Is there anyone here with knowledge of Quad ESL 2912? Have a pair of them and one of the speakers is playing lower than the other. Quad won't help much and just told me to see if the neon bulb N1 was flickering like a stroboscope, if not the panels are ok. Anyone having some idea what to check. Does not have a HV probe so I cannot check the EHT/bias to the panels.
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Quad ESL2912
- Thread starter KorinT
- Start date
solderdude
Grand Contributor
First check the neon lamp.
When there is current leaking in the driver the neon lamp flashes quickly. Compare to the good one.
When both flash in a similar way the HT is most likely O.K. and panels aren't leaking.
Measure the DC input resistance of both speakers.
This will tell you something about the series resistors of the audio transformers.
When you have an AC volt/multimeter you can compare the voltage across R14. They should be closely the same. When they differ substantially there is something wrong with the voltage multiplier.
You can check the audio-transformers by applying 0.1V 1kHz to the input and measuring the AC output voltage across the output of both output transformers (stator and - of the audio input).
When this all checks out to be O.K. most likely there is something wrong with the panel.
When there is current leaking in the driver the neon lamp flashes quickly. Compare to the good one.
When both flash in a similar way the HT is most likely O.K. and panels aren't leaking.
Measure the DC input resistance of both speakers.
This will tell you something about the series resistors of the audio transformers.
When you have an AC volt/multimeter you can compare the voltage across R14. They should be closely the same. When they differ substantially there is something wrong with the voltage multiplier.
You can check the audio-transformers by applying 0.1V 1kHz to the input and measuring the AC output voltage across the output of both output transformers (stator and - of the audio input).
When this all checks out to be O.K. most likely there is something wrong with the panel.
AnalogSteph
Master Contributor
Doesn't look like it, given that the resistor is ahead of the voltage multiplier. Being able to comfortably handle 400-600 VDC should suffice.
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