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DIY Stompboxes => Building your own stompbox => Topic started by: Plexi on May 21, 2018, 10:14:01 PM

Title: Cornish SS-2
Post by: Plexi on May 21, 2018, 10:14:01 PM
Opinions?
Experiences?

(https://img1.daumcdn.net/thumb/R720x0.q80/?scode=mtistory&fname=http%3A%2F%2Fcfile4.uf.tistory.com%2Fimage%2F263F8234575B94610128D0)
Title: Re: Cornish SS-2
Post by: ElectricDruid on May 22, 2018, 06:01:15 PM
Pfft. Rat on steroids.  :P

Never heard one, but it's not an exceptional schematic. Functional enough though, and I'm sure it sounds fine.
Title: Re: Cornish SS-2
Post by: Plexi on May 22, 2018, 06:18:42 PM
Sure..!
I'm into it...
As I'm reading, there's a few pedals 'inspired' on it: like the Top Tone Light Drive.

I'm not sure about the Cornish input buffer: could it modify the overal tone... ????????
(https://image.freepik.com/free-photo/man-thinking_1149-1716.jpg)
Title: Re: Cornish SS-2
Post by: GGBB on May 22, 2018, 08:33:35 PM
More in common with the OCD/Voodoo Lab Overdrive than a RAT I would say. But all overdriven opamp followed by hard clipping followed by tone and buffer are similar in that regard. Of course, they can sound very different because of tone shaping. Schematics for such beasts are rarely interesting after you've seen a few - but it is possible to find something that sounds exceptional to you which has a ho-hum schematic.
Title: Re: Cornish SS-2
Post by: Plexi on May 22, 2018, 08:53:47 PM
Ok... I'll add another comparation, more than RAT, OCD/Voodoo Lab Od: the first stage looks like an MXR Distortion +, followed by another gain/recovery/buffer stage?
(http://www.extraordinaryteam.com/wp-content/uploads/2015/05/Mistakes-new-managersmake.jpg)

Title: Re: Cornish SS-2
Post by: Frank_NH on May 22, 2018, 09:14:51 PM
I've built this overdrive using the vero layout over at the Tagboard effects site.  I think it sounds great and really not like a RAT or tube screamer.   However, in my opinion, you should add the Cornish buffer in front of the input to the SS-2  - makes a great overdrive even better by adding some clarity and a touch more treble.  You can get a vero layout of the Cornish buffer at the Tagboard site as well.
Title: Re: Cornish SS-2
Post by: Plexi on May 22, 2018, 09:27:23 PM
Sure!
Here it is:
http://tagboardeffects.blogspot.com.ar/2012/02/cornish-buffer.html

Title: Re: Cornish SS-2
Post by: samhay on May 23, 2018, 11:45:01 AM
The Cornish effects are not so much remarkable for the circuits involved, but rather for the way they are built.
Can you build one like this?

(https://img1.daumcdn.net/thumb/R720x0.q80/?scode=mtistory&fname=http%3A%2F%2Fcfile9.uf.tistory.com%2Fimage%2F272C7C3C575B96442CBB89)
( http://pedalvantage.com/m/71 )
Title: Re: Cornish SS-2
Post by: Frank_NH on May 23, 2018, 02:22:04 PM
Quote from: Plexi on May 22, 2018, 09:27:23 PM
Sure!
Here it is:
http://tagboardeffects.blogspot.com.ar/2012/02/cornish-buffer.html

Yup, that's it.  And here is the SS-2 (for reference):

http://tagboardeffects.blogspot.com/2014/05/cornish-ss-2.html

Just run the output of the buffer into the input of the SS-2 board.  The buffer and SS-2 boards can share the 9V and ground.
Title: Re: Cornish SS-2
Post by: Paul Marossy on May 23, 2018, 06:06:17 PM
Quote from: samhay on May 23, 2018, 11:45:01 AM
The Cornish effects are not so much remarkable for the circuits involved, but rather for the way they are built.
Can you build one like this?

(https://img1.daumcdn.net/thumb/R720x0.q80/?scode=mtistory&fname=http%3A%2F%2Fcfile9.uf.tistory.com%2Fimage%2F272C7C3C575B96442CBB89)
( http://pedalvantage.com/m/71 )

True. Built to take a lot of abuse and keep working... kind of like a Timex watch.  :icon_wink:
Title: Re: Cornish SS-2
Post by: Plexi on May 23, 2018, 07:09:23 PM
OK... a little update.
Built it, but using a 1458 dual opamp.
Not have the 1N270 diodes... so I've tried without diodes.
Sounds GREAT... nice crunch and great compression without lost definition!

I'll try to use there 1N60 diodes in replacement of the 1N270.

An observations: the B50K in the drive pot sounds awfull..increase the gain in the last 10% of the sweep.
I prefer the 25k or 10k pots: like in the Hot Cake.
Maybe an A50K but in reverse (it's impossible to find a C50K pot around here).
Title: Re: Cornish SS-2
Post by: Plexi on April 09, 2021, 09:37:38 AM
Re-born thread!  ;D

I there another schematic with a few different values:
(http://1.bp.blogspot.com/-BR8Ws2bkqsg/Ty2ELe1YX-I/AAAAAAAAA3g/0appc-QC2uM/s1600/cornish_ss2.png)

Any experience?
Title: Re: Cornish SS-2
Post by: iainpunk on April 09, 2021, 11:40:08 AM
that output opamp seems off.
like, why would you want a weird mis-biassed just below unity gain opamp stage after your clipper? why not a simple voltage follower? it will have more headroom!

cheers
Title: Re: Cornish SS-2
Post by: GGBB on April 09, 2021, 02:14:39 PM
Quote from: Plexi on May 23, 2018, 07:09:23 PM
(it's impossible to find a C50K pot around here).

Use C100k in parallel with a 100k resistor.
Title: Re: Cornish SS-2
Post by: GGBB on April 09, 2021, 02:24:33 PM
Quote from: iainpunk on April 09, 2021, 11:40:08 AM
that output opamp seems off.
like, why would you want a weird mis-biassed just below unity gain opamp stage after your clipper? why not a simple voltage follower? it will have more headroom!

cheers

There's probably lots of headroom as is even with the offset bias - the input voltage is clamped by the clipping diodes. Plus - it looks like there's a fair bit more going on than just buffering - R12, C11, C12, ...
Title: Re: Cornish SS-2
Post by: Plexi on April 09, 2021, 02:33:17 PM
Quote from: GGBB on April 09, 2021, 02:14:39 PM
Quote from: Plexi on May 23, 2018, 07:09:23 PM
(it's impossible to find a C50K pot around here).

Use C100k in parallel with a 100k resistor.

At that moment, was impossible to found some C type potentiometers (purchasing fast/easy at hand in Argentina, without import).
But in those cases where the C type is fundamental, it doesn't matter to me: I use A type backwards.. some kind of "gain attenuator".
Like in the Hot Cake.
Title: Re: Cornish SS-2
Post by: Plexi on April 09, 2021, 02:35:49 PM
There's another schematic from GuitarPCB.
I'll check, and compare.

https://guitarpcb.com/wp-content/uploads/2018/06/BD_Super-Sonic-02.pdf
Title: Re: Cornish SS-2
Post by: Plexi on April 15, 2021, 10:26:26 PM
A little light around here, and all the SS-2 mystery.

Found this great and usefull tracing of the SS-3: https://aionfx.com/news/tracing-journal-cornish-ss-3-soft-sustain/
I highly recommend to read the article.

I've combined both versions, and this mods:
(https://i.postimg.cc/VkXwZ5Kq/SS2-a-3.png)

Verdict: Now this overdrive sounds AMAZING.
Not fizzy and saturated on highs: gain clarity on bass and mids.
Tone potentiometer brings a nice Bass to Highs response without scoop the mids and (again) saturated highs like before.
A bit more and better distortion/compression.