Yes, the case is connected to mains earth, the 0v is connected to the chassis via a CL60 thermistor. Each F5 has its own case and is set up in the same way.
Banned
Joined 2002
Hi - I have a pair of F5s built using Peter Daniels board - apart from the excellent sound I am getting a rather odd effect. If I touch (or just move my hand near) the heatsinks then the volume drops to nothing for about half a second and the fades back in rapidly.
Weird.
Even weirder is that once I have done this and then touch the amp again there is no effect.
static discharge will do this
make sure your heat sinks and chassis is actually grounded properly.static discharge will do this
I will recheck the grounding, but that would fit the facts - once the static is discharged then it does not happen again.
Some pics................
Just for s**ts and giggles I thought I'd post these.
Boards are Peter Daniels amp and Cviller PSU, real nice boards. I'm using Toshiba 2SK1530 and 2SJ201 for outputs with no thermal comp. and no overcurrent protection. It did take awhile to set the bias but it is rock solid now. I'm running the voltage across R11/R12 at .640 Vdc and thus the bias at 1.3617 amps.
Anteck transfo and Pers Anders RFB02 boards which I stuffed with MUR3060s and 10nf caps.
The AC wiring is temporary(probably).
The only problem is now that I have it "mocked" up and running it sounds so good that I have no inclination or motivation to put it in a proper chassis.
Just for s**ts and giggles I thought I'd post these.
Boards are Peter Daniels amp and Cviller PSU, real nice boards. I'm using Toshiba 2SK1530 and 2SJ201 for outputs with no thermal comp. and no overcurrent protection. It did take awhile to set the bias but it is rock solid now. I'm running the voltage across R11/R12 at .640 Vdc and thus the bias at 1.3617 amps.
Anteck transfo and Pers Anders RFB02 boards which I stuffed with MUR3060s and 10nf caps.
The AC wiring is temporary(probably).
The only problem is now that I have it "mocked" up and running it sounds so good that I have no inclination or motivation to put it in a proper chassis.
Attachments
Last edited:
Yes. I had them on some of his 8.5" X 6" X 1" heatsinks and even at lower bias, .590/1.25amps I couldn't touch them for longer than 4-5 seconds.
With the larger sized heatsinks from him that I'm using now, 10" X 8" X 2", they barely get warm.
They are aluminum oxide pads with thermal grease. I did not have any sil-pads on hand and these had been laying around getting in my way.
I had checked that but just in case I have moved something I will check again.
Continuity test shows that Gate/Drain are OK, Source bleeps for a fraction of a second and that is that. The results are the same if the FETs are no longer bolted to the heatsinks. However take out the thermistor from star-ground to chassis earth and Source no longer bleeps at all.
Drain to Chassis earth is steady at 40R - with the thermistor in place - without the thermistor there is no connection.
Drain to 0v is 30R.
I can understand the Drain readings based on the circuit - it is the Source readings that I cannot fathom.
I will run without the star-ground to chassis earth tomorrow and see what happens.
Drain to Chassis earth is steady at 40R - with the thermistor in place - without the thermistor there is no connection.
Drain to 0v is 30R.
I can understand the Drain readings based on the circuit - it is the Source readings that I cannot fathom.
I will run without the star-ground to chassis earth tomorrow and see what happens.
At least the parts which are there look pretty.
The problemo i have is with the rack.
Did everyone in the whole D world build that thread rod and nuts thing ?
I'm going to follow the advice in your sig line and just say that I don't know anyone that has built one.
Everyone I know makes alot more money than me.
Banned
Joined 2002