Banned
Joined 2002
Have any of you tried to raise the idle current in the irf9610 diff-pair to .. 100mA?
I know it is high and you have the lower r16 and r17 to 39ohm, but in the end the one of the dominant pole of the circuit will move up >> lower phase shift in the treble...
Also then you need some cooling of the irf9610's.
I will maybe start build one too. ... but this will in the end of oktober.
Sonny
I know it is high and you have the lower r16 and r17 to 39ohm, but in the end the one of the dominant pole of the circuit will move up >> lower phase shift in the treble...
Also then you need some cooling of the irf9610's.
I will maybe start build one too. ... but this will in the end of oktober.
Sonny
I don't prefer the IRFP240 (plastic) over the
IRF244 (TO-3). As I believe I mentioned, the
TO-3 version of the IRF240 comes with non-standard
pin thickness, but the IRF244 has standard pins.
In either case, IR seems to have ceased production
of the TO-3 versions, and the plastics are what most
people will be living with.
IRF244 (TO-3). As I believe I mentioned, the
TO-3 version of the IRF240 comes with non-standard
pin thickness, but the IRF244 has standard pins.
In either case, IR seems to have ceased production
of the TO-3 versions, and the plastics are what most
people will be living with.
OK, I didn't come up with anything over the weekend, but
I do remember a little tidbit:
The XA200 turned out not to need the compensation
capacitor on the NPN transistor controllling the current
source, nor does it need a lag capacitor on the N channel
gain devices. The remaining compensation cap, 5 pF in
parallel with the feedback loop resistor, is being eliminated
with a board layout revision.
(By contrast, I count 10 compensation caps in the schematic
of the Halcro, and something approximating 30 in each
channel of the ML No. 333)
I do remember a little tidbit:
The XA200 turned out not to need the compensation
capacitor on the NPN transistor controllling the current
source, nor does it need a lag capacitor on the N channel
gain devices. The remaining compensation cap, 5 pF in
parallel with the feedback loop resistor, is being eliminated
with a board layout revision.
(By contrast, I count 10 compensation caps in the schematic
of the Halcro, and something approximating 30 in each
channel of the ML No. 333)
There's plenty of stuff to go on about. How about are there any folks out there who've used, say, Motorola MOSFETs instead of the IR for their Alephs, Zens and X's.
We can never see to many pictures of Peter's workmanship.
Or too much of Nelson's for that matter either.
We can never see to many pictures of Peter's workmanship.
Or too much of Nelson's for that matter either.
Nelson Pass said:It seems a shame to let this thread poop out before
100,000 views, so I guess I'll just have to come up with
something this weekend to give it some life.
And all this time, I was wondering what I was doing wrong that my prototype circuit was stable without that confounded cap on the NPN.
I'm shocked...shocked, I say. Clearly a communist plot to test my sanity!
(It worked. I went over the edge.)
As I understand it, that leaves Nelson's version of the circuit (i.e. the 'real' one) with only a DC blocking cap on the input. I'm brave and/or foolish. I don't use one (two, actually) there.
No, I didn't try the circuit without the compensation cap on the feedback loop. I'll give it a shot.
Grey
I'm shocked...shocked, I say. Clearly a communist plot to test my sanity!
(It worked. I went over the edge.)
As I understand it, that leaves Nelson's version of the circuit (i.e. the 'real' one) with only a DC blocking cap on the input. I'm brave and/or foolish. I don't use one (two, actually) there.
No, I didn't try the circuit without the compensation cap on the feedback loop. I'll give it a shot.
Grey
