(GUS SMALLEY OCTAVE BOX) replacement for radioshack audio output transformer?

[aeiou]

http://www.radioshack.com/product/index.jsp?productId=2103254

as you can see -- out of stock.

not to mention, who wants to do business with radioshack anyway?

whats an easy drop in replacement for this transformer? quality is paramount but i'm open to any suggestion, including new or vintage pieces.

here's what i'm building -- gus' simple octave up circuit.

http://www.generalguitargadgets.com/diagrams/simple_oct_up.jpg?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

thanks!

[garcho]

273-1380 (Radio Shack audio output transformer)

impedance 1kHz , 1V, 0mADC
input 1k ohm +- 10%
output 8ohms (loaded)
dc resistance input 70 ohms +- 20%
dc resistance output 0.62 ohms +- 20%
frequency response 300 - 1000Hz +- 3db
insulation resistance more than 100M ohms @ 250VDC

[PRR]

That part is In Stock at all four Shacks near me.

Quality?? This part was originally for $3 transistor radios. Not sure where quality comes in.

This series of transformers is widely available.

Small Bear: http://www.smallbearelec.com/servlet/Detail?no=599

Mouser: http://www.mouser.com/Search/Refine.aspx?Keyword=42TM013

others:
http://www.cpcares.com/xicon/Xicon_EI_19_Audio_Transformers/42TM013.html
http://elcodis.com/parts/4367302/42TM013.html

If you want to try other parts: a power transformer wired 240VCT:20VAC is the same ratio, will have ample impedance to lower frequency, and be a lot harder to overload. Sizes from 1VA to 10VA are appropriate. 1VA is more than 10X beefier than the 0.1VA 300Hz rating of the 42TM013! Above 10vA you'll be putting more energy into the core than into signal, and the size is too big for pedals.

[aeiou]

what i meant to say -- i'm looking for a distributor of that particular part, or a higher quality alternative.

thanks for pointing me in the right direction PRR. ordered a few just now ..

however -- id still like to try a bigger/higher quality transformer to see if i get a little better sound quality. i'm looking for a clear sounding ringmod type octave. not dissimilar to the one from EHX's microsynth, which is the clearest i've heard, although a bit anemic.

for the purposes of this project, not fitting into a standard enclosure is fine.

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additionally, what's the fundamental difference between the 'sick box' (posted below) and the simple octave up? i heard jimi's video and it sounded good! just a little too fuzzy for me .. i'm no engineer, but it looks like theres just an extra stage of gain here, and some bonus diodes at the end.

http://www.generalguitargadgets.com/diagrams/octave_up_sick_box.jpg?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

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btw, are the diodes at the end of these pedals JUST for soft clipping? can i omit these if i like?

[aeiou]

doing some searching i've come across two transformers that i think will suit my needs -

http://www.ak-modul-bus.de/stat/nf_uebertrager_1_10.html

http://uk.farnell.com/vigortronix/vtx-101-001/transformer-audio-6-3-6-3-1-1/dp/1674300

i think these are the correct ratios?

[Zipslack]

Or you could always try ripping some out of old transistor radios...the ratios might not be exactly what you need...will have to measure, but I'm sure you can come across some that could be used.

[PRR]

> are the diodes at the end of these pedals JUST for soft clipping?

Not at all. That IS the octave-up contraption. The transformer is just a simple way to get both-ways signal. The diodes put both ways the same way.

Not sure why you'd even think of omitting them, except as experiment, since it's only 20 cents.