono switching on the inputs.
SO~~~ If the master expand in is busted or stuck to mono perhapse its all mono now.?

[dwire]

Hey, you cannot use a balanced to unbalanced connector to avoid the possible distortion problem. You must use TRS (stereo) and you will only get a MONO output that is balanced of only ONE output channel (or unbalanced if you wire a TRS for unbalanced connection.) as mentioned before, all inputs ARE unbalanced TS (MONO) like a guitar cable.

Are you plugging stereo headphones in or some other stereo item into one output jack to test these units? If so, you should just familiarize yourself with the manual, as well as from your last response, it appears you really SHOULD familiarize yourself with the manual for these units before using them, to not only prevent having troubles understanding their operation, but as well knowing how to properly wire a TRS (stereo) jack for two wire (say guitar or keyboard; MONO operation) not to mention we don't want to see either of you getting hurt! (Yourself or the fine RANE units you own.)

My guess is that you have way too many of those on your hands, and you need to send me some of your "broken" extras...

Good luck! I also doubt you will need to 1) Tear any of them apart, 2) Or contact myself or GS any further AFTER YOU MERELY READ THE DATA I PROVIDED FOR YOU.

If you in fact have the RANE SM82(S) models, which you did not indicate you did, well that info can be had at the same domain; just Google RANE Audio, and it will be right at the top of the list. I would also suggest after you thoroughly familiarize yourself with your units, and start using them to serve whatever purpose for which you bought them for, you still go ahead and visit the RANE site, as if you read the material online at their site which is very rich and rewarding, you would have very little to post about here for quite a while, as they can pretty much take you from being an audience member to an engineer with the data provided for free on their website. Best of luck, and I am going to wait on either my "free" RANE PI 14, or an offer for me to purchase some cheap SM82 broken rack units...

See ya, and let us know when you find out what your troubles are.
Best regards,
dwire

[frog.jr]

Geez I'm so embarrassed, and I wasn't even drunk or anything. Just a bad cable. I think we're OK. I was gonna sell them on eBay.

dwire, check you email.

[frog_jr]

OK, anybody wants one, they are listed here: Rane 8ch Stereo (16 mono) Mixer w/ Power Supply 1U - eBay (item 160254641553 end time Jul-01-08 19:31:38 PDT)