My LM3886TF weekend project

[Wardsweb]

Here are a couple pictures of my latest chip amp based on the LM3886.

 

[JonFo]

Very cool.

It's funny how these days, the majority of the weight and parts count is in the power supply. Nice toroid there.

That's a nice box, where did you get it from?

 

[jtwrace]

Very cool.
That's a nice box, where did you get it from?

for sure.

+1

 

[Jimna]

yes very cool! whats the specs?

 

[Wardsweb]

The case (ATI-738U) I bought back in 2007 from ATI Research. It had just been sitting, so I decided to use it.

The National Semiconductor LM3886TF is capable of 68 watts. I'm under driving it so I get about 50 watts per channel.

The amp has plenty of heft to drive even non-efficient speakers. The highs are very crisp. I've only got about 15 minutes on the amp, so it should only get better as things heat cycle a few times and the chips get a good burn in.

 

[jtwrace]

The case (ATI-738U) I bought back in 2007 from ATI Research. It had just been sitting, so I decided to use it.
QUOTE]

Too bad they are no longer in business.

How are the Prodigys?

 

[Tj Bassi]

Very nice!

Some of the chip amps have excellent specs, and are even making their way into high-powered tube amps as driver stages.

http://www.electra-print.com/techblog.php?blogid=7

I am thinking about using one to drive my PP 304TL amplifier. In this case a single Pentawatt device can swing 130 volts on the output stage grids, all the way into A2 if you'd like.

Tj

 

[Tj Bassi]

Where did you source the boards/heatsinks from?

Tj

 

[Bernard]

Very nice indeed!

I am not a fan of anything with a power switch at the back, having lived for many years with a CDT and DAC that had power switches in it the back. I found it a major problem reaching round the back every time.

 

[RUR]

Where did you source the ...heatsinks from?

Tj

Shoot, they look like they're milled!

 

[Wardsweb]

Where did you source the boards/heatsinks from?

Tj

You can buy the boards or a kit from chipamp.com The heatsinks I picked up on Ebay.

Here is my previous version based on the LM3875. I got these heat sinks also off Ebay.

 

[Wardsweb]

Very nice indeed!

I am not a fan of anything with a power switch at the back, having lived for many years with a CDT and DAC that had power switches in it the back. I found it a major problem reaching round the back every time.

I don't use the chip amps that often in a permanent setup, but when I do, I power them via a 12VDC triggered relay (Parasound Scamp).

 

[stuwee]

Very nice indeedy! Clean, well thought out.

I'm just curious, which of your wonderfull SAE amps would you compare the sound to?