Red llama mods?

[Jmsteele187]

I've been looking at this schem for the red llama http://www.generalguitargadgets.com/pdf/ggg_whrl_sc.pdf .  I'm thinking about ways to modify the circuit.  I know I can play with the input and output caps to add or cut bass/treble.  I also know I can change R2 to add more gain, and even add a tone control or EQ.  But, I'm wondering if it is possible, or even worth it, to add a switchable clipping stage.  Any suggestions, or thoughts?

[Cozybuilder]

Inverter circuits are fun to play with, its well worth your effort to test your ideas on a breadboard. What you are suggesting are very reasonable things, and you may wind up with a new favorite.

[Jmsteele187]

Inverter circuits are fun to play with, its well worth your effort to test your ideas on a breadboard. What you are suggesting are very reasonable things, and you may wind up with a new favorite.

thanks for your input.  I wanted to see if it was fesable before I nearly go insane fiddling with the breadboard.  My breadboarding skills are severely lacking.  I've been trying to get a simple rangemaster circuit to work, and can't figure out what I'm doing wrong.

[blackieNYC]

This is mark Hammer's 49er. A boost in front followed by the frequency booster, the on-off-on switch gives you 3 frequency bump settings. Variable bump.  Can do a fixed wah sound nicely.  Can also be flat, using that 10k pot in the crew booster circuit. Distortion is after the freq booster.  Oh m'gawd, I love this thing!

[Jmsteele187]

That is quite a bit more than I was looking to do, but very cool.  Probably a bit out of my league on the breadboard at this time.  I definitely need more practice.  I did get that range master to work, though.  I made the stupidest mistake with it.  I forgot to connect the power strips in the middle, lol.  I think I made too many value substitutions though, I didn't really like the sound, and it was a little fuzzy when I dug in on the strings.  Oh well, time to get that red llama on the board, and see what kind of changes I can come up with.

[Cozybuilder]

Those power strips will still get you even after many years of doing this. Glad to hear you have your modded circuit working. I suggest you take it back to the original circuit and simply try out one mod at a time so you get a better feel as to how each change affects the circuit- some you'll like and keep, others not.

The Forty-Niner is a step up from the RL, but certainly not an impossible leap. Good luck!

[Jmsteele187]

Unfortunately, it wasn't the RL on the board, yet.  I was trying out an npn Si rangemaster.  I didn't have all the value components that I needed, so I made a number of substitutions.  I got it working, but didn't like how it sounded.  I'll get the RL on there later tonight and see how each mod sounds.  If I decide to box it up, when I'm done, I'll make each mod I go with switchable.  That way I can have straight up RL, if I want it.

[Mark Hammer]

Having started out with inverter overdrives in the late 70's (original Anderton circuit in the '76 or '77 issue of GP with Jim Messina on the cover...I think, and the original EH Hot TUbes), I came to the conclusion that I liked them better when the gain was not provided primarily by the inverter chip itself, but rather when the first stage was ht with a harder signal, and the inverter provided modest gain.  That was the basis for the Forty-Niner, was also employed for Stellan Lehrberg's "Slowfinger" and some of Frank Clarke's circuits that all went under the general name of "Hot Harmonics".  All of these shared in common the trait of having an initial gain stage of other category (FET, op-amp) feeding a pair or 3 inverters that are set for moderate gain.  I don't have an electronic file handy, but I do recall one Hot Harmonics version that was essentially a single FET gain stage in front of a pair or trio of inverter stages, with the drive/gain set by an attenuator/volume pot between the FET stage and the inverters.

The push-the-front-harder approach is simply something I found I liked, and not necessarily a "best" or "only" or "right" way.  The RL and the original Anderton EPFM circuit aimed for zen-like simplicity and used two inverter stages for everything.  Anderton's earlier pre-EPFM version in GP used an op-amp front-end with a gain of around 4x, to push the inverter harder.

Simple mods?  Many folks have reported they found more flexibility by adding a tone control just ahead of the volume pot.  The RL/TSF has plenty of output, so even if you have some passive loss from adding a tone control, there's still plenty of signal left over.  You can find some useful ideas here: http://www.muzique.com/lab/swtc.htm

I've also found that when the gain is reduced, but the treble and mids feeding the circuit arestill hot, you can get some "instant Rickenbacker" sounds out of it.  I'll suggest putting a 100k and 4700pf (.0047uf) in series, and placing that in parallel with R1/C1 in the drawing.  You can then use a toggle to switch a 33k resistor in parallel with the new added 100k.  While the 33k is disconnected, the new 100k provides no particular advantage for treble content.  Place the 33k in parallel and you now have two paths for the signal: 100k->.068, and 24.8k->.0047.  The former provides a path for the entire signal, while the latter provides a noticeably easier path for content above around 1.3-1.4khz,  That will add more bite to lower gain settings.

[Jmsteele187]

Thanks for the input, Mark!  That gives me a few more ideas.