Possible. But the voltage will drop the whole time you listen and the sound will change and the bias may not be stable or at least not where you thought you wanted it.
Sweet spot will pass by in a cut or two.
It would take a massive set of batteries for any length of listening time.
For the money you would spend on batteries, do a great big ole power supply like Mr. Pass suggests, with a huge transformer VA rating.
I have a Mac Mini music server that I have powered with a 12 volt regulated power supply with a battery backup (when you pull the plug on the supply, the batteries are connected directly to the 12VDC output) and although it pulls less than an amp, it draws the two 12 AH 12 volt batteries down from the charged voltage of 13.4 VDC to 12.3 VDC within a CD of listening and you can hear the difference (higher voltage sounds better). It is smother though at first and but the sound stage starts to collapse as the voltage drops. It doesn't take long before I am plugging it back in.
I also have a straight regulated supply that has been tweaked that sound better anyway.
Rush
If you have 50Hz hummm you have an input loop or signal loop problem, not PSU.
PSU problems are almost always twice the mains frequency, because you are rectifying both sides of the 50Hz AC, charging your caps at 100Hz.
Remove the B1 from the amp for the time being.
Also look at your output wiring, you really should take the speaker output from the center board. (Yes, I know that there are not enough solder holes to do that conveniently...)
But, if you want a battery powered F5, get 4 batteries, stack them and make it 24V+24V
If you are willing to go to the Balanced-F5 such as here http://www.diyaudio.com/forums/pass-labs/213152-balanced-f5-small-footprint.html then you should be good for around 25 watts into 8 ohms.
My F5 was blowing fuses on power-up.
I was using 1.25A slow blow fuses and it worked for several power-ups before the first one went. Then for some reason I could barely get the thing on without it popping them, so I tried a 1.6A slow blow, whihc seemed to resolve my problems for a few days and a few power-ups, but then these again started popping on turn on, and having got though 5 in a row, I went up to 2A slow blow, which is now working fine.
I have a 300VA toroidal, with 240v primaries (not two 120vs joined as it is a UK manufactured toroidal). I see on Nelson Pass's diagram that 1.25A is recommended for 240v supplies and 2.5A for 120v supplies.
Is there anything I can try without resorting to my current (pun intended) 2A fuse? It seems stable now, but maybe even these will blow in time? Curious!
Thanks
I was using 1.25A slow blow fuses and it worked for several power-ups before the first one went. Then for some reason I could barely get the thing on without it popping them, so I tried a 1.6A slow blow, whihc seemed to resolve my problems for a few days and a few power-ups, but then these again started popping on turn on, and having got though 5 in a row, I went up to 2A slow blow, which is now working fine.
I have a 300VA toroidal, with 240v primaries (not two 120vs joined as it is a UK manufactured toroidal). I see on Nelson Pass's diagram that 1.25A is recommended for 240v supplies and 2.5A for 120v supplies.
Is there anything I can try without resorting to my current (pun intended) 2A fuse? It seems stable now, but maybe even these will blow in time? Curious!
Thanks
No CL-60 in the primaries. As I said in my post, perhaps not clearly enough, my toroidal has only two wires on the primary, as it is intended for 230/240v use only in Europe. It is not two 120v sets for joining with a CL60.
Yes soft start is ideal and I may go that route if I absolutely have to, but I guess I am wondering if anybody else has this issue, and what size fuses people have found stable. I am guessing that 2A is safe. Perhaps I am wrong. Anybody?
having NTC in line ?
being in 240Vac country , two CL60 in series will do
edit - that funny Husky was faster
Like I already said, I have no CL60s on the transformer, as my primaries are 240v, not 120v, so no centre to join.
I have a CL-60 from the caps board to star ground - that's all.
Where would I use two CL60s in series please?
I actually went through several T-3.15a fuses over a two day period. I could hear the fuses blow and it was always at power-on. At that time my focus was on the cooling system and as reported, I didn't do either the CL-60s or the newly completed soft start. The thermistor package is almost complete and hopefully will be enough to hold, and also allow lower size fuses. If not I'll try adding the SS.
Just use one. Wherever you decide, beware it's going to get hella hot.
F5 fuse blowing.
I assume you have set up the currents in the output devices as per instructions. How much filter capacitance have you got on each rail. Too much will cause hi primary inrush currents. Are you using highly capacitive speaker leads. I have had trouble with F5's when using one particular brand of speaker cable. I haven't read earlier posts so hope I not going over old ground. Good luck.
I assume you have set up the currents in the output devices as per instructions. How much filter capacitance have you got on each rail. Too much will cause hi primary inrush currents. Are you using highly capacitive speaker leads. I have had trouble with F5's when using one particular brand of speaker cable. I haven't read earlier posts so hope I not going over old ground. Good luck.