Dating fender silverface showman reverb updating ccr registration
Output power with volume on 8 was right around 50W. Played it again for 15 minutes with volumes between 4 & 6 and ended with a 5 minute blast at 8(those poor neighbors)!Some plate glow was still present on the inner pair of tubes – outers were very faint.All 8 new matched Sovtek 6V6GT tubes were tested in low voltage tube tester – one scraped for poor characteristics.The Test: After twice blowing up a tube & screen resistor trying to switch on B after a 5 min warmup–(at)–117VAC with maximum negative bias, I decided to start at -45V bias with the Variac set–(at)–110VAC & got the thing on.Through the JBL in the DR, the attenuated bottom end made the amp seem even more strident.Conclusions: At bias settings with acceptable tone(to me anyway), I don’t see how one could avoid glowing the plates.Sound: (Subjective) Stock, the BF Showman has a very clean preamp compared to BF amps with Reverb.
4 new matched Phillips ECG 470 ohm FP screen resistors were installed – also replaced the 470 ohm resistor in bias circuit with a 470FP.
Silly me , I just published a link on how to date your Fender amp and I just went and dated y Deluxe Reverb ! It sounds great and so I have decided not to mess with what was a factory Mistake/ Change/ Customisation?
This one is an odd amplifier because when I decided to start on the restoraton, I noted that the circuitry was not pure Silverface but a blend of Blackface and Silverface.
Had I gotten to 120VAC with even less idle current and a 4 ohm load, I think the glow would have been solved, but the amp would have been brighter still, and I question whether the screens could take that much voltage.
Maybe the tone is a whole different story with some hot humbuckers, but in no way shape or form does it sound like a Deluxe Reverb – of course the Showman lacks the extra preamp stage & has much higher voltages throughout.