low output altec 1592b

[moons]

I added another 1592b preamp to my studio with the hope of running them in stereo but this one has hardly and output compared to the other unit.I mean you have to crank the master and channel knobs to full before getting any signal, and the tone controls don't seem to have any effect on the signal.There is a diffenence when shutting the units down If this may help to figure out the problem the working unit has about 3 deflections in the vu meter when you turn it off and the sick unit just has one and falls to 0.Hope some one can tell me where to start to bring this great piece of gear to new life.Thanks

[bfish]

With some skill and test equipment, you should be able to compare measuements with your good unit to isolate the problem and affect repair. Otherwise, I'd recommend letting Iratec (or a qualified local shop) handle the job.

[moons]

Ok Thanks for the advice,I think sending it out would be best,all i have to test with is a volt and ohm meter.Again Thanks

[bfish]

You're welcome. There's a few easy things you can try first;

Clean and excersize the rocker switches. Any switch that doesn't "feel" right probably isn't.

Do the same with the pots. Use DeOxIt if you have it.

Insure good connections to the boards, clean if needed.

Verify plug-in accys and/or jumper configuration.

That'll cover the common stuff. As to the circuitry, there's not a lot there, so a little comparative probing with a VOM might be all you need to DIY. If you have to go that far, I'd start looking at the tone board, based on your description.

[moons]

Ok I will check and clean and keep you posted .Thanks Much

[moons]

Hello Again
I have checked plugs and switches and they seem ok, what I do notice though in your suggestion to check the tone control that when I use the tone generator the signal is greater with the tone slect switch turned to out on the tone board,and this is the case regardless of the knob settings on the front of the unit it also has more output reading on the vu meter when the tone slect is out also.
Hope This helps

[bfish]

Hmm, actually that's the opposite of what should happen. The LF and HF controls are boost controls, and setting the board switch to "out" defeats their action, so if anything, the TG output should be equal or lower. Further indication that the problem may be in or near the TC circuit.

My guess at the TC circuit comes from a real fuzzy memory of a similar problem I encountered once, but that was many moons ago, and I don't remember any more, like what it took to fix it.

[moons]

Thanks for your help,I think i will send it out to the elec.shop and see what they can do.I will pass the info you have given it may help if there not familiar will vintage altecs.I do have another question about this amp though.It has some factory writing in french on the front and rear panels, on the front its under the vu meter its a warning about electric shock and the rear is fuse info. just wondering as my other 1592 has just english.Thanks Again

[rghinton]

If you go to this site http://alteclansingunofficial.nlenet...ers/index.html you can download and print the service manual. It may help.

[moons]

Hi and thanks once again for the info.It will defenitly help in making the repairs.This is a great forum to help keep these vintage pieces alive.Thank you guys so much for sharing your expertize in keeping the pure sound of these units in recordings decades after there introduction.I use these vintage altecs as a staple in my studio and they do the trick every time.
Thanks Again!!