Need HELP with DIY power amp.

eatmybrains · #1 11-08-2009, 09:38 PM

anyone know where to buy the components/parts for a DIY solid state power amp. I want it to be able to handle a 2 ohm load and and push 4 300 watt 8 ohm speaker cabinets. Only two outputs are necessary. One for 2 mains and one for 2 monitors. and also where to find some good schematics. Any help would be greatly appreciated.

thanks

projectMalamute · #2 11-08-2009, 10:01 PM

This is going to cost a lot of money and take a lot of time.

fdeck · #3 11-08-2009, 10:09 PM

I have built power amps as part of DIY bass amps, and even gigged with one for a while.

Personally, I would discourage this venture except as an academic exercise. There's no way to save money compared to buying something off the shelf, and there is too much that you don't know about issues such as power transformer sizing, safety, thermal design, stability, and fault protection.

I have seen numerous power amp schematics online, which appear to lack vital features such as active current limiting and short circuit protection. So I don't think you can really trust what's out there.

walterw · #4 11-08-2009, 10:18 PM

Quote:

Originally Posted by projectMalamute

This is going to cost a lot of money and take a lot of time.

and still not be as strong or reliable as a $400 QSC.

eatmybrains · #5 11-09-2009, 08:53 AM

yeah I wasnt sure about the cost of a project like this. What are some good "cheap" ones or some new affordable companies? Kind of on a budget of $1000 and I need a poweramp that can go down to 2 ohms and support 4 15" speaker cabinets. Plan on adding another power amp and two subwoofers later to get full sound. Any suggestions would be appreciated. Thanks

projectMalamute · #6 11-09-2009, 09:10 AM

I've got a Crest CD2000 that I like alright, you can get in to that for around a grand I think. Will putt 500 watts in to each of your 4 speaker boxes.

eatmybrains · #7 11-09-2009, 09:17 AM

thanks but I have $1000 for the power amp and 4 speakers

fdeck · #8 11-09-2009, 06:41 PM

On that budget, whatever you end up with will not be worth upgrading.

fdeck · #9 11-09-2009, 07:34 PM

One more thing. Why did I forget this?

What matters is how much sound you get, not how much power you feed into the speakers. I suggest getting a basic power amp like the Behringer EP1500, and build some decent PA tops using plans from www.billfitzmaurice.com. The efficiency gained by Bill's speaker designs will make up for having a less powerful amp. With the confidence you gain from building the tops, you will be ready to build a couple of his subs later.

If you value your ears, your monitors don't need to be 15". What you are planning suggests that you should definitely be wearing earplugs.

JustDavid · #10 11-09-2009, 08:27 PM

Quote:

Originally Posted by eatmybrains

anyone know where to buy the components/parts for a DIY solid state power amp. I want it to be able to handle a 2 ohm load and and push 4 300 watt 8 ohm speaker cabinets. Only two outputs are necessary. One for 2 mains and one for 2 monitors. and also where to find some good schematics. Any help would be greatly appreciated.

thanks

I don't read that as needing to support 2 ohm loads. I read a 2 channel amp with either channel able to feed 4 ohm loads.

You don't need wattage, you need sound. The remarks about BFM's efficient speaker designs are very good advice.

I won't say "don't do it". I will suggest "slightly defer doing it, & read up lots".

walterw · #11 11-10-2009, 01:42 PM

You won't be able to find a power amp that doesn't handle 4 15s, 2 @ 4ohms per side. With that much speaker, the cheapest 300w per side amp will let you be way too loud!

A better, more powerful amp will let you kick butt with just 2 15s, so that might make a lot more sense.

(edit: you're talking about for PA, not for bass, aren't you? in that case never mind, get the biggest most powerful amp you can afford. 750 watts/side would be a good beginning point.)