Yes Hans, I found it in your model.
A follow up question: I looked at the 1.5R//220uF at the primary.
I wonder what the purpose is, is it a measure of protection for the driving amplifier, to avoid too low impedance at the LF end,
or is it to correct the speaker response?
That response gets much flatter if the R is deleted (and also the elcap of course)
I do my correction with Acourate and would like to get rid of that electrolytic if feasible.
RED with 220u // 1.5, TEAL with 1nF // 1.5
Edit: Hans, there's a 1.5uF cap across the two primaries in your sim, what does that represent?
Jan
A follow up question: I looked at the 1.5R//220uF at the primary.
I wonder what the purpose is, is it a measure of protection for the driving amplifier, to avoid too low impedance at the LF end,
or is it to correct the speaker response?
That response gets much flatter if the R is deleted (and also the elcap of course)
I do my correction with Acourate and would like to get rid of that electrolytic if feasible.
RED with 220u // 1.5, TEAL with 1nF // 1.5
Edit: Hans, there's a 1.5uF cap across the two primaries in your sim, what does that represent?
Jan
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Jan,
I forgot to mention in #603 that the blue line represents the transformer current for a low level 10Hz signal, already showing its non linearity at this frequency and that the teal curve is the current for a higher amplitude 10Hz input signal, suddenly showing these huge current peaks.
Hans
I forgot to mention in #603 that the blue line represents the transformer current for a low level 10Hz signal, already showing its non linearity at this frequency and that the teal curve is the current for a higher amplitude 10Hz input signal, suddenly showing these huge current peaks.
Hans
If you have a tube amplifier (with output transformer) you can shortcut the 1,5ohm resistor. and you can save a lot money on reduced amount of copper in the speaker cable. For demonstration i have used the thinnest wiring wires i could find just to prove how the sound changes between a supra 10mm2 speaker cable and 0,1mm2 wire. Spoiler alert... alway when I do this people prefer the thinnest wire 10/10 since it gives more output in LF, and we tend to like more bass.
Very confusing, in my (an official QUAD) schematic there are some 10nF that are in parallel to get 20nF.
I will check on a spare board I have somewhere.
Jan
Attachments
Sorry for the late reply. Yes, the probe has 100MOhm as it is built with 10x 10Mohm resistors, and I did try it with lower voltages (didnt measure the current though).
Maybe I should have mentioned that I measured the voltage directly at the output of the cascade, before the 10M resistor. This is with new components (diodes and caps) in the cascade.
I am a little doubtful of my measurement now, it should have been 5.25kV.... maybe I'll repeat the measurement. Speakers are playing fine
Maybe I should have mentioned that I measured the voltage directly at the output of the cascade, before the 10M resistor. This is with new components (diodes and caps) in the cascade.
I am a little doubtful of my measurement now, it should have been 5.25kV.... maybe I'll repeat the measurement. Speakers are playing fine
As Hans mentioned before, in simulation, 100Meg maybe too much load and will lower the voltage.
We should find someone with an electrostatic HV meter.
I've been looking for one to buy but they are either expensive or old and decripit.
Demian probably has one?
On a positive note, I just took delivery of a Uni-T type 513A isolation tester.
Jan
We should find someone with an electrostatic HV meter.
I've been looking for one to buy but they are either expensive or old and decripit.
Demian probably has one?
On a positive note, I just took delivery of a Uni-T type 513A isolation tester.
Jan
Funny guy, Peter Walker
Ghirlande ghirlande ... The layout of C-parallelization in Fig. 17 does neatly match your former statement about P.Walker ... assuming he was the designer of this board also. I think he must have been a really creative out-of-the-box thinker and enjoying amusing himself while designing.
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FWIW, Quad is back in the US with their new 2812X electrostats. Heard them two weekends ago at the Capital Area Audiofest. Sounded lovely.
Kent McCollum, the most knowledgeable Quad guy I know says that from a panel longevity perspective, they are the best yet. With a three year panel warranty!. Kent's enthused enough that he may get out of the panel rebuilding business. Quad also added refinements and beefed up the construction to where it should have been in the first place. And dropped the price.
Kent McCollum, the most knowledgeable Quad guy I know says that from a panel longevity perspective, they are the best yet. With a three year panel warranty!. Kent's enthused enough that he may get out of the panel rebuilding business. Quad also added refinements and beefed up the construction to where it should have been in the first place. And dropped the price.