# Sunflower fuzz



## piapium (Oct 17, 2020)

Still having bias issues. Sundial working reverse. Couldn’t figure out why. Found ac128s that I bought years ago. Will try them soon.


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## Barry (Oct 17, 2020)

Love the artwork!


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## piapium (Oct 17, 2020)

Thanks! Just googled some sunflower drawings.


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## piapium (Oct 18, 2020)

When I turn the sundial ccw the voltage rise. And when I turn cw the voltage drops. Is it normal?


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## HamishR (Oct 19, 2020)

Yup that's what it's supposed to do!


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## piapium (Oct 19, 2020)

I can't get enough sustain. But it sounds alright. And doesn't react well rolling guitar volume back.


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## music6000 (Oct 19, 2020)

Try turning your internal bias to where it smooths out & stops starving the circuit of power/ voltage.


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## piapium (Oct 19, 2020)

This is the least voltage on q2. Most voltage is 9v. I think there is something wrong.


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## music6000 (Oct 19, 2020)

Can you confirm what Transistors you have in Q1 & Q2?


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## piapium (Oct 19, 2020)




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## music6000 (Oct 19, 2020)

If you read Analogman Sunface tutorial, He says that the AC128 are the worst sounding Germanium in this circuit & he will not use them!

You understand that -8.46v is around the correct voltage, This is a pnp circuit with reverse voltage positive Ground with a Voltage converter so you can use a negative ground Power supply & Daisy chain it.

What voltages are you getting on the other Transistor?


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## piapium (Oct 19, 2020)

Around 6v


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## music6000 (Oct 19, 2020)

You mean *-6v*?


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## piapium (Oct 19, 2020)

I checked again with the other transistors, its -4,5 least and they sound better than ac128s. Guess I'll buy some nkt 275s soon. But now it souds better after hearing ac128s. Thanks again.


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## piapium (Oct 30, 2020)

Can I use nkt 275 red dots with this build?









						NOS Germanium NKT275 Red Dot Transistor Set (Classic Gain) | Reverb
					

I'm selling a set of matched NOS NKT275 red dot germanium transistors. These are perfect for Fuzz Face builds and the same transistors found in very expensive boutique fuzzes. I bought these for a Fuzz Face build that I'm not going to complete. The leads on this  set have been...




					reverb.com
				




or this one?





__





						10 germanium transistors NKT275 Fuzz for sale | eBay
					

Find great deals on eBay for 10 germanium transistors NKT275 Fuzz. Shop with confidence.



					www.ebay.ca
				





I've got a125s but I wonder how nkt275s sound.


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## PedalBuilder (Oct 30, 2020)

piapium said:


> Can I use nkt 275 red dots with this build?
> 
> 
> 
> ...


I'd focus less on the model number and more on the hFE and leakage, which are the biggest factors for how your fuzz face will actually sound.  Many, if not most of the NKT 275s you'll find on eBay et al. are fakes.  Even if you do find a real pair, it's highly likely that they are out of spec. Due to their popularity in fuzz face builds over the past few decades, what little stock remains has already been picked over by builders, and you're just seeing the rejects.  I had great luck with Japanese transistors like these in my fuzz face builds—cheap, low noise, and in spec for gain and leakage.  They clean up nicely and otherwise sound and behave exactly as a fuzz face should.


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## Betty Wont (Oct 30, 2020)

PedalBuilder said:


> I'd focus less on the model number and more on the hFE and leakage, which are the biggest factors for how your fuzz face will actually sound.  Many, if not most of the NKT 275s you'll find on eBay et al. are fakes.  Even if you do find a real pair, it's highly likely that they are out of spec. Due to their popularity in fuzz face builds over the past few decades, what little stock remains has already been picked over by builders, and you're just seeing the rejects.  I had great luck with Japanese transistors like these in my fuzz face builds—cheap, low noise, and in spec for gain and leakage.  They clean up nicely and otherwise sound and behave exactly as a fuzz face should.


^^THIS^^
Electrons don't care about the ink on the package and there is no magic, for magic isn't real. Mojo is marketing and almost always inferior. Literally any pnp transistor will "work" in there. Find the gain and leakage and bias that delivers the results you want. The brand doesn't impact the ultimate sound, the specific qualities of the actual part do. Measure, socket, and test.
*and for comparison, I pay around $0.15 USD for NOS pnp germaniums in the same spec as the 275's listed above.


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## Jovi Bon Kenobi (Oct 30, 2020)

Also agree. A lot of us have been burned by buying fakes from eBay. I'll happily pay a bit more and buy a matched set from Smallbear (btw, still cheaper than that Reverb link). They have all kinds of choices for germaniums, matched, tested lots, untested lots, etc... I've built lots of picky GE fuzzes using their matched sets, none of which were NKT275's or other "mojo unobtainium", and all sounded fantastic.


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## piapium (Oct 30, 2020)

I agree with all of you. It was just a question but after thinking about it that’s right. What sounds right to my ears is ok. I’ll check out smallbear! Thanks a lot.


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## Bobbyd67 (Nov 10, 2020)

piapium said:


> I agree with all of you. It was just a question but after thinking about it that’s right. What sounds right to my ears is ok. I’ll check out smallbear! Thanks a lot.


Did you ever get your build bias correctly ? I just got done building 2 of them and like you I couldn't get the right voltages. I would suggest to try out what I did, socket r2 and r3, use a jumper on r3 and place your bias pot knob on the pedal to noon and try to get 4.5v on the collector via the bias trimpot. I also had to change r2 to 15k to get the 0.7v needed for the collector of q1 and base of q2. Now it sounds much better !

I basically used the  fuzz face voltages from electrosmash, I also used a standard boss 9v power supply and my guess this and the charge pump maybe screwing up the voltages on my builds

I also tried soooooo many different ge transistor before that .... Low gain, high gain, no leakage, mid to high leakages and it didn't matter I couldn't get it bias :/


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## piapium (Nov 11, 2020)

Bobbyd67 said:


> Did you ever get your build bias correctly ? I just got done building 2 of them and like you I couldn't get the right voltages. I would suggest to try out what I did, socket r2 and r3, use a jumper on r3 and place your bias pot knob on the pedal to noon and try to get 4.5v on the collector via the bias trimpot. I also had to change r2 to 15k to get the 0.7v needed for the collector of q1 and base of q2. Now it sounds much better !
> 
> I basically used the  fuzz face voltages from electrosmash, I also used a standard boss 9v power supply and my guess this and the charge pump maybe screwing up the voltages on my builds
> 
> I also tried soooooo many different ge transistor before that .... Low gain, high gain, no leakage, mid to high leakages and it didn't matter I couldn't get it bias :/


I guess it's impossible to get 4,5V while the bias pot is placed to noon. I get 5V when I turn it cw all the way. And I don't care anymore, it sounds good to my ears. Try AC128s then you will love what you have. They sound shit.


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## TheSin (Nov 19, 2020)

PedalBuilder said:


> I'd focus less on the model number and more on the hFE and leakage, which are the biggest factors for how your fuzz face will actually sound.  Many, if not most of the NKT 275s you'll find on eBay et al. are fakes.  Even if you do find a real pair, it's highly likely that they are out of spec. Due to their popularity in fuzz face builds over the past few decades, what little stock remains has already been picked over by builders, and you're just seeing the rejects.  I had great luck with Japanese transistors like these in my fuzz face builds—cheap, low noise, and in spec for gain and leakage.  They clean up nicely and otherwise sound and behave exactly as a fuzz face should.


What are the acceptable transistor gain and leakage readings for this pedal? Currently looking to build one. Thanks.


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## caiofilipini (Nov 19, 2020)

piapium said:


> I guess it's impossible to get 4,5V while the bias pot is placed to noon. I get 5V when I turn it cw all the way. And I don't care anymore, it sounds good to my ears. Try AC128s then you will love what you have. They sound shit.



If you can't get the Q2 collector biased to 4.5V, it's likely that Q1 is underbiased. Because Q1 and Q2 are DC coupled (Q1's collector is connected directly to Q2's base), Q1's bias will directly affect Q2's. If that's the case, you could try lowering R2 to raise the voltage on Q1.


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## caiofilipini (Nov 19, 2020)

TheSin said:


> What are the acceptable transistor gain and leakage readings for this pedal? Currently looking to build one. Thanks.



Same specs as a regular Fuzz Face. I highly recommend the ElectroSmash analysis of the Fuzz Face: https://www.electrosmash.com/fuzz-face


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## gingerale (Jan 23, 2022)

Bobbyd67 said:


> Did you ever get your build bias correctly ? I just got done building 2 of them and like you I couldn't get the right voltages. I would suggest to try out what I did, socket r2 and r3, use a jumper on r3 and place your bias pot knob on the pedal to noon and try to get 4.5v on the collector via the bias trimpot. I also had to change r2 to 15k to get the 0.7v needed for the collector of q1 and base of q2. Now it sounds much better !
> 
> I basically used the  fuzz face voltages from electrosmash, I also used a standard boss 9v power supply and my guess this and the charge pump maybe screwing up the voltages on my builds
> 
> I also tried soooooo many different ge transistor before that .... Low gain, high gain, no leakage, mid to high leakages and it didn't matter I couldn't get it bias :/


Hey, I had some biasing issues with my Sunflower build too so I searched the forum and found your post. Very helpful, I wish Pedalpcb could have more detailed build docs, if they had stated that you can try different resistors on R2 and R3 in order to help with biasing I would have put sockets there from the start. After reading your post and reading on Electrosmash it makes sense.

Now I did what you described and could get my Q2 to bias correctly to -4,5. It took a lot of trial and error though... The transistors I used were old Russian ones and tricky to get to bias properly.


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