Wednesday, January 4, 2012
I acquired a Sherwood 84-22 a few years ago in a state of disrepair-deshabille might be more like it-and some stinkiness about which more anon, mostly because I liked its looks.
The Sherwood dates from the late forties and was probably sold by Montgomery Wards. It was clear from the beginning that it had been made by Danelectro back when they were in Red Bank and before they'd discovered the uses of Homasote as cabinet material.
The circuit is interesting, as it uses the filament of the first preamp tube as a cathode resistor, in conjunction with a resistance on the ground side-which keeps the filament above ground and dumps the detritus into the center tap of the filament winding. It also runs the 12SJ7 pentode pretty hot which makes for some crunchy sounds-not the typical late forties thing.
Along with the Rola field coil speaker, with modest voltages provided by the iron from the House of Freed, it's got its own groove that owes little to anything else of the era.
The overhaul resulted in some head scratching because the stinkiness got worse and finished up with a cloud of evil smelling smoke and lots of distortion. After puzzling over it I realized I had a similar amp in the collection and on opening it up, it was easy to see where the last owner had bodged the circuit which accounted for the stinkiness and lousy vibrato.
Of course, experimenting with odd circuit ideas was something that happened a lot in the House of Nat Daniel. I've seen several variations on this theme, including one which uses a power tube to modulate the field coil current for a Leslie type vibrato effect, and one that uses a potentiometer to adjust the preamp tube filament voltage for yet more cool Danelectro edginess.
The circuit is the same as the Silvertone 1303, and I've seen it in amps from Wabash, Noble, and Danelectro. As part of a cooperative project I dug up an original copy of the schematic and it was redrawn by Sean Weatherford of Bean Amplifiers, so that was probably the last one the seller got five bucks for.
It is now the world's property, and it would make a great home brew project. Why make yet another tweed Deluxe? This'll get you there in style, plus vibrato to boot.
I've got an 84-23 which is the same amp with an extra 8 inch PM speaker, and it's undergoing a refit as we speak.
How's it sound? Sharp, edgy, and full of fight. It's not smooth at all like a Deluxe but edgy and in your face like you'd expect a guy from Jersey to be.