Red Llama

newfish · February 23, 2011, 06:35:36 AM

Morning All,

My next build is going to be the Tube Sound Fuzz, based on the Tonepad board (http://www.tonepad.com/getFile.asp?id=119), since I've never used Hex Inverters before - this looks like a simple place to start.

Could anyone recommend going either the Craig Anderton Fuzz or Red Llama way?

FWIW, I'm a fan of 'top end' in my overdrive if this helps.

Cheers!

twabelljr · February 23, 2011, 06:46:18 AM

Have you checked out Frank Clarke's website? Lots of info on these circuits. http://guitarpedalseffects.com/HotHarmonics.html I built a Hot Harmonics a few years ago and used all the recommended components for "more gain", and it screams. Good info, schematics, and links on that page. Have fun!

newfish · February 23, 2011, 08:38:24 AM

Cheers!

I can feel a breadboard session coming on when my inverters arrive.

Makes me wonder why 4049s aren't up there with 'Ge' devices for mojo. There are plenty of 'tube-sound' inverter circuits out there.

Maybe all the 'hype' got used up on Tubescreamers...

familyortiz · February 23, 2011, 11:30:07 AM

I think you'll like the Red Llama if you like top end. Here is the link to General Guitar Gadget's schematic of their clone.
It's got a lot of top end due to no filtering after the drive stage, so you get plenty of square wave behavior. Have fun.

http://www.generalguitargadgets.com/pdf/ggg_whrl_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

newfish · February 23, 2011, 11:53:47 AM

Quote from: familyortiz on February 23, 2011, 11:30:07 AM
I think you'll like the Red Llama if you like top end. Here is the link to General Guitar Gadget's schematic of their clone.
It's got a lot of top end due to no filtering after the drive stage, so you get plenty of square wave behavior. Have fun.

http://www.generalguitargadgets.com/pdf/ggg_whrl_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

Thankyou!

I think I'll be including the 100K / 10M (yes, this huge value, allegedly) switch for 'R2' on the above diagram. Supposed to be a Lead / Rhythm boost - and that sounds like fun.

WGTP · February 23, 2011, 04:17:49 PM

IIRC the TSF is sort of woofy. I'd go with the Red Llama and try some LED's or SI diodes in the second feedback loop for fun. Also Frank's stuff is cool. I like it better than the Red Llama.

diemilchmann · February 24, 2011, 12:43:18 AM

i've got an original red lama, and its one of my favorites:)

karter2000 · February 24, 2011, 01:00:38 AM

Is there a layout available for the Hot Harmonics? I did a search and found nothing...

twabelljr · February 24, 2011, 06:00:28 AM

Yes there is,.....somwhere. I used it to build mine. It is layed out on and fits perfectly on one of these Rad Shack boards (half of one):

I will try to find it. Only a couple traces need to be cut. Nice and clean.

Here it is. It is actually Home-wrecker's "3 Legged Dog", but can be easily modified to a few 4049cmos circuits. Sound samples at Home-wrecker, you might like their circuit!
http://www.home-wrecker.com/3leggeddog.html
The resistor under the board can actually be mounted on top by running just the lead under the chip and keeping the resistor body out on the board with a few bends.

karter2000 · February 24, 2011, 10:19:31 AM

Awesome! Thank you! I happen to have a couple of those Radio Shack boards.

newfish · February 24, 2011, 04:01:34 PM

Quote
Here it is. It is actually Home-wrecker's "3 Legged Dog", but can be easily modified to a few 4049cmos circuits. Sound samples at Home-wrecker, you might like their circuit!
http://www.home-wrecker.com/3leggeddog.html
The resistor under the board can actually be mounted on top by running just the lead under the chip and keeping the resistor body out on the board with a few bends.

Fantastic!

That's a decent sound clip.
Inverters arrived this morning. I happen to have a couple of hours spare on saturday. I *think* I know what I'll be doing...

Cheers Guys!

newfish · February 25, 2011, 08:33:58 AM

Have just tried this into the overdrive channel of my Classic 30.

It's a *monster*.

My breadboard has a 470K resistor in place of the 1M 'gain' pot - so the sound a was a little tame through the clean channel, but using a Red Llama to boost the O/D channel is highly recommended.

...just hope my Neighbours enjoyed it too!

Next up - some 'Hot harmonics' tweaks I reckon - simply to try them. The 'stock' sound is pretty much what I was looking for.

stringsthings · February 27, 2011, 04:42:12 AM

Quote from: newfish on February 23, 2011, 08:38:24 AM
...Makes me wonder why 4049s aren't up there with 'Ge' devices for mojo. There are plenty of 'tube-sound' inverter circuits out there.

Maybe all the 'hype' got used up on Tubescreamers...

good observation ... IMO, germanium-based circuits have a bit more mojo since germanium semiconductors are somewhat obsolete ( and therefore harder and/or more expensive to acquire ) ... so there's a bit more of the "cool part" syndrome ...

Ben N · February 27, 2011, 11:44:50 AM

Newfish, which circuit did you build? And how does it sound into a clean channel?

newfish · February 27, 2011, 02:27:56 PM

Quote from: Ben N on February 27, 2011, 11:44:50 AM
Newfish, which circuit did you build? And how does it sound into a clean channel?

Hi Ben,

I built the Red Llama circuit (from the Tonepad link in the original post).

'Stock' into the clean channel wasn't exactly inspiring....

For me, the stock Llama into the clean channel was too 'peppery', if that sort of describes things. Not all that smooth.

so...

I tweaked the feedback caps (470pF and 220pF worked best to my ears - there's no maths here, just 'tinkering'.), and, as per 'twabelljr's suggestion, looked into the 'Hot Harmonics' circuit. I added a pair of diodes in parallel with the 1M feedback resistor on the second gate (pins 9 and 10), and this was much better.

I used a pair of back-to-back Ge diodes - not aiming for 'mojo' here, I just found these ones first and really liked the sound...

With the diodes added, and 'tweaked' feedback caps, what's on my Breadboard now serves as 'booster for dirty channel' *and* 'overdrive for clean channel'.

Also, my input cap is currently .1uF, and output cap is 1uF. This tightened up the bass response to my ears. The stock 10uF was a bit 'flappy' in the lower register.

Undoubtedly, this 10uF output cap will have been selected to work with the 10K volume pot (1/2 Pi (RC)?) - but since my Breadboard has a 100K volume pot wired up, the 1uF worked for me.

Hope this helps you with your build.

Cheers!

Mark Hammer · February 27, 2011, 03:02:49 PM

The Red Llama is essentially a "new improved" Anderton Tube Sound Fuzz, that tweaks it to take advantage of its best qualities.

Personally, having well over 30 years of close contact with the circuit, I much prefer the topography of the original Anderton TSF to the topography used for the RL. The first version had an op-amp stage up front, shown here courtesy of Jack Orman:

The advantage of the op-amp stage is that it can be used for tone shaping to "prepare" the signal optimally for the invertor stages. While Anderton himself does not do this, it is a trivial matter to provide some lowpass filtering via a feedback cap in that first stage, such that the subsequent stages do not generate fizzies. Similarly, small caps in the feedback loops of those stages, as was used in the Red Llama too, helps to tame the fizzies. I find that the invertors behave more pleasingly if you hit them with a hot signal, rather than making them do all the gain, which provides another reason for preceding them with an op-amp stage, or JFET stage as Frank Clarke did.

The 49-er project ( http://gaussmarkov.net/wordpress/circuits/forty-niner/ ) and Stellan Lehrberg's Slowfinger are both examples of interesting ways to use that pre-drive to good effect.

newfish · February 28, 2011, 04:47:41 AM

Perfect.

Thanks, Mark.

I'll get busy with a FET boost stage and see how that sounds.

Cheers.

swillett · April 16, 2011, 10:14:35 AM

Hi This is my first post! I've been tinkering for a while, mainly with fuzz faces and tubescreamer type things, but I got curious about 4049 designs having heard a lot of good stuff about the Blackstone Moseft Overdrive. I'm now also getting more curious about the design side of things.

I've just build a Red Llama copy - as it seemed the easiest build of all the 4049 designs that I've seen - having already tried more complex builds and got either annoying occilation or excess hiss (incase anyone's interested or curious they do sound pretty good although with the strat I found it boosted the treble too much - so I fitted the EQ from the HoT Tubes between the inverter stages). The basic sound is not bad at all, but I think there is room for improvement.

I'm curious about the different designs. A number of the designs (EH Hot Tubes, Double D, Hot Harmonics etc) have large value (1M and 2.2 meg) resistors from the input of a couple of the inverter stages to ground, whereas other designs don't have this (blackstone, Red Llama). What does this resistor do and how come the Red Llama doesn't need them? Does it effect the sound in any way or is it just to stabilise the chip?

My other question is does the current draw go up if more inverters are used, even if they are on a different "channel" and effectively not connected? The Red Llama only uses two inverters and I'm measuring 3.5 mA current draw, which is minute compared to the 20 mA for the Double D accoring to RunoffGrove.

fuzzo · September 10, 2011, 04:09:29 PM

Hi ,

I didn't want to create a topic just for that question so I ask here hope I'll have an answer here

I wanna make a OD/disto with a CD4049 , can I use more than 2 stage to avoid using external gain stage (transistor or AOP ) like we see in several design ? Maybe I can in being soft on gain of each stage ? (the Emma distortion uses the 6 stage of the CD to make the sound )

Mark Hammer · September 11, 2011, 10:55:53 AM

The use of 2 stages has two rationales. One is that the industry tries to have the output be in phase with the output whenever possible. So inverting, then inverting again, gets you there. The other is that multiple gain stages lend themselves to a certain "smoothness", and the hex inverter has 6 potential stages just sitting around and available for duty.

Personally, I've found that I like the way inverters sound when the gain is not concentrated in those stages, but is more broadly distributed. Whether an op-amp or inverter stage provide the better platform for doing that, I can't say. I know how to anticipate and shape the content and gain of an op-amp stage more than I know about discrete or inverter-based stages, though, and have opted for that in my own builds.

Nothing wrong with trying alternatives, though. Just don't expect miracles to increase linearly with number of stages.

Incidentally, take a look at Charles Fischer's interesting 4049-based overdrive here: http://www.generalguitargadgets.com/tech-pages/46-articles/36-em-fuzz You may be surprised to find it uses only a single inverter stage, albeit with current control over the inverter (which we never seem to get around to discussing or experimenting with here, including me) and plenty of op-amp support around it.

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Red Llama