# Old school obscure amp, Rock USA



## Lanson (Jan 9, 2007)

Wondering, does anybody remember these? Handcrafted in the USA, looks Zed-ish built but what's the story?
ROCK USA RA4.55 4-CHANNEL 320 WATT POWER AMPLIFIER - eBay (item 260434380992 end time Jan-19-10 10:20:56 PST)


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## 89grand (Nov 23, 2006)

I know just about every old school amp ever made, but I can honestly say I've never heard of that.


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## ca90ss (Jul 2, 2005)

Looks like a Cadence. Likely Zed made.


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## Lanson (Jan 9, 2007)

I know! But it intrigues me. The tsunami generator 6ch does to, as does the xtant 2.2's

yeah, ebay.


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## Lanson (Jan 9, 2007)

well i asked stephen, they aren't his and he's never seen them before. 

What mystery!

I'm almost tempted to buy them and pop gut shots of them, and have a resident amp guru bench the thing.


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## PimpMySound (Oct 10, 2008)

It seems that Stephen made to many different amps in the mid 90s...

The Cadence path is the right way, probably Stephen can remember, that he made these amps for them.

I don't know all details, but this Rock series was distributed in Germany from 96-98, I guess it was one batch. There were 2 other models in this series, a small 2 channel called 2.55 and a big 2 channel called 2.150.

They were definitely made by Zed Audio, I had one of these amps a couple of years ago and also checked the guts, I believe it was even printed on the board.


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## Lanson (Jan 9, 2007)

I emailed him when I thought that. His response:


No Zed had no input on these amps, and honestly I have never heard of this brand.

Regards


Steve Mantz



So either he doesn't remember it (unlikely) or it wasn't Zed. Regardless, what do you know about them? Share your thoughts


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## orangelss (Dec 20, 2008)

Maybe Cadence rebadged them for a over seas market. The same seller has a dynaquest 4 channel thats identical to the Zed made Nakamichi I have in the closet.


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## PimpMySound (Oct 10, 2008)

This last nakamichi series is nod ZED made. Dynaquest ist the brand name, that an Asian OEM manufacturer uses on his samples. And I have seen this model in one of their catalogues.

Obviously, this eBay seller bought B-stock goods including OEM samples from Cadence.

I remember that the Rock amps came from Cadence, but I don't know any further details.


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## cleansoundz (May 14, 2008)

Nice looking amp, I would interested to see the build quality on it.


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## Guy (Feb 16, 2006)

A hundred bucks isn't much to spend to satisfy a curiosity.


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## Lanson (Jan 9, 2007)

So true. But since Stephen didn't make it, I'm slightly less interested. Only because I mean,..come on..how good could it be if nobody knows about it?

I need a roll's eyes smiley right here..


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## Guy (Feb 16, 2006)

The wink eye smiley meant something in this case. 
One left.


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## Lanson (Jan 9, 2007)

oh, I thought you bought one


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## PimpMySound (Oct 10, 2008)

fourthmeal said:


> But since Stephen didn't make it, I'm slightly less interested.


As I said before, this amp was made by ZED Audio, but probably they left the factory as Cadence amps...


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## Lanson (Jan 9, 2007)

PimpMySound said:


> As I said before, this amp was made by ZED Audio, but probably they left the factory as Cadence amps...



And as I said before, I asked the man himself, and he denied it.

Stephenm on the the forums. I asked him, he immediately replied (which is freaky, considering he's probably a lot more busy than we are) that that Zed didn't have a hand in it. 

A guts shot would end the debate, but I spent all my amp monies on two D4100F's, and one D2100T just now.


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## ca90ss (Jul 2, 2005)

PimpMySound said:


> probably they left the factory as Cadence amps...


Probably made in the same place but not likely just a rebadged Cadence since there are a couple differences in the heatsink.


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## Lanson (Jan 9, 2007)

The fun part...

The guy, when I asked him the poignant question of what the guts are like inside and if he could send pics, he said that Zed did in fact make them, for Cadence, just like you guys have said.

Got a pair on the way.


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## Lanson (Jan 9, 2007)

That ebayer is Jake at Cadence. They are Zed. The first MOSFETs Zed did according to Jake. 

I'll review them when they come in.


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## Luke352 (Jul 24, 2006)

Zed probably produced them in an unmarked condition for supply to Cadence, Zed probably had no knowledge of what naming they ended up being sold under.


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## Lanson (Jan 9, 2007)

When I get them, I'll pop them open and take pics and such.


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## WRX/Z28 (Feb 21, 2008)

Looks like one of the shockwave amps...


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## stills (Apr 13, 2008)

at first glance i thought it was a rockwood w/ a broken label. LOL.


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## Lanson (Jan 9, 2007)

Ouch. 

Well I'll get down and dirty with them, I may even send one of them out for testing by one of our own forum's amp experts. We shall see.


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## TREETOP (Feb 11, 2009)

The amp color, the printing color, font and size, and the RCAs and adjustment knobs all remind me a lot of ESX amps- which were also made by Zed.


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## Lanson (Jan 9, 2007)

TREETOP said:


> The amp color, the printing color, font and size, and the RCAs and adjustment knobs all remind me a lot of ESX amps- which were also made by Zed.


Yep, looks like the Planet Audio Zeds too.

These came from Jake at Cadence. Can't wait to check them out.


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## audiogodz1 (Jan 5, 2010)

Just to add, from the side they look like Hifonics VIII and happen to use the same arrow knobs.


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## basshead (Sep 12, 2008)

This is ZED made

Look is very similar to US Acoustics amps

US Acoustics USA4080 








RockUSA









They both use numbers to identify channels, pot look similar 
US Acoustics USA4080 








RockUSA


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## Lanson (Jan 9, 2007)

Agreed, it is Zed made. But it was from the time Cadence was working with Zed, which didn't go well according to all sources.

Jake said some serious **** went down between the two companies.

I'm not one to gossip and I would never tarnish a name as prominent as Zed or Cadence, but we all know that business deals don't always go smoothly. 

Regardless, they hopefully will have the Zed-ness that I bought them for. We shall see.


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## cleansoundz (May 14, 2008)

If it walks like a duck and sounds like a duck, then it is a duck.


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