The BA-3 as preamp build guide

[albertNL]

Probably, and the extension kit would to, as well as shortening the wiring. The face plate is thick enough for your idea, but I just ordered the 3mm version. I think they share the same rear panel, I guess I could go ahead and drill it for RCA jacks.

I do need someplace to cut a hole for the IEC unit. I do not want a raggedy drill out job, but a nice neat cutout. What kind of biz provides such a service?

Russellc

I get mine done at Schaeffer AG in Germany. They supply Frontpanel Designer CAD software in which you can specify exactly what you want done, including engraving. Sending my own panel is not much cheaper than letting them supply a new one, so I get them to make me a new panel and keep the old one as spare.
A Galaxy 280x80mm panel with a AC input cutout was about 30 euro's.

 

[vdi_nenna]

I do not want a raggedy drill out job

Draw the opening. Drill inside the lines, cut out the opening with a metal blade saw, then file out the edges.

 

[Russellc]

Any small machine shop.

Thankfully there's a local guy in Grand Rapids MI that has a nice machine shop behind his house.

Let me know if you can't find anyone in your area. You could send it to me and I could get it done.

Appreciate the offer. Im going to scout around KC here, surely there is some small shop...if no luck, I will PM you!

Thanks,

Russellc

 

[jdg123]

workin' the faceplate

As vdi-nenna said, you can do these things amazingly well with hand tools. Most attachments are meant to have a beauty ring or trim to hide cutlines and aluminium is pretty easy to work.

Aternately there is the "on-line metals" store where you can have a blank cut and shipped for you at a thickness you'd prefer. But if you have the money to hire an artist (some machinists are!) be a patron!

 

[Russellc]

OK, got everything in the new 3mm front panel box, rear panel drilled, and of all things, the volume pot didnt arrive on Sat. as anticipated. Oh well, I am ready for it when it gets here! just need to drill 3 holes in front panel and mount the on/off, the selector (which is wired) and the volume pot. Jump the pot to the selector, solder selector wires to the 3 sets of RCA jacks and its ready to fire up.

Russellc

 

[Marra]

The board is on it's way

And it has arrived. Seven days not bad going.

Thanks to the store.

 

[Russellc]

If I can figure out this volume pot, all I need to do is attach the power cord, fuse and chassis ground...and hook the shield to it. This depicts one channel,
wires not soldered, just in place how I think one channel should go from board to volume pot, and from pot to selector, obviously not soldered either.

Am I getting close? Any comment appreciated!

Russellc

 

[Zen Mod]

input-selector-pot-board-output

btw - that looks as ladder type attenuator

like this one

edit: aha , that's you ........

 

[Marra]

How low can p/s voltage be for this preamp? tia.

 

[Zen Mod]

say 24

 

[Marra]

Thanks ZM. Should have known I've read the threads enough times

 

[Russellc]

Quote:
Originally Posted by Zen Mod View Post
plenty of tutorials around

Click the image to open in full size.

ladder attenuator diy - Google претрага

Tip_67

http://diyaudio.co.kr/wwwboard1/data/board1/compare.pdf

I wouldn't put two decks in parallel

buy 4 pole and make stereo ladder type

Very nice articles, makes understanding clear...problem is in converting words and flat pictures into use for 3 dimensional object. The picture montage actually has a picture of what appears to be my pot, except mine has a circular board on ends instead of plain wire.

Anyone have a pic of one hooked up? Hakari1 gave me this one, which from where I came up with hook ups in my pics. (scroll down)

http://forums.stevehoffman.tv/threads/tone-controls-etc-any-one-use-them-if-so-why.422911/page-4



Zen Mod, I suppose you are saying my hook up in pics isnt right yet?

Russellc
__________________
Pass DIY B-1, Pass DIY F-5

 

[Zen Mod]

I didn't say that

however - if you're unsure - gimme proper pic of attenuator from shaft side - need to see what's with that round pcb

 

[Russellc]

I didn't say that

however - if you're unsure - gimme proper pic of attenuator from shaft side - need to see what's with that round pcb

Ok when I get home this evening I will macro photo it totally. Thanks,

Russellc

 

[Hikari1]

Yeah...its hard to tell from that pic. Looks ok though. Where are your rectifiers? Under the little pcb behind your reg board?

 

[Hikari1]

Also, it appears you have the selector after the pot. It should be input, selector, pot, amp board, output.

 

[Zen Mod]

yup

I wrote that

 

[Russellc]

OK, I'll get the order right. Here's some pics:

 

[Russellc]

Looking at the available hookups and various tutorials I am "assuming" like this?

From left to right, first pic is one channels ground, second pic is same channels out, and third pic is same channels in?

Other channel goes to other set?

 

[Russellc]

Another oddity, (for me anyway) is that on the opposite side of pot from these hookups are a similar set, but without so obvious ground wire hook ups:

Are these just ignored? Let me know if more pics required...

Russellc