my ruby sounds a bit muddy in the low mids

[Jonkan]

I tested my ruby today with an marshall 1x12 cabinet, together with a fender jaguar reissue. I found the sound to be a bit muddy in the lower mids (like 300-600hz). The only mods to the original schematic i have done is that on Zachary Vex recommendation i have mounted a non polar 5uf cap across the speaker output to tame the treble a bit.

Is it possible that this 5uf non polar cap (well actually its two 10uf connected plus to plus) is taking away too much treble, so that the sound becomes less "buzzy/fuzzy", but at the same time a bit too muddy?

Is there any way i can mod the circuit to keep the smoothed out treble, but get rid of the muddyness?

Any ideas?
/Jonas

[PenPen]

I have one of these on breadboard right now. I also have a Jag reissue ('96 MIJ). I'm trying to tame the treble myself, I did the mods to make it like a Bassman (47n to 100n, 220p across the vol pot). I made the vol pot a fixed 10k resistor and the cap from signal to ground. The treble was hurting my ears, though. I added a 22p cap to ground just before the output cap, it really isn't doing a whole lot there but it does take out some of those piercing highs. I am still messing with this cap to tame it more without doing TOO much to the tone.

I'll try a 5uf like you did and see if I can replicate what you are talking about when I get home. Then I'll try swapping a few different values there to see if it clears up.

[PenPen]

I messed with this last night. To be honest, I couldn't really hear a whole lot of difference from no cap to 5uF there, or 1uF. There was definately some reduction in ear-piercing treble,but not a whole lot. That could just be the poor freq response with my old headphones though. So, its going to be up to you to try out a few different values.

One thing I can say, try upping the 47nF (0.047uF) cap before the vol pot to 100nF (0.1uF). That will allow more frequences through in the midrange. Then lower the 5uF cap you added to 1uF to increase the rolloff threshold, that should give you back more of the upper midrange. Those are guesses, I haven't been able to reproduce the muddiness with my headphones, so thats merely a starting point to try.

[Jonkan]

Thanks, ill definately try that.

I do alot of mixing, both live and recording (im a soundengineer) so i maybe a bit oversensitive to frequency response, etc.

My ruby sounds great, i just hoped i could make it go that extra mile, if you know what i mean. It already sounds shamefully good for being what it is.

Im probably gonna build one for my dad aswell (i built three so far, two for my cousins, and one for my friend). This time im probably gonna build it with the fetzer valve infront instead and see which one i like more. I just hope i dont like it too much, cause then ill have to build two more!

/J