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1968 Silverface Bassman, Modified AB165

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  • 1968 Silverface Bassman, Modified AB165

    I have a '68 Bassman Head for sale. Non-master volume, the logo is just "Bassman Amp", no 50 or 100 designation (this is a 50 watt amp).

    I believe the tolex on the front has been removed, as well as the drip edge. When I had the amp serviced (at MS Audio here in Bellingham), the tech and I saw a 1968 date stamped on the metal inside the chassis.

    This is an AB165 circuit, with a couple of important mods. First, the negative feedback resistors have been removed. This was a bad idea that was added to the circuit to reduce distortion. When present, the resistors cause the amp to supply less gain as you turn the volume up. The amp is much more suited to rock and roll guitar without them.

    Second, the bias circuit has been changed to a normally adjustable one, from CBS' "self adjusting" bias. This was another bad idea that tended to create noise. Now the circuit is more quiet, and bias can be dialed in by a qualified tech like any blackface bassman.

    The above mods are considered "standard must-haves" on the sileverface AB165s. It sounds better now than it did stock.

    Also, a three prong power cord has been added.

    New filter caps and bias supply filter

    New screen and grid resistors

    New JJ 6L6 GC power tubes (biased)

    Controls cleaned

    All this work was done in June (I still have the receipt and original removed parts), and has had very little use since. I am selling it because I have a Music Man 210 HD 130 combo that I use for high power applications (my original plan was to replace it with the bassman now for sale, but I used the MM on a couple gigs and decided to keep it... love that amp), and a Music Master Bass amp for low power situations, and just don't need the bassman (plus I can't afford a cabinet for it at the moment anyway).

    $550 shipped to you or $500 local pickup. Thanks for reading!

    Sorry for the crappy phone pics, I'll try to get better ones up asap.

  • #2

    Hey, where are the pictures? And where are you/the amp located? I'm very interested. Safe to say this is the AB165 with some AA864 mods?