Egnator Rebel Combo Service Summary
I thought folks might be interested to read this Egnator Rebel Combo service summary.
The Egnator Rebel Combo amp is not a common amp in the UK. It is an unusual amp because it has two output stages feeding into one output transformer. One with a pair of EL84 and the other with a pair of 6V6’s. You can you one or the other out stage or mix them together. It has a normal channel and higher gain channel. Both channels use a DSP electronic reverb module rather than a spring line tank.
There is one Cream Back 16 ohm Celestion speaker fitted.
On arrival, this amp sounded awful. It was distorting in a bad way, and dull sounding. It sounded like chewed up mush. The pedal did not work and the power output controls for the two output stages made little to no difference to the sound tone or volume.
The valves had not been changed in years. First job is test the valves and I see that theyare all at the end of their life.
Now I fit a new set of valves and there are a lot of them – four preamp valves, one phase splitter, and four output valves as mentioned before. Ouch !!
The EL84 and 6V6’s are biased. There are convenient measuring pins on the pcb and these need to be set to 40 mV for each pair of output valves .
The amp is powered up and bench audio tested. It sounds much better. The clean channel sounds clean. I was impressed with the DSP based reverb. The tone controls have a nice wide range and the second channel had a nice non aggressive rock tone.
The pedal is still inoperative. The amp owner advised me that the pedal had never worked when he bought the amp second hand from a music shop.
The pedal connects to the amp via a stereo cable terminated in a stereo jack plug. The cable is open circuit. I keep cutting it back to find the break in both the inner cores. I gave up. This normally happens when the cabe has been accidentally given a hard tug. The neatest solution is to do the same as Vox, and put a stereo jack socket on the pedal and use a standard stereo jack to jack lead. If the cable is accidentally pulled in the future, they just need to go buy a new lead and no amp tech needed.
The pedal is now back in operation after many years of being dead. During soak testing of the amp, I see that the pedal does not always switch the channels. A simple mod to increase the drive to the transistor that does the channel switching is made. Now it wors every time.
The power adjustment circuit is now modified so that the power levels could be reduced down to one watt.
The amp is soak tested, re-assembled an PAT tested, and then again soak tested in the case for a few hours. The Rebel was now as good as new.
The key takeaway for me is that old valves/tubes just totally ruin the sound of a lovely well built amp.