Tone Stack?

[Alex C]

Hi, I just built Doug Hammond's Firefly, and it's sweet!  I love it.  However, I'd like some sort of tone control options.  I've heard that adding a Marshall-style tone stack will cause a loss in volume, and since the firefly is only about 1.5 watts, it would be too much of a loss.  My question is this:  why is it a common practice to slap on a FMV tone stack on a 9v pedal (popular with the Double D, Smash Drive, and Paul Marossy's Blackfire)?  These seem to be low power devices, and I would think that it would be more of an issue on these than a big ol' amp.    
Is my thinking correct (probably not) or is it more of an issue of gain or something like that?  

Also, the Firefly, although very low wattage, is a bit too loud when cranked  to be used here in my dorm room.  Is it possible that adding the tone stack would decrease the overall output level to a more suitable level, or would there be side effects?  

That's all.

Alex

[jimmy]

i put a marshall tonestack on mine, and its still plenty loud. you can hear it in my room, from the garage, which is a fair way away. plus it makes it sound good.

cheers
Jim

[Ansil]

try the guvnor tone stack it is very flexible, and for a good fat mod change out the pots to 25k lin


and the 4n cap make it a 4700pf.  to open up the range a bit.

this one doesn't eat too much power

[petemoore]

I put this on the output of a DIST + resterday, first tone control so I can't compare but
 It's quite the usable item, it does a wonderful mid scoop, gets good control on the lows/highs eq ing reacts differently [interestingly usable...highs response seems to be easily alterable by how hard it's driven] if I put more juice [FF or Blackfire stage, Mosfet Boost etc] I haven't had so much fun playing for countless hours in some time.

[Alex C]

What about adding a Big Muff-style tone control to my Firefly?  Any problems with using that?  And in any case, where would I "splice in" the tone control?    Thanks.

Alex

[brett]

Big Muff tone conrol will work well.

Reason why pedals have tone stacks that don't chew the signal is that the signal level is recovered by a tranny or chip imediately post-controls.  Same thing will work in a power amp (ie put a 10 to 20dB booster between the tone controls and the power amp input).

cheers

[Chris R]

if its too loud for you now..  you don't have anything to worry about with the marshall tone stack.

C

[Doug H]

I left off the tone controls on the original circuit without the booster, because I was concerned about getting enough gain to drive the 12au7. With the booster, I suspect a tone control would work fine (might even work without the booster). I just didn't have the control panel space, was too lazy to implement it, and didn't care because I already liked the sound without it.

I would love to hear a sound clip of it with a tone stack.

Doug

[Alex C]

Thanks for the replies, guys.  I think I'll try the Big Muff tone control, as it's easily tweakable and requires only one pot (I don't have the chassis space to add three).   But I still have the question of where to insert the stack. Is it after the preamp section and before the power section (before or after C7 and R12)?   Is it that simple?  Thanks again for your help.  


Alex

[Doug H]

Thanks for the replies, guys.  I think I'll try the Big Muff tone control, Alex

Oh gross... Don't do that...  

(I suppose a tweaked BMP tone control might be okay but stock I think it sounds awful, IMO.)

as it's easily tweakable and requires only one pot (I don't have the chassis space to add three).   But I still have the question of where to insert the stack. Is it after the preamp section and before the power section (before or after C7 and R12)?   Is it that simple?  Thanks again for your help.  
Alex

Put it between C7 and R12.

There are a lot of nice little "one-knob wonder" tone controls you could try. There is a good collection of them right here:

http://amps.zugster.net/articles/tonestacks/index.html#Overview

Another one I like is to tie the "hot" end lug of a 100k pot to C2, put a .01u between the "ground" end lug and ground, and tie the wiper to R12/V3a-grid. This will let you dial in some high freq rolloff when you need it. You can experiment with the .01u and try different values too. IIRC, this will lower the bass response slightly, so you could raise R12 to, say, 500k - 1M to compensate.

Doug

[Alex C]

(I suppose a tweaked BMP tone control might be okay but stock I think it sounds awful, IMO.)

Yes sir, I am definitely planning on tweaking it, as there has been some discussion lately about possible improvements.

Thanks so much for your help, you've been very generous with your information and advice, especially since I should be asking these questions at AX84.   Thanks Doug!

Alex