some more PXXX 
got yet to solder those little upside down bastxxxx... but I've a cunning plan
regards,
CarcasS
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
got yet to solder those little upside down bastxxxx... but I've a cunning plan
regards,
CarcasS
transistors soldered already
now... I'm out of fuse holders.... I can only buy them Monday... oh well, got to drill now...
now... I'm out of fuse holders.... I can only buy them Monday... oh well, got to drill now...
An externally hosted image should be here but it was not working when we last tested it.
it's getting late here...
no fuses (even temporary) for today, but at least one heatsink fully drilled and tapped!!!
no fuses (even temporary
) for today, but at least one heatsink fully drilled and tapped!!!An externally hosted image should be here but it was not working when we last tested it.
SUCCESS!!!!
IT'S ALIIIVE
it bias ok now, AFTER I've replaced my wimpy 250mw (or maybe it was 500mw) 10V zener for a 1.3Watter... it was giving me headaches...
now I've forgotten to replace the 68r to 82r as Carlos suggested and I'm finding that BC556 (B) hot at ~44ºC... so dunno if I'm removing the resistor or simply soldering another 10r over it (78r should be close enough?!)...
anyway ... I'm going slowly, so maybe tomorrow I'll inject it some audio
IT'S ALIIIVE
it bias ok now, AFTER I've replaced my wimpy 250mw (or maybe it was 500mw) 10V zener for a 1.3Watter... it was giving me headaches...
now I've forgotten to replace the 68r to 82r as Carlos suggested and I'm finding that BC556 (B) hot at ~44ºC... so dunno if I'm removing the resistor or simply soldering another 10r over it (78r should be close enough?!)...
anyway ... I'm going slowly, so maybe tomorrow I'll inject it some audio
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Can't wait to see the results bro and yes that particular transistor BC556 it does get hot a bit but I have been using my Dx Super A since last year and no problem, let me know how you find the music, looking good indeed sir, about Carlos I haven't seen any more post from him maybe he is sick or something like that I hope he is ok.
Regards
Juan
and yes that particular transistor BC556 it does get hot a bit but I have been using my Dx Super A since last year and no problem, let me know how you find the music, looking good indeed sir, about Carlos I haven't seen any more post from him maybe he is sick or something like that I hope he is ok. Regards
Juan
my guess is that on powering up (with a 60W bulb and 2 10r resistors) there is some sort of initial "surge" that overwhelms it... doing the math (with no input) gives me just a few picowatts of consumption...
With 1 multimeter across the 10r resistor I got the bias climbing, soon as I connect the other 10r resistor with 2nd multimeter, bias "reseted" to ~0.1v and didn't change no matter how I turned the 200r pot and no voltage arrived at the emitter resistors.
So my guess was to change the 10V zener (BZX79-B10 500mw) to a higher rating and presto the boards started to bias ok with the 2 multimeters attached, and I got that nice soft glow from the bulb confirming the current draw...
With 1 multimeter across the 10r resistor I got the bias climbing, soon as I connect the other 10r resistor with 2nd multimeter, bias "reseted" to ~0.1v and didn't change no matter how I turned the 200r pot and no voltage arrived at the emitter resistors.
So my guess was to change the 10V zener (BZX79-B10 500mw) to a higher rating and presto the boards started to bias ok with the 2 multimeters attached, and I got that nice soft glow from the bulb confirming the current draw...
Hey carcass! I like the detail of bending those parts the way they do not have sharp 90 degrees
I have seen it only a few times. Excellent job
thanks lanchile, it's been a breeze to build (nice work from Juan) and taking my time it's nice to "not" use pliers for bending... I mostly use a small screwdriver, hence the curves
updates now, I really have to change the 68r, it's getting bloody hot, even though far away from the 150ºC Max rating...
I've tested it with 4 8r (32r) 10W resistors and injected 770mv 1KHz sinus several minutes, and after several volume up/volume down, bias remain stable always under 1mv across the .22r resistors (the slow matching payed off ) I'm using a cheap android tablet with a signal generator (voltages measured from the tablet's output)
dc offset with no input varies from 1 board circa 7~10mv and the other 12~14mv, very happy with it... so tomorrow time for a speaker and some music...finally!
For the rest of it I'm in need of €€€ again, missing the case and the VU meters and drivers, already sorted the filter, soft start, dc protection and some other bits
I'm eyeballing an used 30Mhz scope, so maybe I'll torture test it some more...
regards,
CarcasS
updates now, I really have to change the 68r, it's getting bloody hot, even though far away from the 150ºC Max rating...
I've tested it with 4 8r (32r) 10W resistors and injected 770mv 1KHz sinus several minutes, and after several volume up/volume down, bias remain stable always under 1mv across the .22r resistors (the slow matching payed off
) I'm using a cheap android tablet with a signal generator (voltages measured from the tablet's output)dc offset with no input varies from 1 board circa 7~10mv and the other 12~14mv, very happy with it... so tomorrow time for a speaker and some music...finally!
For the rest of it I'm in need of €€€ again, missing the case and the VU meters and drivers, already sorted the filter, soft start, dc protection and some other bits
I'm eyeballing an used 30Mhz scope, so maybe I'll torture test it some more...
regards,
CarcasS
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