It's the 125th installment of the Truth About Vintage Amps with Skip Simmons! Want to be a part of our show? Just email us a question or voice memo to [email protected]. Some of the topics discussed this week: :51 Skip works on a Jim Kelley Amp, built-in attenuators, the magnetic field caused by a Tweed Bassman speaker  3:30 Skip needs an RCA MI-12155 schematic  3:56 Making stuff for the Bay Area Guitar Show 6:51 Our sponsors: Emerald City Guitars, Amplified Parts, Stringjoy Strings, and Grez Guitars. 8:12 Our 2023 Voltic DTF pedal Dad joke winner: Keith F with "Why did Skip have to marry Mrs. Simmons? From the day he solder, he couldn't resistor." 9:34 A basic servicing check-list of what to do when you get a vintage amp   15:36 An early 1960s Tweed Princeton branded Harvard, tensioning the input jack   22:22 Modar-branded guitar amps; tube lineup of EF86, 6BQ5, EZ81   23:51 Trainwreck amplifiers; the tone difference between a single 8 ohm secondary winding vs four separate 1 ohm coils wired at 8 ohms    25:47 Should I buy this Peavey Triumph 120 combo?; five-pin footswitch replacement    28:15 Dummy load vs speaker when working on amps   30:55 How to replace the battery circuit on a Bogen E66 portable PA, ice cream truck-specific amps, the Fretboard Brewery   35:45 5Y3 rectifiers, demystified    39:00 Rancho Gordo beans, redux    39:46 An inspiring 1966 Champ and a vegan pumpkin pie    45:24 A hi-fi Eico ST-84/Dynaco ST-70 with the balance way off, RIP Earl Yarrow    55:22 Servicing a Carr Mercury; 12AT7 versus 12ZX7 pre-amp tubes    1:01:04 What to do with a 1980s Fender 30 with a weak second channel? a rare Ampeg B-15N Hosted by amp tech Skip Simmons and co-hosted/produced by Jason Verlinde of the Fretboard Journal. Happy holidays, everyone!  Love the show? We have a Patreon where you can support it and get exclusive bonus content and surprises:  https://www.patreon.com/vintageamps