Brightening up my Orange Rocker 30 Clean channel

[Loomer]

Recently got myself an Orange Rocker 30 amp which I've been enjoying greatly - loving the drive channel set low and right on the edge, distorting nicely when hit hard but ringing clean when picked lightly.

The amp also has a clean (Natural) channel, which drives the power amp as you crank it higher, with no tone control at all. It gets a lot of flack but I actually think it's not too far from being a good sounding channel, I just happen to find it a little too mellow and somewhat muddy, certainly compared to the lovely tones I can get by cranking the treble on the drive channel.

I'd love some input on what people think might help me achieve this and possibly get some feedback on my own considerations. I tracked down a schematic, attached (apologies for the poor quality, that's all I've got!) and have identified three things I might look at to achieve a clearer, brighter sound. In no particular order:


• Swap the 22uF cathode bypass cap for something much smaller, say the Marshall value of 0.68uF
• Lowering the bright cap to 150pF, as seen on the allegedly very bright Matchless amps (doubt it would be night and day this one and would mostly affect low volume settings, which aren't my favourites anyway)
• Reduce the coupling cap from 4n7 to 2n2

Thanks in advance for any words of wisdom you might be able to impart - it would really unlock the amp to being a two channel affair to me, which at the minute it isn't quite!

[BrianS]

EQ pedal

[dickjonesify]

Changing the cathode bypass cap will cut low end for sure, which doesn’t really make anything brighter but it could be what you’re after.

Lowering the bright cap value is the opposite of what you’d want. I’d try raising it to maybe 500pF, which would let highs AND more upper mids pass through, where 150 is only for high highs.

And yes, that coupling cap value seems high but I’m not familiar with amps without tone stacks.

*I’m relatively new to this stuff but I have experimented with both of those before*

[dickjonesify]

Oh, also the 68K grid stopper on the input, that’s dulling the tone some, too.

The normal for the “high” input in a Fender style circuit is 34K since it sees two 68K in parallel. Some amps like the Dumble ODS even go down to 22K. That will filter less highs. I think this is your first move!

[sluckey]

Look at what Sunn did with the Bright input jacks. It's very effective...

     https://el34world.com/charts/Schematics/files/Sunn/Sunn_100s_sceptre_and_sentura_ii.pdf

[pdf64]

220pF bright caps on a 500k volume pot are kind of a Vox thing, but Vox had a baseline extra brightness over that Laney as Vox had no nfb loop.
I suggest to increase the value of that bright cap. A lot, as you're not too bothered about low volume settings. Try a few values in the range 1nF to 10nF.
I typically fit a 3 way mini toggle bright switch, as different values suit different guitars

[Loomer]

Thanks all for the suggestions - plenty to ponder on! Think my first ports of call will be either the input (resistor value and/or cap in series as in the Sunn) and cathode bypass and go from there. They're all full size components on PCB so swapping any of those out should be simple enough!

Not keen on the EQ pedal option as I much prefer my amps to provide the core tone I can build upon, with that being a tone I like in the first place. Also would make it awkward to channel switch, as both the channel and the EQ would need to be engaged at the same time.

Hoping I can get this to a point where it's clearer and brighter while still retaining the neutral character of it (which should be easy enough seen as it's more or less just a buffer before the PI) to both be that blank canvas but also try out some preamp pedals in the Runoffgroove vein in the future.