RE: Here you go.

Posted by Thomas Mayer (M) on July 21, 2014 at 07:24:33

In Reply to: Here you go. posted by Chip647 on July 21, 2014 at 05:12:58:

Hi!

In his article Broskie also describes a theoretical OTL amp with 13 6AS7 tubes and their heaters wired in series to make up their own cathode resistor. How the hell should such a construct light up? The current will only flow when the tubes are warmed up.

Obvoiusly such a concept only works if you supply some fronted heaters with the current from the output tubes. But if they share a common B+ supply, the input tubes will be hit with B+ before way before the heaters are warmed up.

Best regards

Thomas

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Follow Ups Full Thread

Topic - using cathode bias voltage for preamp tube heaters - DAK 09:36:49 07/20/14 (17)

RE: using cathode bias voltage for preamp tube heaters - Thermionic27609 12:41:43 07/24/14 (0)

RE: using cathode bias voltage for preamp tube heaters - FenderLover 08:54:33 07/21/14 (7)

RE: using cathode bias voltage for preamp tube heaters - shane. 22:10:26 07/21/14 (0)

RE: using cathode bias voltage for preamp tube heaters - Thomas Mayer 09:02:39 07/21/14 (5)

And a great new failure mode of having a shorted input tube heater take out a pair of 6550s (nr) - Chip647 13:59:08 07/21/14 (4)

Not really. - DAK 10:53:28 07/22/14 (3)

I had a Fisher melt all of it output tube because the bias was not held right by the 12AX7 heaters - Chip647 06:37:17 07/23/14 (1)

RE: I had a Fisher melt all of it output tube because the bias was not held right by the 12AX7 heaters - Triode_Kingdom 08:26:59 07/23/14 (0)

RE: Not really. - Triode_Kingdom 12:04:38 07/22/14 (0)

RE: using cathode bias voltage for preamp tube heaters - Chip647 16:59:28 07/20/14 (7)

RE: using cathode bias voltage for preamp tube heaters - DAK 23:10:45 07/20/14 (6)

Here you go. - Chip647 05:12:58 07/21/14 (5)

RE: Not the one. - DAK 08:14:06 07/21/14 (3)

RE: Not the one. - Chip647 12:20:14 07/21/14 (1)

RE: Not the one. - jazbo8 22:10:59 07/25/14 (0)

RE: Not the one. - drsx 12:11:25 07/21/14 (0)

RE: Here you go. - Thomas Mayer 07:24:33 07/21/14 (0)

Follow Ups

RE: Here you go. - Thomas Mayer 07:24:33 07/21/14 (0)

RE: Here you go.

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