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Lost Stereo on 8100

G

Groove1670

Guest
I have lost stereo on a optimod 8100. If disconnect audio from one channel (L Or R)or the other I have output on both channels but it is in mono. When I return the disconnected channel it is in the mix (But in mono) Any Suggestions. Thanks
 
I really don't like asking if you've pushed the small bat-handle toggle switch that's on the upper right to 'stereo'?
 
Time to place the old boy in the pile, or to recap everything.

Or depending on the price and your personal experience...time to buy an Omnia One.
 
Been working on what looks like a relatively new 8100. Marking on a circuit board indicates it was made in 1994...

If you are REALLY attached to this old box, send it out to Bill Sacks to be re-worked.

Otherwise, E-Bay material, help pay for that Omnia One.
 
Or if you are handy with an oscilloscope, put the stereo encoder card on the extender card and scope it,whilst looking at the schematic.

Should be pretty obvious what the problem is.
 
It sounds like the L-R circuitry isn't passing any audio.
When you feed a single channel of audio into the Optimod, do you get a L-R reading on the front panel meter?
 
The cheapest way, you could take this opportunity to place your news/talk with the 8100 and run it in mono.

Jeff in Sa-ra-so-ta!
 
frankberry said:
Why trust a processor that is beginning to fail? Repair it or replace it.
Click to expand...
Bingo!

That's the best response I've heard. You already see a failure, there will be more with that unit.

Jeff in Sa-ra-so-ta!
 
That might be a little extreme. Maybe it only has a blown chip. I've fixed many products over the years, including replacing an op-amp in an Orban potted module. I'm pleased to report many, including the Optimod, are still working well 15 years later. There are many reasons to replace a processor. A componant failure is not a very good one.

I would go a step further and suggest it's actually a good reason to hang on to the analog processor, even if it's kept as a spare. The reason is that almost everything in an Optimod is reparable, assuring an indefinate service life. When that fancy digital processor dies, it may not be field serviced because the entire heart of the system is proprietary. Stations without a good backup box will be off the air.
 
That be so true. Just saw a 8100 on Ebay,by the description,it sounds like his listing.If he's doing talk,mono is the way to go and voice sounds pretty darn good on that 8100...oh well..
 
Kmagrill said:
That might be a little extreme. Maybe it only has a blown chip. I've fixed many products over the years, including replacing an op-amp in an Orban potted module. I'm pleased to report many, including the Optimod, are still working well 15 years later. There are many reasons to replace a processor. A componant failure is not a very good one.

I would go a step further and suggest it's actually a good reason to hang on to the analog processor, even if it's kept as a spare. The reason is that almost everything in an Optimod is reparable, assuring an indefinate service life. When that fancy digital processor dies, it may not be field serviced because the entire heart of the system is proprietary. Stations without a good backup box will be off the air.
Click to expand...
Ok, so keep it as a spare. No problem there. But remember all the components have been in that box for the same amount of time. Heat has been there the all the time. Plus, haven't you noticed how difficult it is finding repair parts?

Repaired unit has more chance to fail than a new unit.

So, the theory goes...

Jeff in Sa-ra-so-ta!
 
I only have experience decommissioning an 8100a and plugging in an Omnia One with the out of the box settings and I'm impressed.
 
badjef said:
Ok, so keep it as a spare. No problem there. But remember all the components have been in that box for the same amount of time. Heat has been there the all the time. Plus, haven't you noticed how difficult it is finding repair parts?

Repaired unit has more chance to fail than a new unit.

So, the theory goes...
Click to expand...

Generally, the Optimod uses very common parts, with the exception of the meters, which aren't critical. There's very little that cannot be fixed easily and cheaply. It is probably true that the unit should have it's electrolytic caps replaced every 10 years or so and that is a fairly big job. Also, heat is seldom a problem on the 8100 as very little runs more than about 15 degrees above ambient. I have no idea why a repaired unit would potentially fail more often than a non-repaired unit of the same age. If the repair is proper, both should perform equally.
 
oldiesstation said:
That be so true. Just saw a 8100 on Ebay,by the description,it sounds like his listing.If he's doing talk,mono is the way to go and voice sounds pretty darn good on that 8100...oh well..
Click to expand...

Yep, that was it - $950 - not bad given a fully working one sold recently for $1225.
 
"should have it's electrolytic caps replaced every 10 years or so and that is a fairly big job. "

Aw, come on. I shotgun the electrolytic caps in an 8100 in an afternoon --at a leisurely pace.

1. Easy to do all the cards, mostly just power rail bypass (varies depends on how old the cards are--normally 100 mfd/35 volts).

2. Difficult to get at--the two caps on the power regulator card on the back panel.

3. Then the most expensive parts--the two computer grade filter caps.

Under $75 for all the parts

Naturally, assumes one can use a screwdriver, soldering iron, and side cutters. Yes, I know, replacing parts at component level?? Can't be done!
 
Kmagrill said:
badjef said:
Ok, so keep it as a spare. No problem there. But remember all the components have been in that box for the same amount of time. Heat has been there the all the time. Plus, haven't you noticed how difficult it is finding repair parts?

Repaired unit has more chance to fail than a new unit.

So, the theory goes...
Click to expand...

Generally, the Optimod uses very common parts, with the exception of the meters, which aren't critical. There's very little that cannot be fixed easily and cheaply. It is probably true that the unit should have it's electrolytic caps replaced every 10 years or so and that is a fairly big job. Also, heat is seldom a problem on the 8100 as very little runs more than about 15 degrees above ambient. I have no idea why a repaired unit would potentially fail more often than a non-repaired unit of the same age. If the repair is proper, both should perform equally.
Click to expand...
A repaired unit won't necessarily fail more often than a non-repaired unit of the same age, the repaired unit only failed first.

Rule #1.) All things break.
Rule #2.) refer to Rule #1.

Jeff in Sa-ra-so-ta!
 
Sure, but a single failure does not indicate a potential cascade. Now, if stuff is failing every so often, then yes, I'd agree. I have never seen an Optimod that exhibited that sort of tendancy to fail, though. Most of them run for many years between failures.
 
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