First attempt of TD Class on Leco Amplifier Module

DjLeco

Moderator
After studying and studying, Yamaha and Labgruppen TD amplifiers schematics, I decided to give a try to implementate something on mine AB class amplifier.

So I go to the Yamaha's Eee schematics (autooscilant) and extracted what I need for implementation to see if it works.

Yamaha uses on each rail +Vcc and -Vcc ,3 pairs of transistors in voltage amplifier (2SA1492A +2SC3856A) ,I used just one pair of MJL21195+MJL21196 , and 3 pairs of mosfets in current amplifier (2SK3004), I used one pair of IXTQ52N30P (very fast and small gate charge mosfet)in tests.

Officially Yamaha's use +/- 155Vcc in idle and in load, the supply falls down till around +/- 110Vdc, they use a very small power supply SMPS, but that's not important.

After tests and tests , starting from +/- 110Vdc, I pushed far to +/- 170Vcc in idle(+/- 165Vcc in full load), because mine SMPS is with PFC, and drops just 10 Volts (+5 -5 on each rail) from idle to full load, and I have obtained what U can see in the movies.

Don't laugh about "spider" connection of SMPS and TD part, just take couple minutes of your life and watch the small movies on youtube.

Comments are very appreciated and welcomed, expecially about output power!

Next week I will give a try, to implement modulate TD like Labgruppen, at 250Khz and 500Khz too, because on autooscilant Yahana TD Design, I hear sounds in colis, and gives small switching artefacts, more visible at 1000Hz.

I obtained 109-110Vrms on 4 ohm dummy load, and trying into clip, smps has shut down (I have calibrate protection to act at around 3400-3500W)





[video=youtube;7bMcDikRjTg]http://www.youtube.com/watch?v=7bMcDikRjTg&feature=player_embedded[/video]

[video=youtube;guoLw9e4Seg]http://www.youtube.com/watch?v=guoLw9e4Seg&feature=player_embedded[/video]





 

DjLeco

Moderator
As long as the project was just for testing, the schematic isn't complete and will never be.

Class AB+B is most clearer for PRO application, then follows ClassG , after is ClassH 2, 3 or 4 step, then TD class, last ones are classI and classD switching power amplifier.
 

fitzroy

New member
class td sunfire amplifier whats the different to me the same
 

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fitzroy

New member
down converter circuit
in going through the white paper by bob carver
years ago on the switching down converter i searched for the schematic for the sunfire amplifier then i heard about class td same down converter circuit little changes which use a switching power supply a blind man can see both circuits are the same one uses hcpl2400 and the other hcpl2411 same ic who found this design first bob carver or lab gruppen?the heart of the class td and the sunfire amp is the switching down converter circuit or the buck boost circuit.without it it just an ordinary class a or a class ab amplifier. which will need massive heat sink and lot lot more output transistors. who is this design acreditted to??????????
 

fitzroy

New member
in going through the white paper by bob carver
years ago on the switching down converter i searched for the schematic for the sunfire amplifier then i heard about class td same down converter circuit little changes which use a switching power supply a blind man can see both circuits are the same one uses hcpl2400 and the other hcpl2611 same ic who found this design first bob carver or lab gruppen?the heart of the class td and the sunfire amp is the switching down converter circuit or the buck boost circuit.without it it just an ordinary class a or a class ab amplifier. which will need massive heat sink and lot lot more output transistors. who is this design acreditted to??????????
white paper
 

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