any public address amp ???

[Ahmad_tbp]

hi all
any 300w+ Public Address pcb layout ????
( i cant convert the schematic , i m lookin for pcb layout ) ...
and not tube plz ... ( wanna use for a bass guitar amp ... )

[Ahmad_tbp]

any ...????

[JensRasmussen]

Hi,

Try looking here:

http://www.sound.westhost.com/project68.htm
Project builder http://web.comhem.se/~u33113170/p68/
http://www.astro.uu.se/~marcus/private/m250.html
http://users.ece.gatech.edu/~mleach/lowtim/
http://users.otenet.gr/~athsam/power_amp_300w.htm
http://www.delta-audio.com/Leach-Clone.htm

\Jens

[Ahmad_tbp]

hii .. thnx a lot .. are they public address amps ??
& what s diffrence between a hifi and a PA amp ???

[Enzo]

Hifi amps are consumer goods intended for use in the home. PA amps are professional Audio products and are intended for use in commercial sound applications.

Largely the difference is in construction and features. PA amps will usually be heavier in construction, and usually made with dimensions suited to rack mounting. The front panel then usually has the rack mounting ears.

PA amps will almost always have level controls. Generally the PA amps have at least 1/4" input jacks and often also XLR inputs. Many include balanced inputs. Hifi amps commonly use RCA jacks at input.

PA amps will often have more than one kind of output connection. 1/4" jacks are common, as are binding posts. More and more amps are now featuring Speakon connectors, especially the higher powered ones. In the case of 1/4" jacks, many times there will be more than one per channel to accomodate multiple speakers connected to a channel.

Many PA amps are bridgeable. I don't know, but I doubt hifi does that much. Nicer PA amps also include low filters, phase inversion,parallel mono input, other options.

And 400 watts per channel is a small PA amp. 1500 watts per channel is relatively large. I would be surprised at a hifi amp with that kind of push.

PA amps can be expected to put out their rated full power at low freqs for extended periods.

PA amps likely have a lot more protection circuitry in them. MAny of them have as part of the checkout testing, driving the output into a dead short to test current limiting.

I am sure there are other things, but yuo get the idea.

On the whole they sound prety good, but getting that last .005% of distortion out of there is a low priority.

[Ahmad_tbp]

wow ,, it seems it s better if i forget to build one .. lol

[Workhorse]

People call PA amp as Public Address amplifier, but in reality its an sound operator's PERSONAL ASSISTANT amplifier

[Giaime]

Originally posted by Workhorse
People call PA amp as Public Address amplifier, but in reality its an sound operator's PERSONAL ASSISTANT amplifier

Does it need some high efficiency speakers? Maybe 104dB?

[AudioFreak]

PA can mean Public Address or Pro Audio ... These 2 terms are usually used for different applications.

Public address is more typically 70V or 100V lines feeding transformer coupled speakers typically mounted in ceiling etc.

Pro Audio more similar to hifi amps except they usually have higher build quality, greater efficiency, more features etc than hifi amps. That is not to say they sound better than hifi amps... with very few exceptions, hifi amps sound better for critical listening.

[Giaime]

Originally posted by AudioFreak
they usually have higher build quality

NO! THIS CAN'T BE! Remember that here there is people who paid 10k$ for an amp... that's offensive

Btw is there a use for an old public address output transformer? I mean is it too low impedance for some tube stuff?