100W Ultimate Fidelity Amplifier

[apexaudio]

I want to use +-20v because i already have a big +-20v power supply.As you know this is the most expensive part in an amplifier.
AA11 like AX11 but in class A.
BTW is it possible to modify the triac protection for this (+-20v)Power supply?
Thanks for reply

Protect with triac can not be simple if you want use +/-20V PSU.

 

[apexaudio]

Hi all, back from from winter holiday, i submit you my latest run on A33 rooting job. Pay attention it's not tested. If some of you could spend a little time on proofing PCB V/S schematic. I spend to much time on rooting job to see anything up to time

Marc

Nice pcb, thank you, I hope someone will build this double side boards.
Regards

 

[apexaudio]

I got my A40 working. I had a bit of a struggle because when I printed out the toner files I forgot to uncheck the fit to page box so the scale was reduced. I had to fight to get all the drivers to fit next to each other on the heatsink and of course, everything is tight. However, it all fit on a 4"x6" board. Now for the good part. This amp has the prettiest square waves I've seen on any amp I've built. Not sure the reason but they are really, really sharp. I'll post some pictures when I get home from church. I've only had a short time to listen to it but so far it sounds lovely. I do have a little hum to sort out but that is probably just a wiring issue.

Blessings, Terry

Good news, is sound different compare to A33 ?
Regards

 

[still4given]

I will A/B them once I have it all sorted out.

 

[thimios]

Protect with triac can not be simple if you want use +/-20V PSU.

Hi Mr. Mile ,i don't want a simple triac protect,the only reason looking for triac protect is that i didn't like the relay contacts in signal path. I prefer some transistors and fuses blown in case of failure than a dirty contact in signal path.

 

[apexaudio]

Hi Mr. Mile ,i don't want a simple triac protect,the only reason looking for triac protect is that i didn't like the relay contacts in signal path. I prefer some transistors and fuses blown in case of failure than a dirty contact in signal path.

Something like this protect from Elektor?

 

[Idefixes]

Nice pcb, thank you, I hope someone will build this double side boards.
Regards

I will build it. Miles i have one request. Have you you logo in 8bitsbalck and white?

Marc

 

[borys]

thimios
There is another way to protect the amplifier.

The idea is very simple, You can monitor DC at the output and voltage drop on the emiter resistor (to minitor the current) at the output transistor and make the protect circuit to swith off the amp, for example you swith off input LTP CCS's so all the stages will be off, including output transistors.
Simple and bullet proof + no relays in circuit !!!

Regards Peter

 

[vargasmongo3435]

I was making a layout A40 using double side and is a bit more easier to make connections I will see if I can continue I'm tired .... is too much thinking for me jejejeje

Regards
Juan

 

[apexaudio]

A33 sch

 

[apexaudio]

I will build it. Miles i have one request. Have you you logo in 8bitsbalck and white?

Marc

In what format (size) you want APEX logo?

 

[apexaudio]

thimios
There is another way to protect the amplifier.

The idea is very simple, You can monitor DC at the output and voltage drop on the emiter resistor (to minitor the current) at the output transistor and make the protect circuit to swith off the amp, for example you swith off input LTP CCS's so all the stages will be off, including output transistors.
Simple and bullet proof + no relays in circuit !!!

Regards Peter

Swith off input LTP CCS's can not swith off broken output transistors and will not protect speaker from DC.
Regards

 

[Idefixes]

In what format (size) you want APEX logo?

BMP 8 bits black/white, i will resize it for use.

Marc

 

[borys]

Swith off input LTP CCS's can not swith off broken output transistors and will not protect speaker from DC.
Regards

That is truth but what if we monitor DC at the output and voltage drop at emiter resistors (current in SOA range at the output transistors) ? They should not fail.
Would be not enogh ?
If not looks like a relay is the only good option.

thx

 

[jwilhelm]

A low RDS mosfet on each power rail would work instead of a relay. Series mosfets on the speaker output works too.

 

[apexaudio]

BMP 8 bits black/white, i will resize it for use.

Marc

Is this ok?

 

[apexaudio]

Some amplifiers turn off main transformer by triac if there is DC on amp output... optotriac MOC3040 can be use instead relay

 

[still4given]

Here are some scope shots. I still have a ground hum. The input is creating a ground loop. I'm going to try lifting the input ground with a resistor and see if that helps.

 

[suryadi5417]

ax400

Not tesed yet.... with 64 VAC

 

[apexaudio]

Not tesed yet.... with 64 VAC

Nice work,
Regards