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FET Input

11/26/2005 6:58 PM
FET Input
Is the FET input (Rumble amp) better than a standard input? Also while reading Andy Fuchs web page: SLX update(sic) a few lengths of critical cable are also replaced with high resolution video/digital cable. Any Thoughts? Thanks.
12/16/2005 2:58 PM
As far as I can tell, that FET is just a buffer for old pedals, not an actual gain stage per se. Newer pedals are more thought-out in regard to the inputs of amps.
12/16/2005 11:38 PM

I think the cable is RG174/U coax. It's supposed to have less capacitance than Beldon shielded cable. I've used it in all my builds but my feeble ears can't really tell the difference.
12/17/2005 9:29 AM
Ben Shelton

The FET boost was originally intended for acoustic guitars and other instruments with a lower-level output. It has an input impedance of 3.3Meg instead of 1Meg. I've never seen anyone plug into it.  
If you're going to run a volume pedal in front of the amp, it wouldn't be a bad idea to put a FET boost of some sort inside the pedal, so you don't lose highs. Dumble did this with Carlton's old Sho-Bud: see  
About the shielded cable: see Gary's site at  
With the holiday break, I've finally got time to get working on my OD/Reverb. I will report back on how that circuit sounds.  
12/17/2005 1:08 PM
Steve A.
Great link for amp pix!
    In case anybody missed this link, it provides access to all of Rob's library of rare amp photos:  
    More Dumbles than you can shake a Steel String Singer at... :D  
Steve Ahola
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