its not clicking any more but now there is a constant hiss

This is another issue and we have to charge you for it.. 

You see, only one issue at a time can be troubleshot for free.. 

sorry im a bit stupid.
surely the hiss is due to removing C4 from the circuit?
are you saying that C4 was the cause of the click because the click is not there any more?

Quote from: scooby on February 20, 2025, 09:22:30 AMsurely the hiss is due to removing C4 from the circuit?

I don't know..

Quote from: scooby on February 20, 2025, 09:22:30 AMare you saying that C4 was the cause of the click because the click is not there any more?

You may verify it by repeating C4 placing & removing several times..

Quote from: antonis on February 20, 2025, 09:35:26 AMYou may verify it by repeating C4 placing & removing several times..

haha, i thought you were being sarcastic at first..
but i recon ill use a pair of roach clips 

Shouldn't diode D1 be placed before resistor R2?
Could D1 reverse leakage be the problem instead of C4?

PNP negative ground ... 

mac

Quote from: mac on February 24, 2025, 07:09:12 AMShouldn't diode D1 be placed before resistor R2?
Could D1 reverse leakage be the problem instead of C4?

PNP negative ground ... 

mac

Sorry Ive only got basic electronics. Could you explain your reasoning?
Thanks

QuoteCould you explain your reasoning?
Thanks

- About protection diode D1 reverse leakage, it's a question for the experts, I play by ear here. Let's wait what they have to say.

- PNP negative ground are a source of misterious problems sometimes.
To be safe I built mine PNP positive ground and with no external power supply because at 0,2ma = (9v-7v)/10kohm current draw a battery lasts years.

From R.G. Keen (GEOFEX):
"While in theory, the negative ground conversion for FF and other PNP circuits ought to work every time, there are a significant number of times where it causes oscillation, motorboating, etc. Sometimes you can clean this up by putting a big freaking capacitor across the power leads, sometimes you also need a low-impedance 0.1uF ceramic, too, and sometimes you need divine intervention. Try it if you want, but be aware that there are conditions and layouts that will not be trouble free if you flip power and ground."

QuoteSorry Ive only got basic electronics.

Electronics? What's this? 

mac

D1 serves for reverse polarity protection..
(it effectively shorts power supply in case of accidentally mixed +9V and GND)

As it is placed (after R2), it only offers a 700mV voltage drop so there are 8.3V at its Anode..
The current through R2 is 82mA so the power  dissipation is hardly 700mW..
(even a 1/4W resistor would need several seconds to be burned out..)

BJT's Base-Emitter reverse voltage "strengh" is hardly 6V so we'll result in a damaged transistor..

I mean if the diode reverse leakage is interacting with R2, C4 in a charge/discharge cycle.

What if you short R2 with some plyers or wire.

mac

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QuoteSorry Ive only got basic electronics.

Electronics? What's this? 

mac


[/quote]
My level of electronics is I understand your explanations. But would not be able compose them 

Quote from: mac on February 24, 2025, 08:54:39 AMI mean if the diode reverse leakage is interacting with R2, C4 in a charge/discharge cycle.

What if you short R2 with some plyers or wire.

mac

Is there potential to damage other components doing this?
If not, I'll give it a go 

Quote from: scooby on February 24, 2025, 10:24:21 AMIs there potential to damage other components doing this?
If not, I'll give it a go 

No... unless you connect a wrong polarity power supply.
R2 and C4 are a Power Supply filter.

- Reconnect C4 first. You could use a new, bigger cap with a 100nf in parallel.
  Power on and check what happens if you momentarily bypass R2.

- What happens if you reconnect C4 and remove D1?

- What happens if you reconnect C4 and place D1 before R2?


Check where protection diode D1 is placed in the schematic below:
https://aionfx.com/app/files/schematics/cornish_g2_2008_trace_schematic.png

Sometimes the order of the factors DOES alter the product 

mac

shorted R2, clicking remains
removed D1, clicking remains

c5 and c4 have also been replaced to no avail 

here is what it sounds like:
https://soundcloud.com/herr-payne/clicking-treble-boost?si=1da7bc3a0fc9407ca6c21047cb35d2d7&utm

I found the culprit:


It's random 
It makes it more interesting, and as Antonis noted, more expensive 
The randomness could point to a bad solder??

mac

Quote from: mac on March 21, 2025, 09:04:37 AMI found the culprit:


It's random 
It makes it more interesting, and as Antonis noted, more expensive 
The randomness could point to a bad solder??

mac

Could be bad solder but is that likely since the problem only manifested after 6 months use?

If I was to drag out my old xp laptop with 20yr old usb oscilloscope- assuming it's still working, what sequence would you recommend signal tracing looking for the source?

solved 

I had the enclosure on its side, base removed, testing with guitar and amp. It wasnt clicking...

I noticed the tines inside the enclosure for the signal in / out jacks were very close to where the base of the enclosure sits (its a slightly smaller than standard, aluminium enclosure). So I put some electrical tape on the parts of the jacks closest to the base and closed it up. It worked 

I also found a very loose and wobbly output jack on my sons guitar. I tightened the ring nut -but I am pretty sure the source of the problem was the enclosure shorting to the signal jacks, not the loose guitar jack.

Anyway, hes happy. Hopefully he will stop saying I'm a shite box builder now.