ultra performance amp

[400kg]

new design , no pcb

 

[KatieandDad]

But what does it sound like ?

 

[400kg]

But what does it sound like ?

very detailed and soft
clear highs and deep bass.

 

[400kg]

diagram corrected

diagram corrected

 

[400kg]

final update

final update

 

[sajti]

Hi,

the input & tha VAS looks like the Pioneer A9 power stage. So it can be quite OK.
Some improvement possible in the VAS. See the attached picture.

Sajti

 

[400kg]

Hi Sajti
I took the Marantz sample

 

[sajti]

Hi Sajti
I took the Marantz sample

OK. My experience, that it sound even better if You connect the LEd to the emitter of Q621. In this case the impulse response is much better too.

Sajti

 

[alex mm]

PCB rev 1.0

...... Ok,right now ,you have PCB , and Q.C. need to check this layout , this is my contribution ......🙂
Regards Alex.

 

[sbrads]

Isn't the DC gain a bit high? And no input cap. I melted a speaker cone once with something like this.

 

[alex mm]

PCB rev 1.2

......have layout again , find some errors , corrected and revised 😉
Regards Alex.

 

[sajti]

Looks nice, as always Alex!

I'm working on my version, with bjt input stage...

Sajti

 

[SSDIY]

......have layout again , find some errors , corrected and revised 😉
Regards Alex.

Hi Alex

Very nice pcb layout. But I have a question. There are 8 transistors laying under the pcb, 8 transistors x 3 leads = 24 leads have to insert to the pcb before soldering. Is there any way to make sure it has no problem when inserting the leads through the pad holes?
I have designed some similiar pcb layouts but keep wondering if there will be any problem to insert the leads of transistors into the pad holes on the pcb.

Thanks

 

[Walkalone]

Very nice layout, Alex.
Your PCB layout skill is great!

 

[alex mm]

Hi SSDIY,

First you can insert , each transistor in position , solder each , and after mount pcb to the heatsink , ofcourse not so easy but with some skill you can do the job 😉 Thanks for kindnes .
Regards Alex.

 

[coolet]

make a metal or galvanized sheet pattern.. for me i cut a hole enough to mount the transistor.

 

[AndrewT]

Solder just ONE lead of each output device. Maybe to just one side of the pad rather than all round.
This holds the transistors roughly, but not rigidly, in place.
Bolt or clamp to your heatsink.

Then when all is correctly aligned, re-solder that first lead to release any strain on that part soldered leadout.
Finally solder all the other leadouts.

 

[coolet]

that is good if your pcb has plated through hole

 

[alex mm]

PCB rev 1.3

.......few mistakes ,revised again , better ground layout etc .🙂
Regards Alex.

 

[michaelkiwanuka]

This amp doesn't have safe operating area protection; short the output and you have one dead amp.