My Neurochrome Modulus-686 Build

[concorde1]

Hi, for the last while I've been designing and building my own amplifier using Neurochrome's Modulus-686 boards.

Finally it has come to fruition.

I designed my own chassis and built it from 5mm aluminium, having the panels water jetted for holes for connectors and ventilation etc. I used the heat sinks as the side panels. I used aluminium rod as a frame around each heat sink, allowing me to attach the panels to the heat sinks.

I had the panels powder coated - in the pictures they will look black but the colour is actually iridescent red; at the right angle it looks sparkly red, and mostly it looks black.

Where possible, I chose to solder the Neurochrome boards myself (other than ISS and amp modules).

It's an incredibly solid chassis. With everything assembled it probably weighs well in excess of 20kg (will measure it later).

I used a blue LED for standby and green LED for active.

The sound: I've just tested it with second hand speakers I was willing to damage and it sounds very clear. I will plug it in to my 530's soon. And then my March Sointuva's will arrive in a few weeks.

Thanks to Tom at Neurochrome for answering my technical questions.

It has been challenging and fun to build this. The most difficult thing was probably building the chassis. Who would have thought it's so hard to make a box?

If you have any questions feel free to ask!

Here are some pictures of my build:

 

[groovybassist]

Nice build!

 

[Hemi-Demon]

Awesome work. Why did you decide against twisting the internal wiring?

 

[tomchr]

Great build. Thank you for sharing!

Awesome work. Why did you decide against twisting the internal wiring?

Twisting or braiding can sometimes work against you with heavy gauge wire. I generally prefer to run the wires parallel and bundle them tightly with wire ties. The point is to get as tight coupling between the forward and return currents as possible. This is especially important around the transformer.

Tom

 

[daniboun]

Nice DIY )

On the other hand, I find that increasing the prices by 100% in 5 years is completely dishonest.

1x Modulus 686 @2018 = $249
1x Modulus 686 @2023 = $499

 

[Sashoir]

Nice DIY )

On the other hand, I find that increasing the prices by 100% in 5 years is completely dishonest.

1x Modulus 686 @2018 = $249
1x Modulus 686 @2023 = $499



View attachment 335151

14% inflation is high vs. general Canadian CPI, but a good many inputs to industrial production have risen by much more over that period (I'm not saying it *is* the case here, but it *could be*): I've had several expense items in my business (not electronics) by more than that.

Fortunately for me, they're a small part of my cost base, but maybe for Neurochrome they are not. It's not necessarily dishonest. If you are comparing against other electronics firms, you still need to look at their volumes, currency fluctuations, labour costs & cetera. As a consumer, I also like low prices, but it's not always possible.

Full disclosure: I've never purchased anything from them, nor had any dealings with them or their management.

 

[daniboun]

14% inflation is high vs. general Canadian CPI, but a good many inputs to industrial production have risen by much more over that period (I'm not saying it *is* the case here, but it *could be*): I've had several expense items in my business (not electronics) by more than that.

Fortunately for me, they're a small part of my cost base, but maybe for Neurochrome they are not. It's not necessarily dishonest. If you are comparing against other electronics firms, you still need to look at their volumes, currency fluctuations, labour costs & cetera. As a consumer, I also like low prices, but it's not always possible.

Full disclosure: I've never purchased anything from them, nor had any dealings with them or their management.

It's a point of view... If we consider that the LM3886 modules are not new, we should rather tend towards lowering the price....
Inflation does not justify the race for profit. We have more than 14% inflation in France: however our salaries have not doubled....

 

[gene_stl]

I think it is very unfair to call raising prices dishonest. All audio gear is a luxury item. Tom has to make a living and pay his bills like all of us do. He also has to have circuit boards made and populated with parts he has to purchase. He has an amp that has a unique position and I am positive he knows about price elasticity and has determined for himself how much margin he needs to make on each item. Compared to amps that cost thousands of dollars his are bargain. They outperfrom everything.

He is entitled both to set his profit and to receive it. "After all we are not communists!" You are free to vote with your feet and buy something different. I think Troels Gravesen offers MUCH less value than Tom C.

 

[groovybassist]

I think it is very unfair to call raising prices dishonest. All audio gear is a luxury item. Tom has to make a living and pay his bills like all of us do. He also has to have circuit boards made and populated with parts he has to purchase. He has an amp that has a unique position and I am positive he knows about price elasticity and has determined for himself how much margin he needs to make on each item. Compared to amps that cost thousands of dollars his are bargain. They outperfrom everything.

He is entitled both to set his profit and to receive it. "After all we are not communists!" You are free to vote with your feet and buy something different. I think Troels Gravesen offers MUCH less value than Tom C.

I agree 100%. Tom has made it very clear he’s not competing in the “race-to-the-bottom” sweepstakes. His products combine his engineering talent, with parts sourced from legitimate vendors, manufactured to a very high standard.

Admittedly, I’m biased in his favor as I’ve purchased 4 different products from him - 2 Neurochrome and 2 from his TCA brand. They aren’t cheap, but they are all very high quality and sure to last a very long time. Something that can’t be said for many products discussed here.

 

[ajar]

I think it is very unfair to call raising prices dishonest. All audio gear is a luxury item. Tom has to make a living and pay his bills like all of us do. He also has to have circuit boards made and populated with parts he has to purchase. He has an amp that has a unique position and I am positive he knows about price elasticity and has determined for himself how much margin he needs to make on each item. Compared to amps that cost thousands of dollars his are bargain. They outperfrom everything.

He is entitled both to set his profit and to receive it. "After all we are not communists!" You are free to vote with your feet and buy something different. I think Troels Gravesen offers MUCH less value than Tom C.

I agree 150%. There is nothing dishonest about raising prices - unless you are misled about the price. If demand is way up, I would increase prices as well. Pricing should be value-based, not cost based (good product marketers knows this). From everything I have heard, Tom builds great stuff. It's very high quality. And there are other low-priced options in the market if that is what one is after.

 

[ajar]

Nice DIY )

On the other hand, I find that increasing the prices by 100% in 5 years is completely dishonest.

1x Modulus 686 @2018 = $249
1x Modulus 686 @2023 = $499



View attachment 335151

What is dishonest about it? Were you misled about the price?

 

[daniboun]

I think it is very unfair to call raising prices dishonest. All audio gear is a luxury item. Tom has to make a living and pay his bills like all of us do. He also has to have circuit boards made and populated with parts he has to purchase. He has an amp that has a unique position and I am positive he knows about price elasticity and has determined for himself how much margin he needs to make on each item. Compared to amps that cost thousands of dollars his are bargain. They outperfrom everything.

He is entitled both to set his profit and to receive it. "After all we are not communists!" You are free to vote with your feet and buy something different. I think Troels Gravesen offers MUCH less value than Tom C.

I would not enter into this debate. I'm not saying that the Modulus are bad but that the price is disproportionate
It is precisely because I am not a Communist that I am still free to think) Besides, I am the first to praise the Purifi Neurochrome Buffers)

 

[tomchr]

On the other hand, I find that increasing the prices by 100% in 5 years is completely dishonest.

1x Modulus 686 @2018 = $249
1x Modulus 686 @2023 = $499

You are not comparing apples to apples here.

The $249 Modulus-686 only had the surface mounted components populated. You had to buy about $100 worth of parts and solder up the rest to make it work. To equal the fully assembled module, you also needed about $30 worth of custom mounting hardware. I have shown the board below for reference:

What you receive for $499 today is a fully assembled module as shown below.

Do you see the difference?

In addition, the module I offer today is Rev. 1.1 which is an improvement on Rev. 1.0 that I offered in 2018. I originally (i.e., in 2018) offered Rev. 1.0 fully assembled for $469. $469 -> $499 is a 6% increase. Prices have gone up much more than that. The LM3886 ICs alone have almost doubled in price.

How about you check the facts before you accuse me of being dishonest?

Tom

 

[daniboun]

You are not comparing apples to apples here.

The $249 Modulus-686 only had the surface mounted components populated. You had to buy about $100 worth of parts and solder up the rest to make it work. To equal the fully assembled module, you also needed about $30 worth of custom mounting hardware. I have shown the board below for reference:
View attachment 335241
What you receive for $499 today is a fully assembled module as shown below.
View attachment 335242
Do you see the difference?

In addition, the module I offer today is Rev. 1.1 which is an improvement on Rev. 1.0 that I offered in 2018. I originally (i.e., in 2018) offered Rev. 1.0 fully assembled for $469. $469 -> $499 is a 6% increase. Prices have gone up much more than that. The LM3886 ICs alone have almost doubled in price.

How about you check the facts before you accuse me of being dishonest?

Tom

Makes sense now. Thanks for the feedback. My bad so )

 

[concorde1]

Amp is still going strong.

When I first got my Sointuva's last year, I connected them and measured the voltage/current (ie wattage) output with an oscilloscope at various preamp volume levels. I put 2 stickers on my preamp where it aligns with wattage levels (100W and 200W) so that I don't destroy my Sointuva's. The power ramps up very quickly past 100W so the stickers are only about 1cm apart. I never go further than midway between the 2 stickers.

Only issue is the big transformer buzzes most of the time really annoyingly.

It has always done this I just haven't bothered trying to fix.

Small rubber rings are placed between the transformer and chassis on both top/bottom of the bottom plate.

My only idea so far is to slightly loosen or tighten the mounting screw for transformer. Or use more rubber.

I might try this later today to see if it helps.

Any ideas are welcome.

 

[tomchr]

Transformer buzz can sometimes be caused by DC on the mains. A DC blocker can help.

Mains DC and Transformers

ESP - The Audio Pages. Even a small amount of DC offset on the mains is enough to cause problems. Find out how it happens and how to fix the problem.

sound-au.com

Tom

 

[Speedskater]

and Transformer Buzz can sometimes be caused by high AC line voltage in old transformers designed for 110/115 Volt operation.

 

[HarmonicTHD]

Makes sense now. Thanks for the feedback. My bad so )

Maybe it would be nice to edit your original post.

BTW. In 2018 I bought 2 unpopulated Mod 686 boards. I made a mistake when soldering one SMD (and there are many). Tom helped me to track down the bad solder within less than 12hours. That service, I also call value for money, which some not really appreciate in today’s mass market sell and forget approach where vendors don’t react for weeks if at all if there is a problem.

 

[HarmonicTHD]

Amp is still going strong.

When I first got my Sointuva's last year, I connected them and measured the voltage/current (ie wattage) output with an oscilloscope at various preamp volume levels. I put 2 stickers on my preamp where it aligns with wattage levels (100W and 200W) so that I don't destroy my Sointuva's. The power ramps up very quickly past 100W so the stickers are only about 1cm apart. I never go further than midway between the 2 stickers.

Only issue is the big transformer buzzes most of the time really annoyingly.

It has always done this I just haven't bothered trying to fix.

Small rubber rings are placed between the transformer and chassis on both top/bottom of the bottom plate.

My only idea so far is to slightly loosen or tighten the mounting screw for transformer. Or use more rubber.

I might try this later today to see if it helps.

Any ideas are welcome.

Next to DC being the cause.

Does it also buzz under load?

 

[Jukka]

I once looked at Neurochrome and after comparing the apples to a battlecruiser I decided that it's not worth it. The alternative build totals for less and you can put it in a box too.