Class D Bass amplifier

[pyrohaz]

Hey guys!

I recently finished my first larger project (in a long time!)

As Hero will probably remember, I was considering building a Class D Bass amplifier! Well I have done so and completed it now.

Spec:
240v Input, Dual laptop supply-age!
170w Output (Theoretical)
+/- 24v PSU
Based around the TDA8920BTH in BTL mode
4Ohm 12" speaker
Laney Bassman 40 Preamplifier

I had intended to convert my Laney Bassman 40 into a much better amplifier because to put it bluntly... It sounded like utter cr*p due to the lame-ass power stage!

Luckily with this amplifier, the power amplifier and preamplifier stage were two separate PCB's meaning I could hopefully savage it and use the preamp stage with a new power stage (I diagnosed the problem of which stage sounded so bad by testing the line-out section of the preamplifier on my Marshall Bass 20 amplifier (a lovely amplifier!) and the preamp stage sounded very sweet.

So! I ripped out the horrible power stage along with the bulky transformer (this reduced the weight a lot! And prepped the Preamplifier stage for use with my new power supply (the transformer was a 30v-30v non-torroidal one). After testing the preamplifier stage at +/- 24v, I concluded that it worked fine.

I bought the power supply and power amplifier board off eBay for a total of:

[audioguru]

The Philips TDA8920 class-D dual amplifier IC is a good one.

[pyrohaz]

Agreed 100% :)