just breadboarded a Red Llama

[blanik]

by reading about the 4049 chip i became interested in it's different versions (i'm so happy i bought a breadboard!) so i tried the Red Llama first, i must say it's pretty impressive... i read a lot of complaints about the "fartness" of the 6th string (specially on the neck pickup) and i had also this... i found out that by lowering the input cap to 0.047 uF instead of 0.068 uF but keeping the output cap at 10 uF Tant, the whole thing tightens up even on neck pickup! this pedal is really sensitive to the guitar you're using, so those who really like it tend to play teles, strats and P-90, those playing a guitar with humbuckers seem to like it the least

[the recluse]

I just built an RL for someone, and was pretty surprised at how much I liked it.  I had built the Tube Sound Fuzz early on in my DIY habit, and it didn't do much for me.  I found the RL had a bit more bite and volume and was a nice improvement on the Anderton circuit.

[frokost]

Interesting... I use humbuckers, and the Llama is my favourite overdrive. However, I have it set for really low gain and the amp close to breakup, but not close enough that the Llama functions as a booster.... At high gain, I don't like it.

[earthtonesaudio]

I just built an RL for someone, and was pretty surprised at how much I liked it.  I had built the Tube Sound Fuzz early on in my DIY habit, and it didn't do much for me.  I found the RL had a bit more bite and volume and was a nice improvement on the Anderton circuit.

Huh.  I thought it was a direct clone.

[gutsofgold]

Same circuit, slightly different values.

[blanik]

i fined tuned it to my taste, now i have a question: i want to put a switch for "regular gain stack" or "more gain" the only problem being that at max gain there's way too much bass in the signal (probably one of the reasons people prefer this pedal on lower gain settings) so i'll put the gain pot ant cap coming out of pin 14 and 15 on a switch to completely switch both the pot and the cap so on my second "channel" which will probably only have a 1.XX Meg resistor instead of a pot (on the regular channel, i'll put a 10K resistor in place of the 100K, with a 10K and the volume maxed it becomes a clean boot but lively) so the second channel will have a fixed value but how could i cut bass from it? i've tried different caps i place of the 56pF from 10 pF to 100pF without cleaning up the low freq mess, is there some way to put a cap or resist to ground to acheive this?

it's taken from Tonepad's schem (i can't draw that well...lol)

[bluesdevil]

I had a Red Llama circuit on a breadboard for a month.... wished I still had it on to help you. You could try having a switch that changes out the output cap to a smaller one while switching out the pot for the fixed resistor at the same time. Also reducing the resistor connected to the power supply seems to tighten bass and make the signal clearer and less muffled.... I used a 100 ohm resistor in series with a 1k pot on my build.
   I also put in a footswitchable "boost" circuit for my lead channel... I was thinking of just having a switch to swap between 1M pots at different settings, but opted for the booster because it adds more distortion and bite. I basically used the JFET thing on Frank CLarke's "Hot Harmonics" with a couple of changes.
   I'll post a pic in the picture thread of my build in the next day or so.... it's a Red Llama gone too far!!

[earthtonesaudio]

Lots of different ideas here, links to different CMOS distortions, etc:
http://www.diystompboxes.com/smfforum/index.php?topic=67584.0

In this design, I like a .022uF cap for humbuckers and a .047uF for single coils.  Very much a "tweak to taste" circuit. 
I think Seymour Duncan has a distortion that has volume, tone, and a 6-way switch labeled "rumble," which is probably the same idea.  A bunch of tone caps on a switch would be a good fit for this type of circuit.

[Mark Hammer]

I still think the way to go is to put either a JFET or op-amp input stage ahead of the basic circuit and use THAT to tailor the frequency content hitting the first stage.  There are some really nice Rickenbacker-y tones to be had by using the basic RL/TSF circuit at lowest gain and driving it a little harder with the upper mids than with the lower mids and bass. 

Why is this "better"?  Using a lower input cap on the RL circuit rolls off low-end on a progressive basis.  In contrast, if you have something like I normally use, where the invertor gain is fixed and the drive adjusted via a voltage-divider between op-amp and invertors (i.e., a 10k or similar pot, just ahead of the 100k input resistor shown in the schematic), you can stick a bypass cap on that pot (just like the brite cap on an amp's volume pot) to produce progressive treble advantage above a given frequency without affecting the bass content.  In this way, when you turn down the gain, you get a nice bite without having to sacrifice your low end.

You can read more here, which will show you just how long we have been tinkering with this circuit: http://www.harmony-central.com/Guitar/Faqs/faq/faq.tubeSoundFuzz.txt

[WGTP]

http://www.aronnelson.com/gallery/main.php/v/WGTP/Red+Rhino.GIF.html?g2_imageViewsIndex=1

A Rhino seems more R&R than a Llama.

This incorporates some things from the Red Llama, STM's 22/7th's, Gus modded Muff Fuzz and various other CMOS distortions.

The Fuzz control should help the farting at high gain by reducing the bass.  Or values are suggested for a "Rumble" switch. 

3rd stage option for more Rhino

BMP tone stack option   

More to follow   

[AM]

I still think the way to go is to put either a JFET or op-amp input stage ahead of the basic circuit and use THAT to tailor the frequency content hitting the first stage.

Mark, it seems like the general concensous that the best booster in front of a Llama is a Mosfet booster. Have you ever had any experience with other boosters? I was thinking about the minibooster or a treble booster.

[Mark Hammer]

I don't know that there is any selective advantage to using a MosFet front end, given that the advantages of a high input impedance are totally lost on the remainder of the circuit.  That is not to say that it is worse.  After all, it can be built in a smaller space, and may even have less hiss.  But it is not critical to the optimal functioning of the RL.  All you really need is to hit the front of the RL (i.e., first invertor stage) with a hotter signal.  How you get there is your business.  Personally, I have a stack of NE5534 chips someone gave me, so that's what I use.  In this context, my feeling is that pre-gain is pre-gain.  As long as you kick it up a notch somehow, by "outsourcing" the gain to a preceding stage or even pedal, and shape the tone appropriately in anticipation of subsequent clipping, you'll be in good shape.

And just to answer the question: no, I have never used a discrete front end for the basic dual-invertor clipper.  I'm willing to try, but I rather like what I've been able to extract from the op-amp+invertor arrangement so far, so there is no big hurry on my part.  YMMV

[AM]

I'm willing to try, but I rather like what I've been able to extract from the op-amp+invertor arrangement so far, so there is no big hurry on my part.  YMMV

Oh, I see......I checked a schem of your 49er after reading your post and I realised you don't use a mosfet booster there. For some reason I thought that this was what you used. My mistake. Since a lot of other people have report very satisfactory results using the mosfet I thought you had done the same. I actually think your way gives more flexibility since one can choose what frequency range to be boosted. That was kind of what I was asking in a way. If it's better to put a clean full frequency booster in front of the llama or a mid/high frequency booster. Just wondering...

[blanik]

i tried a super-hard-on in front of the RL and the gain was interesting but it boosted the bass even more so it would need some serious tone shaping between the BS170 and the RL... the IC approach might be interesting, i have to admit that the RL on medium to low gain is hard to beat, it ads a nice "shine" to the sound...

[WGTP]

http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html

Check out the CMOS Drive and CMOS Boost for some ideas at:  http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html

The CMOS Boost into the RL is sort of what I have been working on.

A .0047uf cap at the input instead of .047uf cap will reduce the bass.  Also reducing the .033uf cap to .022uf should help with the flatulance.   

[blanik]

http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html

Check out the CMOS Drive and CMOS Boost for some ideas at:  http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html

The CMOS Boost into the RL is sort of what I have been working on.

A .0047uf cap at the input instead of .047uf cap will reduce the bass.  Also reducing the .033uf cap to .022uf should help with the flatulance.   

there's already a couple of designs that uses a third CMOS channel in front of a "RL" and using another CMOS would drain too much power from the battery...yeay, the cap change works fine... though i noted that the fartiness of the lows is more prevalent in my small amp, on my twin it's not there...

[earthtonesaudio]

I've run all 6 inverters and still had acceptable current draw (under 10mA), at least at 5 Volts.  They tend to be a little thirstier at 9V.

[blanik]

I've run all 6 inverters and still had acceptable current draw (under 10mA), at least at 5 Volts.  They tend to be a little thirstier at 9V.

would it sound the same at 5V??  i've put a pot on my breadboard power line and below 7V it starts to oscillate and shuts down... how do you get it to work at 5V??

[earthtonesaudio]

Hm... I've run both 4049's and 4069's at 5V, done several ways with no problem:
1. Using a LM317 adjustable voltage regulator (preferred)
2. Using a 10k pot wired as a variable resistor in series with the positive power lead
3. Using a 200k pot as a voltage divider to drop 9V down to 5V, with a 10uF cap from the wiper to ground.
4. I've also done #1 and #2 simultaneously, in different proportions.


These chips should work from 15V down to (and below) 3V, but yes they do sound different at lower voltages.  Not bad, just different.  More clipping, less volume, more compressed, etc.

If you drop the voltage with a resistor on either the power OR ground leads, the clipping becomes very asymmetrical.  You can use equal resistors to both the power AND ground lines, but you have to watch out for oscillations even more.  Be good with your power supply filtering cap: it should be as physically close to the V+ pin and ground as possible.  Long leads make it less effective.

If you drop the voltage with a regulator, it sounds subtly different, but stays symmetrical.