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Forum Home > Layout Gallery - GuitarPCB Build Documents, Mods and Tips > G-02 Animal

Barry
Site Owner
Posts: 8780

G-02 Animal - New Enhanced version of the original Tonmann Layout

 

Board Dimensions (W x H) 2.33” x 2.2” ca. 59.1mm x 55.9mm

 

Compare to the infamous and practically unobtainable Cornish G2™.

Enhanced version of the discontinued circuit formerly known as R2G2.


G-02 Animal Build Document

 


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G-02 Animal Demo 1 - Shows Sustain Capability. Les Paul/Twin Amp - G-02 Animal - Shure 57 Nothing else!


G-02 Animal Demo 2 - Strat - Fender Twin Clean - G-02 Animal - Shure SM57 - Nothing Else!


"G2" is a Trademark of Pete Cornish Pedals. Guitarpcb.com is not affiliated with Pete Cornish". Our unique boards are for comparison and education only and are not intended to be represented as clones or copies.

 

All original copyrights, trademarks, and artworks remain the property of their owners.


--

Welcome to my informational signature:

See our Home Page for all Guides!

Check the Layout Gallery section of the Forum and find your project before building.

Pre-Build Reading Guides:  Crash Course#1 , Crash Course#2 & Tips, Tricks and Tutorials.

Troubleshoot threads must have pictures and voltages.

All builds are 100% verified. Be sure to use Genuine Transistors and IC's

Any serious builder should have an Audio Probe to diagnose problems quickly.

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November 2, 2014 at 7:40 PM Flag Quote & Reply

Wilkie1
Moderator
Posts: 1378

OOOOWE!  This sounds awesome!  I can't wait to pump this into my new Ceriatone amp!

--

I just LOVE Wires and Sparks!

November 2, 2014 at 9:25 PM Flag Quote & Reply

Barry
Site Owner
Posts: 8780

Analysis and Mod Ideas courtesy of Tonmann:


The pedal is basically a Big Muff (Q3 - Q5 sections), with a couple of buffers (Q1 -Q2) tacked onto the front, a very basic high pass/low pass filter (C24 - C17) instead of a Pi filter and a slightly different recovery stage from a standard muff.

We do not make clones, we make what sounds best to our ears. If you choose to use different components that is up to you. Since this is based highly off a Muff circuit there will be little difference between transistor choices typically used in any Muff circuit.

 

The input buffer has no gain and shouldn't color the signal (flat frequency response) going into the first stage (Q3), the amount of signal reaching the first stage is determined by R15 - lower value means more signal. This Q3 stage is the first one that provides gain and cuts a bit of the high frequency off - Q4 and Q5 are basically the same gain stages as Q3 (except they have the clipping sections) and Q5 provides a bit more gain than Q4. The tone stage is nothing spectacular and just provides a means of cutting the high frequencies (tone pot and C17). The gain from the recovery stage is quite high, due to C19.

 

How's that for a short analysis !

 

Measure the collector and base voltages of Q3 to Q6. The collector voltages should be around the 4V - 5V range and the base voltages around the 700mV - 1V range, except the base of Q6, this should be about 1.5V - 2V. You could also check the emitter voltage of Q2 which should be in the 4V - 5V range.

 

Clip your audio probe to lug 3 of the sustain pot, guitar at the input and you should be getting a boosted signal (gain of about 4.5) that sounds a bit low to mid-range. Don't change any component values yet, but bear in mind:

 

You can increase the signal amplitude to the first clipping stage by changing the amount of signal you let in or out of the first stage or by increasing the gain of the first stage:

 

Reduce the value of R15 to let more signal through to the transistor stage.

Increase the value of the sustain pot (100 kΩ;) to let more signal out of the transistor stage.

Drecrease the value of R19 and/or increase the value of R18 to increase the gain of the stage (if the output at lug 3 becomes distorted when doing this, check the collector voltage).

Increasing the value of C8 will let more bass frequencies into the transistor stage, increasing C10 will let more bass frequencies out of the transistor stage.

Reducing the value of C9 will increase the high frequencies coming out of the stage.

 

We'll leave the two clipping stages for the moment.

 

Checking the recovery stage. You can either check the recovery stage alone by disconnecting the wire from lug 2 of the tone pot and connecting your guitar to the wire, or, an easier way is disconnect the wires from lug 2 of both the sustain and tone pots and connect the tone pot wire to lug 2 of the sustain pot, so you have a circuit consisting of the first stage and recovery stage, bypassing both clipping stages. Guitar at the input socket, output socket connected to amp.

 

You should have lots of gain here (calculates to a gain of about 50).

 

If you need more gain from the recovery stage:

Reduce the value of R36 - making this a wire jumper will give maximum gain.

For a few dBs more, you could change the volume pot to 100 kΩ and remove R37.

 

All of the above covers the "pure gain" of the circuit, which I would do first before looking at the clipping stages.

 

As with the first stage, the amount of gain is not spectacular, but then again, if you are using germanium diodes it doesn't need to be very large to get the diodes to clip.

 

Rather than changing the gain of the clipping stages, it is better to change the amount of signal applied to each stage. This is done by lowering the values of R21 and R26 for more gain, or increasing the values for less gain.

Two more changes to look at:

Lowering the value of C11 will let more bass frequencies through to the first stage (C16 is already very low and shouldn't need decreasing).

Reducing C12 and C14 will increase the high frequency content of the signal at the output.

 

This just leaves the diodes and the two capacitors, C13 and C15. I would socket the diodes and possibly the capacitors as well. Although there is not a lot to say here, I would suggest the following.

 

Get a pile of germanium diodes and measure the forward voltages with a DMM and sort them into pairs. Use the pair with the highest forward voltage for D1 and D2 and the pair with the lowest forward voltage for D3 and D4. Doing this (at least in theory) will:

Clip the low frequency end but not the high frequency end of the signal in the first clipping stage.

Clip the low frequency end even more (heavily clipped) and lightly clip the high frequency end in the second clipping stage.

 

Changing the values of C13 and C15:

As they are - you should be getting a signal that looks like a square wave signal with rounded shoulders. If you reduce the value of these capacitors enough the signal will start to look like a triangle (with an increase in amplitude). Increasing the values will make the signal look a bit like a church with a steeple on the left hand side (sorry, I can't think of a better way to describe it). It might be fun to experiment with these capacitors.




 

Q1 E: 4.72 B: 4.53 C: 9.18

 

Q2 E: 5.27 B: 5.10 C: 9.07

 

Q3 E: 0.18 B: 0.77 C: 4.87

 

Q4 E: 0.18 B: 0.77 C: 4.91

 

Q5 E: 0.03 B: 0.63 C: 4.15

 

Q6 E: 1.13 B: 1.63 C: 4.95

 

 

 


 

I hope that was helpful.

--

Welcome to my informational signature:

See our Home Page for all Guides!

Check the Layout Gallery section of the Forum and find your project before building.

Pre-Build Reading Guides:  Crash Course#1 , Crash Course#2 & Tips, Tricks and Tutorials.

Troubleshoot threads must have pictures and voltages.

All builds are 100% verified. Be sure to use Genuine Transistors and IC's

Any serious builder should have an Audio Probe to diagnose problems quickly.

When using our Photo Gallery:

  • Read this easy link to learn how to ADD FLASH plugin to your browser.
  • The Upload Photo Button is FLASH. Right click in its location to activate.
  • Here is a Quick Video Tutorial for uploading photos.

Our site will also accept direct links from many other photo host sites as long as they are direct links which must end in .jpg, .png etc. to work.


November 26, 2014 at 6:25 PM Flag Quote & Reply

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