Parasitic oscillation!!!!?..........

flemingmras · Post by **flemingmras** » Fri Jul 16, 2004 2:22 pm

The "active shield" explanation is correct. However, something else you must remember is is that to the guitar signal, the power supply is seen as a dead short. In other words, the signal sees the positive side of the power supply exactly the same as it sees the negative side.

Also, since ground is negative and the plate is positive, I think a humbucking effect exists. Since between the input jacks and the 68K resistors the shield is going to ground and between the resistors and the tube the shield goes to pin 1, being a positive voltage, this would make sense but I could be wrong. George???

Jon

5150loveeddie · Post by **5150loveeddie** » Fri Jul 16, 2004 4:58 pm

well it is working great.............

Other question!!!

Once in a while when flipping the stby swt to ON it makes a relatively loud static noise for a few seconds and you can see in the swt little bleu sparks, have to flip it OFF for a few seconds, then back ON then it's OK!

It like it's building static inside that swt.

Aren't those Xicon .22uf caps suppose to stop that?

JF

Post by **VelvetGeorge** » Fri Jul 16, 2004 5:07 pm

Those .22's are there stop the initial transient that happens when the switch is thrown.

This sounds like a problem with the switch itself. You can try cleaning it with electronic spray. Just spray some (a little goes a long way) into the opening around the handle and flip the switch several times.

If that doesn't fix it, then the switch will have to be replaced.

Please don't let this slide, it isn't safe.

George

5150loveeddie · Post by **5150loveeddie** » Fri Jul 16, 2004 6:43 pm

Ok, will do that ASAP!!!!

Other than that, I really like the tone a little on the bright side but great, really punchy, the dynamic respond is awesome. It is difficult for me to give you an exact picture of it because of my lack of English vocabulary.

Please excuse my very basic English communicative correspondances.

Will keep the amp stock (PTP 69) for now and let the zoso break in more than will try the 68

JF

5150loveeddie · Post by **5150loveeddie** » Sat Jul 17, 2004 5:46 pm

George in your opinion will it alter the tone if I use shield wire for "V2 pin2"?

1) With shieldering at the plate (pin1)
2) or with standart grounding only

JF