2203kk (Kerry King Signature JCM800) noise issue

[Mr_bibbles]

Bother... I had no idea. I think you're out of luck there. SIL's are few and far between. I suggest you get a turned pin strip for a socket and another as a carrier to hold the DIP package with the wires. That way you can try a few alternatives by simply plugging and unplugging.

WOOF. This is still very helpful! I might just order a direct replacement or try doing a DIP conversion with some hot glue... Overall though thank you much for your time and effort.

[Mr_bibbles]

It gone

The new SIP works excellently, no more flicker. Thanks again boys!

[g1]

Can you clarify the exact part you used for replacement? Was it another NJM72BL ?

[Mr_bibbles]

Can you clarify the exact part you used for replacement? Was it another NJM72BL ?

Yes it was! There's still a tiny amount of the flicker noise, but it's far reduced from what it was.

[klimbo]

I have a 2203kk (Kerry King Signature JCM800) on the bench, the owner was complaining about a 'clicking / crackling" when the 'Beast' mode is on. The Beast mode seems to be a SS boost with a noise gate, but after a little investigation it seems like he was sitting on the threshold of the gate, meaning it was just turning off and on quickly while riding the noise.

https://drive.google.com/file/d/0B9W...Tc0/view?hl=en


https://drive.google.com/file/d/0B9W...DM0/view?hl=en


It SEEMS like the noise gate is working correctly, but I can't really tell because I'm not even sure the progression of signal in this amp.... I think the issue maybe be excessive hiss itself, which is causing the noise gate to 'sputter' more than usual. Without the beast mode engaged, there's more hiss than any JCM800 I've played,Bluestacks Kodi Lucky Patcher even at low preamp gain..

Yes, I've tried swapping the preamp tubes!
Checked all the KT88's and they're drawing appropriate current and are biased correctly.
Hiss is affected by all controls.

I traced the signal to the first preamp tube, and the excessive hiss is NOT there at r138, but IS there at r125. Replaced r125 just in case it was the plate resistor, no change.

What the goddang heck am I looking for here? Is this some awful byproduct of the solid state additions?

please what is the voltage exactly : HT1, H2 HT3 en the +15V and -15V ?

[v-man]

Tag.