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yggdrasil
11-30-2006, 07:39 AM
Just trying to bring all my gear up to the level of my speakers.

Built a Pass Bosoz pre-amp. Since it is my first pre-amp build it has taken a loooot of time.

The sound is so good it's almost shocking. I have been using the pre amp with an old potentiometer for a while. When I finished the amp, installing it in the chassis and replaced the pot with the relay based volume control, the amp came even more to life.

Facts: It is a balanced preamp, Class a. I have attached a remote controlled input selector and relay based volume control.

The design: http://www.diyaudio.com/forums/showthread.php?s=&threadid=50267
The pcb: http://www.diyaudio.com/forums/showthread.php?s=&threadid=67448
The pre amp kit: http://www.twistedpearaudio.com/xbosoz/xbosoz.aspx
The volume control/input selector/remote control: http://electronics.dantimax.dk/Kits/Selectors_-_attenuators/index.html


I have attached pictures of the finished amp, internal view and construction of the chassis.

Don Mascali
11-30-2006, 09:20 AM
Thanks for the pics, very nice.:D

Mr. Widget
11-30-2006, 10:13 AM
Cool project... I guess that messy shop look is just to keep the women folk away. :D


Widget

Ian Mackenzie
11-30-2006, 11:12 AM
Johnny..

Nice project. Must check out the relay volume.

How did you go about making the chassis?


Ian

yggdrasil
11-30-2006, 01:01 PM
Johnny..

Nice project. Must check out the relay volume.

How did you go about making the chassis?


Ian
Front panel is 10mm aluminium. Gives a robust feeling. Finished with a belt sander and 80 paper.

Bottom is cut from a 3mm aluminium sheet.

Rear, top and brackets are bent from 1mm aluminium. For this (and future) project I built a tool to bend sheet metal. (Pic's attached with the top plate).

Parts mostly mounted with wood screws. Soaked the screws / predrilled holes with methylated spirits and they went in like butter.

Knobs and power button are turned from poplar wood. At least 6-8 coats of lacquer to get a smooth finish.

Ian Mackenzie
11-30-2006, 03:24 PM
I like the home made bending tool.

I plan to make a router table with the router (overhead to avoid lubricant on the router) with a down cutting 1/2 inch bit to finish the edges.

My days of hand finishing are over. The router bit (for aluminium) when used with a paste or lubricant gives a very smooth finish. The table will also ensure the work is square. I will post details when its complete.

But my next purchase is a Makita compound mitre saw with 10 inch aluminium saw blade for true and straight cuts.

Ian

yggdrasil
11-30-2006, 03:59 PM
But my next purchase is a Makita compound mitre saw with 10 inch aluminium saw blade for true and straight cuts.
That should come in handy. I have cut all my aluminium on a table saw with a wood blad. The results are rather rough. The first grinding on the edges are done with an angle grinder and 40 grade sand paper on it.

And keep us posted on the router table.

Are you planning a ZV9 build?

Ian Mackenzie
11-30-2006, 08:37 PM
The Zen 9 is in the corner waiting completion.....

If you can try an aluminium cutting blade in your table saw, your trade store should be able to advise on options.


Ian

Mr. Widget
11-30-2006, 08:51 PM
If you can try an aluminium cutting blade in your table saw, your trade store should be able to advise on options.We have several Aluminum cutting carbide blades for our table saw... the Matsushita 10080AP is by far the best. To be fair, our saw has a 5Hp motor, but this blade will cut 1" aluminum plate like plywood and the surface finish of the cut is bright polished. None of our other blades do quite the same quality of cut.


Widget

yggdrasil
12-01-2006, 01:29 AM
I guess that messy shop look is just to keep the women folk away. :D

:yes: , and it works well... Besides it is so small and full of "things" that it looks messy in all conditions.


The Zen 9 is in the corner waiting completion.....

Mine too. Just heatsinks missing I believe. Most likely it will stay there for a while. Maybe I'll do a pair of Tractrixes and / or a pair of Smiths for the 2435's first.


If you can try an aluminium cutting blade in your table saw, your trade store should be able to advise on options.



We have several Aluminum cutting carbide blades for our table saw... the Matsushita 10080AP is by far the best. To be fair, our saw has a 5Hp motor, but this blade will cut 1" aluminum plate like plywood and the surface finish of the cut is bright polished. None of our other blades do quite the same quality of cut.
Thanks for the advice, I'll have a look at my next visit to the toy store.

Oh, and I almost forgot the 115mm / 4.5" saw blade for the angle grinder. Superb at cutting rectangular holes. Mind the fingers though. A friend of mine made a quick entry on the inside of his palm exiting through the index finger. Got 3-4 months on the side line and a hell of sewing job to put it all back in place.