Orange Amps Forum

Has anyone converted a Rockerverb 50 MKiii to cathode bias?

Haven’t heard of anyone doing it. It’s a fairly busy pcb, would really have to go over good to pull/cut the right parts.

Converted my rockerverb 50 mkiii to cathode bias. It now sings like a rocker 30 with reverb and effects loop. Half power specs on the el34’s are identical to my rocker 30. It’s reversible and no drilling on the chassis. Would be cool if Ade included it in future versions of the rockerverb like the Custom 50.
Rockerverb is a nice amp but there is something very special with cathode biased el34’s that just does it for me!

I love the cathode biased EL34’s on the R30. I think its what makes the Rocker 30 what it is. The new models with EL84’s are cool amps, but just not the same.

We are in agreement on cathode biased EL34's. EL84's are nice but nothing like EL34's.
Oddly enough the specs on the Rocker 30 El34's are almost identical with a 50W Marshall fixed biased amp with a variac used to lower line voltage to 90 volts and hot biased as Eddie Van Halen did for his brown tone. My son verified this and that's his setup for his grail tone.
Ade is a brilliant designer and has put Orange in the forefront of modern tube guitar amps. I sent a suggestion that future version of Rockerverbs include a cathode bias option like the Custom 50.

The switchable bias looks like it was intended for the Rocker 30 originally as well. The PCB has all the holes and traces for the components to be installed for a switch and bias circuit. The schematic shows this circuitry as well. The chassis also has a mysterious hole on top that I can only assume was meant for the switch as it's the right size for a carling style switch.

Yes, I noticed the area for components on the Rocker 30. Would increase the cost with a 50 watt transformer, switch and components. My guess is it sounded so good with cathode bias Ade decided it wasn't worth it.
It's interesting to note my Rockerverb 50 actually has a more pleasing 3d chime/clean tone with cathode bias and dirty channel has great overtones. It's not the same as the Rocker 30 but still much better for my tastes. 4 gain stages is over the top for my style so I use a 12AU7 for stages 3/4 of dirty channel.

Jealbe49 wrote: ↑

Wed Dec 18, 2019 6:27 pm

Yes, I noticed the area for components on the Rocker 30. Would increase the cost with a 50 watt transformer, switch and components. My guess is it sounded so good with cathode bias Ade decided it wasn't worth it.
It's interesting to note my Rockerverb 50 actually has a more pleasing 3d chime/clean tone with cathode bias and dirty channel has great overtones. It's not the same as the Rocker 30 but still much better for my tastes. 4 gain stages is over the top for my style so I use a 12AU7 for stages 3/4 of dirty channel.

I would love to see pics of the mods you've done. Have you got any you could share?
How did you manage the wiring?
Would be very interesting to see!!!!

That said my RV50 is a MKI, with the 6V6, which I don't particularly intend to mod.

As Jondog mentioned, the R30 PCB as traces for bias circuit to take the amp between 30 (cathode bias) and 50w (fixed bias) also has traces for a choke, which I bought and still haven't fitted......