DIY Audio Projects Forum
http://diyaudioprojects.com/Forum/

GB: Millett UniAmp PCB groupbuy
http://diyaudioprojects.com/Forum/viewtopic.php?f=13&t=700
Page 4 of 6

Author:  Gio [ 29 Apr 2009, 21:12 ]
Post subject:  Re: GB: Millett UniAmp PCB groupbuy

Hi Greg, is there any chance we could get a custom build with 4 and 8 ohm taps?

Author:  Bluesman [ 30 Apr 2009, 04:02 ]
Post subject:  Re: GB: Millett UniAmp PCB groupbuy

Gio,

Both those OPTs with the MS designation mentioned in the reply from Edcor have 4, 8, and 16 ohm taps. But if you would like to eliminate the 16 ohm tap, we could get anything custom made. If it's something they've done before and have on file, they will waive the $20 set-up fee, and as long as we buy enough units the cost structure should be the same as for one of their "regular" production items. At least that's the way I understand this to work. I'll reply to their email and get some more clarification.

BTW, according to tracking info forwarded to me, I will receive the boards today, unless UPS takes the day off.

Still 3 pair of boards remaining.

Cheers, Greg

Author:  Gio [ 30 Apr 2009, 06:53 ]
Post subject:  Re: GB: Millett UniAmp PCB groupbuy

16 ohm tap is good too! :) BTW - where are those transformers on their website? I could not find any with multiple taps.

Author:  Endspec [ 30 Apr 2009, 08:25 ]
Post subject:  Re: GB: Millett UniAmp PCB groupbuy

http://www.edcorusa.com/Products/ShowPr ... spx?ID=482

Author:  booangler [ 30 Apr 2009, 16:31 ]
Post subject:  Re: GB: Millett UniAmp PCB groupbuy

greg,

i'll take another set.

Alan

Author:  Gio [ 30 Apr 2009, 17:13 ]
Post subject:  Re: GB: Millett UniAmp PCB groupbuy

Endspec wrote:
http://www.edcorusa.com/Products/ShowProduct.aspx?ID=482

Well that was dumb, I was looking at the SE page.

I will go with either open or closed frame and I am in for all the iron required.

Author:  Bluesman [ 30 Apr 2009, 18:01 ]
Post subject:  Re: GB: Millett UniAmp PCB groupbuy

How cool is this???? These are beautiful.

Image

I've done some measuring so we can get a head start on compiling a parts list. I'll try not to make any errors, but everyone double check.

The board itself is 5.5 inches X 8 inches. Or about 140mm x 203mm.

C1, C6, C8, C9, C11, C12, and C13 spaces on the board are 25mm in diameter. Those are the 450V electrolytics. Six 100uf and one 47uf.

C4 and C10 spaces are 16mm. Those are 330uf/50V electrolytics.

C2, C3, C5, and C7 spacing is 43.5mm hole to hole. Those are .22uf and .33uf film caps and I'm going to use at least 500V myself.

R1, R2, R3, R6, R7, R8, R9, R10, R12, R13, R16, R17, R18, and R19 spacing is 15mm hole to hole. I'm going with Vishay/Dale CMF20s. The body of this resistor is right at 10mm, so it's the ideal size. Conservatively rated at 1/2W. Check the schematic on Mr. Millett's site if you want the values right now. I'll post them later in a dedicated "UniAmp build thread".

R4, R5, R15, R20, and R23 spacing is 22.5mm hole to hole. The schematic specifically calls for 1W here for 4, 5,15 and 20, but 2W for 23. However, the pcb actually is silkscreened with 5W Mills for all five of these positions.

R11 and R21 are also 1W in the schematic, but the spacing is different very slightly from the above. 20mm from hole to hole.

R14 and R22 are 400R/5W in the schematic, and spacing is 43.5mm hole to hole. Strangely, the pcb says 12W Mills, but directly under it says 400_5W.

FWIW, the space for the Sowter transformer is 35mm in diameter.

Another thing to keep in mind during this....when looking at the side of the pcb marked "TOP", this side will actually be facing DOWN in the chassis if you decide to mount you tube sockets on the pcb and have the tubes through the top plate of the amp. If that is the route you take, those sockets will be the only thing mounted on the side of the board marked "BOTTOM". Those and some standoffs.

I'll be getting things together for shipping these to everyone. I would like for those who commited to this to PM their mailing address to me. I will ship and then collect money after I know each person's actual total cost. I think I can trust the guys here. I would prefer Paypal, plus 3% fees. If everyone is OK with it, I'll probably round up to the nearest US dollar.

Later, Greg

Author:  Bluesman [ 30 Apr 2009, 18:03 ]
Post subject:  Re: GB: Millett UniAmp PCB groupbuy

Alan's in for another pair.

2 pair remaining.

Author:  Bluesman [ 30 Apr 2009, 19:15 ]
Post subject:  Re: GB: Millett UniAmp PCB groupbuy

pistolsnipe on Head-Fi is in.

And if Paypal is a problem for anyone, just drop me a money order. Something that will spend. Let me know and I'll get my address to you.

Down to 1 pair.

Cheers, Greg

Author:  Gio [ 30 Apr 2009, 22:25 ]
Post subject:  Re: GB: Millett UniAmp PCB groupbuy

Boards look great. PM sent.

Page 4 of 6 All times are UTC - 6 hours [ DST ]
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/