And I quote myself again in post 4 of that thread:
"basically it's a classic."
Really?
I'm sorry that I'm not good at reading spice simulation - what was the gain you obtained from the above simulation ?
flg, it is beneficial to do the experiment [and simulation] both ways; no harm. Inventions happen under circumstances this way. Somebody says it doesn't work and the inventor finds otherwise. And writes in the patent application: To my surprise.... a statement the patent examiner loves to read and lawyers love to write.You don't think so?
I used a 1:1 transformer winding ratio. The closed-loop (feedback-loop) gain was 6, as in the F5. I have not yet computed the open-loop gain in order to compute the amount of negative feedback.
You don't think so?
Maybe I'm just not old enough? Or I didn't try hard enough?
so guys - Pa just gave you another tip - at Jensen , that piece is well under 50 greenies a piece
who's gonna be the first to complete on-line order ?
(nota bene that there is highly esteemed DiyA member from Serbia , selling original PL amp cases , very cheap ; 2K5 for smallest ones - good for stereo F6 ;
with each third case you buy from him , there is gratis recipe how easily to make relaxation oscillator of your F6
)Attachments
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Yes.[SIZE=-1][FONT=Courier New, Courier, monospace] The JT-123-FLPCH[/FONT][/SIZE] has four windings with equal winding count.
See http://www.jensen-transformers.com/datashts/11flpch.pdf.
covered
by Mighty Moi - several times in thread
it's 4 x 150 ohms , or 600CT:600CT
http://www.jensen-transformers.com/datashts/123flpch.pdf
as said previously - impedance is (same as ground ) very often just state of mind
it isn't 600 or 150 in this amp - think of reflected impedance from secondary to primary - that's the load for input buffer
by my experience , with lowish impedance category xformers , inductance ( more precise - enough of it ) is always most critical
by Mighty Moi - several times in thread
it's 4 x 150 ohms , or 600CT:600CT
http://www.jensen-transformers.com/datashts/123flpch.pdf
as said previously - impedance is (same as ground ) very often just state of mind
it isn't 600 or 150 in this amp - think of reflected impedance from secondary to primary - that's the load for input buffer
by my experience , with lowish impedance category xformers , inductance ( more precise - enough of it ) is always most critical
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What is the main difference between the cores for driver transformers used for MOSFETs in switching applications (e.g. SMPS) and such for linear (audio) application like Jensen?
Here several URLs:
http://www.ferroxcube.com/news/gate drive trafo.pdf
http://www.ti.com/lit/ml/slup169/slup169.pdf
Pro Audio Design Forum • View topic - THAT1646 Current Booster and Transformer Driver
http://www.diyaudio.com/forums/solid-state/11162-transformer-driven-sepp-output-stage.html
Here several URLs:
http://www.ferroxcube.com/news/gate drive trafo.pdf
http://www.ti.com/lit/ml/slup169/slup169.pdf
Pro Audio Design Forum • View topic - THAT1646 Current Booster and Transformer Driver
http://www.diyaudio.com/forums/solid-state/11162-transformer-driven-sepp-output-stage.html
.... , 50% nickel , 38$
you can beat that only with something like this (there are also 600ct:600ct types , looking exactly the same -all of them having toroid nickel core ) :
see more here : http://www.diyaudio.com/forums/pass-labs/174674-papas-koan-papas-surprise-2.html#post2356057
same jobbies made by Tamura and WE are having price equaling their weight in gold
and they are plain and simple repeater coils , as called in Telephone Service duty
so - here is another tip - look for old repeater coils , and stash them in quantity .....
(in my previous life , we were using pairs of these (pair for stereo on sending end , pair on receiving end ) for transmission between concert venue and recording studio ; line was made of simple twisted solid core telephone cable, per channel )
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you can beat that only with something like this (there are also 600ct:600ct types , looking exactly the same -all of them having toroid nickel core ) :
see more here : http://www.diyaudio.com/forums/pass-labs/174674-papas-koan-papas-surprise-2.html#post2356057
same jobbies made by Tamura and WE are having price equaling their weight in gold
and they are plain and simple repeater coils , as called in Telephone Service duty
so - here is another tip - look for old repeater coils , and stash them in quantity .....
(in my previous life , we were using pairs of these (pair for stereo on sending end , pair on receiving end ) for transmission between concert venue and recording studio ; line was made of simple twisted solid core telephone cable, per channel )
Let us consider experimenting with toroid power transformers; like kasey197 has been doing. For example the transformer by TRIAD VPT230-110. It is rated at 25 VA [$20 at Mouser; made in China]. It has 2 independent primary windings each meant for 115 VAc, and two independent secondary windings meant for 115 VAC. They are clearly labelled for phase by the color of the wires' insulation. Thus, it has the desired 1:1 transfer ratios, and is designed on purpose for large voltage swings which are needed to drive the FETs. It is over rated for this application [output current per secondary winding = 110 mA rms] which implies linear operation because the demand for current is low by the FETs.
The telephone repeater transformers may have low frequency limitations because they were designed principally to transmit voice. Their published bandwidth rating begins at ~300 Hz.
generally very good idea ,but you must consider that those Jensens aren't expensive
regarding repeater coils - each type demands testing
these which I pictured are flat 20-20
edit - in fact , they're flat from lower than 20Hz (if driven with lowish impedance ) and at least up to 50Khz , if memory serves me well
regarding repeater coils - each type demands testing
these which I pictured are flat 20-20
edit - in fact , they're flat from lower than 20Hz (if driven with lowish impedance ) and at least up to 50Khz , if memory serves me well
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