Bogner Shiva FX Loop Mod
The older Bogner Shiva amps (built before december 2005 with the Shiva 3.0 PCB) have an FX Loop which is way too hot for stompbox effects. This makes these effects distort and effectively makes them unusable with these amps. The “fix” Bogner recommends involves the use of a specially made cable, with built in resistors, to lower the FX Send signal to stompbox level, and then the use of the special Boost Amplifier to amplify the FX Return signal level back up again…
Apart from the fact that these amps have a very good tone, have been designed and tuned with a lot of care and are built like a tank, this solution is ridiculous! Dr.Tube has designed an elegant and simple solution for this problem, without the need of the opamp based Boost Amp. Stompox effects can now be used in the Shiva FX Loop. At the same time an annoying ground loop problem in this amp is solved as well. The good tone of these amps is not compromised by this mod.
This mod can only be applied if the rear of your Shiva has the Boost Amp Input and Output as shown!
If this amp isn’t fitted with a reverb then the Reverb footswitch can be modified so that the FX Loop can be switched in and out with the Reverb footswitch. Very handy!