# Ground Zero Plutonium Reference 4



## csuflyboy (Apr 20, 2005)

eBay link: Ground Zero Gzpa Reference 4 Car Amplifier | eBay

$2,295

Ground Zero Plutonium Reference 4 
- Anodized black. 
- Upgraded by the legendary Gordon Taylor of Genesis in England with LME preamp chips, and corrected bias setting. 
- Symmetrical dual 2-Channel design 
- Sanken output transistors 
- Mundorf MCap capacitors 
- Variable Bias (Class A - Class AB) 
- White LED illumination under plexiglass 
- Temperature - sensitive controlled fans 
- Highpass, Lowpass, and Bandpass filters 
Reason for selling: Honestly, I just don't have a need for this amp. It's no secret I've got a small warehouse of high end gear, and this needs to be playing music, and enjoyed daily, rather than collecting dust. 
Plenty of references, and 100% positive feedback on eBay. That said, there's no warranty. This is the epitome of high-end car audio. It is in pristine and working condition when it leaves my house in a well packaged box. Your install and remaining equipment needs to be up to par.


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## DragonMouse (Jun 6, 2013)

Well, this is really interesting, the measured values of the output are approx 15% UNDER the rated output RMS power, both @4 and @2 ohm ... ?


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## csuflyboy (Apr 20, 2005)

I wouldn't get too carried away with MAX power ratings, as they're usually limited by a distortion threshold. Besides, the first few watts are what's most important.


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## DragonMouse (Jun 6, 2013)

I am aware of that:

but still, I copied this from their website:

"*The WRMS output power is based on the CEA Standard CEA-2006-A ( 14.4V, 1% THD) 

ModelGZPA Reference 4
Type4 Ch Class AB > A
Output Power @ 4 Ohm (CEA*)4 x 150 W
Output Power @ 2 Ohm (CEA*)4 x 270 W" ..

of course there is the factor of the THD, but still..


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## csuflyboy (Apr 20, 2005)

0.1% (Gordon's threshold) vs. 1.0%....


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## DragonMouse (Jun 6, 2013)

Anyway, it is a beatiful amp. It was on my wish-list for a long time.. Was.

glws


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## Victor_inox (Apr 27, 2012)

0.1 vs 1% is huge difference, in real world situation means nothing. 

What brand new amplifier was doing at Amp doctor?


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## soccerguru607 (Nov 4, 2009)

Well, testing numbers at 0.1% will show much much less power than at 1%

Edit: I had a MAC mc4000m repaired last year and the test sheet shows about 33% less power than rated. Why? because they were testing at like 0.005% instead normal 1%


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## aztec45 (Jul 23, 2007)

I have a ground zero 4125sq, bought it new. As soon I connected the power wires, poof white smoke was coming from it.... All Caps on the power side blown. But the amp was still working.. 

Had Dave from las Vagas(don't remember his user name) change them out.. He said he replace it with some that will last 20 years... 

But to the OP, great amp. Looks sexy...


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## SkizeR (Apr 19, 2011)

guys, let the man sell his amp. good seller here people


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## soccerguru607 (Nov 4, 2009)

I had a set of Uranium 4125SQ and 2250sq, never problems. There are always going to be few bad ones out of manufacture warehouse...This include all other brands...Had brand new never powered Soundstream reference 700sx and 500sx both had defective outputs. These should be B-stock but does not have a sticker on the box or on amp says that.


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## soccerguru607 (Nov 4, 2009)

SkizeR said:


> guys, let the man sell his amp. good seller here people


I agree!!!


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## aztec45 (Jul 23, 2007)

Sorry, I shouldn't have said anything. Good luck with sale!!!


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## [email protected] (Jun 12, 2008)

aztec45 said:


> I have a ground zero 4125sq, bought it new. As soon I connected the power wires, poof white smoke was coming from it.... All Caps on the power side blown. But the amp was still working..
> 
> Had Dave from las Vagas(don't remember his user name) change them out.. He said he replace it with some that will last 20 years...
> 
> But to the OP, great amp. Looks sexy...


That is interesting to hear. We have sold quite a few of them and have never had a warranty issue. I am curious as to if it was purchased new from a dealer, why was it not sent in for warranty?


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## csuflyboy (Apr 20, 2005)

BUMP & PRICE REDUCTION! 
$2000 SHIPPED!


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## csuflyboy (Apr 20, 2005)

Victor - the amp is in Denver, if you're interested in seeing it. This particular one has been upgraded with new OpAmps by Gordon.


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## Victor_inox (Apr 27, 2012)

Thank you,I'm not on the market for this bad ass amplifier.

Sent from my SAMSUNG-SM-G925A using Tapatalk


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## csuflyboy (Apr 20, 2005)

I've lowered the accepted price for the "or best offer"! This needs to go to a good home!


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## csuflyboy (Apr 20, 2005)

Bump for reduced price!


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