Behringer 1002B mixer Diagram.

peterlnic

New member
Hi All,
I'm new to the site but I hope i'm in the right place? I was in the recording world a long time ago, but now im retired and I want to play again but mainly just for fun as my hearing is now damaged, however I do not let that stop me, I'm also wheel chair disabled and I don't let that stop me either! (but being stubborn helps:ROFLMAO:).

Now I have made a number of the 'OPA-Alice' studio condenser mic's, and I enjoyed doing that, but my current problem is I have a "Behringer 2001B" mixing desk, its a cute little thing, it works well for what it is and I like it, but it has problems with one channel and I need to 'UP' the Phantom power from its 18-20Volts to a bit higher, I am a retired electronics engineer so I'm well happy to do any work myself BUT I need some technical information on it, PLEASE does anyone have a diagram for the 1002B mixer? I know a 'Service Manual' exists for one of these but I do not know anyone with one,
The "Behringer 2001B" is a mains (via an adaptor) and battery powered mixer, but not to be confused with the Behringer 2001, this is quite a different mixer, and a bit daft of Behringer to produce two quite different mixers with a similar model number.

My "Behringer 2001B" is marked "UBB1002B" on the PCB inside, I belive this mixer is also known as the "Behringer MXB2001". The main difference between this 2001B and most if not all other Behringer mixers is it can be battery powered from it's internal batteries, -it works well on battery too!

I have contacted one or two official places and I was advised it's just a cheap throw-away mixer and to buy a new one, well I refuse to accept this, it is perfectly repairable all the parts are off the shelf, and I have the skill and stubbornness to do it and I definitely REFUSE to chuck it away, I can fix it I just need a diagram, anyway, I simply can't afford to buy another.
So Please can someone help this silly old fart out and on my knees, PLEASE CAN ANYONE HELP ME??? I JUST NEED A DIAGRAM!

Take Care All,
Pete.
 

ecc83

Well-known member
Hi Pete and welcome. The problem with 'web schematics' is that they are often wrong! I worked for Blackstar amplification and some 'reverse engineered 'diagrams have found their way online. Most of them inaccurate in some way.
What I am trying to say Pete is that a gash schemo' might be more hindrance than help. I doubt you will find an official Behringer one.

If all you need is full fat 48V spook juice I suggest and external supply. These can be found quite cheaply. I have one that is USB powered. Not quite 48V but close enough (I shall dig it out and test it). Or, you could build one. An AC-AC wall rat and a voltage double/tripler and a regulator.

Are you in or near the UK Pete?

Dave.
 

ecc83

Well-known member
Me again! I have found that mixer on the Behringer site (no map, sorry!) and since it delivers 18V on battery power I suspect it has a DC-DC converter in it?
Often these are discrete devices in older kit Pete and you can faff about with the feedback resistor values to change the OP voltage (Blackstar use a chip + bits to make a 'charge pump' converter that turns 22VDC into 300V and I have frigged one of those down to 48V with excellent regulation) I guess they limit the phantom voltage to preserve battery life?

Dave.
 

peterlnic

New member
Hi Dave,
First a HUGE thank you for getting back to me. (And Sorry, the length of this message has got out of hand😂🤣😂).

im pretty sure the dead channel, well the left half of the dead channel is a failed chip, I think(?) the chip in use Is a TL602c which, if I’m right is an off the shelf job and cheap enough to substitute and try.

yes my main problem is I need more volts for my home made condenser mic’s they are a little thirsty for power and about 22 -23 volts is their threshold, the little mixer happily runs some Audio-technical PRO-37 mics without any problem, but they are happy with 9 volts and up, (they are Great for strings and pianos by the way).
I have come to the same conclusion as you, the phantom must be a step up device, on battery it uses three 9v PP3 batteries, two run the mixer and one for the Phantom, and I agree keeping the voltage low-ish would help save battery power, but that’s no god if it can’t drive the mics, it is very rare I’d need battery power, but it does happen, my daughter got her first degree in music and I love to hear her, her second in the medical world as music rarely pays the bills, but a few weeks back she came across a piano in the middle of a field of sun flowers and of course could not leave it, the piano was in a terrible state as it had rained all night! The sound was so bad it was great! I have a short video of it. Anyway, just for fun I wanted to go back and make a half decent recording.
back to topic,
now that I know it’s not worth looking for tech info I’ll give up trying and plod on, thanks for that useful info, I did see a wall wart on eBay that had +-15 and +48v, perfect I thought, but it has disappeared before I could purchase, so for mains use I’ve ordered a simple 0-20 0-20v transformer, that should give me a decent 30 ish volts for the phantom and plenty of volts for the mixer, 20v a/c is probably too much for the 7815/7915 reg’s (with No heat-sync) so may take a few windings off to drop the a/c to about 16 or 18v A/C, to be honest I’m not sure what it is supposed to have A/C wise? the mixer was an eBay special, with No PSU, where do they all go???
But this still does not fix the portable phantom problem, I did think for simplicity sake I’d just stuff in three PP3’s, but 27v from a battery is still a bit close for comfort with three or four thirsty mic’s all pulling power as it’s a case of how long before it drops Below the threshold? So maybe four PP3’s! But that is now getting expensive not to mention a bit silly, so back to some kind of step-up circuit. I have tried to identify the built in step-up circuit, so far without success, I did quickly look around eBay late last night for a step-up device I was sure there would be loads for a few pound, (have to watch the pennies), but I found none! but I probably worded it wrong, I’ll have another try later.

Dave, Thank You So much for getting back to me, I have no one locally I can bounce ideas off or just chat with about such things, oh, I almost forgot, yes I’m in the U.K. a place called Skelmersdale In Lancashire, but I’m a Devonshire lad really, both daughters are up around here so it made sense a while back to move up here, but we did it Via France, we lived there after my accident back in 96 and came home in 2013.

but one thing is for sure, it’s not going in the bin! I can’t cope with this throw away thing, i fully understand if your in business that time is money, but time is one thing I do have, so it will be fixed! . . . or modified, but it will run again!

Apologies to anyone reading this, as I’m chatting and not really posting.

Thanks again for getting back to me Dave,
Good Health to You and Yours,
Pete.
PS:- do you know the max size of attachment I can send, the piano file is about 10-12Mg and you may find it entertaining to see.
 

ecc83

Well-known member
No worries Pete, I am retired. I may be wrong about a DC-DC converter? Two PP3s give a nominal 18V, The 9V for the rest of the mixer is pretty low and I suspect it has pretty poor headroom. Check the chips but I don't think going for an 15V supply would hurt but check the electro-caps are 16V minimum.

I am not sure what the attachment limit is but I don't think you have enough posts to use it yet Pete. When you can just do as I do, turn .wavs to 320k MP3. Very little is lost but the file size is reduced by about a factor of 10? You cannot attach .wavs in any case.

I don't think you can send a Private Message yet either so stand by! One is coming soon.

Dave.
 

peterlnic

New member
Behringer 2001B update.
sorry for the long delay, but life, Christmas etc.
I've now had the chance to have a good look at the little mixer, I have also given up on trying to find any tech info, and what little I did find was Wrong! Confirming the earlier comment. The little mixer is quite straight forward, the mixer uses thee 9volt PP3 batteries, two are used as the supply to the mixer in a 9-0-9 configuration, and the third for the 18v Phantom supply, but no step-up circuit, it uses one of the supply batteries to add to the phantom battery to make the 18v, this I consider a very poor arrangement as it means there is a higher drain on one of the main 9v supply batteries meaning the 9-0-9v will quickly become 9-0-8, then 9-0-7 volts etc etc, and if you have hungry mic’s like mine you will quickly have a lop-sided supply with it’s obvious problems, even when on its original mains PSU the phantom supply is barely 20 volts, but this is academic as I don’t have its original PSU.

The fix, or rather my fix.
the +15/-15/+48v wall-wart power supplies on the well known auction site reappeared for £13, bit of a bargain I thought, so one was purchased and it proved ideal, I removed the original awful 3-pin mini-din socket and replaced it with a four pin Lumburg din plug and free socket (a posh din plug and socket), these are a bit expensive at about £10 for the pair but I had them in the draw, I’d never normally recommend Din plugs for anything but these are the exception and it never pays to scrimp on connections and they are lockable too. The little mixer has a separate PSU board, this made things a lot easier, once removed I could see the board has a number of diodes in the supply lines making the addition of a new external supply much simpler, the three lines were identified +9/-9/+18, and the external adaptor was wired in, the diodes automatically doing any switching should any batteries still be in place.

The end result.
For very little work and just £13 and a couple of plugs I had in the draw, I now have a mixer that works significantly better with its full +15/-15/+48v supply than it did before and a proper 48v Phantom supply, and the full battery operation has been retained, and should you so wish the original setup could easily be restored just by removing the new external PSU wiring and it’s socket, and the old mini-din socket replaced, but why would you want to do this?
I am so happy with the set up that suits my needs perfectly I have obtained a second 1002B with the intention of slaving them together by connecting the busses together, why not just get a bigger mixer I hear you ask? Well I have the problem of being wheelchair disabled and two small mixers are a lot easier for me to cart about than a nice SoundCraft or A&H mixer or some such, and I just do this for a bit of fun.
Take Care all,
Pete😊.
 

peterlnic

New member
Hi Raymond,
Thanks for your comments, and I agree with all of them, a long time ago I used to repair and renovate A&H analogue desks, but I was injured in a RTA which left me in a W/chair and damaged my hearing, but thanks to a few chaps on here they gave me encouragement to have a go again, and so I find myself having fun with audio again, I now do it for fun, so if I do screw-up it really doesn’t matter, I even make my own mics too, yes totally Nuts!
Have Fun everyone,
Pete.
 

ecc83

Well-known member
A very paradoxical fact has come out of this thread. I am sure the US people think of China as "full of bloody commies!"
But we have had revealed a 'right wing' self determined side to the Chinese economy?

Say a GM engineer were to go to Fords and say "If you pay me $xxx more than GM I can give you the secrets of their new 'Xm56##' Smart differential" They would be shown the door*. One because Ford would know if they copied the diff design, GM would sue their arse off. And Two because they would not trust the guy not to give THEIR secrets to VW!

So it would seem the Chinese worker is practicing market forces economics but at a personal level.

*But only 'for show'. The guy would go back to GM but with several 1000 bucks in back pocket and Ford would then start working out how to make the diff and beat the patents!

Oooops! I have put that in the wrong thread! Needs to go with "fake Neumanns"

Dave.
 
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