Cheap Powerful Amplifiers

[Grant Bunter]

In the end, it is simply whether or not you can believe the figures and stats quoted with these "cheaper" amps.
Real world experience with some of them is that the figures are reasonably accurate, others are outlandish crap.
The age old adage "you get what you pay for" also comes into play, in some cases. While the price of electronic components has generally decreased and the specs of those components improved, companies that can pump out amps that supposedly have the same output as more expensive models must cut corners somewhere to be able to manufacture them and sell them at the price point they do.

Crown and the like are not newcomers to the market. Generally, their figures are more accurate. They are road proven and they've built a name based years of experience and real world reliability.

Hope this helps...

[But it Hertz]

I went through a string of cheap no name, big RMS amps that were all crap and I sent them all back before I settled on a good one.

This is a great little amp http://www.amazon.com/gp/product/B00364 ... 00_s00_i00 I'm using it in my office / test rig. Right now it is driving a T18 and pair of SLA's. Very happy with the results.

Pioneer GM-D9500F Class-FD 4-Channel Bridgeable Amplifier.

Matches your requirements perfectly. 100 quid and 12v (I see on another thread you have an auto tuba)

Class D. Very small. Plenty of adjustment (but I bypassed everything and my miniDSP takes care of it all).

It actually delivers more than advertised RMS and sings clear as a bell. The clarity really surprised me. I would hesitate to say audiofile quality but it is getting there for sure.

It does get warm to the touch when working hard but nothing like some cheap analogue amps would. I give it 5 stars!

If this doesn't have large enough numbers for you there are bigger models up the range but I haven't tested them personally. I assume they would be a slightly bigger variation on this theme but you never know!!

[byacey]

Crown and the like are not newcomers to the market. Generally, their figures are more accurate. They are road proven and they've built a name based years of experience and real world reliability.

Hope this helps...

I was considering buying some dead Crown amps and rebuilding them for my own use until I started researching their track record for service issues and reliability. Have a look at this thread:
http://www.audioforums.com/forums/showt ... p-Problems

[Grant Bunter]

Crown and the like are not newcomers to the market. Generally, their figures are more accurate. They are road proven and they've built a name based years of experience and real world reliability.

Hope this helps...

I was considering buying some dead Crown amps and rebuilding them for my own use until I started researching their track record for service issues and reliability. Have a look at this thread:
http://www.audioforums.com/forums/showt ... p-Problems

Interesting. 13 posts since 2008, with 4 or 5 comments about amps from 2006 and 2007.
I'm sure there are more complaints about, bad news always travels faster than good news.

I wonder what the percentage of complaints is compared to the amount of units sold worldwide? Probably about the same as every other company out there.

In the early 90's I had a good mate buy 5 x QSC (various model) amps from an install. They were put in brand new, and were 4 years old. 3 of the 5 had issues. 1 was not commercially viable to repair.
Doesn't mean I wouldn't buy QSC though...

[maxo]

Im pretty sure crown have fixed the flaws on the xti production line
or on their sub contracted third party factories

the posted link to the reliability issues where from 2010
2 years ago
so.. i have heard nothing bad now
also the xti line have version 2 now
all the amps have a 2 at the end of the number

xti1000 is now xti1002 and so on

[But it Hertz]

I would advise against buying anything from the US to use in the UK that has a mains transformer in it UNLESS it specifically says in the specification it can work OK at 50Hz as well as 60Hz.

Even if you buy a builders transformer in the UK and run the amp at 110v you'll find that the transformers will run very hot! It's all about the power factor.

Same applies to anything with an electric motor (I used to import RV's into England and we had to frig the A/C units to stop the motors from over heating).

[byacey]

The transformers require more iron in the core to run efficiently at 50Hz vs 60Hz due to the reactance of the core. To run on 50Hz, there is also more turns required on the windings to make them run efficiently.

[But it Hertz]

Yes. We got around it by keeping the voltage to frequency ratio the same.

This describes it well http://www.lmphotonics.com/motor_50Hz_60Hz.htm. We found the sweet spot for American RV's running at 50Hz is about 104v to 105v because current consumption increased exponentially as voltage increased.

Then we added some more power factor correction to bring the apparent current down and everything ran OK... if a little slower!

We had special transformers wound so they could change the voltage depending on the camp site. In England the mains voltage where we did our conversions was at 245v, on the continent it could easily fall below 220v.

If he gets the amp running without over heating there's no telling how it would perform.

[byacey]

I guess that would be a good case for using a switching supply. I'm not overly fond of switching supplies, but any gear that needs to travel around with different line voltages, a switcher is a positive asset.

[DJ Nada]

I was considering buying some dead Crown amps and rebuilding them for my own use until I started researching their track record for service issues and reliability. Have a look at this thread:
http://www.audioforums.com/forums/showt ... p-Problems

Crown has switched production from the US to China. Shame.

[rotebass]

I was considering buying some dead Crown amps and rebuilding them for my own use until I started researching their track record for service issues and reliability. Have a look at this thread:
http://www.audioforums.com/forums/showt ... p-Problems

Crown has switched production from the US to China. Shame.

Why?

[Bas Gooiker]

I was considering buying some dead Crown amps and rebuilding them for my own use until I started researching their track record for service issues and reliability. Have a look at this thread:
http://www.audioforums.com/forums/showt ... p-Problems

Crown has switched production from the US to China. Shame.

Why?

Maybe the loss of jobs. Can't be about quality, sinds all components have been made there anyway. Lots of known brands are made in China nowadays.