> is it giving you problems now?
frank57 has been posting many-many messages on many forums asking for help with this low-price clone "HiWatt". He's had detailed responses representing hours of time from several gurus. I don't think he's understanding any of it.
They don't just disconnect like on the output pcb where the send return jacks are.Yes (perhaps), try that and jump the red and white wire. Then move the wire away from the output jacks.
Would simply disconnecting it there achieve the same end?
Maybe some of that buzz is from the unshielded power transformer?Probably not.
If I tried the board idea with the diodes,what would the best way be to put that board together?
The centers of the screws are about 3" and 2 .75".Might be worth a shot.
So is the grid on the first half of v2 the big problem?
Going to the ground bolt from pin 2 with my multimeter on the v2 tube,
kills the hum and buzz.
So is the grid on the first half of v2 the big problem?
I think you are just shunting the signal to ground, which means no signal no buzz.
Crap. Looks like a rookie mistake.
I checked again, and I must have somehow knocked the meter to measure resistance.
So when you do that you kill the hum buzz.
Hopefully that helps?
If you measure the voltages, you still get a change in the frequency of the hum on that grid.
Also on r40 the diode resistor, the buzz goes down a little when I measure voltages.
On one side I get 124 on the other .08.
On the .08 side, the buzz goes down slightly.
Pretty sure that's rectifier buzz getting to the treble mainly somehow.
Pulling v1: Hum and buzz still there.Has that mod been completely undone? The problem could exist because of how V1 was removed and later restored.
Pull V2, (v1 back in), hum and buzz are gone.
The original mod someone did on this amp had v1 out.
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Is the noise loud with the gain pot turned all the way down? (fully counter-clockwise) yes or no?No, primarily less buzz.All controls at high noon.There isn't as much buzz there.
s it as quiet as when pin 7 of V2 was shorted to ground, with the gain pot turned all the way down? yes or no?I would have to say yes and no: it's similar but somewhat louder. I could check again.
Does the noise get louder when you turn up the gain pot (turn it clockwise)? yes or no?Yes, does it ever.
would putting it on the jack do anything at all?
What should the resistance to ground read on the grids of v2 if I measure them?
Should it be close to zero?
Here's Paul Ruby's idea for the board idea.
Looks like there's a bias pot there too.
Also trying to reduce the heater high voltages.
The diodes on the main pcb would come out too right?
Would reducing r8 to 100k or r17 to 10k do anything?
You're right.
Someone was telling me the circuit was poorly designed
and that v1 was too strong for it and so on.That may be true but the real problem is elsewhere.
I think Paul's board idea will help overall.
Moving those hv wires and first filter cap out of there will help things.
Maybe I should redo the ground wires on v1 the way they were?
That shielded wire I'm sure was not there.
Could it be a hardware problem?
Socket itself?
Other oddball thing is the jack itself.
The tabs are reversed on it.
They close on the left not the right.
Where on earth they found these jacks and why did they use them is beyond me.
When I pull the guitar cable out the noise stops, until I move the controls again,
then all the noise is back.On the jet city amp I tested that did not happen at all.
That amp was very quiet with nothing in there and moving the tone stack.
I do have new jacks that fit, but because of the directional aspect I don't think they'll work.
I'll try it anyway.
Could the problem be right at the front of the amp at the jack itself?
Acting as a reciever because of the placement of the first filter cap and diodes?
... started to cut out,it works but now and then fades out ...