My "audiophile" LM3886 approach

[float]

Well, I finished stuffing my boards yesterday. This was so much more fun than my usual scabby stripboard efforts!
Only problem now is the chassis and connections, and this seems to be a far bigger headache than the boards. An MDF creation is on the way, and hopefully I'll hear my baby cry for the first time Friday sometime.

Comments so far....

Kit arrived about 3 days after posting
Great labelling- thanks Brian- you can't go wrong here
Boards look superb, real pro stuff
Easy assembly, plenty of room to swing the iron, took about 4 hours to stuff both boards. Not tested yet, but ( I think )

The only slight concern was the difference between my ref c schematic and the kit for a component or two. I 'm happy to trust you've changed things for the better here, but it might be an idea to post an up to date schematic, just for the sake of completeness. Of course, I may just have missed it.

More soon

[BrianDonegan]

Hi float-

The only discrepancy I am aware of is one resistor marked on the board as 270r but is now 47r. This was a last minute change suggested by Mauro.

What discrep's are you referring to. We would like to fix or note them for others.

Thanks, btw! Glad you like the kit.

[float]

thats the one

[Russ White]

Hi float,

Very glad to hear your experience has been so positive this far. I bet you can't wait to fire it up!

Although the schematic does not say so you could actually use a broad range of values for R42 from 0R to 270R I have tried 0R, 4.7R, 47R, 200R, and 270R all with success.

Mauro suggested 47R as being very stable, and thus we decided to use that value. But you could substitute anything in the range of 0R to 270R if you choose.

Mauro controls the schematic.

Cheers!
Russ

[lazyfly]

Hi fellas.

What's the best way to hook up a dual secondary toroid to a Rev C mono setup? (2 rectifiers) :/

I plan to get a pair of 160VA's in future but could be a few weeks off.

Thanks to Mauro for sharing the design and all his support. Thanks to Russ & Brian for the massive effort put into the board design and kits. Excellent job all round

Cheers!

[Russ White]

Hey lazy,

With dual secs it is actually pretty easy. Most trafos have a wiring diagram either on the trafo itself or in the documentation. You need to wire the secondaries in series and take the center tap (GND) from the point where you join the two, and the two "ends" of the trafo go to AC1 and AC2.

Essentially you turn a dual secondary trafo into a center tapped trafo.

Cheers!
Russ

[lazyfly]

Hi Russ.

Thanks mate. Got that part sorted out. I'm wondering do I just run 2 wires from each secondary to the rectifiers (assuming yellow and blue are tied)?

Cheers

· RED----------- +V	AC1
  YEL----------- 0V ---->
			PGND
· BLU----------- +V ----<
  GRY----------- 0V 	AC2

[Russ White]

Originally posted by lazyfly
Hi Russ.

Thanks mate. Got that part sorted out. I'm wondering do I just run 2 wires from each secondary to the rectifiers (assuming yellow and blue are tied)?

Cheers

· RED----------- +V	AC1
  YEL----------- 0V ---->
			PGND
· BLU----------- +V ----<
  GRY----------- 0V 	AC2

Right you have it, you will need to run two wires from each RED,PGND, and GREY.

Red
------->Board A AC1
------->Board B AC1

PGND
------>BOARD A PGND
------>BOARD B PGND


Grey
---------->Board A AC2
---------->Board B AC2

[Russ White]

My previous post is assuming the monobloc PCBs.

[lazyfly]

Hi Russ,

Roger that - getting onto it now. Would like to post a photo but the wee issue if not raising the 1 and 2W resistors off the board means it's a bit embarassing... wait, erm New bits tommorow

Thanks very much, Russ

Cheers!