Hi there
I'm about to order fets for my balanced Z4. Since I have very large transformers, and also much aluminium heat sink, I would like to try the high bias version of the Z4 that nelson mentions in his article.
"If you manage to cool the amplifier very well, you can consider
whether you can get more power out of it. I would say the practical
limit to this will be Q1, which is run at about 44 watts with the 2
amp bias. Personally, I hesitate to operate this device at greater
than 50 watts, but you can crank the supply voltage and bias up
higher if you want. With the IRFP044 I would not exceed 50 volts
on the regulated supply. If you want to try higher, I suggest the
IRF140 or 240 devices."
I think the 240 is a large step up from the 044 - is there any of the devices below that would be considerd a better choice, audiophile choice, that is - and still be able to deal with 2,8 amp bias instead of 2,0 amp ??
IRFP044N N-FET TRANSISTOR 55V/53A/120W (the original supposed by nelson in the article)
IRFP048 IRFP048 N-FET TRANSISTOR 55V/64A
IRFP054 IRFP054 N-FET TRANSISTOR 60V/70A
IRFP150 IRFP150 N-FET TRANSISTOR 100V/41A
Personally i'm leaning towards the 054 - what are your opinion ?
Should I use larger fets on Q1 only ?
Cheers
Hans
I'm about to order fets for my balanced Z4. Since I have very large transformers, and also much aluminium heat sink, I would like to try the high bias version of the Z4 that nelson mentions in his article.
"If you manage to cool the amplifier very well, you can consider
whether you can get more power out of it. I would say the practical
limit to this will be Q1, which is run at about 44 watts with the 2
amp bias. Personally, I hesitate to operate this device at greater
than 50 watts, but you can crank the supply voltage and bias up
higher if you want. With the IRFP044 I would not exceed 50 volts
on the regulated supply. If you want to try higher, I suggest the
IRF140 or 240 devices."
I think the 240 is a large step up from the 044 - is there any of the devices below that would be considerd a better choice, audiophile choice, that is - and still be able to deal with 2,8 amp bias instead of 2,0 amp ??
IRFP044N N-FET TRANSISTOR 55V/53A/120W (the original supposed by nelson in the article)
IRFP048 IRFP048 N-FET TRANSISTOR 55V/64A
IRFP054 IRFP054 N-FET TRANSISTOR 60V/70A
IRFP150 IRFP150 N-FET TRANSISTOR 100V/41A
Personally i'm leaning towards the 054 - what are your opinion ?
Should I use larger fets on Q1 only ?
Cheers
Hans