You probably need more space in your listening room too.Hello Group
My name is ZM
I'm ZM
I just need more speakers
Sunday videos are now up. Saturday to follow shortly. https://burningampfestival.com/videos/
Chris Dollar (duck552) sat in front of a camera for two days recording them and then sat in front of a computer for many days editing them.
Thank you Chris!
-Tom-
Chris Dollar (duck552) sat in front of a camera for two days recording them and then sat in front of a computer for many days editing them.
Thank you Chris!
-Tom-
During the BAF 2023 presentation of the F5m by Nelson Pass, he commented on the R3, R4, R5 feedback network needing 2W resistors, and the role of the high (22.1K) value of R1, the gate stopper for the JFETs in reducing the overall bandwidth of the amplifier and eliminating square wave overshoot.
My suggestion is that the bandwidth could also be reduced by increasing the values of R3, R4, R5 by a factor of 2 or more, allowing for lower power resistors and a reduction of the value of R1.
My other observation is that the F5m feedback topology is actually very different from that of the F5, as shown below. The F5 has two half-amplifiers, each with its own feedback loop.
My suggestion is that the bandwidth could also be reduced by increasing the values of R3, R4, R5 by a factor of 2 or more, allowing for lower power resistors and a reduction of the value of R1.
My other observation is that the F5m feedback topology is actually very different from that of the F5, as shown below. The F5 has two half-amplifiers, each with its own feedback loop.
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I believe there is just a minor difference vs. later iteration wit 3rd pot, not performance one but more in setting procedure
it's (NFB) integrating in source summation path either way
for more drastic example of "2 SE amps acting as one PP", take a look at MF A1, work of Tim deP.
just one of his, working in different way was sorta his motto
it's (NFB) integrating in source summation path either way
for more drastic example of "2 SE amps acting as one PP", take a look at MF A1, work of Tim deP.
just one of his, working in different way was sorta his motto
In the "F5 Power Amplifier" thread, EUVL post 1470 https://www.diyaudio.com/community/threads/f5-power-amplifier.121228/post-1568095 discusses the balancing of the open-loop gains of the two half amplifiers and presents a simple adjustment procedure that doesn't require a distortion analyzer.
OTOH, Papa apparently figures that the F5m 2nd harmonic is satisfactory without and adjustment.
OTOH, Papa apparently figures that the F5m 2nd harmonic is satisfactory without and adjustment.