多謝Accphoto兄

Really respect accphoto.


Dear accpohoto,

I got a question to ask, if we use lower Voltage for tube filamet what will happen? what's the effect of filament voltage to the sound? is it only inharge for amplification?

e.g for a 6.3v filamnet i use only 5V?

currently i'm running the 6x4 & 5687 at ~5V, them seems to sound normally.... so is it ok i just run them at 5V instead of 6.3V?

ok..thanks.

For filament, u prefer using AC or Dc? Some people say, using AC is better sound.... i also feel that running filament at AC seems sound more natural, noise is slightly higer but acceptable.

if use AC for filament, u think the noise will be higher in the signal tube or rectifier tube?

Do u think using AC filament voltage at rectifier tube and use DC on signal tube filament is a good combination?

Dear accphoto,

you mean the filament voltage for rectifier tube must use AC not DC , any reason?

Attached is the power supply i recently made, still not completed. Do you think i shall parrallel all transformer & choke or made them 90 degree to reduce interference?

What is your recommendation while design the location to place the transformer, choke and capacitor? any special arrangement to obtain best sound?

Thanks accphoto!

So far never use 5U4G (direct heating type) as i'm a bit confuse on the connection. For 5U4G is it the output positive must be pin 8? can it be pin 2?

Doest it mean that the pin 8 will have  2 connection, 1 connect to the ac transformer , 1 to the B+?

TQ accphoto,

i got another question.

If i want to put in the bleeder resistor (to discharge the capacitor for safety purpose) which location shall i place it?

retifier tube ---L1---c1---L2---C2

Shall i connect the bleeder resistor in between rec tube and L2? or on the C1? or on the C2?

How justify what value of bleeder resistor to be use?

oh i see, if i use CLCLC, then i will need to use 3 bleeder resistor loh.

Thank you very much on the info.