Hello everybody

[Crusty shadow]

hey im new here, but not new to audio.
my name is nate, im 34 live in the st louis area, have been a mobile electronics installer since 1996. lots of knowledge here, looking forward to learning more and dishing out any i have to offer.
this winter while its too cold to work on my project car i want to build my own car audio amp. a sub amp with around 1000 RMS unregulated power supply and triple darlington output. first real shop i worked at sold phoenix gold and still to this day have not heard any other amps sound as good.
ive designed and made my own circuit boards and sucessfully built and ran megasquirt, so i have some experience with board and circuit design.

i expect to fry hundreds of dollars worth of semiconductors and may even be blessed with a fireball or 2.
look forward to meeting you all!

 

[Pano]

Hi Nate, welcome to the forum!

 

[anatech]

Hi Nate,
Welcome!

There are some real experts here in the car audio forum. Well known in the industry.

a sub amp with around 1000 RMS unregulated power

Really? How much input current are you expecting to deliver to that amp? I'm assuming 1 KW RMS, load impedance unimportant. It's a lot, that's for sure.

-Chris

 

[planet10]

Welcome to the forum... you do know the smoke won't go back in once you have let it out

dave

 

[Crusty shadow]

i have a brand new stinger 225 amp alternator just sitting here. current supply wont be an issue.

 

[anatech]

Hi Nate,

i have a brand new stinger 225 amp alternator just sitting here. current supply wont be an issue.

Wanna bet? Work out the current requirements.

I used to be a warranty shop for most higher end brands, including Alpine in the early days. Current starvation was a common cause for failure back then. Your best bet may be to use that shiny, new alternator plus a new deep discharge battery back where the amp is. Isolator as well, of course!

"Back in the day", what worked the best was to concentrate on efficiency for the speakers. Needing the least amount of power allowed for more dynamic sound and cooler voice coils. That's up to +2 dB right there. We could get 118 SPL using a 50 wpc amplifier (not a cheater amp). It was rough on Chevettes (am I dating myself?). These systems also sounded far more natural and more enjoyable. Not killing the battery when parked is a huge plus.

If you're going for pounding sub bass with some highs clicking along, that is a different direction and a road I haven't traveled. But in any event, I wish you the best success.

You may want to look at early Linear Power amps, or the ancient MGT2100 for inspiration. These amps used higher internal supply voltages and delivered stupid power. I think some Linears ran as high as +/- 50 or 60 VDC! MGTs ran +/- 35 VDC and were rated at 50 wpc only. The MGT amps used a home amp schematic, but the inverter wasn't near as good as todays products. I think some old Alpine amps got as high as +/- 40 VDC. That's a lot of power!!

What is your target for power supply rails in the amp section? Looking back at the Carver car amps, they used similar switching supply rails and tended to be very efficient, as well as brutal to speakers in the hands of an idiot.

-Chris