Catalinbread - SFT - FETs

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Catalinbread - SFT - FETs

Postby greenskull » 04 Apr 2010, 05:50

Preparing to build this one from Madbeans's new layout (thanks, man!!) and would like any thoughts on using 2n5458's instead of the 2n5457.
I have a load of them on hand and only 3 2n5457's. :slap:
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Re: Catalinbread - SFT

Postby greenskull » 05 Apr 2010, 21:15

AAAAARGGGHH!! Built it, but have problems with the gain control not giving hardly any distortion like a light overdrive at max and really affects volume when turned down.
Could it be the 2n5458's I subbed in? Went over the board carefully for shorts/bridges and checks fine.
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Re: Catalinbread - SFT

Postby greenskull » 06 Apr 2010, 02:04

Well alright, I managed to exchange emails with someone else who posted the same problems and it seems you gotta use 2n5457's with this. 2n5458 or 2n5459 is a bit too weak to drive this properly.
I managed to scrounge up enough 2n5457's for the first 5 positions and it made a big difference. I'm getting the Stones "Get Your Ya Ya's Out" sound, but not quite distorted enough for the heavy slab of stoner doom. Will get the last jfet spots filled when I can and that should do it I hope.

So to answer my own question: No, you need 2n5457 you blockhead!! :block:


:horsey:
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Re: Catalinbread - SFT

Postby coldcraft » 04 May 2010, 15:48

does anyone get an overly low gain sound with their build? I'm using a tele with not-so-hot output pickups. I followed madbean's schematic and used 2n5457s everywhere and even switched to the 1M Linear Gain Pot.

The only difference in mine is I included a pre-buffer to do a split/clean blend.



to clarify, I don't get any clipping until about 11 o clock on the gain, and this is if I turn up the EQ. I'd say light overdrive is about 1 o clock and grind is 3 and higher. I'm not sure if its capable of getting the stoner sounds.
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Re: Catalinbread - SFT

Postby Hirti » 04 May 2010, 16:16

Hi guys!

I have similar problems with my build.. all knobs work like they should when the gain pot is at 5 o'clock. But when I move the gain pot to like 12 o'clock its suddenly really silent. I already changed the pot and it didn't solve the problem. Any tips? :cry:




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Re: Catalinbread - SFT

Postby coldcraft » 04 May 2010, 16:22

I've checked over my build numerous times, and I believe I have the same values as madbean's schematic. The only change I expected to hear from the buffer was a bit less touch sensitivity.
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Re: Catalinbread - SFT

Postby madbean » 04 May 2010, 16:44

Which layout have you guys built? I'm confused as to who is building what.
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Re: Catalinbread - SFT

Postby coldcraft » 04 May 2010, 17:27

I made my own, following your schematic. sorry for the confusion. I'll have to check the build for errors again tonight. This thing should be fairly high gain right?
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Re: Catalinbread - SFT

Postby madbean » 04 May 2010, 17:47

Yep, tons of gain on tap. I actually finally verified mine last night. Here's the latest stuff I'm working off in case it helps you debug. It's been revised a little from the previous one uploaded to make it smaller.
Faulltline_ver1.pdf
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Re: Catalinbread - SFT

Postby Hirti » 04 May 2010, 19:22

Oh right, i used your layout madbean. The one you posted a page earlier. ;)
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Re: Catalinbread - SFT

Postby coldcraft » 05 May 2010, 02:09

how much gain/breakup should there be with all knobs at noon? i'm getting next to none.
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Re: Catalinbread - SFT

Postby rcubed » 05 May 2010, 03:15

I can't comment on how it works with passive guitars since I haven't used my guitar with it yet. But depending how hot your signal is coming in, you're not going to get breakup until around noon or 1 o'clock. Below breakup, on bass, you get a classic Ampeg B-15 sound. I'm not sure how that would translate to guitar. But that's how the circuit supposed to work. Feel free to make modifications. I always like to tune circuits to my liking.
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Re: Catalinbread - SFT

Postby coldcraft » 05 May 2010, 03:35

and here I thought I built it wrong...


i think I have it correct now. I swapped out the log gain pot for a linear, but there's still a jump in gain towards the end. Any ideas how to smooth out the transition, or possibly shift the range a bit?
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Re: Catalinbread - SFT

Postby madbean » 05 May 2010, 04:04

Use a reverse audio taper pot to shift the breakup to earlier in the sweep.

Or, use the linear pot and move R8 between lugs 2 and 1 of the pot. Keep lug 1 connected to ground. This will change the taper a bit.
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Re: Catalinbread - SFT

Postby JMFreak » 05 May 2010, 12:25

Hey,

got this built from Mike's layout, many thanks. And to the rest for the work done tracing this.

Just want to check the noise with this pedal. I haven't yet boxed it up, I've just tested it with my little test box (free plastic Specsavers case :)) where I connect the leads with crocodile clips.

It all sounds as it should, though with gain and treble up high, I'm getting quite a bit of hiss+hum. I'm sure I get a bit of extra noise when testing circuits that are not enclosed in a metal case (is this the 'Faraday cage' affect?), but it's quite a bit noisier than other circuits I've tested this way, i.e. Super Fuzz and Shin Ei FY-2. Input and Output leads aren't close to each other.

Is this what I should expect with this circuit/layout, or will it all clear up when boxed? Are there any leads that shouldn't run parrallel?

Cheers,
Steve.
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Re: Catalinbread - SFT

Postby coldcraft » 05 May 2010, 15:38

thanks for your help everyone, I think I've got it all sorted out now! I'll post a picture when I'm done
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