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Jolida 302B biasing EL34/6AC7

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Hello all,
I recently purchased a Jolida 302B amp - has been working fine for a few weeks. I read in the manual that it should be biased when you first receive it. Went to radio shack, bought a multimeter ($30), adjusted all bias levels to their lowest settings and attemped to bias the amp.

At present, all four of my 6CA7 tubes are reading between 36 and 44mV, as recommended by Jolida, but, the small red lights labelled V3, V4, V8, V7 at the top of my amp that had been lit previously (before the re-bias) are no longer lit. In order for them to be lit, I need to boost the power up well above the recommended 36-44mV.

The amp sounds a little flat now but I am hesitant to turn it up past the recommended voltages for warranty-related reasons. That said, I can't be sure if there is a problem with my tubes, amp and/or multimeter at the present.

Scenarios on which I would like comment

1) the red lights indicated that the tubes were not biased properly when I received them. now that the bias is right, the lights no longer turn on

2) the multimeter I bought isn't accurate and in fact my reader is reading higher voltages as being much lower

3) your suggestions please.

thank you.


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Topic - Jolida 302B biasing EL34/6AC7 - mmmonaco 14:14:04 01/22/06 (2)


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