Author Topic: Kazak -- A tiny Selmer Buzztone build  (Read 381 times)

midwayfair

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Kazak -- A tiny Selmer Buzztone build
« on: May 03, 2019, 07:20:26 PM »
Bit of a rarity.

Made this for one of my best customers (he also got the Bunny Bender and a couple other pedals from me over the years.) It's an odd little pedal and not exactly what I expected from three transistors, but the name "buzztone" is pretty fitting. I made a few modernizations.



Here's the layout. I'm sorry I don't really have time to redraw a schematic right now, but the gist is:
1. It's NPN instead of PNP.
2. I added polarity protection and filtering to the input. The rest of the power section is a crude regulator in the form of a 3.3v zener to drop the supply voltage to 3.3V, and then a second 1N5817 to drop it the rest of the way to 3V. (You can leave out the second diode if you have a 3V zener; I didn't).
3. I think the circuit sounds far better with the input resistor jumpered, and I added a bypass resistor to the emitter of the first transistor. The latter doesn't actually increase the gain very much, but the first does. I actually used 50KC for the gain pot, but the original did use a 25K linear.
4. I actually had to put my first transistor in backward to get this to work. I think you need a very low-gain transistor, even though the original part number was ostensibly high hfe. So take the notes on the layout with a grain of salt.


« Last Edit: May 03, 2019, 07:22:18 PM by midwayfair »
Myself's music & things I make: http://jonpattonmusic.com. My band: http://midwayfair.org. PCBs of my designs from: http://www.1776Effects.com (Bearhug Comp & Cardinal Harmonic Trem); http://www.jmkpcbs.com (Hamlet+ delay & Blue Warbler envelope vibe); Snow Day OD/Flabulanche: www.madbeanpedals.com

alanp

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Re: Kazak -- A tiny Selmer Buzztone build
« Reply #1 on: May 03, 2019, 09:33:48 PM »
Those transistors are muy groovy :)
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midwayfair

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Re: Kazak -- A tiny Selmer Buzztone build
« Reply #2 on: May 04, 2019, 07:56:06 AM »
Those transistors are muy groovy :)

Yeah. Got them from Smallbear. They're like the size of one of the mini electrolytics.
Myself's music & things I make: http://jonpattonmusic.com. My band: http://midwayfair.org. PCBs of my designs from: http://www.1776Effects.com (Bearhug Comp & Cardinal Harmonic Trem); http://www.jmkpcbs.com (Hamlet+ delay & Blue Warbler envelope vibe); Snow Day OD/Flabulanche: www.madbeanpedals.com

lborl

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Re: Kazak -- A tiny Selmer Buzztone build
« Reply #3 on: June 17, 2019, 12:31:31 PM »
Hi - I've been hoping someone would do a layout like this for while so thanks! I'm populating the board right now but it's just occurred to me that middle 39K (H/E to K/E) doesn't seem to connect to anything?

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Re: Kazak -- A tiny Selmer Buzztone build
« Reply #4 on: June 17, 2019, 02:29:10 PM »
Very nice as always!

I need to dip my toes in the perf world sometime.

I gotta ask, what is the Vonnegut book. Hes one of my favorite authors.

lborl

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Re: Kazak -- A tiny Selmer Buzztone build
« Reply #5 on: June 17, 2019, 02:33:57 PM »
Sirens of Titan isn't it?

midwayfair

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Re: Kazak -- A tiny Selmer Buzztone build
« Reply #6 on: June 17, 2019, 04:27:13 PM »
Hi - I've been hoping someone would do a layout like this for while so thanks! I'm populating the board right now but it's just occurred to me that middle 39K (H/E to K/E) doesn't seem to connect to anything?

It connects to the collector of Q2 and lug 2 of the fuzz pot. The traces are under the resistor.

EDIT: I just realized I labeled the fuzz and volume pots backwards. The one labeled depth should be the volume pot and it's 100K. The one labeled volume should be the depth pot and it's 25KC.
Myself's music & things I make: http://jonpattonmusic.com. My band: http://midwayfair.org. PCBs of my designs from: http://www.1776Effects.com (Bearhug Comp & Cardinal Harmonic Trem); http://www.jmkpcbs.com (Hamlet+ delay & Blue Warbler envelope vibe); Snow Day OD/Flabulanche: www.madbeanpedals.com

selfdestroyer

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Re: Kazak -- A tiny Selmer Buzztone build
« Reply #7 on: June 17, 2019, 04:58:37 PM »
Nice Jon! Love seeing your hand painted builds. 

lborl

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Re: Kazak -- A tiny Selmer Buzztone build
« Reply #8 on: June 17, 2019, 05:15:00 PM »

It connects to the collector of Q2 and lug 2 of the fuzz pot. The traces are under the resistor.

EDIT: I just realized I labeled the fuzz and volume pots backwards. The one labeled depth should be the volume pot and it's 100K. The one labeled volume should be the depth pot and it's 25K.

Ah. Makes sense now. Thanks!

pickdropper

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Re: Kazak -- A tiny Selmer Buzztone build
« Reply #9 on: June 17, 2019, 07:40:53 PM »
Wow, Jon built a pedal again!

Very nice, Jon.  It wasn't the same without seeing your hand crafted minis.
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nzCdog

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Re: Kazak -- A tiny Selmer Buzztone build
« Reply #10 on: June 18, 2019, 12:13:34 AM »
Awww... cute lil thing ;D
Neat build Jon