Is there something wrong with your 1250? test the heck out of it on the bench with R loads, full power
I think it more a case of methods, setup, expectations
Some/many of these old speakers use low power drivers. I have blown my share of them. that is why I replace with something like a Morel, ones that are rated for much higher powers than OEM.
I have yet to blow a Morel, still have the replacement tweeter diaphragm if I do blow one. They are not cheap but worth every penny
I said to my friends I am sick of blowing drivers, I am going buy the next ones so that your ears blow this time
If you are clipping your amp, you are in danger of blowing up higher freq drivers, hook a scope up to the o/p and you will be surprised how much your 1250 clips with vol set at 12 o'clock
With multiple speakers, it is best to use more amps, that way they are driven at lower powers,less clipping, which actually results in lower speaker distortions and fatigue.
Excellent! thanks. I will try it tonight.Volume to zero, input to aux, nothing connected to aux, tone controls flat. Speaker selector to A. Connect one lead to A positive and one lead to A negative. Multimeter to DC voltage (mV setting). To avoid chances of shorting across the speaker terminals (NOT a good thing), connect meter with 1250 turned off. Once meter is connected, power up the 1250.
Can you further detail what you mean by turning it into an oscillator?
I loaded a couple pics of the MV offset at speaker outputs.Volume to zero, input to aux, nothing connected to aux, tone controls flat. Speaker selector to A. Connect one lead to A positive and one lead to A negative. Multimeter to DC voltage (mV setting). To avoid chances of shorting across the speaker terminals (NOT a good thing), connect meter with 1250 turned off. Once meter is connected, power up the 1250.
I checked it tonight.Has the OP checked the DC offset??
The entire amplifier needs recapping, suspect and known transistors replaced, certain resistors, relays replaced etc etc, if you don't, you'll be chasing your tail and pulling the amp out of service every other week to repair it.
Get one of the BOM's off here, Mattsd has the best ones, hit it, order up and get the work done, and it will then give you years of trouble free service.
I hear what you are saying but I didn't know at the time. I am going through the same issues trying to find quality parts trying to restore a vintage car right now also. I have learned more in the past few days just talking with you guys and am greatfull to have found this site.I would have sourced parts from Mouser and / or DigiKey. People here have gone through the trouble of making BOMs and posting them. How do you know the quality of the parts or source from eBay? From a distributor, you get fresh, authorized, genuine parts.
That doesn't look bad, good actually!!I checked it tonight.
Yes it does according to most peoples experiences. So now I'm thinking when it gets warmed up after a few hours of use something is giving way inside and causing damage to speakers.That doesn't look bad, good actually!!
Good luck on the refurb!