^ second that. Also, are your audio input cables not screened? Looks like 2 individual wires, but I could be wrong...
They are single wires. I have made many amps and never used screened cable and never had a hum problem. As this sounds like 50/60Hz hum, would screened cable make any difference?
Just as long as the wire isn't passing too close to the xformer magnetic field. In my case it was only a matter of about one inch farther away from xformer. I have an F2J clone.
Exactly same experience here!
I had hum on an F2J clone. The amp is dead silent when moving the Transformer about 1 or 2 inches back, or by turning it a few degrees. It can be tricky as the "silent zone" is very slim .. just a few degrees wide.
Fred
Exactly same experience here!
I had hum on an F2J clone. The amp is dead silent when moving the Transformer about 1 or 2 inches back, or by turning it a few degrees. It can be tricky as the "silent zone" is very slim .. just a few degrees wide.
Fred
OK, I will give it a try.
I built a Pass F2 using Peter Daniels board. The tx was orientated as normal (on floor of case) and there is a lot of air around it as the case is a lot bigger.
Rob.
Hi there ,
How is your capacitance filtering bank ?
In that amp I needed 150000 u F for a good S/N ratio ( almost unaudible ) .
About 18,000uf per channel. I didn't want to spend zillions on caps only to find that the amp sounded crap. 100v caps are expensive (mind you so were the nice heat sinks) Nelson's schematic shows 25,000uf.
Blimey, loads to read. I always hope for the simple fix
The amp is dead silent when moving the Transformer about 1 or 2 inches back, or by turning it a few degrees. It can be tricky as the "silent zone" is very slim .. just a few degrees wide.
Instead of changing tx location perhaps just rotating will do the trick.
Well, if no change at all in buzz after moving tx then at least that is one thing you can cross off the list.
Yes, i'll try anything!
Thanks for your input.
Hi,
Attached it is drawing of the star ground that I used to fix a hum problem in my amplifier. It may help you fixing your problem.
Yes, I was going to make a ground breaker circuit as per Elliot Sound Projects.
well - I wrote that one proper pic is worth as zillion words
problem can be wiring , but also physical layout of ripple currents in your C bank
how's that made ?
it's easy to make pics today , to shrink them and post them
don't use flash but some other source of additional light
anyway - look here - maybe you'll learn trick or two ( same as I was doing long ago before internet , first read , look , think ........ and ask only if you're in deep drek)
Babelfish J2 , ongoing ; Part Four - diyaudio.rs
problem can be wiring , but also physical layout of ripple currents in your C bank
how's that made ?
it's easy to make pics today , to shrink them and post them
don't use flash but some other source of additional light
anyway - look here - maybe you'll learn trick or two ( same as I was doing long ago before internet , first read , look , think ........ and ask only if you're in deep drek)
Babelfish J2 , ongoing ; Part Four - diyaudio.rs
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