It's nice to hear the bias issue isn't returning. I would reflow all the solder joints on the boards that were having the original issue. Cold or cracked solder joints can disconnect and reconnect with temperature change/expansion. I see this all the time in automotive applications with the extreme temperatures and vibration.
I hope for VFA test finalizing today or tomorrowGood! Thimios, thanks a lot for the pictures
Jeff, i don't believe that is a matter of a dry solder....
I have doubts about these new old stock non inductive resistors. Some of them have pins not so consistently and they stretched a bit in this pcb.
That's quite possible too. Did I send emitter resistors along with the parts? If so they would be non-inductive IRC resistors. CAW5R220JLF INTERNATIONAL RESISTIVE, Through Hole Resistor, Ceramic, 0.22 ohm, Axial Leaded, 5 W, ± 5%, CAW Series, Newark element14 Canada
For the Right Mark?These ones are not 100% clear
What are the output swings (RMS)?
It is at -1db
Sorry Valery,i don't know,i seen that is just under clip level,but i will measure if it is necessary to know the exactly value
P.S i think that is about 25v/7R(this is the clip level according to sinusoidal test).
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Sorry Valery,i don't know,i seen that is just under clip level,but i will measure if it is necessary to know the exactly value
P.S i think that is about 25v/7R(this is the clip level according to sinusoidal test).
It makes sense to measure at some intermediate level - say, 20V RMS at the load. Close to clipping you see some higher distortion - which is also interesting to see, but it's a kind of close to the edge.
It would make sense to gust connect the oscilloscope to the output and calibrate the output swing of the sound card to the desired level.
OK - that's what I meant - nominal 0db level is a bit too high
At -10db they are rather close to each other with THD below 0.002%
At -3db, CFA's distortion becomes around 10 times higher - because it clips earlier, I think.
X4 is very cool - consistent performance at any swing.
Ok the vz-x4 distortion at -10db has been posted here. http://www.diyaudio.com/forums/soli...-old-ideas-1970s-ips-ops-130.html#post4828204OK - that's what I meant - nominal 0db level is a bit too high
At -10db they are rather close to each other with THD below 0.002%
At -3db, CFA's distortion becomes around 10 times higher - because it clips earlier, I think.
X4 is very cool - consistent performance at any swing.
#post 1297.
I will test the CFA at -10db and i will post again these two files for comparision.
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