Dan Armstrong Yellow Humper Schematic!

[RLBJR65]

Someone pointed this out to me a while ago. It's been discused but I don't think anyone has ever posted a link here before?
http://www.geocities.com/dbalde.geo/dayellowhumper.jpg

[Mark Hammer]

I'm getting a "site unavailable" message.  Not sure if it is a work-based filter or the URL is simply not valid anymore.

[snoof]

works fine on my end.

[RickL]

Works okay for me.

[tcobretti]

I don't think I've seen that one either, so thanks!

Maybe this'll work for those who can't see it:

[Barcode80]

site has a data transfer limit, that's the problem. see if you can save it and post with photobucket.

[blanik]

never heard of the yellow humper.... what is it?

[puretube]

http://filters.muziq.be/model/danarmstrong/yellowhumper

[mountainking]

never heard of the yellow humper.... what is it?

It's a bass booster. Interesting design, two twin t/notch filters in series connected between to input and output of the circuit. Probably gives a pretty "deep" sounding boost without cutting all the highs like alot of other old bass boosters do.

[aron]

Aha for bass. The purple peaker was one of my favorite pedals of all time a while back. It just did the right things for my Ibanez 335-like guitar.

[Barcode80]

i'll add this to my "need to make a layout for" list. i'm trying to contribute layouts gradually since i can't really get my head around circuit design yet...

[Dan N]

The antichrist transistor! Kind of an odd choice for an american effect. Were these made in Japan?

Thanks for posting the schematic!

[spudulike]

Sorry, but all the Dan Armstrong pedals were discussed and layed out to death ages ago. The Yellow Humper is just a Purple Peaker voiced for bass frequencies.
The Yellow Humper folder also has the schematic ROG style.
http://www.indyguitarist.com/torchy/Dan_Armstrong_Effects/

[RLBJR65]

Yep, I was in on that thread (not in an important way though ) It's here  http://www.diystompboxes.com/smfforum/index.php?topic=30085.0

It's not quit the same. R1 / C2 high pass is there like the PP. That doesn't really make sense to me?
Also there is another resistor on each filter R11 and R14. That changes the depth of the notch right?

B's version may sound better than the original! I don't know haven't built either one yet. Both versions are in the stack though

[markm]

Don't know if you guys know about this site but,
Have a look;

http://www.geocities.com/dbalde.geo/musitronics.html

[Harry Peters]

Hey, I understand I'm resurrecting an old thread here, but none of the schematic links are functional any more (I know, late to the party, blah blah)

I've attempted to build this twice, on a breadboard, with very disappointing results, per the instructions above on modifying the PP. I'm getting far less than unity and the signal fizzles pretty quickly..........

not sure what I could be doing wrong - did the double checking, component wiggling, and some heuristically hopeful connection swapping: nada.

My test rig is a Bronco SH, Rumble 15, known good cables, and a Radio Shack breadboard.

Have any of you successful builders still got a YH specific schematic you could post? Any anecdotal advice?

Thanks in advance!

[hannibal827]

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

Please post your voltage readings.

Anecdotal advice: this circuit isn't all that.  I breadboarded it, successfully, according to Brian Tremblay's instructions re. the Purple Peaker in the other thread.  I wasn't impressed--not because the instructions were bad, but because the effect is too subtle. 

It might just be a matter of taste.  What I was looking for, and ultimately built, was something more like the Electro-Harmonix "Hog's Foot" [a.k.a. "Mole"].  That is basically an LPB-1 with an aggressive LPF.

[Harry Peters]

Ah, your link/advice is well taken. I'll be more diligent to do so.

It sounds like your result is similar to mine; I too expected something..........not subtle for something called a Yellow Humper; and presumed the instructions were good/accurate - I've had good luck with the offerings of the wizened ones like Tremblay, et al.

I tried just removing the entire filter by jumping the two points where it connects to the base of Q1 and the emitter of Q2. That pretty much gave me unity.

I still have it sitting on the board, perhaps I'll do some poking w/ the ol' meter leads.

I LOVE the Mole - have made a few of my own mods/additions for more Moley goodness.

Thanks for the reply.

[hannibal827]

It sounds like your result is similar to mine;

Not sure; I had no problems with volume or fizzling signal.  Both low and high boosts "worked" as advertised.  Just not a big enough change from my regular bass tone to warrant the build, or the cost of boxing it up!  That's what is so great about the EHX circuit--instant dub bass tone.

edit: *boosts*

[B Tremblay]

...I've had good luck with the offerings of the wizened ones like Tremblay...

I'm not THAT old!