100W Ultimate Fidelity Amplifier

[still4given]

http://www.diyaudio.com/forums/atta...ltimate-fidelity-amplifier-apex-a2-preamp.jpg
You can also find it in post 5859

 

[egra]

An update.

Because the AX10 worked so well without a trimmer I wanted to try the FX8 with just the diode per the schematic. With just the diode in place of the trimmer I see 26mA on the rail. However, there is still no sign of crossover distortion and the sound is still very good. The amp will certainly work as designed if one chooses to not use a trimmer.

I'm really curious for the result. Shaan's new amp runs with only ~30mA Iq as well. Not a sign of any compromise in highs or elsewhere. Or look at the back of Goldmund Mimesis 3 (OEM). So tiny heatsink for a 150W stereo amplifier clearly indicates the use of low quiescent current of laterals (50mA or less).

http://file.blog-anison.audiounion.jp/20e889a6.jpg

 

[sownel]

Greetings mr.terry apex ax10 singing sweet and nice.thanks for your kind help.thank you apex sir.

 

[sownel]

Greetings mr.terry apex ax10 singing sweet and nice.thanks for your kind help.thank you apex sir.
Fx8 not working sir. 100w sereis bulb glowing brightly

 

[prasi]

Greetings mr.terry apex ax10 singing sweet and nice.thanks for your kind help.thank you apex sir.
Fx8 not working sir. 100w sereis bulb glowing brightly

K1058 lettering and text color seems doubtful. Just see whats the offset. ALso its not clear from pic, if the BD140 is isolated from H/S.

 

[still4given]

Greetings mr.terry apex ax10 singing sweet and nice.thanks for your kind help.thank you apex sir.
Fx8 not working sir. 100w sereis bulb glowing brightly

make sure the trimmer is set to 0ohm for initial start-up

 

[ivanlukic]

Toshiba does not produce lateral MOSFETS! That transistor seems fake to me. K1058 was originally produced by Hitachi, and later by Renesas.

 

[sonal kunal]

AX15TEF layout 2 pair to 4 pair version. I'll make 5 pair version later.

There may still be some mistakes.

 

[apexaudio]

AX15TEF layout 2 pair to 4 pair version. I'll make 5 pair version later.

There may still be some mistakes.

Schematic is wrong. AX10 can use only one or two output pairs for more pairs use AX11TEF schematic with predrivers.

 

[sonal kunal]

Hi Mile, isn't first 2sc5200 and 2sa1943 are drivers and MJE340 and MJE350 predrivers in AX11TEF, AX15TEF and BX20?

 

[apexaudio]

Hi Mile, isn't first 2sc5200 and 2sa1943 are drivers and MJE340 and MJE350 predrivers in AX11TEF, AX15TEF and BX20?

Yes AX11TEF, AX15TEF and BX20 have predrivers, this amps are based on AX10 circuit with predrivers add.

 

[sonal kunal]

Schematic is wrong. AX10 can use only one or two output pairs for more pairs use AX11TEF schematic with predrivers.

Yes AX11TEF, AX15TEF and BX20 have predrivers, this amps are based on AX10 circuit with predrivers add.

I didn't understand which schematic is wrong because I followed AX15TEF schematic.

I used MJE340 - 350 instead of MPSA42 - 92 for VAS, 2SC4793 - 2SA1837 instead of MJE340 - 350 for predriver and BD139 for vbe.

There are some mistake, like emitter of 2sc5200 and 2sa1943 are not connected to 2R2 resistor in first image with 2pair op.

Regards,
Sonal Kunal

 

[gaborbela]

I think there is some error
I did not debug the whole layout but to me these jumps out
Marked with red arrows
Otherwise nice layout!

 

[apexaudio]

I didn't understand which schematic is wrong because I followed AX15TEF schematic.

I used MJE340 - 350 instead of MPSA42 - 92 for VAS, 2SC4793 - 2SA1837 instead of MJE340 - 350 for predriver and BD139 for vbe.

There are some mistake, like emitter of 2sc5200 and 2sa1943 are not connected to 2R2 resistor in first image with 2pair op.

Regards,
Sonal Kunal

OK, my mistake... Vbe multiplier no need to be on heatsink. Amp is made to work without bias seting and without bias transistor on main heatsink this is advantage if you compare AX10 and AX11.

 

[apexaudio]

A class

AA11 with BC546 instead MPSA13 in Vbe multiplier.

 

[sonal kunal]

Hi Mile, do you have schematic for low impedance detection(less than 2 ohm). I'll like to implement on one of you speaker protection so that relay will not re-engage once it has disengage, as long as there short circuit at speaker terminal.

 

[apexaudio]

Hi Mile, do you have schematic for low impedance detection(less than 2 ohm). I'll like to implement on one of you speaker protection so that relay will not re-engage once it has disengage, as long as there short circuit at speaker terminal.

Use schematic of Elektor LFA-50, LFA-150
http://pagesperso-orange.fr/francis.audio2/LFA50.doc

 

[sonal kunal]

Wow I forgot about that protection board. It can be easily implemented on you NE555 protection schematic.

 

[ammel68]

http://www.diyaudio.com/forums/atta...ltimate-fidelity-amplifier-apex-a2-preamp.jpg
You can also find it in post 5859

Terry, wouldn't that circuit invert the signal?

Thanks...

 

[still4given]

Terry, wouldn't that circuit invert the signal?


Thanks...

There is a non-inverting version also.

http://www.diyaudio.com/forums/atta...100w-ultimate-fidelity-amplifier-apex-pre.jpg

I built both. They work equally well. I'm not sure where inverting makes a difference since they are stereo and invert both channels.

If you start reading from post #5859 you can kind of follow the development. I made a layout for them if interested.