Neurochrome Modulus-686

[Firebottle]

The 286 I have is using the switch mode psu's (2x) with built in soft start.

The 686 build has the Neurochrome board.

[CageyH]

Thanks Alan.

[CageyH]

A question about the case.

I am going to order a case from Modushop, the 4U/400 Dissipante.
I am just wondering how you specify the holes in the back panel? I have the CAD file, but how many holes do I need to pay for?
Did anybody get the case engraved/printed as well?

[CageyH]

This weekend has seen me altering the CAD files that Tom makes available for my specific build.
I noticed that the distance between the hole centres was not correct for the Mod 686 V1.1, so I had to find a decent CAD package, learn how to use it, and produce the drawing file for Modushop to prepare my case.

Mod686 side_V2.jpg
The first is the side view, with the positioning of the boards, with the holes drilled and tapped for me to fit the PCBs.

686_Rear.jpg
Then we have the rear layout, to which I have deleted the trigger, and added RCA inputs as I want the option of both inputs.
WBT binding posts will be used, so the cutouts have been modified for them.


Mod686 base.jpg
Then we have my proposed layout, where I will be putting the power 686 boards up on a mezzanine floor.

[killie99]

20% off at Modushop from 20-30 Nov with code BLACKFDAY

[CageyH]

I am still waiting for the ISS and Mod 686 boards, but thought I would progress with what I can.
So, I fitted the transformers, built the Mezzanine and fitted the Power 686 boards to it, and trial fitted it in the case, just to make sure I can get the top on.



I am happy with the progress so far.

[CageyH]

One thing that I have learnt this weekend is that the 19mm spacing of the binding posts limits the choice of posts.
If you are getting a dissipante case machined up, increase this to the 30mm standard, and you will have more choice of a quality post.

[CageyH]

Not much progress has been made recently, as I am mainly waiting for parts.
I have fitted the binding posts, and I have connected the transformers to the Power 686 boards and check that they function correctly.
I am happy to report that they do.

Tomorrow should see my Intelligent Soft Start and Mod686 boards arrive, so I may be able to wire this up at the weekend.

[sailor]

Hi Kevin, just noticed this thread. I would like to make a suggestion regarding your binding posts. When I repurposed an ancient GAS Son of Ampzilla chassis to build a Neurochrome 286 I connected it up with the ubiquitous brass, nickel and gold speaker posts parading as 'connectors'. I used these to fire up the amp knowing that from experience I would later modify the connection.

This mod. consists of a pair of 8mm diameter cheapo binding posts chosen merely for strength, although stainless steel 316 nuts and bolts would allow more torque and be better. The posts or bolts are used merely as clamps and are not used to conduct the delicate audio signal.

I bring the cable directly from the Neurochrome modules outside the amp and terminate to a FUREZ pure unplated copper lug. The same make of lug on the speaker cable and the lug from the module is then placed back to back and clamped with as much force as you think it will stand. I took a spanner to my 8mm posts and torqued the hell out of them. This method does away with the great expense of quality binding posts and the usual terminals, and more importantly removes any possible deleterious effect of the binding posts.

I use the same principle to connect to my speakers. Obviously this is not appropriate for components that you may later wish to sell but I am happy to do it to my DIY stuff.

Short of soldering your speaker cables directly to the modules, which is not very practical, this is the next best thing. You have effectively removed the posts from the signal path. I modded a friends Aragon 4004 but at his urging retained the original binding posts. My old Hafler power amp also responded well to this.

BUT: does this really make a difference? Yes, it really does.

I have always had a soft spot for James Bongiorno's amps, the design genius behind Great American Sound but feel Tom's 286 is possibly better, certainly possesses a lower noise floor but is ruthlessly revealing. Good luck with your build.

[hornucopia]

....so, you thread the wire from amp board through the case hole, then add lug?
Keeping the wires insulated against touching the case, of course!
Having a Hafler DH200 makes me think.....(besides the 86 amp!)
Looks like DNMs idea of speaker pins is parallel here? Less metal in circuit.