Explendid amplifier designed by Michael Bittner, our MikeB

[tlf9999]

Originally posted by bocka


The LEDs are reversed mounted...

and that's the least of his problems, unfortunately.

[destroyer X]

Thank you.

regards,

Carlos

[GEirin]

Destroyer X.

Hola hermano.

Thanks for "all then sensitive persons..." (post 188).

I read attentively this thread. I also plan to build a amp with 120-150 W 8 ohms.

regards

Guillermo

[htrinkle]

I have attempted a PCB for symasym5. Untested.

It's my first amp PCP, so I'm not sure if the layout is any good.

Some points to note:

Not shown are two jumpers (holes are there):

- One for supplying the ground to the VAS and 330pf/47K load.
- Connection between high and low side outputs.

I am thinking of using a double-sided PCB, and making the top side a big ground plane with channels cut to implement the above two links. Not sure if I need to isolate the gound for the VAS stage or not, but feel that I don't want decoupling noise on it - therefore seperate. I would connect the ground-plane to the de-coupling grounds (solder legs both sides, or use vias) but probably not to the signal grounds. I think that a, say 3mm, drill would be OK for removing copper from the ground-plane where component leads should not connect.

Would welcome any feedback.

Hans.

[SY]

Originally posted by tlf9999



and that's the least of his problems, unfortunately.

I see that the output caps are returned to the wrong spot. Anything else?

edit: the redundant led on the lower right is missing a series resistor, besides being backward.

[destroyer X]

Saludos Guillermo, gran satisfaccion tener el hermano acá
regards Guilhermo, a big satisfaction have the brother here.

Htrinkle, i will let Michael wake up and give you the answers you need.

Thank you Sy, because always tracking us.... pretty avatar SY

regards,

Carlos

[MikeB]

Originally posted by htrinkle
I have attempted a PCB for symasym5. Untested.

It's my first amp PCP, so I'm not sure if the layout is any good.

Hi htrinkle, i will take a close look to your PCB this evening.
I see that you use eagle for layout, i could upload my eagle-files,
but they are for syamsym4 and contain a confusing part, i had
no 2n5401/mpsa models, so used bc546/556 throughout, but
this way they are all mirrored. Because of that i had not uploaded
this layout, it does confuse... (lazy me...)

With my first PCBs i made some heavy mistakes with grounding,
resulting in heavy hum...

BTW, how do you transfer the layout to the board ?
I could send you 1200dpi-bitmap for transfer...

Mike

[MikeB]

Hi Hans !

I tried to check your PCB, but have real trouble reading it...
It's a bit to dense... But i saw no problem.
I attached a shot out of eagle, showing symasym4, the one i used
for my boards that i showed earlier. Are you interested ?
Some of the traces could be thicker, but this pcb plays without any
problems, and should not take long for me to adapt to symasym5.

The pcb-size is 10*8cm.

Mike

[destroyer X]

over 8 ohms..... considering the voltage used, that can be dangerous to humans, i think he can accept 250 or a little bit more over 4 ohms too.

But i am afraid that you have not time enougth to do that for us...so.... let this clear, if will make or not, because i will develop a Sony, will adapt, convert and test, T-O-D-A-Y, to offer to forum guys..... the unit will be simple and powerfull, awfull to treble, terrible to voices, and wonderfull to sub woofer.

Yeah!..i know in advance that you are working hard, Saturday and Sundays included, sleeping in your Office and inside a terrible dead line pression...so...asking you very clearly...will do?

regards,

Carlos

[bengt]

Out of topic.....
Soon you will have summer in Recife
Sunny days at Boa Viagem, a BOA ..... (Antartica) in your hand or a Skol.........
I have a BOA in my hand now named >sao joao dos bebedores oficiais de Antartica.....< Obrigado !!!

I miss Brasil!!!


So... good work and keep on working

Regards
Bengt