Six String Stinger - missing output and too dark

[ntuncer]

Hello,

I have an issue with my Six String Stinger build. I have already searched in the forum and see that there are others who have the same issue. When I compare with the original one, output is missing, when I dimmed volume and gain it is still less than original volume and gain 12 o'clock. It is too dark, too much bass even filter is all the way up. Could you please help me to solve the issue? By the way C12 is 22nf in my build as it is the correct value.

Q values:

Q​	D​	S​	G​
Q1​	8.86v​	5.01v​	4.06v​
Q2​	5.01v​	0.46v​	0v​
Q3​	8.86v​	4.90v​	4.06v​
Q4​	4.90v​	0.55v​	0v ​

Cheers

 

[music6000]

Are you sure you used B100K for Volume & Filter.
Mine is Unity with Volume at 9.00 O'Clock <-- with Gain at 12.00 O'Clock ^???

 

[ntuncer]

Are you sure you used B100K for Volume & Filter.
Mine is Unity at 9.00 O'Clock <-- with Gain at 12.00 O'Clock ^???

Yes I am sure. My unity gain with strat is volume 12.30, gain 12.00, filter 5.00 o 'clock to have same eq.

 

[music6000]

Yes I am sure. My unity gain with strat is volume 12.30, gain 12.00, filter 5.00 o 'clock to have same eq.

Mine with a Tele!
What brand of SMD J201's did you get & from who, were they pre soldered to the adapter board???

 

[ntuncer]

Mine with a Tele!
What brand of SMD J201's did you get & from who, were they pre soldered to the adapter board???

I got them from musikding which were presoldered to the adapter board probably they were MMBFJ201s.

 

[music6000]

I got them from musikding which were presoldered to the adapter board probably they were MMBFJ201s.

That is the big question, what did you get???
If my volume is at 12.00, I would have all the neighbours belting down my door!!!!
I used Vishay J201 TO-92 in mine.

 

[ntuncer]

Unfortunately I don't have further information about smds. How can I check them if they are ok or not?

 

[music6000]

With a transistor checker, There cheap & quite a few Members here use them

 

[ntuncer]

Do I need to pull out before testing or is it ok to test them soldered? I think it is very difficult to desolder them from the pcb.

 

[music6000]

They have to be tested out of the circuit, you will have to try and remove them from the S S S PCB with solder wick braid.
If that fails, Cut pins & desolder individual, Do just 1 to start with & see if that meets j201 specs
Chuck D, Bones has a tutorial on J201 testing to se if they are in spec!

 

[ntuncer]

They have to be tested out of the circuit, you will have to try and remove them from the S S S PCB with solder wick braid.
If that fails, Cut pins & desolder individual, Do just 1 to start with & see if that meets j201 specs
Chuck D, Bones has a tutorial on J201 testing to se if they are in spec!

Thanks for the information. This is the first time I have an issue of smd J201s from musikding. Before removing them with the help of audio probe, is it possible to detect which transistor(s) is faulty if we assume that those are MMBFJ201s? What do we expect to hear from each transistor's output?

 

[ntuncer]

So when I use the audio probe, with volume 9, gain 12 o'clock there is more than unity gain volume on the positive side of C10 but somehow the output is low than unity gain from the output. By the way I hear more than unity gain from output of the transistors.

 

[music6000]

So when I use the audio probe, with volume 9, gain 12 o'clock there is more than unity gain volume on the positive side of C10 but somehow the output is low than unity gain from the output. By the way I hear more than unity gain from output of the transistors.

Just woke up!
This is why I asked about the B100K pots at the start of this discussion as you have a Volume issue & Filter issue????
Where is the unity gain at C11 & R15???

 

[ntuncer]

Just woke up!
This is why I asked about the B100K pots at the start of this discussion as you have a Volume issue & Filter issue????
Where is the unity gain at C11 & R15???

Below is the photo that shows I use B100Ks both for Volume and filter.

I have almost same volume between R15 and C12 when I compare after C10 but very less volume between C11 and R16. As volume part is at the end of the circuit, I cannot say there is a huge volume differences from the unity gain to reach all the neighbors.

 

[music6000]

Is the Volume the same at the - Pad of C10, R15 & C11 junction as the + pad of C10????

 

[ntuncer]

It is the same volume between the - pad of C10 and + pad of C10. Could be the problem that transistors somehow couldn't amplify the signal enough?

 

[music6000]

Are you saying that up to R15 side of Filter pot, you have louder audio than after Filter pot
If yes, you need to remove & test 100K Filter pot to rule out being faulty???

 

[ntuncer]

Here is the status, "More than unity gain" means if the unity is 1, it is 2.5 on 10 as a volume.

 

[music6000]

Here is the status, "More than unity gain" means if the unity is 1, it is 2.5 on 10 as a volume.

View attachment 23009

Cool, What about Leg 3 of VOLUME Pot???

 

[ntuncer]

Cool, What about Leg 3 of VOLUME Pot???

It seems like unity volume, more gain, more bass but way less volume than after R15 junction.