Walter -
Use only one bridge as the resistance between chassis earth and audio ground... having two seems like it will only add a potential loop.
Take the speaker return (black or negative speaker connection) from the amp PCB, not the PSU - it's much quieter that way.
Also, if possible, please draw a schematic of your wiring, it will help us understand your connections.
Nice work, by the way - neat wiring, good layout, I'm looking forward to seeing more photos of your amp!
Hi 6L6,
I don't know if I can use only one bridge, cause I have two separate main audio grounds. Or should I connect those first and then go through one bridge to earth? Hmm...
The schematic is attached, it's from the F5T. Only twice in my case; for each ampboard one PSU.
Thanks for the compliment ! I will post more.
Grtz, Walter
Attachments
There is too much concern about these particular Jfets for the front end
of the amplifier. Yes, the 2SJ74 and 2SK170 are really superb, particularly
on the noise front, but this is not as important when we are already dealing
with line level volts instead of millivolts.
You can still get the Fairchild J174, J175, P1086 P channel devices from such
places as Digikey and Mouser, and they are cheap.
The N channel are even easier to get, such as the Fairchild J111. Worst
case you might have to parallel two, but even that is unlikely. You might
have to select them, but at prices like $0.11 for quantities, you can hardly complain.
Better buy them before I do....
Well, I can not find any P-channel J-FET, the Toshiba is available, but at a high price and is operating outside the specification if I am using 32V rail voltage. I also noticed that both J111 and 2SK170 have no problem with the higher voltage, but the 2SJ74 is specified for lower voltage, and none of the other types seem to be available at the usual suppliers around here. Was hoping to do a Turbo V1 with .8A/device.
The special audiophile rectifiers come in pairs with 3 pins and only one polarity.
You can't configure them as a standard 4 connection bridge, so you use them
in parallel.
Most of the 3 legs dual diodes rectifier comes in two types of configurations, either it is common anode or common cathode, standard bridge can be form by two dual diodes, one of each type.
But I don't know if this types of configuration also applied to "special audiophile rectifiers" or not.
But I don't know if this types of configuration also applied to "special audiophile rectifiers" or not.
The F5 already runs lots of feedback, but you can go for more if you are
willing to put some of those little compensation capacitors in the circuit.
I'm thinking the other way around. Less feedback and more gain (+P3 regulation for 2nd harmonics character) to get leass damping and a little more pleasant distortions.
What are MAX recommended resistor values? Is it wise to use even more ohms than in F5Turbo?
