Death by Audio - Octave Clang

Glass_Hero · Post by **Glass_Hero** » 02 Oct 2011, 13:58

davidnaas wrote:
Just great! This will be my next build, just a couple of questions....

1. Is this scheme sure to work?
2. What hapens if you switch the values of the transformer? Seems quite hard to find the exact values in my part of the world. Also is the middle-left leg of the transformer left open?
3.Is the symbol at pin 7 only the 9 V DC input? And which pin is pin 8?

the schem came from tracing the actual pedal..

the transformer is available from mouser 42tm002 or the 42tl002..digikey has a more expensive version..i'm not sure what the difference would be if you changed to a different part.. in the mouser catalog this transformer is listed as a driver, all the other ones are either coupling, interstage, or output..

pin 7 is the 9volt connection.. pin 8 is NC and left open.. the chip is an LM741..look at its datasheet for more details on this..

Glass_Hero · Post by **Glass_Hero** » 02 Oct 2011, 14:00

oh don't forget to ground pin 5.. its part of the null offset on the chip..

devastator · Post by **devastator** » 02 Oct 2011, 14:30

it's me or the schematic looks really odd , espcially on the biasing and resistors to set the gain ? (coming from DBA it won't be a suprise

)

there's really any DC bias to the "+" input ?

davidnaas · Post by **davidnaas** » 02 Oct 2011, 20:38

Ok. Thank you fot the tip with mouser. They seem to be shipping to sweden but then there's the horrid shipping cost and customs (sadface). A bit boring but maybe worth it!

davidnaas · Post by **davidnaas** » 17 Oct 2011, 13:42

My octave clang - clone is working as it should and sounds really nice. Just wanted to say thanks to the guy who trace and also recomend this build as it is easy and gives you a really nice octave(sort of)-fuzz

biech · Post by **biech** » 19 Nov 2011, 11:15

Hi,

is there anyone who wants to post a vero for this?
thx in advance!

Glass_Hero · Post by **Glass_Hero** » 23 Nov 2011, 14:53

biech wrote:Hi,

is there anyone who wants to post a vero for this?
thx in advance!

i had some space in on the last PCB order i placed.. i threw in the octave clang because it was small enough to work.. I get the boards next week. i'll send you one if you want?

Glass_Hero · Post by **Glass_Hero** » 04 Dec 2011, 04:21

here is a perf..

smacca · Post by **smacca** » 10 Mar 2012, 10:37

hi,
i've built this using glass-hero's layout above, and im having problems with it...
im just not getting an octave clang...
ive got a fuzz sound happening (it sounds mild compared to the videos), but no octave/craziness...
there is also a volume drop, which goes against this apparently being a loud pedal...

ive followed the layout point for point... and i just don't get it...
i cant figure out what i could have missed or done wrong....
and this is a really easy build, so it's driving me crazy!!

anyone have any ideas as to what could be wrong?
should i post pics?

thanks

Seven64 · Post by **Seven64** » 12 Mar 2012, 03:10

pics help. did you get the jumper under the transformer (i think i see one there)

Mrutg · Post by **Mrutg** » 09 Apr 2012, 22:19

Hey guys.
Mouser has pretty expensive shipping costs to my country.
Do you know if maybe this would work as a replacement?
TRIAD MAGNETICS - TY-142P - TRANSFORMER, AUDIO, 0.1W
http://uk.farnell.com/triad-magnetics/t ... dp/1610410

bubstance · Post by **bubstance** » 09 Apr 2012, 22:38

That'll work fine.

smacca · Post by **smacca** » 25 Sep 2012, 12:55

ooooppss... got busy and forgot to post pics

any thoughts as to what ive done wrong greatly appreciated....
and go easy on the soldering job

EdGrip · Post by **EdGrip** » 25 Sep 2012, 18:34

Glad to see that just letting the battery rattle around in the box like an unwanted loose end is the way the pros do it too... I thought I was just lazy.

benweasel · Post by **benweasel** » 05 Oct 2012, 17:35

I have just built this pedal ,but i have problem with low gain.
I have used lm741cn from banzai music and 1N34A diodes from tayda.
Has anybody any idea have to fix a low gain (no fuzz) ?
Is any ic with more gain?

benweasel · Post by **benweasel** » 05 Oct 2012, 18:31

I fixed it. It works with no problem.

smacca · Post by **smacca** » 01 Apr 2013, 13:00

no ideas on what i may have done wrong?

Post by **GRbit** » 22 Apr 2014, 20:21

Trying to build a clone, but haven't lm741. OP07 working fine, but offset must be connected to gnd through 1meg resistor.
In attached archive there is eagle schematic, eagle board and pdf image on the front side of pedal for 1590bb

Couple of tips:
- Use germanium diodes, or schottky with with high reverse current, or your project just won't work.
- OP07 is very sensitive, use anti-static bracelet or something like that
- Transformer model doesn't affect the sound if it's 10k primary and 2k secondary. I test many of them and choose 20k primary and 1k secondary, a little less harsh and more sensitive on quiet sound.
- Using any (ANY) other opamp is although possible, but it's more complicated, schematic in attached pic. Resistors values is optimized for tl072,

johnk · Post by **johnk** » 23 Dec 2014, 02:43

i etched a PCB I built one up and it works properly but it's pretty quiet when running the tone control CCW. i can't really see where the knobs are set on the youtube demos so i'm not sure it the original is like that or not.
it sounds good with a lot of octave up going on but it doesn't seem to have quite as much dirt as the proguitarshop youtube demo.
when running a booster in front of it, IMO, it sounds A LOT better.
i also added a 47u filter cap to mine, but i tried it with and without it and there's no difference in the sound.

for those that want to etch a verified PCB, here's mine:

Mr. Lime · Post by **Mr. Lime** » 22 Jan 2015, 11:13

Hi,

I did a schematic with the Octave Clang in mind using a CMOS 4049 instead of an OP-amp.
Because of the small amount of gain produced by one CMOS gainstage, I decided to boost it with a JFET as Input-Stage.
There's a recovery stage to get even more gain out of it followed from a buffer.

I wanted to create a flexible overdrive that is able to bypass the transformer part.
The idea was to get a wide range from a Red Lama to something like a MP Stone Grey Distortion.

Any suggestions on this?
Does anybody think I will get close enough to the Octave Clang with my circuit?

Is there enough gain from the JFET into the CMOS stage compared to a TL081 or LM741?

Best regards

Death by Audio - Octave Clang [traced]