100W Ultimate Fidelity Amplifier

[engel dela pena]

mje15030/15031

 

[apexaudio]

mje15030/15031

MJE340/350 in VAS, MJE15030/31 as drivers.

 

[apexaudio]

I love this project , it is like a old school but very high quality of basical Yamaha AX series HiEnd amplifiers , this is very good sound , precision & natural 100%
Congratulations for true power !

In post #1 I say this amp was made for testing speakers, sound is good, precision and natural, but there is another adventage sound not change much with all kind of speakers wires, x-overs, and box topology (bass reflex, TL...)

 

[engel dela pena]

MJE340/350 in VAS, MJE15030/31 as drivers.

apex,
i have an old amp with 2n3055 and its matched pair 2pcs. each
i want to modify it to ultimate fidelity
how much power can this go using ultimate fidelity board
what ideal voltage and how much kva(trafo)
thanks

 

[apexaudio]

apex,
i have an old amp with 2n3055 and its matched pair 2pcs. each
i want to modify it to ultimate fidelity
how much power can this go using ultimate fidelity board
what ideal voltage and how much kva(trafo)
thanks

Do you have BDX18 as matched pair with 2N3055, or you want use another 2N3055 in quasi output? Modify NX14 useing this schematic (not tested).
Rail voltage +/-30V is maximum, power 60W/4R with 100VA transformer (200VA for stereo)
Regards

 

[apexaudio]

IF you use regulated PSU set to +/-30V, power will be increase becouse there is no voltage drop on full power. Power will be 40W/8R or 80W/4R.
Regards

 

[engel dela pena]

Do you have BDX18 as matched pair with 2N3055, or you want use another 2N3055 in quasi output? Modify NX14 useing this schematic (not tested).
Rail voltage +/-30V is maximum, power 60W/4R with 100VA transformer (200VA for stereo)
Regards

mj2955

 

[apexaudio]

mj2955

OK, for 2N3055/MJ2955 outputs use AX14 pcb with +/-30V rail voltage.
Regards

 

[engel dela pena]

Do you have BDX18 as matched pair with 2N3055, or you want use another 2N3055 in quasi output? Modify NX14 useing this schematic (not tested).
Rail voltage +/-30V is maximum, power 60W/4R with 100VA transformer (200VA for stereo)
Regards

and this is for nx14 a bunch of irf,& 2sk

 

[apexaudio]

and this is for nx14 a bunch of irf,& 2sk

Some 2SK mosfets can't be use for NX14 (2SK1058, 2SK135...)

 

[apexaudio]

AX14

APEX Ultimate Fidelity Amplifier

 

[apexaudio]

Speaker Terminal

Speaker Termial with Zobel Network and DC Protect with Triac.

 

[engel dela pena]

Speaker Termial with Zobel Network and DC Protect with Triac.

apex,
choke coil wire size & turns
does the +&- going to speaker?

 

[apexaudio]

apex,
choke coil wire size & turns
does the +&- going to speaker?

16 turns 1,5mm wire on 15mm coil.
+ & - going to speaker, out & gnd going to amp.

 

[apexaudio]

Speaker Terminal PCB size: 60x45mm

 

[engel dela pena]

apex,
what is db3?
and triac replacement Amp?volt? equivalent
thanks

 

[apexaudio]

apex,
what is db3?
and triac replacement Amp?volt? equivalent
thanks

DB3 is DIAC, any TRIAC over 400V, 8A can be use,
Regards

 

[coolet]

BR100 diac is common in the market

 

[apexaudio]

Any available diac and triac will work.

 

[apexaudio]

Speaker Termial with Zobel Network and DC Protect with Triac.

Speaker Terminal can be add to any amp with rail voltage over +/-36V DC and rail fuses. I prefer this protect more than protect with relay.