Small power amps

[buggyboy]

Boy I'm excited to be closing in on completing a project at my church.
(Brad, I've got video headed your way!)



So... I'm running our mixer out to 2 old 100 watt pa amps.
These are the kind with about 4 mic inputs and a barrier strip output.

The issue at hand is that the mixer main fader has to be set very low to prevent clipping the mic inputs on the pa amp.

I believe the correct solution here is to get a power amp that doesn't have mic inputs but rather has a line input for the mixer.

The question then is, "what small (100 watt) power amps are out there, and what do they cost?"

I'll need to channels, so 2 units, or a stereo unit. Used is perfectly fine with me.

What is the difference between pro audio type with 1/4 inch inputs, and the consumer hifi type with rca inputs? Is there any electrical difference?

[side note, what about building a small power amp from scratch?]




The rest of the sound gear is coming together, so I'm a bit giddy thinking of the day when it's all finished.

Thanks for the input guys

[waynehoskins]

The first low-power install amps that come to mind are Crown's CTs600, they're like a couple hundred watts a side into 4 or 8. Another option would be QSC's CX line. If you want inbuilt processing, consider Crown's XTi line.

There are many differences between consumer, pro, and semi-pro amps. Generally, pro amps have better protection circuits, are rated into a wider range of loads, have linearity measurement circuits, are rack-mounted, have better ventilation, are designed to run 24/7, may offer some kind of system-integration options (eg, Cobranet cards, 232/USB/network, etc.), and so on.

A quick internet look shows the CTS600 at about 1K street price new, but you can regularly get them used on the Ebay in the sub-500 range.

[Frank DeWitt]

What kind of amp is it? Some have input cards that can be swapped TOA is one. Also, look close, is there a jack somewhere for connecting amps together? It might be a RCA jack That would be a line input. Last, Just use a DI box between your mixer and the amps. Make it a good one because all your sound will go through it.

If you do need a amp on a budget, TOA amps used on Ebay are under priced.

Frank

[buggyboy]

The current amps are 1 radio shack and one realistic. both 100 watts.

This is certainly a budget project. And not a hard wearing application. the system is one for only about 3 hours per week.

It just struck me that I might be able to bypass the mic preamps and just feed the mixer into the main power amp circuitry. hmm.

I haven't done much tinkering with amps. Might be an interesting project.

[Frank DeWitt]

Doesn't it have a input labeled Aux, or CD, or something like that?

Frank

[buggyboy]

Duh,*kicks self* yep, that did it.

I could have sworn Ihad tried the aux input before, but it wasn't working. A second try this sunday worked just fine.

now my main fader can be set at unity without overdriveing the amp.

I'm embarrassed that I didn't work out the kinks with the aux before posting.

Thanks

[waynehoskins]

Glad that fixed it.

It's probably in the grand upgrade plan already, but let me of course recommend upgrading to pro amplifiers (Radio Shack, if you can't tell, isn't close to pro). Among other things, they don't have the problem you just had there.

[buggyboy]

Yes Sir! That upgrade is on the list, just under acoustic treatment.
I learn as I go and do the very best I can with the tools God gives me.
I'm thankful for what we have, and I'm glad that my efforts have caused positive changes. People are hearing better now than ever before...and I'm not done working.

I'm also very thankful for this forum, I've learned an awful lot here. And I expect to continue learning as I go.

God Bless

[Frank DeWitt]

Originally Posted by buggyboy

I learn as I go and do the very best I can with the tools God gives me.

God Bless

Smart. Very smart. It is easy to say I can't work with this stuff" Much better to pick the low hanging fruit, fix that, then move to the next thing.

Frank

[buggyboy]

Thanks for the encouragement. The fruit analogy is is apt. I tend to fix whatever will make the biggest improvement, provided I know how to fix it, and i have the gear needed to fix it. The rest goes on the to do list.