My Take on X-BOSOZ

[Russ White]

It seems there are a lot of people, besides me of course, who have been wanting a good quality PCB for XBOSOZ. Well I have been pointed to several thread and tried to glean as much as I could. This is a completely no area for me, and my first pass at a Pass design. 🙂

First of all thank to all those who have paved the way. They did the real work here, this is very small thing compared to what those people have done.

So thanks to these people in Particular:

Nelson Pass, of course.
Metalman, Terry Aben whose circuit I followed.

But I am sure there are others who deserve credit, and to those I apologize for not knowing who you are.

Anyway they say a picture is worth a thousand words, so here are 2000 words worth.

First the Schematic:

 

[Russ White]

And the layout

Here is the layout:

 

[Russ White]

The PCB is pretty compact at 4.2" x 2.7" and is designed for a common HS.

It allows for either a radial output cap or axials up to 2.1" long or so.

Cheers!
Russ

 

[steenoe]

Excellent job, Russ. Looking forward to order a couple if at all possible😉

Steen😎

 

[lgreen]

nice!

Nice work, I like how you have all the Q's on one plane.

While you left room for very long C5 and C4, I think you did not account for how fat these tend to be and might want to re-look at this.

What's with all the CPA's and CPB's? Are these where the vol control attaches?

 

[Russ White]

Re: nice!

What's with all the CPA's and CPB's? Are these where the vol control attaches?

Hi,

Thank you very much.

CPA/B and CPA1-4/CPB1-4 are for the AXIAL C4/C5 caps, which if you used axials you would omit the radial C4/C5

I printed the layout on papaer and check a 33uf cap which is about 1-1/4" diameter. It fits fine, but it will extend off the sides just a bit. But no need for PCB over on the sides that does nothing. 🙂

Cheers!
Russ

 

[lgreen]

Re: Re: nice!

Hi,

Thank you very much.

CPA/B and CPA1-4/CPB1-4 are for the AXIAL C4/C5 caps, which if you used axials you would omit the radial C4/C5

I printed the layout on papaer and check a 33uf cap which is about 1-1/4" diameter. It fits fine, but it will extend off the sides just a bit. But no need for PCB over on the sides that does nothing. 🙂

Cheers!
Russ

OK......Now I see how stupid I am! Sorry about that!

Since I am making suggestions, how about you modify the schematic and put in the vol control? The only reason is that you would then be the only one to have a full X-CCS-BOSOZ schematic with vol control, apparently since its so "obvious" no one includes it in their schematics.

Plus if you are making boards people will wonder where to hook up the vol so even if you just have some holes with a label it would be a little easier for beginners. Also its kind of odd to have a preamp circ lacking volume.....but of course its up to you.

 

[adolphe]

If you end up having some pcb's made, I'd definately be interested if cost was reasonable.

Nice job.

 

[phoneisbusy]

While we're on the subject of requests, would Russ consider a version of his source selector for the x-bosoz? A volume/balance controller circuit would be appreciated also. I was wondering if Russ could not reuse some of his work with his preamp (i.e. the volume control section).

regards

Dave

 

[steenoe]

While we're on the subject of requests, would Russ consider a version of his source selector for the x-bosoz? A volume/balance controller circuit would be appreciated also. I was wondering if Russ could not reuse some of his work with his preamp (i.e. the volume control section).

If done in a modular fashion so one can pick and choose, that might be a great idea.
IMO, it would be a bad idea to design any of that into the board itself. Are we talking remote control here also?😉

Steen.🙂

 

[mpmarino]

Have it made..and they will come😎

 

[ble0t]

Looks really nice!

I'm not sure what the tolerances of the PCB manufacturer are, but I noticed that the upper pad of R5 is awfully close to the trace above it.

Keep up the good work 🙂

 

[Russ White]

I noticed that the upper pad of R5 is awfully close to the trace above it.

Thank you,

How is this?

 

[Russ White]

Fixed an oops. 🙂

Accidently had R3,R4 as 21.1R instead of 22.1R 🙂

Fixed:

 

[Russ White]

Fixed schematic

schematic:

 

[Nisbeth]

Nice work as always Russ 🙂 But why the layer change for the traces from C4/C5 to CPxx ?

EDIT: Same question for the trace from C1 through R9 to R5?

/U.

 

[Russ White]

Nice work as always Russ 🙂 But why the layer change for the traces from C4/C5 to CPxx ?

EDIT: Same question for the trace from C1 through R9 to R5?

/U.

Thanks for pointing that out to me, i missed the first thing simply becaue I have been looking at it too long I think. 🙂 It is now fixed. Picture will be in next post.

The second is not exactly correct, but its hard to see, so I have attatched a zoomed image.

 

[Russ White]

Better optimized traces.

Thanks Nisbeth:

 

[BrianDonegan]

Looks like there is trace-doubling between the pins of the references as well (top and bottom).

 

[Russ White]

Looks like there is trace-doubling between the pins of the references as well (top and bottom).

That was actually intentional. I built a version of that part in the library with those two pins coupled because the datasheet says so. And I wanted to be sure it was the same on both sides since I knew it would have traces running to/from it on either side. But I could easily remove one trace. Not sure it matters..