Subwoofer amp

[diy didi]

Hi.
Anyone have a nice design for a 100Watt subwoofer amp?
I've alreadt built a nice active low pass with adj freq. My power supply will be about +/- 39V when fully loaded with a 4ohm speaker. My heatsink that I have already "ready-ed up" will be able to take 4x T0-3P style cases.
Just wanna build something thats gonna last! must be simple to build. discrete would be nice.
P.s there is no space for a fan!!

[Aucosticraft]

if you are looking for subwoofer, would you be happy to use Class-D amp ?

[AndrewT]

There must be at least hundreds of built and tested 100W into 4r0 amplifiers on this Forum.
Join a thread and get a feel for how that particular choice works out. If the feedback is not to your liking, choose another.

[ingenieus]

A 100W into 4ohm? The world is your oyster!

This thread might help:
"ST151" 100W amplifier

However, your requirements to use an existing power supply and heatsink does narrow down things a bit.

Regarding the OPS, the first thing that comes to mind in a TO3 case is the MJ15003/MJ15004.

The 39V PSU rails are good for 190W into 4 ohm. In theory at least. What is the VA rating of your transformer? Will the speaker unit(s) that you have in mind handle it?

[AndrewT]

Originally Posted by ingenieus

The 39V PSU rails are good for 190W into 4 ohm. In theory at least.

No it won't. Not in theory, nor in practice.

You can expect 100W to 120W into 4r0 from your +-39Vdc PSU.