Metropoulos Forum

I have a handmade 18W amp. It's called the Ace Pepper Thundertweak Buzzbomb.

I had it modded to tame the low end because it was extremely boomy and muddy. Now there's a significant dip at say 900Hz or so. It sounds like the tone knob on my guitar is turned down.

I've attached an image of the original schematic.

I'm still not crazy about the low end. Could you give any advice to tighten it up a bit? I play modern rock. I love the amp. But that bottom end needs to be tighter and snappier.

To give you an idea of my style, I really like the feel of a 6505.

Thanks

Hard to say without knowing what has been done already, the front end of the preamp is not in the least Marshally.

Is it loose at all volumes? Is the Resonance pot (Earth) not effective with those values?

Those 0.1uF output caps in the PI are huge for an 18w. Drop them to 0.022uF and consider 0.01uF later.

I would use 0.68uF/2k7 on the first stage into 4k7/0.1uF second stage but the PI caps will help, after that we could be talking about tweaking the output section cathode resistor and cap

Oh and this is not a Metro kit so you might get more traffic in the other amps or DIY builds section?