SYMEF amplifier

[Nico Ras]

PauloPT, regulate everything short of the output devices, it is unnecessary to regulate the output devices.

 

[PauloPT]

PauloPT, regulate everything short of the output devices, it is unnecessary to regulate the output devices.

That was my first though too. But how do I separate everything else from the outputs? Can I just disconnect the tracks and use a separate supply?

Thank you.

 

[PauloPT]

Does something like in the pics attached will work?

Thanks.

 

[OnAudio]

Hi Paul,

Dont do it

 

[drowranger]

hi paul..

first if you have a cd player or dvd you can use it because it sounds better.I have noticed it when playing music specially when it comes to chorus the sound get compressed or the amplitude has limitation when using computer eventhough you have soundcard.

about board I have come up with a new layout and tomorrow I will upload it.I have tried the jurassic style,in terms of THD it is superior than straight lines.

regards,
joel

 

[PauloPT]

Hi Harrison,

Dont do it

Ok, I won't
Regulating the VAS and input would be sooo nice! I don't have the skills (yet) to design such a modification, but you have. Can you think about it please! But don't change the sonics of the amp, I'm too in love with it!

Hi Joel,

first if you have a cd player or dvd you can use it because it sounds better.

I have a DVD player. But it's so pratical to have all the music in the hard drive and use your favourite media player... You're right, it sounds better with the DVD player

I have tried the jurassic style,in terms of THD it is superior than straight lines.

Then lets go with round lines

 

[OnAudio]

Hi Paul,

Heres something for you to investigate

You will need a separate winding, rectifier and power capacitor bank for the regulated supply.

kind regards,

Harrison.

 

[drowranger]

Proposed pcb for Symef.

Hi Harrison,

This is what I have come up yesterday.If you have something to change let me know.

regards,
joel

p.s.
straight lines pcb to follow.

 

[drowranger]

straight lines.

followed your block diagram.

 

[OnAudio]

Cute

 

[PauloPT]

Hi Harrison,

Heres something for you to investigate

Gold over blue, many thanks!

Hi Joel,

This is what I have come up yesterday

Good work!

 

[PauloPT]

Harrison,

is it possible to use the same transformer feeding two separate supplies, one regulated for the regulated section and other unregulated for the outputs?

And how much current the regulated section needs?

Thanks!

 

[Nico Ras]

PaulPT,
could be less than 150 mA per rail, calculate worst case current.

 

[OnAudio]

Hi Paul,

Nicos', estimate should do . Do you have a separate winding on the same transformer? If not use another transformer.

kind regards,

Harrison.

 

[PauloPT]

Hi Harrison,

Then a small transformer will do. Nice!

Thanks

 

[drowranger]

Check this...

Hi Harrison,

Is it ok?its not yet final.

regards,
joel

 

[PauloPT]

I've been experimenting with input and VAS regulation with LM317/337 chips but I seem to prefer full amp regulation. I added a 15000uF of caps after the LT1083 the bass in good, also the dynamics are impressive. I don't know if adding this much capacitance after the chip will negate the ideia of regulation in the first place...

Anyway, does a single LT1083 per rail (Imax = 7.5A) be enough for the SYMEF?

I don't know if Joel could find away to put this regulators in the same pcb as the main amp... Just an ideia.

 

[OnAudio]

Hi Paul,

Create a stereo amplifier of the SYMEF that you will keep constant and not modify. It will be for your listening pleasure and also for reference. You can use it for AB comparisons with the modified versions.

You may choose to use the latest PCB we are just about to roll out.

kind regards,

Harrison.

 

[OnAudio]

Good going Drow

 

[drowranger]

Here it is...

made this pcb for SYMEF amp. with Harrison collaboration

regards,
joel