Alternate source for Millet-Hybrid PCB
Mar 23, 2005 at 10:14 PM Thread Starter Post #1 of 589

n_maher

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Please read this thread if you would like to learn more about the revisions to Peter Millet's Hybrid headphone amplifier.
 
Mar 23, 2005 at 11:00 PM Post #2 of 589
I think a couple people have built, or are building, this P2P. Perhaps you should start an interest check thread to see if a few members might want to try it that way as a group. You might even be able to build in some upgrades that would be difficult with the PCB. I'd be interested in trying this P2P.

-coma
 
Mar 24, 2005 at 1:26 AM Post #3 of 589
I agree that $40 seems a little high for this, it is a high quality board, however.

The gerber files are available on Pete Millett's web site. If you get a few people together to share, you can probably have boards manufactured for under $40 each.
 
Mar 24, 2005 at 1:30 AM Post #4 of 589
When I got my board it was $25.00 from DIYCable.com.

But the main reason why it's a tad expensive is if you were to have it made with the soldermask and silkscreen in small quantities like less than 50 it would cost around $30.00

It's a thick board with heavy copper.

Pete also posts the eagle brd file and the gerber drill file so you can have them made yourself.

I was thinking of trying to lay it out in Express PCB and have them make the boards as they would at least be the same price as diycable if you ordered 4 or 6. I's like to remove all the board mounted rca's, power jack, switch etc. That will make the board smaller. Also I'd like to make the space for metalized film caps bigger so that you could try solen or something else without any trouble.

It's still worth paying $40.00 for it though. It's a sweet sounding amp.
 
Mar 24, 2005 at 1:47 AM Post #5 of 589
[edit]

I'd love it, and help however I could, if some one wanted to streamline this board as you suggested and see if there was any interest in a group buy.

Nate
 
Mar 24, 2005 at 1:52 AM Post #6 of 589
vksy emailed me earlier today to share his not-yet-built Millett Hybrid P2P layout. He's done a good job and it looks pretty straightforward to me, but it's not yet tested. He's the one who posted yesterday about using diamond buffers with the Millett. Modifications include parallel tubes (2 per channel) and the possibility of diamond buffers. Pete has commented on the modifications but hasn't built, tested, or heard anything like it, so can't vouch for how it would sound. Pete said paralleling tubes increases Gm and lowers noise (at least on paper).

I want to do this P2P Millett myself. vksy said total cost for amp and (Tangent's) LM317 PSU (not including case, knobs, shipping) was just ~$135.

-coma

P.S. Even the Dynahi boards were only around $8/pair, so I know what you mean. I think it all comes down to "do you want to make things easy".
 
Mar 24, 2005 at 2:08 AM Post #7 of 589
A few enterprising people could get together and send the Eagle .brd file to PCB Fab Express and have the boards made for about $19 each with a five day turn. I've used them for protos and the quality is good (the silkscreen can be a little blurry sometimes).

-Drew
 
Mar 24, 2005 at 3:05 AM Post #8 of 589
Consider me looking into it - I'll be contacting PCB Fab tomorrow to check on pricing and lead time for a larger order, say 25 boards. Might be time to put together my first group buy...

Thanks for the help Drew!

Nate
 
Mar 24, 2005 at 4:04 AM Post #11 of 589
Depending on price / improvements to the DIY cables board, I'd probably be in for at least one.

I'd definitely be down if someone wanted to use economies of scale to make a cheaper kit version of this.
 
Mar 24, 2005 at 6:01 AM Post #13 of 589
Count me in please.
 
Mar 24, 2005 at 7:27 AM Post #15 of 589
Assuming that it is alright with Pete, I'd be in for one.

Among changes I can think of off the top of my head

- there are some long traces in the original where power and signal run the length of the board that can be shortened by moving some components around
- space for an alps blue or a noble pot would be great
- there is in general a lot of space on the board, and it could be compacted to about half its size without too much difficulty -- this should lower the cost a bit
- the heatsinks are unnecessary
- the 8 pin DIP version of the buffers are cheaper and might save a bit of board space as well

-d
 

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