Symasym - the sequel

[MikeB]

Hello !!

I'm finally building my Symasym ! 😀

It was laying on the shelf a long time !

But building, I noticed that the Symasym of the picture is using a wire instead R16/19 (22Ohms), and have sc5200/sa1943 output.

Using with the stock 3281 / 1302 I must use 22R to R16/19 right ?


Thanks !!!!

Fernando, it's not necessary to have R16/19 unless you reduce closed loop gain or want some extra bit of stability margin.
It's your choice,
Michael

 

[-_nando-_]

More stability margin sounds nice to me ! 😉

Thank you mike !

I think that tomorrow I'll listen to stereo Symasym !

One channel is ready, the other I have the PCB done and tomorrow I'll build it, and put everything into a good case with OPA2134 Buffer (already done too) 😉

I'm anxious to listen to it !


Have a great week


Best Regards

 

[-_nando-_]

Just because of these posts I'll use pink wire on my amp!

😀

 

[TomWaits]

Just because of these posts I'll use pink wire on my amp!

😀

Where is the Pink PCB layout? I dreampt I was soldering MikeB parts into a Mouse board.
nando, do you have the sparkle polish? 😎


Shawn.

 

[anatech]

Hi Shawn,
You have no idea how much this hurts to do!!

-Chris

 

[TomWaits]

Hi Shawn,
You have no idea how much this hurts to do!!

-Chris

OMG! I saw the light. It wasn't a dream after all.
Though you may be hurting, I don't really know why , I'm loving it.

This will take pole position in my to-do-list of amp building. Love the pink...but I guess it is up to me to make it Sparkle?

Jah

Shawn.

 

[TomWaits]

Catch

Chris,

Awe there is a small catch. Pink was cooking up an extra strength beefed up output. Still, a little tweak here and there...voila! 😎

Shawn.

 

[pinkmouse]

Been busy, it is coming, promise!

Have you run out of 300's to fix or something? 😉

 

[-_nando-_]

OMG !

WHAT THE HELL !??? 😱

I'm LISTENING to SYMASYM !

I'm on the lab right now... Listening to Symasym in a pair of 4" very junk speakers. I CAN'T BELIEVE in what I'm listening.

HOW? I cannot accept that this sound is coming from that junk speakers !

The amp is so died quiet ! But when starts to play is like magic.

What a great dynamic !!

The piano is incredible, the sax !! The violins are for the first time the way I like !

My gainclone sounds compressed playing with symasym.


The highs I don't know exactly yet because the junk tweeters will not ever reproduce anything above 14Khz heheh !



PINK OR NOT this amp is incredible !!!!!!!!



Congratulations MikeB, many congratulations, it's the best SS that I ever heard.



Keep designing, you're great on SS !


Would be VEERY nice if you design a Symasym 100W @ 8Ohms with this quality !




Best Regards !

 

[pinkmouse]

Play some Disco, the Sym loves it! 😉

Just firing up the PC to work on the PCB as I type.

 

[-_nando-_]

Listening to:

Quincy Jones's finest hour
Stan Getz for Lovers
Eric Clapton Unplugged
Adriana Calcanhoto Perfil (from my contry, great disc!)
B.B. King The Living Legend
B.B. King 80th birthday

But I'll do serious listening when I arrive at home, I have a pair of JBL E60 floorstanding speakers there 😀

I'm also building a pair of Beyma Speakers with 10BR60 and T2010, great drivers !

At home I'll play some disco ! 😀 😀

 

[pinkmouse]

I'm really not happy with the output stage, I might have to rip it all up and start again...

 

[roender]

Pinkmouse,

Nice work!
There is no need to put the drivers on the same heatsink with ThermalTracks.
And don't forget to put a bias pot instead of R35.

 

[pinkmouse]

Yeah. The problem I'm currently having is based around the overall size of the pcb and the way it gets laid out in a real chassis. I might split off the output as a separate board, that way it will make it more practical to fit on a standard heatsink. It also means I might be able to fit the PSU on the main board as well, to make it totally self contained.

Bias pot is in already. 😉

 

[Upupa Epops]

Al, try to get power terminal plate ( and output ) between power transistors - lines will be in this case much shorter and layout will be much more logical and all can be smaller - isn't good to give side-by side output and input terminals ... 😎

 

[Upupa Epops]

...side-by side power terminals and input... 😎

 

[pinkmouse]

I was wondering how long it would take my Sensei to get here! 🙂

I've put it hold for tonight- after playing around with different layouts, I need to sleep on it I think.

 

[MiiB]

Pinkmouse.

Is there anyway you can post the eagle schematics and Brd files Then I can have a go also.

I'll then make some small modifications. and redo the layout just for the compaireson
I have a little trouble seeing your highcurrent traces going through vias.

Michael Børresen

 

[-_nando-_]

It's so stable ! Like a rock !

 

[pinkmouse]

Michael, the red traces on the top are links, so no power will be going through vias.In fact, all the power and output rails will be beefed up once I have a layout sorted, at the moment they are just placeholders for the real thing whilst I get component positioning organised.

The layout is way too big to fit in the freeware version of Eagle at the moment, and I still have to optimise some cap sizes as well as add all the output network, so I wouldn't be happy to post Eagle files yet. The way I work it would be far too easy for someone to go wrong with what I have done.

Nando, have you played Boogie Wonderland yet? 😉