I have a Sundown Rebel that is letting in an incredible amount of treble through the tone stack. I can have the presence, mids, and treble all the way down, and pull the mids up a small amount, and bam, harsh treble.
I want to mitigate this, but only have a loose understanding of tone stacks.
I feel like I need a "Reverse bright cap" so to speak. Something that will bleed more highs to ground on the input.
xtian wrote:Are you sure it's a tone stack issue? How about jumper the tone stack to take it out of the equation. --Oh, I see, it's not a traditional tone stack.
If you plug a guitar cable from the preamp efx send to the power amp efx return, you effectively bypass the tone circuit - albeit with a little less gain. But it might be worth a try to see if the amp sounds less harsh. Start with your guitar volume all the way down.
Reeltarded wrote:Prime candidate for fixed resonance.
Might do everything you want with a single cap on the NFB to the out.. might have to add resistor under it.
Do you know what I mean?
Yeah, I just put a cap in series with the 100k resistor going from the presence control to the speaker outs, right?
I think I have a .0047uf i bought just for this, but never put it in....
Try removing the .001uF bright cap on the Gain control. If it's still too harsh, remove one or both of the 270pF caps connected across the 470K resistors.
LOUDthud wrote:Try removing the .001uF bright cap on the Gain control. If it's still too harsh, remove one or both of the 270pF caps connected across the 470K resistors.
+1 on the 270pf cap deletion.
Tube junkie that aspires to become a tri-state bidirectional buss driver.
LOUDthud wrote:Try removing the .001uF bright cap on the Gain control. If it's still too harsh, remove one or both of the 270pF caps connected across the 470K resistors.
+1 on the 270pf cap deletion.
Perfect. Yanked them out 1 at a time, both of them out did the trick. It kinda made the amp less.. lively I guess. Its cool.
Another option was to just not use a rat pedal with a telecaster I guess, haha.
I'm wondering what I actually did to the amp, in technical terms, for future reference.
In general terms this type of high gain amp needs treble boost and a little bass attenuation to get the mud out of a humbucker guitar. With single coils it can be too much. That .001 on the Gain control is a bit heavy handed unless the pot is turned up to the 7 to 10 range. If you run the gain down around 5, 100 - 180pF might make a better choice. You can tame the effect of the 270pF caps if you put a resistor in series with one or both of the caps. Something like 220K to 470K will cool them off.
That is pretty big if you aren't wanting it, generally.
I agree with that. Go back to peaking and then bright cap even down to 100p. 100p sounds pretty good over the transition to full open control. It's just a tiny sparkle below 7ish.
I think the amp needs more ass though.
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
Reeltarded wrote:That is pretty big if you aren't wanting it, generally.
I agree with that. Go back to peaking and then bright cap even down to 100p. 100p sounds pretty good over the transition to full open control. It's just a tiny sparkle below 7ish.
I think the amp needs more ass though.
I clipped both bright caps before posting, so no dice on that.
I think I might play with the "peaking" values to try and get a good balance going.
More testing will determine this though. I only got to play for 15 minutes before I had to leave the cave.
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