Hello everybody. I picked up an old zenith record player am/FM console tube stereo. In good condition but not working properly and needs the electronics replaced. I've already decided to go with modern capacities and resistors but was curious if I could get a "kit" that is basically a bunch of similar valued capacitors and replace the caps with equal or higher values than they are. My understanding is that you can go higher value with caps, just not lower. Also should I replace the diods? Lastly, it's an eight speaker system, one woofer two mids and a tweeter on each side that has what I would assume is a passive crossover, meaning the speakers are capped to pass higher frequencies. Should I just replace those caps or look into a more modern design or even an active crossover? Thanks for any and all help given.
?bastafari said:
Or merely repaired and then, perhaps, refurbished?
No. Some cap values are not critical, some are very critical. Some caps may need replacing, some will not. Replacing some caps will do little harm; replacing others will require a re-alignment (for which you need to necessary experience and RF test equipment).
If you understand radio well enough to fault-trace and repair then do this. Otherwise find someone who can. Start by finding and studying a circuit diagram - even better, a service sheet.
OK thanks, I'll look into realignment. What I meant by the condition of the radio is the wooden console itself is fine. The radio itself turns on, and has output but eventually the sound dissipates and sounds cruddy.
I wish I could answer that but I can't. I'll try to find that out if I can. Im a noob hobiest and my biggest undertaking since guitars and amps.
So from browsing the internet, should I do the realignment only if there is hum or noise after I swap in the new caps and resistors?
Could be a gassy audio output valve. Don't leave it on in this condition for too long as you could do some expensive damage. Check the cathode voltage as it warms up. Could be a leaky coupling capacitor.bastafari said:
No. Realignment is required if it suddenly stops receiving signals or gets 'deaf'. My advice is that you don't touch anything in the RF and IF sections. It is very easy to stop it working, and much harder to fix it.
Whatever you do, do not change lots of resistors and capacitors then try it to see if it works. Instead, if you must change things, change them a few at a time and keep checking that it still works. That way, when you make a mistake you will know that it can only be in a few places. Better still, fix faults first then think about refurbishing.
OK thanks that's very helpful. What about the crossover, keep it "passive" or updated to a modern circuit?
That would depend on whether your aim is a repaired and refurbished vintage unit, or a new system in an old box. If your ultimate aim is high-quality sound reproduction then you wouldn't be starting from here anyway.
In all honesty I was just wanting to keep it pretty close to vintage because I like it's sound. I'll be making a new box with speaker boxes to hopefully get the most out of these drivers. The crossover was just a thought that might eek out some oomph from the speakers. But this being all new to me, I'm not sure.
any chance of pic's of your new new found treasure...
still curious as to the tube compliment and salient details like model # etc
still curious as to the tube compliment and salient details like model # etc
These are just what I happen to have on my phone at the moment I'll take a picture of the cabinet later. When I googled tube compliment this thread was the only thing that popped up! So what is tube compliment? Is it aka something else?
Attachments
there's usually (but not always) a chart/drawing listing the tube types and their positions somewhere inside the cabinet or on the removable backing
looks to be a tube front end for the receiver but is the output solid state?
looks to be a tube front end for the receiver but is the output solid state?
Not solid state at all from what I can tell. I haven't gotten the schematic yet. Apparently it's still under copyright or some such thing and have to pay for it, but it's only like $20. Anyway these are in the cabinet and a little worse for wear.
Attachments
Hi,
The first and last pictures cleally indicate a solid
state stereo power amplifier with a quasi output.
rgds, sreten.
The first and last pictures cleally indicate a solid
state stereo power amplifier with a quasi output.
rgds, sreten.
Just saw the tubes and assumed it was all tube. So it's a solid state radio driven by a tube amp? Interesting.
Hi,
You may be biting off far more than you chew
if your jumping to such clueless conclusions.
rgds, sreten.
You may be biting off far more than you chew
if your jumping to such clueless conclusions.
rgds, sreten.
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