My Sure IRS2092 Amplifier Build

[Indispus]

Re: My Sure IRS2092 Amplifier Build

Awesome! ...Job well done! Thank you for sharing. I love seeing stuff like this. Higher satisfaction when you build something yourself.

[[email protected]]

Re: My Sure IRS2092 Amplifier Build

I still have a bunch of those. Steve Slater's store is half an hour from my house, so I'm like a kid in candy store when I go there. Are you building another IRS2092 by the way?

yes. This one will go in a 20-16164B case with a softstart and 37,600 per rail via dual rectifiers and a 1000va toroidal with snuber.
I hope the 45-45 works ok.

[hongrn]

Re: My Sure IRS2092 Amplifier Build

The 45-45 should work OK, but that's pushing the limit Lowell. Man, that toroid must weigh a ton. Good luck with the build bud. Please post plenty of pics.

yes. This one will go in a 20-16164B case with a softstart and 37,600 per rail via dual rectifiers and a 1000va toroidal with snuber.
I hope the 45-45 works ok.

[[email protected]]

Re: My Sure IRS2092 Amplifier Build

Fingers crossed. They were out of stock on the 800va. 45 via the math should work, but I hear you.

[neildavis]

Re: My Sure IRS2092 Amplifier Build

Z100 determines the overvoltage protection threshold (see the table I posted elsewhere in this thread). If Z100 has the marking "P26" on it then it is a 75V zener, which should be adequate for 65V rails. If you need a higher value to account for spikes on the rails, you can always change the zener. Two-pin SMD devices are fairly easy to replace.

[neildavis]

Re: My Sure IRS2092 Amplifier Build

Since the OVP is 91V on the AMP7S-200 could I use one of these boards with a PS that puts out slightly more than 70V? I have an old Leach 250W amp that died but has a big toroid PS that's still good.
Ron

You would need to replace Z100. Once you do that the amp should work fine with the higher rails.

[donradick]

Re: My Sure IRS2092 Amplifier Build

Hong: You will certainly save money by building the wooden case, I would love to see what you come up with !

In spite of the frigid weather here in PA I have already started building 3 more Amp cases...I have gotten used to working in 10-15 degree weather(with garage door open) :D.....I would type more but my frostbite is killing me.

Regards
Bob C.

Hi Bob -
I'm getting started with a Gainclone LM3886, and have thought about a wooden case, but I'm worried that the heat will discolor the
wood and/or mess with any veneer. I suspect you only use solid wood, but can you give feedback on heat effects on the wood?

Thanks,

[hongrn]

Re: My Sure IRS2092 Amplifier Build

Don,

I'm going to answer your question for Bob with one of the pics he sent me.

Hong

[donradick]

Re: My Sure IRS2092 Amplifier Build

Don,

I'm going to answer your question for Bob with one of the pics he sent me.

Hong

Totally gorgeous of course. The face is obviously solid wood and corian - is that a metal case behind it?

[robertcottiers]

Re: My Sure IRS2092 Amplifier Build

Hi Don: I have not had any heat discoloration with anything I have built in the past. I usually will leave a gap on the rear panel towards the top
(About 1 inch). I will drill holes in the bottom across the width of the heat sink,convection will draw air from the bottom of the case up through the heat sink fins and out the rear. We are not talking a whole lot of heat here,I have not had any real concerns regarding this.

If you run the LM3886 near the maximum supply rails you will generate more heat of course.

The photo that Hong posted is a Pre-Amp,it has a Corian face(5/8 thick).The side posts are just veneered PVC with a slot cut in the side.The sides are not metal,just veneered MDF. The whole case is put together with pocket hole joinery,You can really put this together real quick and very cheaply IMHO. I would encourage you to use some contrasting woods, light/dark seems to work well visually.The Corian is very easy to work with,drilling and routing no problem!

Good Luck with your build

Bob C.

[hongrn]

Re: My Sure IRS2092 Amplifier Build

Bob,

1. How is the Corian sold? How large a piece does it come in?
2. Can it be cut with a regular table saw?
3. How do you polish it?

Thanks.

[robertcottiers]

Re: My Sure IRS2092 Amplifier Build

Hong:

I just bought some scraps from a fabricator many years ago....I have pretty much exhausted my supply.

You can cut it with your table saw in increments,with my saw I will cut about 1/4 inch with each pass.

As far as polishing... I just use 400 grit sandpaper and then I will use some rub on Poly for the finish,I am happy with the results I get.

EDIT: It does make a mess when you cut it... be prepared!

[robertcottiers]

Re: My Sure IRS2092 Amplifier Build



Here is a Nelson Pass Amp with a very nice front panel design,I think this would be easy to replicate with solid wood or Solid surface material(ie Corian).All you need to do is use a cove bit on either side of the power switch and a simple chamfer around the perimeter....You could also secure it to a metal chassis if you prefer. The meter of course would be optional.

EDIT: I only use forstner bits for drilling solid surface material,You will get a nice chip free hole.

Bob

[donradick]

Re: My Sure IRS2092 Amplifier Build

Thanks Bob - I'll probably give wood a try - I'm finding that nice metal cases are not cheap.

[neildavis]

Re: My Sure IRS2092 Amplifier Build

I'm finding that nice metal cases are not cheap.

A good compromise is wood with protruding heatsinks to draw the heat outside the enclosure. Apexjr has some nice heatsinks for $4 that have a lip that makes them easy to flush mount into a wood enclosure. One is probably sufficient for a pair of LM3886 chips, or slice them down to use two smaller heatsinks with one chip apiece.