Here is the amp before the makeover.
When Del brought in this Fender Twin Reverb I was impressed on the mods
that had been done to it. Del mentioned that Sal had boogied it up back in the 80's when he was working at Prune Music,
and it sounded great. It had a master volume added ( Look closely at the Twin Reverb lettering...ouch that hurts.) with another
preamp gain stage. Also they added a presence control on the back. Anyway Del wanted the amp back to original, he said that
it sounded great back in the day but wanted his Twin Reverb back to stock.
| No not the faceplate in the name of tone!! |
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| step away from the drill!!! |
The first thing I did was take alot of digital photos of the amp if I needed
to refer back to them during the project. Next I had to order a few parts that were not in stock such as the Blackface Twin
Reverb face plate. With a little bit of convincing I talked him into putting some of the New Mojotone aged grill cloth on
his amp. I was unsuccessful at removing the spray paint with a few different solvents on the original grill cloth.
| notice the presence knob next to the |
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| external speaker jack. |
I then gutted the mods, and let me tell you Sal is a thorough tech!!
Unlike some of these repair guys who will change a couple resistors and caps and charge you $200.00. This amp got a complete
workin. The vibrato stage had been gutted and used for the mod so I had to re-build the vibrato stage. I then disconnected
the presence control and removed the wiring. I removed the extra preamp socket and tube after carefully de-soldering the wires,
capped the hole with a dummy plug. After everything was out I started wiring the amp back to the original circuit. I had a
hard copy and a PDF of the schematic that I would use to check and re-check my work against the original circuit. The PDF
is great because you can zoom in on a particular place on the circuit. Once all the wiring looked complete I re-checked the
work again. Once it all looked good I hooked it up to a current limiter and powered it up. After doing some de-bugging
I got the amp sounding good, then the amp was powered down and new Sprague Atom Filter caps were installed.
The amp cabinet had some issues and the baffle board was not aligned properly
due to a loose wood support within the cabinet, refer to the above pic and you can see how the baffle was recessed near the
top. The support was glued and clamped to dry over night. The next day I started forming the caps slowly while I worked on
disassembling the baffle board from the cabinet. I removed the speakers and lightly sprayed all the dust bunnies out. I then
removed the spray painted grill cloth and rolled it up to give back to Del. The new grill cloth was stapled on and the baffle
was put back into the cabinet. The speakers were added. Once the faceplate arrived I was able to complete the project. I installed
the power tubes and biased the amp after the caps had formed, then did a play test on both channels checking reverb and vibrato
functions before installing the chassis into the cabinet. The amp sounded just as it had left Fender in the mid 60's
Here is the completed amp looking and sounding more like it did when it
left Fender, all ready for the Jazz gig. I was very happy to hear back from Del about the gig, he said Jazz great
Mimi Fox had played the amp before and after the restore and she likes it better now. Frank Potenza who is a well known music
Professor at USC also played the amp at the festival and wanted to buy it, the band had to convince him to turn it down!!
I am very thrilled to have been a part of the restoration of the amp.
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