So on 28 January 2007 I sent off the email on the right to the main support address.
Note the question about the reverb level control add-on. At that stage I couldn't really believe that Bruce Zinky had supplied it!
I also raised some observations about the behaviour of the reverb when the retro-fit level control was not in-circuit.
I was pleasantly surprised to receive a reply the same evening - see part 4.
Hi, I wonder if you would tell me if there are any known issues around the following little problem?
I bought a used Superfly Combo a few days ago here in London, England (private sale via eBay, for the record). By the way, it's the best sounding amp I've played in 25 years, but you're probably used to people saying that. The previous owner stated that there was a "factory mod" to provide a global reverb control. There is indeed a little metal box hooked up between the "black" end of the reverb tank and the main amp chassis with a single pot and a capacitor inside. On looking at it closely I was immediately doubtful that it was supplied by yourselves as some of the components, particularly the phono connectors, look about 40 years old with corrosion to match. I couldn't find a serial number on the amp to indicate when it was made.
My interest in this mod was driven by the fact that since I've been using the amp, I've noticed the reverb cutting out periodically. It doesn't vanish entirely but is barely audible even at maximum setting. Suspecting a bad connection I disconnected this extra box completely so that the amp should work as designed. However the reverb (when it worked) was almost swamping the guitar sound except on the first two control settings, and it sounded distorted even when the actual gain setting was low for a clean sound.
With higher amounts of gain, any adjustment of the gain knob generated a slight click (possibly normal), which was magnified by the reverb circuit as a loud "plink" (surely not normal). Shortly after that the reverb cut out again. All this was at living room volumes.
I can't believe that the excessive distorted reverb experienced when the "factory mod" is not in place is a design feature so I'm wondering if it's a tube issue? The amp is supposed to have had a service recently but I'm waiting on the previous owner to find out if any tubes were changed. Would it be possible to send me a schematic so I can check that the right tube is in the right socket? I have downloaded the PDF manual but it stops short of providing those details.
I read on a web forum about a "reverb update" for the Superfly, but could find no more details. Hopefully by now you can understand why I'm curious. If it comes to professional intervention, do you have someone in London who knows the insides of these amps?
Hope you can shed some light on this frustrating problem as I'd like to get the amp (which is otherwise in very good condition) back to full usability and reliability.
PS A far more trivial question - is there any problem with transporting the combo laid down flat (on the front to avoid damaging the speaker plug at the back)?