The Detour

So this one is another 2xEL84 amp in a Valve Junior chassis. This amp is the result of many hours of soldering and resoldering and rewiring etc. I’m not exactly sure what the circuit resembles at the moment but it can get some fairly grinding EL84 tones. I suppose it’s a sort of an odd 18 watt variant at this point. I went through a lot of trial and error with with this amp but I’m pretty happy with it now.

For the power transformer I’m using the Weber WPTGP like in the Mimosa. The output transformer is a OT15PP from Musical Power Supplies. Again, same one I have in other amps. This OT sounds great and is a good deal.

Instead of a tonestack I’m using a mid notch filter along with a cut control. This mid control is in some Framus amps and it can produce a nice mid scoop or you can turn it up for a fatter tone. In operation in also acts as a kind of drive control. When you cut the mids the drive decreases or more mids gives you more drive. Just adjusting the mid control also keeps the volume close to the same level. The design is a little bit unusual but works really well. I like that it’s fairly simple but at the same time it’s capable of a range of sounds.

My goal with this one was to get some EL84 grind and I think it works pretty well in that regard. However, there’s no master volume so it does get loud!

I’m using a dual ganged pot for the volume control. Half of it is the regular volume control between the gain stages and the other half is a sort of variable resistor/half a voltage divider before the phase inverter. This give the amp a more usable volume range, not just off and LOUD. It also controls the drive into the phase inverter pretty well.

Here is the current schematic:



This is a little bit cranked with the mids most of the way up. It’s going through a 1×12 cab with a Celestion V30.

Detour clip 1

This a little lower volume, some mid cut and a strat. Same speaker as above.

Detour Clip 2

Some pics…..

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