Tell me about the electroluminescent panel in an ADL1000 like LA2A limiting amplifier

[mikeydee77]

Hi there, long time lurker here and participant on music-electronics-forum mainly on reparing amps.

I wonder if anyone can help me here with a broken ADL1000 that I am working on. It came to me with no effect and had two burned out resistors around the 6AQ5; plate and grid pull-up. So, I replaced those thinking that would be it, but the effect doesn't do anything like it should the controls make things louder but no compression.

I removed the opto device's black plastic cover and as soon as light hits the inside LDR, then the signal is attenuated massively which tells me that the LDR side is OK.
I am wondering if the EL panel is blown it seems to be getting an absolute peak voltage of 30v when all controls flat out and about 10v at moderate levels. Should it be lighting up with these kind of voltages? I know nothing of these devices but according to wikipaedia 50v is typical turn on voltage for an EL panel.

Can anyone guide me on how to test the panel and the expected voltages from the 6AQ5 and 12AX7. I have a couple of schems that I understand are representative but the voltage markings are pretty fuzzy.

 

[juanito2008]

I don't know if you resolve your problem, but here is what i measure between 6AQ5 and C11 :
91VDC
10VAC peak to peak give me a compression of 4db (1khz)