37-690 Bass Amplification

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37-690 Bass Amplification

Radiodial
Junior Member

Posts: 13
Threads: 5
Joined: Oct 2024
City: Manchester State, Province, Country: California

12-13-2024, 03:38 PM

Have been able to verify that there is no amplification occurring at the 1st Bass amp stage (6K7G). The 2nd stage (6J5G) is fine, it is just not getting anything from the 1st stage.

The voltages are fine, the grid is -2.88v and the screen grid is -2.5v, the suppressor grid +60v and the Plate is 235v. Injecting a 200Hz AF signal at the Plate of the tube, the whole bass amplification comes alive, with bass volume control working and everything. If I inject the same 200Hz signal on the other side of the choke I loose the amplification, but still can (barley) hear the AF tone and it is no longer measurable at the Driver tube.

RJ Dial
"Radiodial"
Mendocino, CA

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Messages In This Thread

37-690 Bass Amplification - by Radiodial - 12-07-2024, 03:43 PM

RE: 37-690 Bass Amplification - by morzh - 12-07-2024, 05:18 PM

RE: 37-690 Bass Amplification - by Radiodial - 12-07-2024, 07:19 PM

RE: 37-690 Bass Amplification - by morzh - 12-07-2024, 07:40 PM

RE: 37-690 Bass Amplification - by Radiodial - 12-08-2024, 12:52 PM

RE: 37-690 Bass Amplification - by morzh - 12-08-2024, 04:36 PM

RE: 37-690 Bass Amplification - by tbone - 12-13-2024, 12:40 PM

RE: 37-690 Bass Amplification - by morzh - 12-13-2024, 02:18 PM

RE: 37-690 Bass Amplification - by Radiodial - 12-13-2024, 03:38 PM

RE: 37-690 Bass Amplification - by Radiodial - 12-13-2024, 10:12 PM

RE: 37-690 Bass Amplification - by morzh - 12-13-2024, 10:38 PM

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