# Old School? Autotek Stealth Info



## BoostedOne (Nov 15, 2012)

So I was out pawn shopping today and came across this Autotek Stealth. Never seen them before. I am very familiar with the old 7XXX BTS lines and bought some of those when they were first introduced, but kind of quit following them in the mid 90s.
This thing weighs a danged ton, had the "Bass Thrust" logo on it. Its a XS-900.2. Most of the time when I run across anything other than a BTS I pass, figuring its made after they went to heck. I tried to do some googling in the store, found what seemed to be relatively impressive power numbers considering the price.. [email protected] ohm, up to 900x1 at 2ohm mono. Supposedly all at 12V..

After I got home, got on the net and really cant find much of any info on this thing. Maxxsonics doesnt have the manual listed. 

The board says 500S, but I did find a manual for the 500S and it says it would have two small fuses.. This thing is stated to run a single 60A fuse, but whoever had it before me stuck a 80A in it...

Can anyone tell me some stuff on this thing? When were they made? Is it a class A/B or a D? Do they really make the power that they say? If they do is it right at 900W or are they underrated?

One thing that does have me a bit concerned is I did get a Maxxsonics manual that covers the 500S... If the S series came out before the XS and they were just reusing boards on these things it kind of bugs me that the 4 ohm stereo numbers from Autotek were at 12V, then the 2 ohm and bridged ratings were at 14.4... would lead me to beleive that the ratings I saw that were stated to be at 12V were really 14.4...

Thanks for any info yall can share on this thing.


----------



## ATOMICTECH62 (Jan 24, 2009)

The amp you have started selling in 2000.They are class A/B amps.It is the same thing as the 500s that came out in 98 with a new fuse style because Autotek was have problems with the small ones melting.If you look under the Maxi fuse holder you can see where the two smaller ones use to be mounted.
The 500.s was the first Stealth series made.They were still trying to keep the the good name of Autotek going so they didnt over rate the 500.s and the other lines.The 500 was rated at [email protected] ohms and [email protected] claimed they were 1 ohm stable but I dont think they gave a power rating at the lower impedance.But I could be wrong.Its been a long time.When they were run at 1 or 2 ohms bridged they would blow the 2 30 amp fuses so everyone put 2 40's in them.This is how the fuse holders started melting.
Anyway,when they came out with the new line of amps a couple years later they jacked the power ratings on them at 14.4volts and did nothing more then change the fuse style.
The SX900.2 was re-rated at [email protected],[email protected],[email protected] and [email protected] ohm.
I remember they claimed they were regulated but they weren't.Which is funny in itself since they claimed rated power at 14.4 volts instead of the previous 12.
They are not bad amps.I use to repair tons of them back in the day but that's only because people beat the crap out of them.I still have a few carcasses around here.
They were full mosfet designs that were overbuilt for the limited power the transformers could produce that's why they could take abuse.
IIRC they would do about [email protected] ohms.If you do the math,a 60 amp fuse or even an 80 amp fuse couldn't supply enough current on a class A/B amp to do 900 watts RMS.I never knew anyone who ran these amps on highs so I couldn't tell you what the SQ is like.
This was the biggest 2 channel the made in this style.They made the XS1500 class D monoblock that was the most powerful of the Stealth line.
A few years later they came out with a XS1600 classX that used a Tripath chip.These are probably all gone.They all blew up and the Tripath chip was discontinued.
The Hifonics series X Industria amps were also based on the Autotek XS line that you have.


----------



## BoostedOne (Nov 15, 2012)

Wow.. Wow.. Wow.. 
Thanks for all the back ground info! I searched for a couple hours last night and didn't find a 1/3rd of that.
I was honestly thinking the same thing regarding the fuse vs power.. Even with a 80A, it would be amazingly efficient to be able to do 900W at 12V. At 15V, meh, maybe.. But to me 14.4V ratings are so BS.. it would be like Chevy putting wild ECU tunes in every one of their cars and rating the power on 118 octane fuel. "Damn this Malibu seems like a real dog for having 400hp! LOL".. Anyhow...

So what you are saying, is I should really consider this amp in the class of about [email protected] ohm mono.. around [email protected] Not earth shattering, but I guess it would make a decent sub amp for a beater. Maybe it will go in my girlfreinds car on a pair of 12W3's I have laying around.

Do you know if these were still US made, or did the production go overseas on these? 

THanks a ton for the info!


----------



## ATOMICTECH62 (Jan 24, 2009)

These were made in Korea at a time when Hifonics and Autotek where going through ownership change.They were bought out by a company called API.After that Maxsonics owned them.
The Autotek and Hifonics Industria series were being made in Korea but at this same time the Hifonics generation X was still a Zed design and made in the USA.Ive heard people claim these Korean amps were still Zed designs.I dont think they were because around 00-01 the new Hifonics Generation XI line was introduced and they same design as the Korean Autoteks.The Hifonics have API in big letters on the end plates and the larger models say Had Crafted in the USA or Designed and Engineered in the USA,but made in Korea or China(cant remember) on the bottom.The Hifonics models with lower output power(from the Thor and down)still have API on them but no claims of USA anywhere.These are the Autotek models.I believe they where intentionally trying to confuse consumers into thinking they were all still USA models at that time.
Im still a little confused as to when they changed from ZED>API>Maxsonics and who design what.They also introduced the Zeus XI line of amps at the same time.UGH.
The XS 900.2 was basically the same amp as the Hifonics Thor XI.The circuit boards are a little different due to the heatsink designs but all the parts are the same.


----------

