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FS: Neurochrome Modulus 686 Amplifier - top of the line build!

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Edit: The amp is now sold.

Hi all,

It’s time to part with my Neurochrome flagship amplifier build. This no-holds-barred setup employs two Neurochrome Modulus 686 modules in a dual mono configuration. These are Class AB amplifiers specced to provide 360 wpc into 4 ohms with a vanishingly low THD+N of 0.00025%.

Some build notes below before the Bill of Materials and asking price :

1.) Power Supply
Not one, but *two* Power 686 modules provide the DC, backed by a massively oversized 1kVA toroidal transformer by Antek. This transformer has two 25V secondaries with a shield in the middle, making a true dual-mono configuration.

2.) Power Inlet
Neurochrome's Intelligent Soft Start was added to limit inrush current and provide a variety of switching options. Currently the IEC inlet's toggle switch is connected. I will include a trigger jack in the box that you can add if you wish.

3.) Power Output
The amp's power is tapped through Furutech's FT-867 binding posts (connected using their recommended FT-210 pure copper disconnect terminals). Unlike all-metal binding posts that carry a lot of conducting mass, this model uses a single OCC wire conductor wound around a ceramic+nylon+fiberglass housing. The minimal conducting mass allows the post to be electrically and sonically transparent.

4.) Signal Input
The amp's signal comes in over 23 awg UPOCC Silver wire by Neotech via Neutrik XLR connectors. I do have a pair of Furutech XLR inlets (FT-786) that can be included at cost ($80).

5.) Chassis
Everything is assembled into Modushop's 4U Deluxe Chassis - their top of the line offering, with Universal Mounting System holes for easy repurposing or expansion in the future. Since the amp does not use UMS, its mounting holes were CNC milled into the heat sink using Neurochrome's provided template.

NOTE: The rear panel came pre-milled from Modushop, and while the Furutech binding posts fit perfectly, their teardrop-shaped barrels bump into each other when twisting. You will need a strong twist to move past the interference, which is a one time exercise if you use spades, and a non-issue if you use bananas.

6.) Module Construction
The Neurochrome Modules were purchased fully populated, because Tom puts his boards through a complex wash cycle after soldering to rid them of residual flux, then tests them. He no longer offers fully populated versions of either the Power 686 or the ISS.

7.) Heat
The heat generated is minimal, even when playing at moderate volumes. The heat sinks remain cool to the touch.

8.) Sound Quality
The sound quality is really something to marvel at. The impetus for this build was to compete against my friend's Gryphon Diablo 300 at a fraction of the cost. Comparing them head to head, it is hard to tell who comes out ahead as they are very very close.

9.) Age
The build was completed in fall of 2019 and the amplifier has about 300 hours on it since then, meaning it is only just breaking in.

10.) Bill Of Materials
The Bill Of Materials is as follows:

2x Neurochrome Modulus 686 - $499 x2 = $998
2x Neurochrome Power 686 - $249 x2 = $498
1x Neurochrome Intelligent Soft Start (ISS) = $249
1x Antek AN-10425 1000 VA Transformer = $119
2x Furutech FT-876 Binding Posts - $75 x2 = $150
1x Deluxe 4U Modushop chassis w/ Anti Vibration feet = $355
2x Neutrik NC3FD XLR Sockets - $6 x2 = $12
1x Schurter IEC Inlet = $15
3 ft Neotech UPOCC Silver Solid Core 23 AWG - $11 x3 = $33

Total Bill of Materials = $2429 without shipping of components or assembly

* * *

I am asking SOLD + PayPal and Shipping as an adoption fee. The unit is in San Francisco with me.

Thank you!


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PM’s have been responded to.

What an absolute beast. If I didnt already have a bridged monoblock pair of tom's early mod86p amps I'd be all over this.

Anyone looking for one of the best measuring and sounding power amps at any price should be giving this serious consideration.

Good luck with the sale

Thank you so much! My system without it loses a lot of definition and soul.
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.