Sub Amp

[XOtothelight]

I'm looking to actively power a subwoofer (HT project). Is there a recommendation on a kit or amp out there? The room is 12 x 15. The driver will be a 10" NHT or 12" HiVi or Peerless. Leach Amp and/or clone?

[amplifierguru]

Hi X0tothelight,

Have a look at my 300W modulated bias cascode amp -

300W 'modulated bias' cascode Killer Amp

Or my website -

http://members.dodo.com.au/~gregball/guru_007.htm

This patent pending topology has numerous advantages over the old Leach.

1. rugged modern MOSFET (8 x 150W IRFP) outputs.
2. R2R design requires smaller power supply for given power and doesn't require secondary PS for early stages.
3. Uses filtered 2BJT current sources for best amplifier operating point stability and much lower supply intrusion (vs cheap zener and tail R).
4. modern topology with lower distortion 'modulated bias' cascode
5. compact 7" x 2" low cost double sided board and easy to build kit.

Todays technology today. See pic -

Cheers,
Greg

[acenovelty]

Howdy XOtothelight,
Might check out a "plate amp" from under their Audio Amplifiers section at,
http://www.partsexpress.com/
Very reasonable prices. A Leach amp would be a big waste for a sub amp, tho I have also done it. And spent much more than $150 to do so. Except of course, you want the learning experience. Then it is most reasonable.

Regards

[XOtothelight]

Ace,

Thanks for your input. I was considering a plate amp but was considering saving a few $$s by building a kit. 300W is the max I'll need.

Greg,

Looks promising. This will definitely be something I look at further. This is only the beginning (HT speakers and sub). Eventually I'll build a dedicated amp and/or preamp. 300W is a definite sweet spot for me, not much lower, not much higher.