Sweet! Thanks 😀 I am so slow it will probably Feb before I get mine built anyway. I will be looking forward to your results...
Dont get me started about how many projects I have staring me in the face 😉
I just finished rebuilding my main speakers with a new woofer and crossovers... been working on them in various guises for about 2 years...
Of course I am getting old too
I just finished rebuilding my main speakers with a new woofer and crossovers... been working on them in various guises for about 2 years...
Of course I am getting old too
same story here ....
done with current speakers last year .... still I have something in mind for the future 😎
done with current speakers last year .... still I have something in mind for the future 😎
fired it up .......
58ma stable, B+ at start was 335V soon to drop to 240V ....
dc offset was strange , both channels werent stable, one measured between 20-22mV and the other 76-80mV ... changing all the time ...
output cap leaking ? oscillation ?
at least no boom kaboom , no smokes ... 🙄
output cap similar to this one only 2uf (http://www.ebay.com/itm/MBGP-2-Pape...526&pid=100011&prg=1005&rk=1&sd=250906640986&)
58ma stable, B+ at start was 335V soon to drop to 240V ....
dc offset was strange , both channels werent stable, one measured between 20-22mV and the other 76-80mV ... changing all the time ...
output cap leaking ? oscillation ?
at least no boom kaboom , no smokes ... 🙄
output cap similar to this one only 2uf (http://www.ebay.com/itm/MBGP-2-Pape...526&pid=100011&prg=1005&rk=1&sd=250906640986&)
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How you got the sense and force wires hooked up? Can you describe or sketch the power and ground nodes they meet?
Maybe it draws much. Try boost the CCS at say 70mA to see if it holds before other investigations.
they are tied together along with cathode resistor ground / pot ground and ac mains earth ...
yes, then droped to 240V ..
trimed for 70mA but by mistake I turned r11 anti-clockwise ...
shall I put it at 340V ?
840 sink cold (not ice ...) ...
trimed for 70mA but by mistake I turned r11 anti-clockwise ...
shall I put it at 340V ?
840 sink cold (not ice ...) ...
input dc is 360V ...
with R4 at 70mA trimed R11 ... only reaches 300V ...
dc offset still varies ...
I think i smelled something like smoke (not sure) ... turned off power ...
with R4 at 70mA trimed R11 ... only reaches 300V ...
dc offset still varies ...
I think i smelled something like smoke (not sure) ... turned off power ...
There is strong biasing. It may be up to 30-35mA per tube though and not be abnormal. The fact that you can go up for B+ as you allow more CCS shows there is current demand in the output for one thing.