Catalinbread - SFT REV 2

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Visualdistortion
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Post by Visualdistortion »

Someone share me the SFT REV 2 for the week, so I take pictures and get values of capacitors and pots, maybe it can help for helping debugging the previous tracing.

This is pictures: https://www.dropbox.com/sc/p76h70dy0ch3 ... G8ttR24Bxa

I can give you more information but you need to be really fast, because I will give back the pedal tomorrow.

Catalinbread SFT REV 2

Pots:
Treble & Bass : A1M
Vol: A250K
Gain: A1M

1N4001 protection diode

Q1-Q6: MPF 4393

CAPACITORS:

C1: 104K
C2: /
C3: 4n7
C4: 1uF
C5: 683K
C6: 151 1KV blue
C7: /
C8: 1uF
C9: 104K
C10: 102K
C11: 4n7K400
C12: 681K
C13: 472K
C14: .47 1KV blue
C15: 1uF Pol
C17: 2,2uF Pol
C18: 472K
C19: 472K
470uF
I wanna make it
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French... sorry ;)

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SonicRiff
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Post by SonicRiff »

That's great. thanks ! The SFT Rev2 is awesome.

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Post by Blend »

Here is a schematic based on "Visualdistortion" pictures, concrete differences compared to the first version of the SFT removing 2 of the 8 original 2N5457, replaced with mpf 4393 and used here with variant mu-amp SRPP, adding gain boost, reshaped tone etc. Has anyone had a chance to compare the sound of both versions? I version is reliable with bass (top 18/24v), whose guitar. For those shown in the schematic (?) It was impossible to verify the value (R) and the connection (Q6 source resistance).

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Post by Visualdistortion »

I compared a clone of version I I did few years ago (apparently the tracing of the first version have some errors) with this one, I can really say that the version II it's really really better, awesome ampeg tone on a clean bass amp.

I can try to get again the pedal, and verify what you want with pictures, please tell me asap what you need to confirm.
I tried to label the resistors; but they are really close to the pcb.
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French... sorry ;)

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Post by SonicRiff »

I have the V1 and had the opportunity to test V2.

The V2 is really awesome, much easier to use thanks to the switch and has a wider tonal range (like 2 amps in one pedal). Like the V1, SFT V2 works like a charm with my bass.

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Post by Blend »

hello, I'm sending you the pictures in which you can understand where I miss the connecting traces, i reloading the schematic for writing correction R17 is 1K8.
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sft nuovo schema 2.JPG

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Post by Blend »

If you can control tracks under Q1 and Q6 is perfect.
Attachments
sft layout 1.jpg

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Post by Visualdistortion »

On Q6, C14 go on the center pin S
On Q1, the 2 1M resistors are NOT connected to the D pin
R10 go directly to G pin of Q4. C5 is not connected to G PIN

I've added tons of pictures, tell me if you need something more. It's actually sunday 10am here, I can take the pedal with to monday 5PM.

https://www.dropbox.com/sc/p76h70dy0ch3 ... G8ttR24Bxa
I wanna make it
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(again and again and again)

French... sorry ;)

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Post by Visualdistortion »

https://www.dropbox.com/s/tkz6y23cny55o ... 1.jpg?dl=0

On left of Q6: Brown black Red Gold so 1K
I don't have nothing to measure the blue cap it's writted
'47
1KV

and the " ' " it's clearly in front of number 47

ALSO:
- The + leg of C4 go on the the left point of C3.
- On Q1, the 2 1M resistors are NOT connected to the D pin
- R10 go directly to G pin of Q4. C5 is not connected to G PIN
Attachments
IMG_5142.JPG
IMG_5143.JPG
I wanna make it
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French... sorry ;)

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Post by Blend »

It finally, thanks to Visualdistortion for the many pictures taken, C14 is 47pF and downhill from source Q6 the resistance value is 1K. In conjunction with the drafting of the schematic, I have tried to adopt some improvements on my clone of the first version of the SFT and it really worth for those who kept him in a drawer or as a doorstop or if you do not want to deal with the new building of the SFT II.
Attachments
SFT II Rivelation layout.JPG
SFT II schematic.jpg

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Post by Visualdistortion »

Awesome! hope someone will do a pcb or a vero soon =D
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French... sorry ;)

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Post by Blend »

In the meantime, try these simple mods on an old SFT, may be enough. (The schematic used had been done by gkoerselman to page 5)
Attachments
six mods in I sft.jpg

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Post by roseblood11 »

That switch will make a loud noise... Better place a large resistor in series with the cap and short it with the switch.

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Post by Blend »

If I connect the capacitor 22uF, the problem arises, but with the complete switch as in the original I do not hear any crackling noise, other mod that suggest you do in the 1st SFT is to replace R5 22k with 10k. :wink:
Attachments
schema SFT +8 mods da II vers.jpg

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Post by Visualdistortion »

I made the vero from Tagboard and it seems to get the same problem than the others people who made it:

- The pedal is really low/dark tuned compared to the original, I think there is a problem on the bass pot, like you can't shut up the bass frequenciens (on the original, on bass at 0, you only get treble)
- There is a switching mode problem, on "stoner mode" in the clone, I get the same the same amount of gain than the "stones mode" on the original, and on the stones, I've clearly less gain.
I wanna make it
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(again and again and again)

French... sorry ;)

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Post by Visualdistortion »

Finally on the tagboard there was a problem on the pinout of the swtich, I rewired it, and now the pedal seems pretty close to the original, like 90%.
Just a bit less volume and bit more bassy, when the original get a lot of high medium, the clone are more on low medium.
I wanna make it
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(again and again and again)

French... sorry ;)

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Post by Blend »

What kind of jfet are using in place of the originals ?

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Post by Visualdistortion »

The same than the original
I wanna make it
I wanna make it wit chu
(again and again and again)

French... sorry ;)

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Post by Blend »

... Pictures with shadows, colors ambiguous or unfocused, mmmm: everything ok except 3 red rings = change the last stand with 2k2, benefits in the output impedance, in db volume and in eq and remember to clone the doubt! :roll:
Attachments
SFT II schematic.jpg

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Post by Visualdistortion »

:applause:

I will try this tomorrow. Thanks.
I wanna make it
I wanna make it wit chu
(again and again and again)

French... sorry ;)

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