Hey Zen ! , here is my modest comment :
N.P. F6 is basically SE SS Amp !
Where upper output power device contribute only for output current amplification .
But lower output power device contribute for output voltage & current gain in the same time .
It is somehow designed to be very similar to JLH Amp concept , but main difference is that F6 both output power devices work `` in phase ``( SE ) , Not `` 180deg. out of phase`` like is done in JLH ( PP ) Amp design .
Best Regards ! ( Pozdrav Druze ! )
Possible bias, yes. But, I notice your xfrm'r secondary phase is a more std. Push-Pull drive. Where the F6 is an in phase drive to both transistors?
hi all, i had a tx driven push-pull with complementary ops (2sk1058/2sj162) on the ticle amp thread set up, so was not hard to change over to try out the bias network in post 161 and cfm whether my rough understanding was corect so far....
Results: works. By comparison to the complementary outputs I have lost some gain. Gain dropped from 15x to about 11x - the input tx in my setup has a stepup of about 4x for ref. I didn't attempt to set up any loop feedback to tx primary so the only feedback is through the bias networks.
The reduction in distortion is pretty stunning ..... at 5.25V pk-pk into 6R8, it went from 0.13% to 0.03%. 15V pk-pk, 0.13% to 0.07%.
At 32V pk-pk, it went from 1% to 0.33% .....
speechless ....
i'll post the thd spectra if any interest (either here or on the other thread as you guys feel appropriate)
Results: works. By comparison to the complementary outputs I have lost some gain. Gain dropped from 15x to about 11x - the input tx in my setup has a stepup of about 4x for ref. I didn't attempt to set up any loop feedback to tx primary so the only feedback is through the bias networks.
The reduction in distortion is pretty stunning ..... at 5.25V pk-pk into 6R8, it went from 0.13% to 0.03%. 15V pk-pk, 0.13% to 0.07%.
At 32V pk-pk, it went from 1% to 0.33% .....
speechless ....
i'll post the thd spectra if any interest (either here or on the other thread as you guys feel appropriate)
Congrats. I bet NElson's version will be even more surprising. My guess is that the F6 might is an upgrade to the M2 which has a bit of a cult following but does not measure well. Now flks will having nothing to fuss over because it will sound awesome and measure awesome. Some folks do get hung up on numbers.
Congrats. I bet NElson's version will be even more surprising.
Indeed I am certain that it will be a stunner for sure! His ideas & circuits always have a way of doing just that
also zm was exactly right about the smilies... the drives has to be out of phase - a point made here by him and many others - apologies for my thick skull !
flg, thnaks for helping explain further - indeed Vds is a vital factor. The many interactions you pointed out may well account for the reduction in gain (that is something for me to digest tomorrow... right now i'll just listen to miles davis!)-edit but not on this circuit yet lols
flg, thnaks for helping explain further - indeed Vds is a vital factor. The many interactions you pointed out may well account for the reduction in gain (that is something for me to digest tomorrow... right now i'll just listen to miles davis!)-edit but not on this circuit yet lols
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I have impression that Pa is having enough customers for FW products , careless regarding THD numbers
speaking of that , my skin is yellow , too
Not so much need as opportunity for laughs.
You are correct flg about my error in phasing. Here are the questions which nag me: Hundreds of Audio luminaries, designers, scientists and DIYers [around the world] fooled with and developed commercial amps with the schematic in the pdf of thread #38; whereby the phasing is push pull or Out of phase to the bjts . Why did none of them think, and make amplifiers using In-phase drive? We are faced with only two pathways: In-phase drive is the genius of Mr. Pass, or the phase labels in the simplified schematic of F6 were inadvertently mislabeled. Let us wait for the Master to weigh in. Patience is a virgin!
line splitter cinemag......
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Audio Splitter Transformers
Dear Gerd;
Thank you for your inquiry about the CMOL-4x600T2. They are $163.79 each. This is an expensive transformer originally designed for feeding satellite trucks and venue recording consoles at the Academy Awards, which gives you an idea of its application. Tell me about your application if you wish so that I might help you figure out the best transformer. If you only need two of them, Priority Mail Flat Rate will be $16.95. Express Mail will be $41.85. We manufacture to order, so the lead time will be a few weeks.
Best regards,
David Geren