Amplifier kit several hundred watts

"Bushy Pete"

** There have not been any such kits for a very long time.

( Since the Dynaco ST400 kit from the late 1970's ..... )

It is FAR more sensible and economic to buy one.

Shame if it is not your fantasy Xmas gift for that cute gal !!

IMCE:

The biggest bargain in new power amps at the moment in Australia is this one by Behringer.

Gives 400 watts per channel, at 4 ohms.

For under $500.

Made in China, OK - but a shameless clone of the justly famous QSC RMX1450 model.

...... Phil

On Fri, 16 Nov 2007 21:18:44 +1000, "Bushy Pete" put finger to keyboard and composed:

Let's hope that you really are "Bushy" and that your nearest neighbour is at least a kilometre away.

- Franc Zabkar

--
Please remove one 'i' from my address when replying by email.

Wot Phil ses. I've been down this path already as an edumacational exercise for my son, a bass player. Bought a pair of amp kits which he built up with the intention of bridging them, then we started looking for ways to adapt the vast variety of nice components I've scavenged over the years, like a transformer the size of your head, and caps the size of an upper arm. Then a case strong enough not to bend when you mount this heavy hardware, and... when I a plan we started thinking about pre-amps, speaker protection circuits, overload protection for the amp, proper sockets to take professional PA speaker cables (connectors are $30 and you need 8 for stereo), etc...

It's simply not worth it. You'll spend twice as much to get a result that's half as good. We quit after building the amp circuit boards and decided to buy an amp. Spent a couple of nice weekends teaching him how to do solid speaker cabinet work (a pair of 80 litre bins) and that was much more productive. The 350+350 watt amp we bought for under $200 never gets cranked anyhow, but the stereo bins do give his band a small PA or a good bass set when needed.

Clifford Heath.

**Not even then. The ST400 was rated at 200 Watts @ 8 Ohms. **Agreed.

**If it's anything like the Behringer crossovers I've used, it should be just fine.

Here's one I worked on recently:

Passable construction quality.

Trevor Wilson

"Trevor Wilson" "Phil Allison"

** So what?

The OP did not specify 8 ohms.

Power output into 4 ohms is the commonly quoted figure in the world of PA a stage sound - as it represents the practical maximum clean power ability of such amps in normal use.

Then folk like to divide the total 4 ohm watt figure into the dollar price to get "dollars per watt".

A result less than 1 = good buy.

For the Behringer EP1500, that figure = 0.625.

....... Phil

**Perhaps I misunderstood these words:

"She has 8 ohm 800 Watt stage speaker bins with 18 inch woofers, and a Yamaha Stagepas 300 PA system to go with it and I'm looking to make a 400 odd Watt amplifier for her for Xmas......"

**Indeed.

**OK. I guess that makes the Altronics offering almost as good. (0.67)

Trevor Wilson

"Trevor Wilson" "Phil Allison" "Bushy Pete"

** Yep - two of them. What load does that make ?

Dunno a thing about the world of stage PA systems - do you Trev?

( Hint - they do not need to and only rarely operate in stereo )

** Not at all, the "dollar per watt " figure improves as you go up the power output scale in a given design range.

Obvious why - if you understand the economics of power amp manufacture.

The larger Behringer model is the EP2500 ( 2 x 750 watts @ 4 ohms).

This one is also a shameless clone of a QSC model.

The magic figure now is a mere ** $ 0.43 per watt **.

I'd give the Altronics "no name" (???) offering a big miss.

....... Phil

**I never claimed to. **Better to examine them first. IMO, their construction is barely average. It is certainly a long way from what I would call good. I don't know about the Behringer, though their crossovers are excellent.

Trevor Wilson

"Trevor Wilson" "Phil Allison"

** By implication - you did.

** Read what I just wrote - for Christ's sake. ** Then shut up - cos others do.

All YOU have done is to confuse the matter with pedantic crap.

As bloody usual.

...... Phil