Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: jim on May 05, 2014, 02:24:00 pm
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I love the sound of my London Power preamp modded Deluxe Reverb. But, unless you hold back some guitar volume in a live situation, you can't really cut through for a lead. I have a added a 10k RAW pot between the 6.8k mid resistor and ground pot that is relay switchable that can increase my volume maybe 3db without too much grit. 10K is not much--it adds mids and mostly a nudge of volume to the overdrive signal. The relay also switches in a 50pf Fender style bright cap that gives some edge to the lead tone. Wasn't much real estate in the amp to park the relay so I fabricated a housing and put it on top of the cap can.(Dog Condo with Cable) The RAW pot is on top of the housing. Set it and forget it. It adds a great lead tone. This particular relay board uses only one phase of your heater supply for power so it can be noisey because there is nothing to twist with it. The stereo footswitch jack also controls the JFET volume mutes on the clean and overdrive channel as well as the relay.
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One more thing. There was an extra switch pole left over so I also automated the bright cap on the clean side. Can someone tell me why does the footswitch LED lights up when the effect is turned off? Can't figure that out... Jim
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What's the extra transformer betw the PI 12AT7 and the first 6V6?
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That is the choke that I needed to move for the oversized transformers. Jim
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Thanks! I guess that conclusion was fairly obvious.
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:worthy1: Brilliant idea, that homemade doghouse saves you easily 20 bucks.