Sunflower Fuzz (Analogman Surface Ge)

harmaes · Apr 10, 2024

I’ve build all my Sandspur and Sunflower PCBs with the clean externally as well. Helps to dial in the fuzz face better for different guitars. Slightly different than rolling down the volume and allows you to leave guitar volume full.

For Ge I prefer lower gain with GT308 with 60-70 and 80-90 HFE pairs. I also like the IT115G I received with similar HFE. Both are in the Bonamassa fuzz territory.
I’m about to receive a set of GT402B soon with HFE 80-90 and 120-130 which I will build in an AION Solaris. The Epsilon and Solaris feature a transformer and a little more control with the bass/lows knob.

For Si I’m not a fan of BC108 or 109. I liked BC183C best and I build one with 2x 500 HFE and one with HFE values 250/500 (BC183B and C) with lower gated bias (like EJ fuzz).
Also try 2n3903/2n3904 or a hybrid with Si and Ge.

ChrsGuit · Apr 10, 2024

harmaes said:
I’ve build all my Sandspur and Sunflower PCBs with the clean externally as well. Helps to dial in the fuzz face better for different guitars. Slightly different than rolling down the volume and allows you to leave guitar volume full.

For Ge I prefer lower gain with GT308 with 60-70 and 80-90 HFE pairs. I also like the IT115G I received with similar HFE. Both are in the Bonamassa fuzz territory.
I’m about to receive a set of GT402B soon with HFE 80-90 and 120-130 which I will build in an AION Solaris. The Epsilon and Solaris feature a transformer and a little more control with the bass/lows knob.

For Si I’m not a fan of BC108 or 109. I liked BC183C best and I build one with 2x 500 HFE and one with HFE values 250/500 (BC183B and C) with lower gated bias (like EJ fuzz).
Also try 2n3903/2n3904 or a hybrid with Si and Ge.

do you prefer the matched or offset BC183 option? I'm building one mainly to be used with strats that have more "vintage" vibe pickups... say, vintage 62 type flavor.

Im not a fuzz guy at all, as I feel they all sorta sound "the same" to my ears... The only fuzz I dig is an octavio/Roger Mayer style octave fuzz... in small doses...
I'm building the sunflower for a good friend who wanted me to build him a fuzz face type circuit, and I knew the Analogman clone would be an "upgrade" to his traditional mini Fuzz face...
I accepted his request without doing my due diligence in researching that it would be a rabbit hunt for transistors... Kinda like the Phase 90 I wanted to build, then discovered I needed 4 identical testing transistors that were obsolete and would cost as much in parts as just buying a used MXR...

harmaes · Apr 11, 2024

ChrsGuit said:
do you prefer the matched or offset BC183 option? I'm building one mainly to be used with strats that have more "vintage" vibe pickups... say, vintage 62 type flavor.

Try both and see what you prefer. Get BC183B and BC183C and experiment with the Q2 collector bias between 3 tot 4,5v.

andare · Apr 11, 2024

ChrsGuit said:
do you prefer the matched or offset BC183 option? I'm building one mainly to be used with strats that have more "vintage" vibe pickups... say, vintage 62 type flavor.

Im not a fuzz guy at all, as I feel they all sorta sound "the same" to my ears... The only fuzz I dig is an octavio/Roger Mayer style octave fuzz... in small doses...
I'm building the sunflower for a good friend who wanted me to build him a fuzz face type circuit, and I knew the Analogman clone would be an "upgrade" to his traditional mini Fuzz face...
I accepted his request without doing my due diligence in researching that it would be a rabbit hunt for transistors... Kinda like the Phase 90 I wanted to build, then discovered I needed 4 identical testing transistors that were obsolete and would cost as much in parts as just buying a used MXR...

I found that most transistors work in this circuit. It's very forgiving. Just bias it to where it sounds good to you and maybe play around with the input and output caps and the volume pot to adjust how bassy it is.

ChrsGuit · Apr 11, 2024

andare said:
I found that most transistors work in this circuit. It's very forgiving. Just bias it to where it sounds good to you and maybe play around with the input and output caps and the volume pot to adjust how bassy it is.

I'd considered doing the "mod" like I did on my Rangemaster build... an ON ON ON with three separate value caps to adjust low end/brightness

ChrsGuit · Apr 11, 2024

andare said:
I found that most transistors work in this circuit. It's very forgiving. Just bias it to where it sounds good to you and maybe play around with the input and output caps and the volume pot to adjust how bassy it is.

I was just looking at the circuit thinking about the tone modification, and was surprised to see the clean blend trim pot straight off the input ... I'm going to assume that the "input cap" I would use to adjust bass would then be C2 (since it feeds off the center lug of the Fuzz control)? Or would it be more prudent to focus on C3, since that's the last cap before hitting the volume pot
You'll have to forgive me, as I'm still kind of a novice when it comes to comprehending circuits...

harmaes · Apr 12, 2024

ChrsGuit said:
I was just looking at the circuit thinking about the tone modification, and was surprised to see the clean blend trim pot straight off the input ... I'm going to assume that the "input cap" I would use to adjust bass would then be C2 (since it feeds off the center lug of the Fuzz control)? Or would it be more prudent to focus on C3, since that's the last cap before hitting the volume pot
You'll have to forgive me, as I'm still kind of a novice when it comes to comprehending circuits...

Check the Solaris or Epsilon from Aion, it features the clean trim and low end.

andare · Apr 12, 2024

ChrsGuit said:
I was just looking at the circuit thinking about the tone modification, and was surprised to see the clean blend trim pot straight off the input ... I'm going to assume that the "input cap" I would use to adjust bass would then be C2 (since it feeds off the center lug of the Fuzz control)? Or would it be more prudent to focus on C3, since that's the last cap before hitting the volume pot
You'll have to forgive me, as I'm still kind of a novice when it comes to comprehending circuits...

The input cap is where I usually intervene. Drop the value for less wooliness. I just find it easier to tweak at the input. You can put a couple of caps on a toggle or use a blend knob.

You can also increase/decrease the other two caps for more/less bass but I find that less effective. You can add a pot to ground after the emitter cap as a Fuzz control like in the Mastotron instead of the conventional fuzz pot.

If you bias Q2 higher, it will be brighter. That's why a Tone Bender 1.5 is brighter than a Fuzz Face despite the larger caps - the leaky transistors bias at around -7V to -8V instead of -4.5V.

The clean blend trim is there to limit the amount of signal going in if you want to cap the total gain or if you switch to hot pickups and want to keep the same cleanup.

darwin999 · Saturday at 4:47 PM

I thought I would add to this thread, and show how the various bias settings impact the output waveform using some oscilloscope pics.
I used @Robert's fine PCB, and installed an MP16B for Q1 (Hfe=77, Ileak=23µA) and an MP20B for Q2 (Hfe=124, Ileak=61µA); transistor measurements were taken by a Peak DCA Pro. I set the front bias pot in the middle position, and then adjusted the two internal trimpots so that Q1(C)=0.70V and Q2(C)=4.50V (as recommended by @andare).

I used an old Tektronix signal generator as my signal source, with ~100mV pk-pk sinewave at ~750Hz (roughly).

Here are the waveform pics :

Pic 01 shows bypass, with input signal on top, output on bottom. That orientation stays the same in all subsequent pictures. But I do occasionally change the Volume or Output scope range in subsequent pictures (when the output gets quite high), although this does NOT alter the shape of the waveform.
Pics 2-5 show the output waveform for the lowest Bias (front knob), with Fuzz knob set at low, mid, med high, and high; respectively.
- Low Bias has the greatest span of linear unclipped signal as you increase the Fuzz setting. And when it does finally clip, it starts at the bottom of the waveform; at higher Fuzz, the clipping is close to symmetric.
Pics 6-9 show the output waveform for the Bias set in the middle, and the Fuzz knob set at low, mid, med high, and high; respectively.
- Mid bias has somewhat reduced span of clean unclipped signal compared to low Bias. And when it does finally clip, it starts at the top of the waveform; at higher Fuzz, the clipping is again fairly close to symmetric.
Pics 10-12 show the output waveform for the Bias set in at High, and the Fuzz knob set at low, mid, and high; respectively.
- With a ~100mV pk-pk input signal, these is no linear region at high Bias, the signal already is clipped.
- The clipping starts at the top of the waveform; and at higher Fuzz, the clipping is strongly asymmetric.
Pic 13 shows the gut shot.