HD One Fifty Bias question

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Author Message   Paul Posted on Thursday, October 23, 2003 - 05:39 pm:    I've just bought myself an 2x12 HD 150 with the original Sylvania 6l6 in them. The reading across the cathode resistors was about 44 mV, I've set them to 25 mV, but there was a loss of volume. Probably just old tubes. They sound ok otherwise. I'm waiting for new ones and wanted to confirm the bias settings for this amp. Unfortunately the board ID is under the board, and I was too lazy to take it apart just enough to read whether it was a GB-2 or a DB-4. Looking at the schematic 2475-150, it seems that these two configuration would be the same bias. Thanks, Paul   Terry Posted on Thursday, October 30, 2003 - 11:35 pm:    Paul set the bias on the 3.9 OHM resistors to the 25MV it may not be the same.