Albion TCT100 bias

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Jered
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Albion TCT100 bias

Post by Jered »

I picked up a TCT100 recently
Albion TCT100H Circuit Diagram.pdf
according to the schem the power tubes only have a single 1 ohm resistor per side on the cathodes. plate voltage is 468v, so bias works out to 32.1 mA per tube at cathodes. But since there is only one resistor per side and not per tube, do I adjust bias to 64.2 mA per side? Thanks for the help
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xtian
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Re: Albion TCT100 bias

Post by xtian »

In looking at the schematic, I see there is one 1R bias sense resistor for each TWO power tubes. So you should expect to see current for TWO power tubes going thru each 1R bias sense resistor. About 60mA per side is a good target, as you suggest.
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Jered
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Re: Albion TCT100 bias

Post by Jered »

Perfect, thank you
Stevem
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Re: Albion TCT100 bias

Post by Stevem »

With some 468 volts on the plate here's how things look in terms of individual idling EL34s being biased either cool, average or hot and then the percentage of max current in class A/B.

Cool = 27 ma/ 50%

Average = 33 ma / 60%

Hot= 38 ma / 70%
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Jered
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Re: Albion TCT100 bias

Post by Jered »

Thank you very much. Surprisingly great sounding amp. Very JCM800 sound. Clean and dirty channels and (my fave) a mix switch which allows both channels at the same time. The two channels together, solos really cut through with a live band
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