[skyskraper]

quick question, at this net cafe your schematic doesnt want to display for some reason (not your fault, crappy slow machines they have here are responsible). but iirc, the dynalo needs +/-16v. will i be ok with +/-15v? or is it essential to have the 16v either end???

i ask simply because i have a nice +/-15v psu pcb populated and running nicely with a toroid from another project that isnt being used presently.....

dg: can you please pm me to let me knwo what the story is with the boards etc you mentioned in pm before?

thanks

 

[dgardner]

Boards arrived:

Out of town at the moment... Won't be able to build one up for confirmation until this Friday.

EDIT: Original Copy Machine scan
Topside View
Bottomside View

EDIT: Revised Images

 

[Garbz]

nice picture, it looks like it was taken through a noisy electron microscope.

 

[dgardner]

This is what images look like when you scan with a copy machine....

 

[Garbz]

The boards do look like they came out beautifully in the end. I love the almost exclusive use of large planes for power and ground.

 

[dgardner]

I populated one board last night. Went together pretty well. Still missing some caps and the LEDs. Didn't bother to thermally bond the diodes to the output transistors yet. A few parts (like the pots) are cramped and some silkscreens for the connector hookup are needed.

I'll revised the layout before the next go around and consider a group buy if there is enough interest.

This morning I'll start the testing. Test results to be posted before anyone get boards first-pass prototypes shipped to them..

 

[dgardner]

Here's the list of first-round interested parties:

dgardner (me) - 6
skyskraper - 2
stackofhay - 2
Earwax - 2
jmedin - 2
ShiroZ - 1
jogor - 2, plus 4 dynahi psu
z2trillion - 1 or 2
scott916 - 1

This pretty much exhausts the stock from the 20 piece build.

Some bad news:

I thought I was going to get a discount for this order that would have put the price at around $5 ea. That did not turn out. So my cost on these is $10ea + shipping. If anyone is not interested at $10ea anymore, please PM me.

Exceptions are:
jogor - working a swap arrangement.

 

[skyskraper]

i need one board for stereo operation right? at least thats how ive read the schematic and board. pls correct me if im wrong as i havent had much time to spend on it.

 

[dgardner]

One board for stereo.

 

[skyskraper]

what value are you using for c8/9/23-26? the schematic reads 100uF. so i was thinking 120uF 25v.....

edit: or 50v 100uF

 

[dgardner]

I popped in a 120uF 63V, Panasonic EEU-FC1J121 (Digi-Key P11271-ND). Same series as used on the dynahi's. It was the only thing in my parts bin that fit. Nothing magic about it.

Options... Options.... Options.... let the fun begin.

 

[skyskraper]

oh yeah tell me about it. ive been pouring over catalogs all day thinking about it. but i am going to have to wait until i get the boards to start speccing it out.

btw if anyone wants a board, i only need one, i would be happy to let my other one become available again

 

[dgardner]

This board is running!! Jammin' a little Jack Johnson pretty hard on it right now. DC offsets are around 5mV at startup and the servos drop to 1mV or less within about 30 seconds. Idle currents in line for all stages.

Errata List: (so far no show stoppers)

1) LED polarity silkscreens are backwards.
2) Bourns 3296 series pots don't have a big enough outline/keepout.
3) Terminal Connectors don't have any markings. (kinda dangerous)
4) C8 interferes with R44.

 

[dgardner]

Quote:

Originally Posted by skyskraper oh yeah tell me about it. ive been pouring over catalogs all day thinking about it. but i am going to have to wait until i get the boards to start speccing it out. btw if anyone wants a board, i only need one, i would be happy to let my other one become available again

FYI all caps with "box" outlines are ideal for WIMA type poly caps. Specifically the MKS4 and MKS2 series. The red caps in the picture are 4.7uF 63V, MKS4475J63-6 from Epassives.

C10,11,21,21 can take a 22.5mm, 15mm, or 7.5mm lead space.

C1,2,3,4,12,13,14,15,16,17 take a 7.5mm lead space, but any small axial or radial cap will fit. I was planning to put 0.1uF and 0.01uf values in these locations.

 

[Pars]

I'd be interested in one if it is available or someone backs out. Nice looking boards, and I really like the ground plane. PM me if something frees up, or just put me down for it.

Chris