Tube Amp Archive

I have owned 3 different Ken Fischer built Trainwrecks (x2 Express, x1 Liverpool) and almost always ran about a 35-40’ cable going in. Before getting into TWs I did the same with my 4 input Marahalls. I originally started doing this because on a large stage with TWO stacked 4x12s, you needed this ki...

12AYZ tubes in both V1 and V2 will bring the gain down considerably. IF you are using humbuckers try to find VIPots which come on much slower than most 500k pots. This will help quite a bit to get a nice clean tone. Without the very slow rising taper of VIPots (or original Centrlabs) it is much tric...

Just now saw this. Yes on my original TWs (and 2 clones I built for myself) can be fully dined without instability issues. This is with the stock PI cap value. On my ‘89 Express early on it had some stability issues, but the fix was a little piece of foam rubber under the power supply board to keep ...

I do still prefer old long plate Sylvania 12AX7s in my ‘89 Pacific transformer equipped Express in all 3 positions. However when I got my ‘85 Express it had last been retubed with help from KF himself. I’m not sure what they are actually but I think one is a Tungsram, a Mullard, and not sure on the ...

Very cool to see those amps out on tour!

I seriously doubt Ken had the $ to order 50 transformers at a time. I once sent a Celestion pre rola G12H speaker to Chris to be repaired, but he lost my speaker in a move...

A few things come to mind for starters, basically I'd suggest shorter lead lengths where possible but here are some more ideas: I'd turn your output transformer around 180 degress so that the primary wires are closer to the output tubes, and then the primary wires can be shortened. My original '89 E...

Some amps are more prone to oscillation without a ground plate, especially ones with high gain. Original Express amps were built on an aluminum chassis that is fully enclosed once the bottom is screwed on. In original Express amps a few wires were typically super glued to the chassis, to keep them f...

Are you running a grounded metal bottom plate on the amp chassis or some sort of ground plate in the headbox?

Your lead dress is considerably different than a KF build, same goes for the ground scheme. Many folks have also not had luck in these uncharted waters. I’d suggest to drop the star grounding and let the pots and jacks get their grounds from the chassis contact. This may require filing away any chas...

On my original KF built Express amps, and my 2 clones the potentiometer grounding is critical. Even with the buss bar ground IF the pots get loose or the chassis surface gets dirty under the pot mountings oscillation can result. That said all my amps have bright switches which IMHO are quite importa...

Most of the time I run RFT EL34s in my original TWs. Lately though I love a set of XF1 Miullars EL34s in my ‘85 Express but I got lucky and found those tubes in an abandoned Dynaco ST70. On my clones I’ve found some nice tone with Groove Tubes EL34Ms, though they don’t last as long as the NOS RFTs. ...

The Fryette power station 2 works well with my original and clone Express amps. The ability to use a pedal board “post amplifier” is very cool using the loop on the PS2. The PS2 is actually a reamper with a tube power amp, vs a typical power attenuator. I was a sceptic of the PS2 due to the complexi...

Something about the transformers (my guess) makes the Ceriatone Express a very loud and bright amp. I put a Ceriatone next to my original TW, and even with 6V6s in the Ceri it was noticeably louder than my original with EL34s. That said the Ceri I played was a factory built amp, and the build qualit...

Glen here! Probably the best way to reduce the hiss for home use is to simply use a power attenuator. These amps in my experience have less hiss than most amps that (very importantly) have similar gain. Cranked up in the room with a 4x12 these amps can hit between 110-120db. That said attenuate it d...