Fender Twin with 12AT7 in the preamp

Day 3 with the Twin Reverb and I managed to get a couple of hours to explore further. I tried swapping the 12AX7 tube in V2 (the Vibrato channel) for a 12AT7. It’s a fairly subtle change. It means that the preamp doesn’t slip into overdrive as easily. I’ll leave it in for now but no doubt I’ll be going back to the 12AX7 before too long.

I also got chance to experiment with my collection of pedals. As many of others have already documented, the Twin Reverb is a great amp with pedals. I had most fun with this stripped down setup. Perfect for rockabilly twang. The gem of these is Alfie’s Blue Alpaca. It just makes the amp sing.


Right to left they are: Behringer DC9 Compressor, Nocturne Brain Seltzer, Alfalfasprout Custom Shop Blue Alpaca (inspired by the Way Huge Red Llama) and finally a DigiTech DigiDelay for a bit of slapback.

All of this was with my Telecaster. I’m really looking forward to 12th Jan when I’ll have my Gretsch 6120DSV back home.

Twin Reverb gets a “spring” clean

The Twin Reverb, whilst sounding remarkably clean was looking anything but. Time for a good clean.

The tolex is quite badly knocked about in places so I wanted to make sure it didn’t get too wet.

I dismantled everything, removing the valves and the amp chassis too. While it was apart I took pictures of the valve chart and serial number for future reference.



I gather from this site that the “F09” denotes 1979-80.

In small sections with slightly soapy water and a firm nail brush I’d work in small circles, wipe dry and repeat a couple of times until all the ingrained dirt had lifted.


Here’s a before and after of the top.



Not a massive difference on first appearance until you look at what it did to the water and detergent mix.


The reverb bag was particularly dirty but cleaned up very nicely.


There had been an intermittent problem with the reverb disappearing which I’d traced to a dodgy connection on RCA Phono plug on the return from the reverb tank. I replaced the whole cable with one I had in my parts drawer.

The interior of the chassis itself was pretty clean but I gave it a light dusting and checked everything looked OK.


I put everything back together, returned the valves to their original position and checked that everything worked. Now the outside is almost as clean and sparkly as the sounds it makes. The valves fitted all look pretty recent. They’re Electro-Harmonix in the power tubes and a full set of JJs for the preamp.


One last job for today was to make myself a “fake” footswitch for the tremolo. As standard you need to have the footswitch plugged in for the tremolo to operate, whereas by default the reverb is on. I like to keep the tremolo on all the time but at a very low, almost imperceptible level. Rather than connecting up the footswitch and leaving it rattling about in the cavity at the back, I simply took an old RCA Phono plug, soldered the centre to the shield and hey presto, full-time tremolo with no footswitch.

Next job will be to experiment with the preamp tubes. I’ve got a spare 12AT7 knocking about and this can be used in place of the 12AX7 in V1 or V2 for the Normal and Vibrato channels, respectively, dropping the gain slightly, giving even more clean headroom (if such a thing is possible).

Another interesting idea I want to try out is that, because unlike most amps, the two channels are totally independent and can be used at the same time, you can take the return from the reverb tank and feed it directly into the normal channel, allowing you to control the volume and EQ independently of the dry signal. All that is required is an RCA Phone to 1/4″ adapter.

New Amp Day

The Behringer GM110 has headed off to a new home (a gift for an ampless friend) and so I was in the market for a replacement. I’ve spent a while enviously and forlornly looking at classic Fender amps. Over the last year everything I’ve been looking for has been summed up by that shimmering, sparkling Fender clean sound. In Nashville earlier this year I spent a very happy afternoon with a Princeton Reverb and I was sold and have been keeping my eyes peeled for one at a reasonable price. Unfortunately they rarely appear for sale, and when they do they’re far from reasonably priced.

I’d always assumed that the big boy of the Fender range was out of my price range and then I stumbled across a silver-face Fender Twin Reverb on eBay at around half the price of a Princeton. Deal done and the new baby arrived at home this afternoon. It is one of the late 70s models which is not loved by the cognoscenti. The downside is that it is 135 watts! I’ve got plenty of headroom to play with! Everything is working fine but it is overdue some TLC. It’ll get a clean and fettle over the next few days. To say I’m happy with it would be something of an understatement. In fact, let’s leave it there. I’ve got a new toy to play with. Ciao.