BitMo Blues-J Mod Kit for the Ampeg J-20 Guitar ampWith the BitMo Blues J Mod Kit, the Ampeg J-20 guitar amp does not sound like other modern amps in my collection (this is a good thing). It really fills out my tonal options for recording and gigging. I would say it is especially suited to blues (also sounds fabulous with harmonica), classic rock (killer for slide guitar), rock-a-billy, or jazz. If you have any kind of arch-top guitar, you need to check this out! This kit includes several modifications to the amp’s circuitry. The useless Bright channel is re-voiced (the amp is too bright anyway, in my opinion). The 2 input channels are ganged in parallel from one input jack The 2nd input jack is removed and replaced with a version of the famous BitMo 3-way Voicing/Gain switch, (see switch near input jack in the 1st picture) specially configured to enhance the attributes of this amp. My descriptions of the settings are: Thick – great for jazz, emphasizes the “doink” of a Gretsch for rock-a-billy, woman tone at higher gain settings Crispy – a kind of hyper tweed, very much like a tweed Deluxe – fat and crispy as pan-fried chicken! Punch – great for a bluesy crunch or full-on overdrive The 2nd preamp gain stage bias is changed The bias is changed on the output tubes (I recommend that you have the amp professionally re-biased for your favorite set of output tubes, but I think the bias resister included with the kit is a better default than the stock one. It seems to make the crossover to distortion range much smoother, especially with the tremolo engaged. Warnings, etc: These amps contain potentially lethal voltages. You must discharge the capacitors. They are not “self-discharging” like some more modern amps. The kit include a discharging probe. Always unplug the amp while working on it. You should also use goggles or glasses while soldering. We disavow any responsibility for damage, injury or lost hours. We do not recommend this kit for complete novices. Skills needed - must be able to solder and drill a hole in the metal chassis. Tools you will need - screwdriver, soldering iron, rosin core solder, wire stripper, needle nose pliers. Availability: Usually ships within 24 hours. |
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