Original ToneBender Mkii Gated sound

[Atodovax]

Hello everyone, so i just built a Mkii with OC75 transistors all with high leakage 400 ua (aprox) and gains around 100hfe
So the pedal sounds very good but theres definetly to much gating on the decay notes.. It has not very much sustain on either low gain settings and even less with the gain pot maxed.. All the videos i see in youtube are from reissues and the only video i have seen of an original with oc75s seems to gate the notes at the decay and has not very much sustain.
So my question is.... Should i lower q1 and q2s leakage by swaping for diferent transistors? I have no more Oc75s to test...
Voltages are somehow in the ballpark.
Q1c is 7.89 volts q2c is 0.08 and q3c is 8.3 volts
I noticed that when i put the air conditioner in the room the voltage from q1 rise to 8.5 and q2 rise to 0.15 and then the pedal sounds fantastic. But its summer here and my room is boiling so i dont know if this is expected from the heat of the room in a Oc75 Tonebender.
I notices that rising q2c to 0.15 volts with transistors with lower hfe makes the pedal sound with more sustain but theres definetly a change in its character. I dont know what to expect with higher voltage at Q1c, but Q2 is really peaky and controlling the "gating" effect. If anyone has a vintage unit that could clarify my this would be awesome .
Thanks !!

[Rob Strand]

Q1c is 7.89 volts q2c is 0.08 and q3c is 8.3 volts
I noticed that when i put the air conditioner in the room the voltage from q1 rise to 8.5 and q2 rise to 0.15 and then the pedal sounds fantastic.

I don't have my good voltages with me but you should check the Q3c voltage when it's working well.   Q2c isn't much use as you have no control over it.

Reply #6 from Electric Warrior has some voltages.  Check some of his other posts (on this forum and free stomp boxes) for more voltages.  I know I've posted voltages a few times as well.
https://www.diystompboxes.com/smfforum/index.php?topic=111775.0

[Atodovax]

Q1c is 7.89 volts q2c is 0.08 and q3c is 8.3 volts
I noticed that when i put the air conditioner in the room the voltage from q1 rise to 8.5 and q2 rise to 0.15 and then the pedal sounds fantastic.

I don't have my good voltages with me but you should check the Q3c voltage when it's working well.   Q2c isn't much use as you have no control over it.

Reply #6 from Electric Warrior has some voltages.  Check some of his other posts (on this forum and free stomp boxes) for more voltages.  I know I've posted voltages a few times as well.
https://www.diystompboxes.com/smfforum/index.php?topic=111775.0
Thank you very much for replying! The pedal sounds good but theres too much gating... I wonder if this happened with originals in hot rooms

[Rob Strand]

I noticed that when i put the air conditioner in the room the voltage from q1 rise to 8.5 and q2 rise to 0.15 and then the pedal sounds fantastic.

Q3.c voltage is missing when the air-conditioner is on (and when it sounds good).

[Atodovax]

I noticed that when i put the air conditioner in the room the voltage from q1 rise to 8.5 and q2 rise to 0.15 and then the pedal sounds fantastic.

Q3.c voltage is missing when the air-conditioner is on (and when it sounds good).

Hehe sorry yeah. I dont remember exactly but It also rises. Do you think the gated sound depends more on Q3 than Q2? I though Q2 was to blame for its leakage (more than 400ua)

[Electric Warrior]

When you say boiling, what room temperature are we talking about?

A MKII may still sound great when gating. The MK1.5 tends to fart out in warmer temperatures, so I guess they added a buffer to the front to keep the signal from reaching the threshold of cutting out so quickly, so that behaviour is to be expected to a degree. It's the nature of the beast

My vintage units are biased at the sweet spot between gating and clean up and are very stable. They rarely clean up well, but I usually have a great range of different fuzz tones to be dialed in with the guitar's volume pot. At around 28 °C  the gating gets more noticable, though. Over 31 °C things may start to get unpleasant, but they have never been unusable yet.

Lower leakage on Q2 is one possible fix. If you only have three transistors you may try swapping them around until you find a sequence that gates less.
Alternatively you could replace Q2's collector resistor with a trim pot, so you can dial in the sweet spot. It's probably the most comfortable solution if you have to deal with extreme temperatures often.

I wouldn't mess with Q3's bias. As its collector voltage mostly depends on Q2's leakage and bias setup, tweaking on Q2 makes more sense to me.

[Atodovax]

When you say boiling, what room temperature are we talking about?

A MKII may still sound great when gating. The MK1.5 tends to fart out in warmer temperatures, so I guess they added a buffer to the front to keep the signal from reaching the threshold of cutting out so quickly, so that behaviour is to be expected to a degree. It's the nature of the beast

My vintage units are biased at the sweet spot between gating and clean up and are very stable. They rarely clean up well, but I usually have a great range of different fuzz tones to be dialed in with the guitar's volume pot. At around 28 °C  the gating gets more noticable, though. Over 31 °C things may start to get unpleasant, but they have never been unusable yet.

Lower leakage on Q2 is one possible fix. If you only have three transistors you may try swapping them around until you find a sequence that gates less.
Alternatively you could replace Q2's collector resistor with a trim pot, so you can dial in the sweet spot. It's probably the most comfortable solution if you have to deal with extreme temperatures often.

I wouldn't mess with Q3's bias. As its collector voltage mostly depends on Q2's leakage and bias setup, tweaking on Q2 makes more sense to me.

Thank you very much Electric Warrior ! Temperature in my room was 32 celcius all this week so maybe the gating is to be expected. I just wanted to clarify that with the owner of an original unit. So i will lower the Q2c resistor a little bit to reach at least 0.12 violts there. Should i be concerned about Q1c being around 7volts? It rises inmediately to 8.9volts when i turn on the air conditioner and the pedal has much more sustain but when warm the voltage stays between around 7 volts and i read on different posts that you marked it should be around 9volts.
This one also do not clean up when rolling the guitars volume knob but i heard that is normal on vintage units.

[Electric Warrior]

My Supa measures rather high on Q1C. I think 8.6V is probably closer to average, but these are tricky to judge because they change a lot depending on the supply voltage.
With Q1C being too low, you probably get a very saturated sound with little range on the attack knob (though some people apparently like that). Too high and the lowest attack settings don't feel gainy enough. A trimmer on Q1b could help.

[Ben N]

... that behaviour is to be expected to a degree.

I see what you did there. 

[Atodovax]

My Supa measures rather high on Q1C. I think 8.6V is probably closer to average, but these are tricky to judge because they change a lot depending on the supply voltage.
With Q1C being too low, you probably get a very saturated sound with little range on the attack knob (though some people apparently like that). Too high and the lowest attack settings don't feel gainy enough. A trimmer on Q1b could help.

Is the Supa exactly the same as the Solasound?

[Electric Warrior]

Yes. When they were being made concurrently by Sola Sound, they got exactly the same circuit boards. It seems they dropped the Sola Sound branded version early on, though, so some of the later circuit variants are exclusive to the Vox branded units, Marshall Supa Fuzzes and other OEM versions.