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65 Deluxe Reissue Schematic

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9/15/1999 8:56 PM
Mike T	65 Deluxe Reissue Schematic I've got a 65 Reissue Deluxe on my bench with fried R62 and R63 and no schematic. Fried beyond recognition. Could someone tell me what they are and their values? Damn PC boards.....Many thanks. Mike

9/16/1999 3:48 AM
Tim C.	Mike, I will let you know tomorrow as my schematic is at the office. Tim C.

9/16/1999 10:29 PM
Mike T	Thanks, Tim...

9/17/1999 3:25 AM
Tim C.	Mike, R-62 and R-63 are both 470 ohm 1 watt resistors. I would suspect that you have failed or shorted 6L6/5881 output tubes. Replace the resistors and check voltages with the output tubes out of the socket before reinstalling them and playing the amp. According to the schematic,the bias should be set to -37 volts at TP36 which is the wiper of the bias control. Best of luck to you, Tim C.

9/17/1999 4:07 PM

Mike:

Those two resistors are the series screen grid current limiting resistors. These reissue amps are supplied with Sovtek 6V6GT tubes. This amp supplies 394vdc to the end of those resistors, and @5ma screen current draw, only drop the actual screen grid voltage down to over 391v! I'm surprised more of these quasi-stable tubes don't fail in that environment.

Let me make a suggestion. Replace those 470 ohm babies with 1.5k resistors. Any size from 2w to 5w will be fine. Install them with about a 1/4" gap above the circuit board. This will happen anyway, because the wirewound power resistors will have slightly larger bodies and the leads will have to double-back a bit to fit the existing hole spacing.

With the larger screen resistors, there will be no noticeable difference in fender tone, and you'll be able to run the amp hard without worrying about sovtek tube failure again. Of course the amp will sound better with some good ol' american tubes, but many guitar players are actually ok with the sound of the stock tubes in their RI DR.

Did the fuse blow, or did you only find burned open screen grid resistors?

9/17/1999 9:21 PM
Mike T	Doc, I like the idea of increasing the screen grids. I'll run it by him. It did blow the Sovteks that were in there, but not the fuse. Those resisters were really fried though, I'm hoping the PC board (Grrrrr...) is OK. He's got a set of NOS Sylvanias for it though, so I imagine the voltage would be OK with the 470s. Thanks. Mike

9/17/1999 9:15 PM
Mike T	Tim, Thanks a lot, man. It uses 6V6s, and it blew out the Sovteks that were in there. He replaced them with NOS Sylvanias. Again, thanks. Mike

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