Just built a Red Llama - should there be farty/fuzzy bass notes when chording?

[markm]

What should the voltages be on this IC in this circuit? Do mine look ok? Or maybe I should've socketed the IC rather than heat it up with my soldering iron?

I just realized nobody answered that.
I don't think 1K should drop the voltage down that low.
I'd measure mine but, I don't have it close by to do so. 

[Pushtone]

What should the voltages be on this IC in this circuit? Do mine look ok? Or maybe I should've socketed the IC rather than heat it up with my soldering iron?

I just metered it again.
I think your voltages are fine, at least they are exactly what I'm getting.

The 1k resistor is not dropping the 9v to 5.47
It's the load doing that.
If I pop the IC out of the bread board the junction after the 1k (R4) meters 9v.
With the IC in it meters 5.47v DC.

I think you've got it. Now make it better, or suited to your needs.

I tried the hi-pass filter from here with Joe's suggested values.
But I find changing the 10uf output cap does the same thing.
I'm using a film 0.047uf cap now at C5.
That alone is a substantial improvement. Tightens bass response and improves the character of the distortion too.


Here's a pic of the circuit on the breadboard. Note the 10uf tant has been removed in favor of the .047uf film.

[markm]

Dave,
Do you use this at mainly higher gain settings?

[Pushtone]

Any other distortions out there that use a 4049 hex buffer? To compare.

Found one. The Insanity Box, of course duh, from the PEDALS section off Aron's homepage.
A CD4049 distortion to compare.
http://www.diystompboxes.com/pedals/insanity.GIF

Check out Jack Orman's comments about the CD4049, a link from the Insanity Box page.
http://www.diystompboxes.com/pedals/jo4049.html


And here is the source of the above links, the PEDALS page.
http://www.diystompboxes.com/pedals/schematics.html

[markm]

 

[joelap]

@ Pushtone:  I added the high pass filter, because I was going to be adding a low pass filter anyways to remove some of the highest highs (I use a vox) from the circuit, so I figured what the heck, make it a band pass.  Unfortunately, I'm waiting for an order to come in from smallbear on those cap values I didnt have on hand, so I think if I pick my values right, I might be able to eliminate the need for the high pass filter.  Also, I've since added a tone control on the output, which is doing a good job of acting as a presence control anyways, so I might be able to drop the band pass in favor of a single cap now.  Unforuntately, out of .047, .033, .068, values.  Only had .01, .022, .0047, .0022, and .1!!  So I was left with too little bass or not enough bass for the time being    Hopefully with I get those caps in, I can drop the band pass filter in favor of the .047uf output cap.  Not to mention, I was worried about loading on the output from having the band pass circuit without any kind of impedance changer... like a source follower or something. 

I can't imagine why the Red Llama would have a 10uf cap on there!  I know the TSF has a 10uf on there, but its supposed to be a fuzz, I'd expect some cap choices to make it nice and woofy.  I ended up getting a really nice sound out of this pedal after a few tweaks, that I think work REALLY well with my vox.  I'm going to tweak it a bit further, and then piece it together and box it up.  I bought the parts... actually going to try board mounting the pots with the new alpha's smallbear is selling... looking forward to this one a lot!

@grolschie:  I sincerely think that changing the output cap from a 10uf tantalum or electrolytic or somehting like .022 or .047 will remedy what you are hearing.

[markm]

[Pushtone]

Dave,
Do you use this at mainly higher gain settings?

I'm trying it over the whole gain range but focusing on the bass response and comparing it to the BSIAB.



I've been trying different values for R4 (the 1k at the power supply) and lowering it to 380ohms seems to help the high end.

I'm thinking about switching between 0.047 and 0.33 output caps with a toggle. Perhaps call it a bright switch.
0.33 sounds better on the bridge PU while 0.047 sound better on the rhythm PU. That would solve the farty problem too.

I can't believe there's a 10uf in there either!

[markm]

See, I'm thinking that perhaps on the higher Gain settings is where some of the issues may lie.
I think the cap switch is a good idea.....I don't have these problems myself.
I can't figure out why? 

[grolschie]

Hey fellas, if you have a good sounding Red Llama near your workbench, could someone please post voltages and cap values please? Thanks in advance.
grol

[grolschie]

.....I don't have these problems myself.
I can't figure out why? 

Maybe yours is the one that is faulty. hehehe     

[grolschie]

Thanks for all the replies and tips. I will continue the debugging and also try some different output cap values. My tant has "10μ 25" on it. So film caps are ok here?

[joelap]

So film caps are ok here?

Absolutely.  The reason tantalum was used is because I dont think a 10uf film cap exists, and if it did, it'd probably be pretty big.

[markm]

So film caps are ok here?

Absolutely.  The reason tantalum was used is because I dont think a 10uf film cap exists, and if it did, it'd probably be pretty big.

Mr. Huge told me awhile ago that the 10uF was a Tant because of the tone the Tant provided.
Mojo?-----Maybe.
Legend?----Perhaps but, Mine sounds good!
I think Jorge did stuff for particular reason personally but, that's just my opinion. 

[soulsonic]

This is only my opinion so take it with a grain of salt, but I think tants are nasty awful worthless things to use for coupling caps. I think they sound like total garbage and the first thing I do when I see one in a commercial pedal is replace with either a film cap or a non-polar electrolytic. I replaced the tantalum input coupling cap on my Dunlop Fuzz Face with a film cap and it instantly sounded 1000 times better. Tants or OK for filters - that's their intended purpose - but I absolutely hate them more than anything for coupling. I rather use cheap ceramic chip caps for coupling than any tant ever.

[markm]

Alot say and think that.
I was a bit "floored" when Mr. Huge mentioned this to me as well but, then I remembered a Telephone conversation that I had with Dan Armstrong circa 1992 or so.
He stated that he used Tants in the O/S (maybe some of his others too but I was talking with him about the O/S) because of the tone.
He also mentioned that the circuit didn't sound "right" to him without Tant caps in it......go figure huh?! 

[grolschie]

Ok. I have just found a 0.047uf MKT cap in my bag of goodies. Will try that later on. Thanks very much everybody! I will post back when I have tried it.

[grolschie]

Replaced tant with 0.047. Replaced 0.068uf input with a 0.033uf.  Still sounds messy still on chords at low gain. Chords on higher strings are fine. Lead sounds nice until I hit the lower 2 strings.

Funny thing is, if I turn the volume knob down on guitar to almost off, and amp up to compensate, the overdrive is very smooth and nice. Maybe something is weird with the gain part of my built. I will check the pots and wiring next.

[Mark Hammer]

Any other distortions out there that use a 4049 hex buffer? To compare.

Take a listen to the Forty-Niner sample embedded here: http://hammer.ampage.org/files/FortyNiner-1.zip
The notes on the sample included are at the bottom of the screen here: http://hammer.ampage.org/?cmd=lt&xid=&fid=&ex=&pg=12  Obviously, it sounds better through an amp than it does going into a USB convertor box.

This is essentially an adaptation of one of Anderton's Tube Sound Fuzz circuits.  The Red Llama follows up on the second one that appeared in EPFM.  Personally, I found I liked the tone of the first one that appeared in GP around 1977 or so (Jim Messina cover if I'm not mistaken).  This added an op-amp input stage, which I found provided opportunities for tone-shaping the input signal more than the EPFM circuit did.  I found I also liked the tone better when the first invertor was hit with a hotter signal, as opposed to making the invertor do the gain boost.  Question of taste, I suppose.  The Forty-Niner was something I whipped up a couple years ago to present to David Lindley.  He seemed tickled by the gift, but I have no idea if he ever used it or even tried it out. 

You can leave out the section between points A and B.  It provides some interesting "revoicing" and selective pre-boost, but isn't critical.  A bypass cap (say, .01-.047uf) between the input and wiper of the Drive pot also adds some nice bite to lower drive settings.

[joelap]

Ok, now I've finally gotten the bass under control, and the highs are fine as well... but they're a bit harsh.  There seems to be high end crackle harsh-sounding distortion on the highs even when I lower the drive control.  Its very odd... any remedies?  I tried putting a cap after the 100k to ground, as well as raising values of coupling caps to bring more bass in, but even with a large value cap shunting a good chunk of highs to ground at the input, there's still that crackle... its absolutely weird and I cant get rid of it no matter how hard I try.