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I sold my '58 5F10 a few years ago...but a year or so later, I kinda missed it. But I figured I could always get or build another one and a couple months back I finally decided to build one. I decided to use a blank aluminum chassis which I could drill out myself. I also wanted to use my own layout. The main things that I changed layout-wise were the grounding of the filter caps; they're grounded with the stage that they are supplying. I also decided to add a bias pot. On the cab side, I wanted to go with a slightly larger cab so that it could easily accommodate a 12" speaker if I decided to use one instead of the 10.
The only difficulty I had was deciding transformers. I wound up going with the Classic Tone 40-18027 pt which as a 550V B+ winding. Loaded, that wound up coming in around 320V...too high. I used a Zener diode mounted on a heat sink to knock it down. Now I'm seeing about 280V on the plates...on the low side, but still within spec. With 100mA current, there's plenty of current on tap compared to the original 70mA transformers. There's no 50V neg bias lead so I did what Fender did with Princetons and took a lead off the 5V winding on pin 4 of the rectifier, then used a 100k resistor in place of the 50k resistor to knock the voltage down. For OT, I'm using the Classic Tone 40-18090...a bit bigger than the Harvard OT and multi-tapped (which is something I wanted as I also have a 4 ohm 2x10 cab that I love and I figured I might want to use that sometimes).
All-in-all, I gotta say, it turned out better than I expected. I actually like it more than my old Harvard. Seems to have a bit more clean headroom and the overdriven sounds hang together a bit better before falling into that tweedy "wooliness." I've gigged with it a few times (I play almost exclusively in small clubs these days...a few private parties...but no big stages anymore) and it's damn near perfect, at least for my classic rock/r&b band. Has the right balance of clean headroom to overdriven tones / volume. Here are some photos and a clip.
Oh and being from California...I wasn't about to label it after some Ivy League school...so I've called it The Stanford
BTW, cab is loaded with a beautiful old teal-framed Jensen C10Q...one of my all-time favorite speakers.
The only difficulty I had was deciding transformers. I wound up going with the Classic Tone 40-18027 pt which as a 550V B+ winding. Loaded, that wound up coming in around 320V...too high. I used a Zener diode mounted on a heat sink to knock it down. Now I'm seeing about 280V on the plates...on the low side, but still within spec. With 100mA current, there's plenty of current on tap compared to the original 70mA transformers. There's no 50V neg bias lead so I did what Fender did with Princetons and took a lead off the 5V winding on pin 4 of the rectifier, then used a 100k resistor in place of the 50k resistor to knock the voltage down. For OT, I'm using the Classic Tone 40-18090...a bit bigger than the Harvard OT and multi-tapped (which is something I wanted as I also have a 4 ohm 2x10 cab that I love and I figured I might want to use that sometimes).
All-in-all, I gotta say, it turned out better than I expected. I actually like it more than my old Harvard. Seems to have a bit more clean headroom and the overdriven sounds hang together a bit better before falling into that tweedy "wooliness." I've gigged with it a few times (I play almost exclusively in small clubs these days...a few private parties...but no big stages anymore) and it's damn near perfect, at least for my classic rock/r&b band. Has the right balance of clean headroom to overdriven tones / volume. Here are some photos and a clip.
Oh and being from California...I wasn't about to label it after some Ivy League school...so I've called it The Stanford
BTW, cab is loaded with a beautiful old teal-framed Jensen C10Q...one of my all-time favorite speakers.
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