Modulus-86 build thread

I tried to use you BOM to order components for my Modulus-86, but two of the listed capacitors are currently out of stock at Mouser.ca.

That's sadly pretty common. Mouser doesn't seem to keep a very large stock. Digikey is better in that respect, but as you point out, they don't stock the parts from THAT Corp. Thankfully, it's pretty straight forward to find replacements for most parts. These two will be suitable substitutes for the caps you need.

Mouser P/N: 667-ECE-A1HKA220 (22 uF, 50 V)
Mouser P/N: 81-RDE5C2A101J0M1H3A (100 pF, 100 V)

Tom
 
Here's a picture:D

uhf5MWPh.jpg


Just ordered this case for my build which I've just started. Power 86 built but not tested, Modulus 86 boards have resistors but nothing else. As a total newbie to all this including soldering at this scale it feels as though it is going OK but it does scare me!
 
As a total newbie to all this including soldering at this scale it feels as though it is going OK but it does scare me!
Scared is wise. But, if you have any questions, ask right away.

Pertinent items to review are:
GFCI for your workspace area safety
"Light Bulb Test" apparatus to current limit new builds during first power on.

The materials for these are available at your local hardware store.

P.S.
For the soldering, there is the Gel Flux, which is a prefabricated mixture of petroleum jelly and rosin, and that is the quick way to make fantastic quality connections most of the time, at the cost of also making a little bit of sticky mess to wash off with simple green, alcohol soap or equivalent. I do use the Gel Flux. So, every solder connection is more shiny than a polished chrome Buick bumper.
 
Last edited:
Here's a picture:D
Just ordered this case for my build which I've just started. Power 86 built but not tested, Modulus 86 boards have resistors but nothing else. As a total newbie to all this including soldering at this scale it feels as though it is going OK but it does scare me!

Nice chassis! Where did you order it from?

billshurv said:
I should point out 2 things.
1. Tom's build instructions are extremely thorough
2. It's dead easy to build as long as you get the 3886 to heatsink part right and there are photos of this.

But apologies if build pron is your thing and we haven't fulfilled that.

I've built plenty of other amps before (some including tomchr's SMD boards) and I like to see how different people approach the same problems. Pictures are also a nice way to break up the Asperger's flavored debates.
 
Thanks Daniel. What does GFCI mean?
I've got the link Tom posted about dim bulb test although I'm not certain what wattage bulb to use.
low wattage is safer.

It depends on the quiescent load you attach.

A small transformer draws so little current, that even a 60W bulb provides little protection. Try to find a selection of incandescent filament bulbs from 25W through to 150W.

I generally use 38W (halogen) and 60W, but I have 25, 38, 40, 60, 75, 100 & 150 lying on the shelf.
 
I've got the link Tom posted about dim bulb test although I'm not certain what wattage bulb to use.
I use a clear bulb made for oven use, because that incandescent bulb isn't banned yet. The clear bulb is a bit more informative than frosted. Also, if the bulb is clear, you can use a much lower wattage bulb and still be able to see if the filament is orange or black.
 
Last edited:
As far as I know, all XLR are latched.
All balanced impedance interconnect require Pin1 to be directly connected to Chassis via the Pin1 in the socket.

I prefer metal shell XLR since they can make for a shorter "hole" around the metal to metal contacts where the Chassis/enclosure makes contact with the shell.
If there is a long "hole" around the shell, or a non conductive shell, then lower frequency interference gets in via that bigger hole.

There are now some XLR plugs that have an annular capacitive connection around the signal wires to minimise the leakage of interference in through the hole. These require a metal shell to conduct the interference from the capacitors to the enclosure. A pig-tail from the shell tag has too much impedance.
 
I'll use it with my Focusrite Saffire PRO24 sound card and a laptop running Reaper for the crossover.

Tom, did you get this running? How did you chose the Saffire over the miniDSP 4x10? Any problems with programming the transfer function with Reaper? My guess is you were pretty much on your own.

I want to replace my miniDSP 2x4, something with digital in and 4 balanced out. I am staring a vacant R13 in the face. The price of the PRO24 looks good.
 
Last edited:
Nice touch with the build pictures. Please keep them coming. It's really cool to see everyone's implementations of my circuits.

Now to XLR panel sockets. There seems to be a wide variety of 3 pin panel sockets around, metal or plastic bodied, latched etc. Neutrik do lots of different ones. Anybody got a favourite?

I used Neutrik NC3FD-L-1. Got them at Mouser, I think.

As far as I know, all XLR are latched.

Nope. I've seen non-latching on Parasound and Ashly gear.

Tom
 
Last edited: