U-boat. NEW Smooth sub-octave / synth effect!

merlinb · August 25, 2011, 05:18:58 PM

Quote from: auden100 on August 25, 2011, 04:50:15 PM
Sounds great, Merlin. Playing around with a perf layout. Just wanted to check if a j201 could replace the j112?

Yeah that should be fine.

artifus · August 25, 2011, 05:21:46 PM

http://www.bbc.co.uk/news/uk-england-leeds-14662402

Skruffyhound · August 25, 2011, 06:11:10 PM

Grosse Fahrt I'm guessing is high speed

iccaros · August 26, 2011, 09:16:30 AM

Quote from: merlinb on August 25, 2011, 07:33:19 AM

(I wonder what Grosse Fahrt means? I know what I *think* it means... )

great ride

its all I can add..

Mike Burgundy · August 27, 2011, 02:05:43 PM

It translates to Full Speed, with Auss. Kraft maximum power available for short periods. I'll never be able to hear "full speed ahead, captain" again without my inner child giggling ;P

Great work!
What's the technique you used to get the rust look?

Gurner · August 27, 2011, 02:49:02 PM

Got to say...top notch work, an elegant (but well thought out) simple circuit (I show traits of obsessive compulsive disorder when it comes to designing a circuit vs parts count) ...presented impeccably too...and all this from a bloke way up in Yorkshire ....by 'eck!

Well done.

blue_lu · August 27, 2011, 03:19:29 PM

Nice work! How is the Uboot sounding and tracking on a Bass?

DC9V · August 27, 2011, 03:21:28 PM

Damn you, Merlinb! Another one to add to the endless to-do list!

merlinb · August 27, 2011, 05:32:06 PM

Quote(I show traits of obsessive compulsive disorder when it comes to designing a circuit vs parts count)

Heh, I really like getting things into 1550b size enclosures!

QuoteWhat's the technique you used to get the rust look?

I soaked the enclosure in detergent to make it look like steel, then I just painted the rust on with acrylic paints (red, yellow, a fine brush and patience!)

Quote from: blue_lu on August 27, 2011, 03:19:29 PM
Nice work! How is the Uboot sounding and tracking on a Bass?

Dunno, my bass doesn't live with me here. I'll have to get one of my bassist friends to try it for me some time...

~arph · June 15, 2012, 08:06:09 AM

Just discovered this thing

I feel lit deserves a bump to the present. Great pedal!!!!

njkmonty · June 15, 2012, 08:24:33 AM

hey Merlinb , hows the sine wave generator build on you photobucket site? also what rotary pot did you use?
uboat sounded good!

~arph · June 15, 2012, 08:25:47 AM

Signal generator is here: http://www.freewebs.com/valvewizard2/siggen.html

njkmonty · June 15, 2012, 08:27:44 AM

i just downloaded that, ive not come across small style rotary switches like that, are they available from mouser?
the 2p4t switch used for range.

merlinb · June 15, 2012, 09:19:22 AM

Quote from: njkmonty on June 15, 2012, 08:27:44 AM
i just downloaded that, ive not come across small style rotary switches like that, are they available from mouser?

I dunno, I got mine on ebay off a Chinese seller. There are loads on there:

http://www.ebay.com/itm/2-Pole-4-Position-Panel-PCB-Wiring-Rotary-Switch-2P4T-/330588499247?pt=LH_DefaultDomain_0&hash=item4cf89c2d2f

Here's the original thread for the signal generator:

http://www.diystompboxes.com/smfforum/index.php?topic=83930.20

Colonel Angus · June 15, 2012, 10:20:11 AM

I like it!! I want one, this would be perfect for discretely incorporating guitar in this synth project I just started.

Spence · July 29, 2013, 10:51:51 AM

Long time lurker, first time poster. I just found this incredible gem and would love to build one.
I'm not a fan of buffered bypass and would like to make this one true bypass. When doing so, can I just leave out Q1, C13, D1, R26 and R27 and put a jumper where the trannie was?

I also noticed an irregularity between the schem and the BOM. C7 is 2n2 in the schematic but on the BOM it's 330pf and C8 goes from 22n to 3n3. Which values are the correct ones?

Thanks in advance.

Spence · August 11, 2013, 01:36:30 PM

Anyone?

merlinb · August 11, 2013, 03:43:12 PM

Quote from: Spence on July 29, 2013, 10:51:51 AM
Long time lurker, first time poster. I just found this incredible gem and would love to build one.
I'm not a fan of buffered bypass and would like to make this one true bypass. When doing so, can I just leave out Q1, C13, D1, R26 and R27 and put a jumper where the trannie was?

Yes, exactly.

Quote
I also noticed an irregularity between the schem and the BOM. C7 is 2n2 in the schematic but on the BOM it's 330pf and C8 goes from 22n to 3n3. Which values are the correct ones?

Both will work, but the PDF schematic is the most recent and preferred. 22n and 2.2n, with 47k resistors.

scuzzphut · August 11, 2013, 06:58:30 PM

Just a thank-you, Merlin

Been waiting for a good sub-octave to build and this is it.

Chollowell · August 13, 2013, 04:05:32 AM

Im new to the site and was looking around for something fun to check out to start learning about stompbox design and found this gem!
I whipped up an LTspice design to understand all the steps and i have a few questions.

I noticed that the pre-gain and lowpass filter has a gain of 5.5 which clips an input signal of more than about 800mV peak to peak. (In my spice simulation it clips at about 650mV)
My understanding is that a guitar signal can be upwards at 1V peak to peak?

When using a sound file as input and generating a sound file as an output i get alot of noise in my output. This is probably due to the way i simulate so im wondering if you have any tips on how to simulate so you atleast have an idea of how it would sound.
Is it possible to get a good sounding simulation?

I have been thinking of making an octave up pedal and thought maybe i could take the inverted square wave coming from U4b and put it straight to the gate on the first jfet to make it a full wave rectification.
What are your thoughts on that?

I am very new to stompboxes and im very excited to learn more about everything and anything.
Hope you can help me a little on the way

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U-boat. NEW Smooth sub-octave / synth effect!