Modulus-86 build thread

[tomchr]

Originally Posted by Richidoo

Almost finished the amps today.

Purrdy!

Originally Posted by Richidoo

The Modulus-86s took about 6 hours to build both boards.

That sounds about right. I'm at 2-2.5 hours per board. But then, my fingers have also been preset to bend resistor leads to a 400 mil pin pitch since, oh, about sixth grade...

~Tom

[supernet]

Any listening session already made with this amp?

[billshurv]

I wont be fired up for some time yet as a lot of interim steps for me.

[Richidoo]

Workin on it! Hopefully tomorrow. The good weather in NC had me divert to painting. Tomorrow is rain, so I have a chance!

[tomchr]

Just injecting that the Modulus-86 board can be used with the LM3876 as well.

I'm listening to a Modulus-86 in >>>STEREO<<< where one channel is LM3886-based and the other LM3876-based. The supply voltage is ±15 V. This is intended as a low-power build to drive a pair of computer speakers.

I stand by my previous comment that if the amp sounds good in mono, it will sound amazing in stereo. It really does sound amazing. I'm spinning Eric Clapton, "Unplugged"; Dire Straits, "On Every Street" and "Brothers in Arms". I'm seriously impressed. The speakers are Alpair 6P in an enclosure designed by Planet-10. The enclosure is originally designed for the metal cone version of the driver, but take the center port fill out and it'll work with the paper cone version.

I actually can't tell any difference in sound quality or measurements between the LM3886 and the LM3876 channels. I'm sure I can measure a few minute differences, I just haven't gotten there yet. I was a bit eager to get the contraption hooked up to my speakers...

~Tom

[Richidoo]

Originally Posted by Richidoo

Workin on it! Hopefully tomorrow. The good weather in NC had me divert to painting. Tomorrow is rain, so I have a chance!

No mic cable in the house, so I can't make ICs.

[billshurv]

Annoying. Hope you can sacrifice something to the cause. Not even a ratshack near you?

I have made interconnects out of solder in the past when desperate. And Pano has proved that 8 out of 10 listeners cannot tell a banana from wire!

[dominique-tanguy]

I have received my board yesterday. I decidied to test my capability with the easiest part, the power supply. I am still waiting for the enclosure.

So far so good... Instructions provided by Tom are very clear.

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Dominique

[Philfr]

Originally Posted by tomchr

Just injecting that the Modulus-86 board can be used with the LM3876 as well.

Hi Tom,
Good news !
It is available from mouser, and it looks better regarding datasheet.
For low power needed (10/15 watt) with low voltage (12/18 volts), maybe it's a good way ?
Phil.

[tomchr]

Originally Posted by Philfr

For low power needed (10/15 watt) with low voltage (12/18 volts), maybe it's a good way ?

I'm running mine at ±15~16 V using an Antek AN-0512 (2x12 V, 50 VA) and a Power-86 board with 2x33000 uF, 25 V caps. Works great!

To run at low voltage, you need to swap a couple of resistors on the MOD86 board to ensure proper regulation of the on-board voltage regulators. That's now described in the design doc.
If you need the latest doc, just email me. List the email address you used to buy the boards so I can find you in my records.

~Tom