The Truth about Stetsom amplifiers

[dtbrown 10+ year member]

There is some misinformation out here about Stetsom Electronics and I wanted to share some information as to answer some questions or clear up any misinformation.

Been in business since 1989

All amplifiers designed, built and tested in house.

We use only American Components, IR, Fairchild, Micrometals http://www.fairchildsemi.com/ , we do R&D for IR testing the latest mosfets out in the market.

We use LITZ WIRE (384 enameled wires) on the output filters, it’s extremely expensive and the best you can use.

We test our amplifiers directly on sun light in 100F+ temperatures running the amplifiers on CLIP and 9 hours straight.

On our Digital line we have smaller amplifiers that produce big power due to the fact that we use 100AMP Mosfets instead of 40A or 50A.

We bench test every amplifier that goes out on a bench with 2000AMPS of available amperage and a voltage availability up to 20V, from 0,5 ohm up to 8 ohms.

And we love customer feed back or input on how to make our product better. Because we design, build and test all amplifiers in house, making changes or upgrades a product doesn't take that long and in a matter of speaking "easily done".

This is just some information on our amplifiers and about Stetsom Electronics but please feel free to use this post to ask any questions regarding anything technical on the product line or about the company.

Click to read more...

 

[lilmaniac2 5,000+ posts]

Jeff is a good guy here //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[DBBOOM 10+ year member]

Any 4 channel component amp plans?

 

[dB-r 10+ year member]

Not trying to hate on Stetsom, but I DO have a few questions regarding them as I have never had the oppurtunity to test one or work on one yet:

1. Which mosfets are you referring to that are 100 amp rather than 40 or 50A? The power supply fets or are you talking output FETs. I have never seen a 100 amp output mosfet that I can recall browsing through mosfets anyway? If you mean 100 amp mosfets in the power supply, most all, probably 90% of modern amplifiers use 100 amp mosfets in the power supply these days, if not 100 amp, then no less than 60-70 amp, the only amps I have ever seen with 40-50amp mosfets are the el-cheapos from years back and really old amps because they didn't make 100 amp mosfets back then. Also that being said, most modern amplifiers that use mosfets in the output stage use various, from 11A to 53A that I have seen. Please do give some info on this as I am dying to know what is in those things (the stetsom amps) as I do not understand the power/weight ratio of those amps, seems like they would just burn up if you run them more than 15 minutes at full power. Some amps use the 169amp or maybe even the new 200amp mosfets that IR is putting out.

2. Does the expensive wire for the output inductors become necessary for the great heat generated by the advertised output specs on these amps? Why such expensive wire?

3. I would think the amp would thermal easily running into a lowest rated impedance load in 100+degrees F. Do you remove the thermal protection for those tests?

4. You say american mosfets, but aren't all IR mosfets made in Mexico? Just wondering because all of them I have ever purchased say Origin: Mexico. Nothing wrong with that, as I believe IR is the best choice for mosfets.

5. Since 1989? Has it been called Stetsom all along? I thought I had heard the name before, as I have been into Car Audio since 1987.

Please don't get mad at me, just answer my questions, I am not hating, just curious, and since you posted this here I figured I would ask here.

 

[sundownz Pro Seller]

Chris,

I can answer the last one - they were in business in Brazil for years - just recently in the USA as far as I am aware.

 

[dB-r 10+ year member]

I have heard the name before I started doing repairs... I just don't recall when/where I heard it or saw it... Happens when you work on hundreds if not 1000 amps in the course of a year, lol....

I do have questions as I don't understand these amps, they look similar to the soundigital amps but I really haven't looked that hard, and have never seen one in person (can someone please send me samples?). Seems like to me, that if you can get gobs of power out of such a small package amp, it would either a. thermal very quickly or b. be pushing the mosfets to their extreme limits, which could cause a shortened lifespan. or c. be a boatload (10%-20%) THD. Just curious what makes them tick. If noone will send me a sample I might just have to buy one and check it to see what makes them tick and post it here.

 

[Rashaddd 5,000+ posts]

I have heard the name before I started doing repairs... I just don't recall when/where I heard it or saw it... Happens when you work on hundreds if not 1000 amps in the course of a year, lol....
I do have questions as I don't understand these amps, they look similar to the soundigital amps but I really haven't looked that hard, and have never seen one in person (can someone please send me samples?). Seems like to me, that if you can get gobs of power out of such a small package amp, it would either a. thermal very quickly or b. be pushing the mosfets to their extreme limits, which could cause a shortened lifespan. or c. be a boatload (10%-20%) THD. Just curious what makes them tick. If noone will send me a sample I might just have to buy one and check it to see what makes them tick and post it here.

And then when you're bored of it you can send it to me //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[andrew2944r 10+ year member]

Seems like to me, that if you can get gobs of power out of such a small package amp, it would either a. thermal very quickly

I think thats why alot of people dont use these for streetbeat applications, from what I have read on forums... Thats the reason I didnt invest in Stetsom, but I could be wrong...

 

[dB-r 10+ year member]

And then when you're bored of it you can send it to me //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I don't know seems like if it's all that it's said to be I would want to keep it.... I know people have won comps with these things, but I hear they thermal easily. I am wondering if all that power coming out of those amps is sine or square wave.... I need one to test so I can see for myself.... could understand it doing a bazillion watts of square wave output, that's what mosfets do best, is square wave...

 

[JimJ 5,000+ posts]

2. Does the expensive wire for the output inductors become necessary for the great heat generated by the advertised output specs on these amps? Why such expensive wire?

I'm not sure if you'd get the same kind of benefits at audio frequencies (used to output transformers here //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif) but at least in my experience with RF, Litz does have useful properties in reducing losses in the toroids...not sure if you'd get the same higher-Q benefits at audio, though.

 

[scarolinablazin 10+ year member]

the quality of the parts play a big role as well. if he's using American made parts they are going to be far superior to the chinese junk that companys like sundown etc use. therefore he is able to get better numbers. the fact that you have never even seen one also says they are better quality than others like sundown chinese crap.

 

[JimJ 5,000+ posts]

the quality of the parts play a big role as well. if he's using American made parts they are going to be far superior to the chinese junk that companys like sundown etc use. therefore he is able to get better numbers. the fact that you have never even seen one also says they are better quality than others like sundown chinese crap.

Sundown's SAZ line isn't made in China, just FYI.

 

[captaincheesey 10+ year member]

I want to see tests done by db-r. Would be good to see how these amps work seeing as they are uber small and put out large amounts of power.

 

[sundownz Pro Seller]

the quality of the parts play a big role as well. if he's using American made parts they are going to be far superior to the chinese junk that companys like sundown etc use. therefore he is able to get better numbers. the fact that you have never even seen one also says they are better quality than others like sundown chinese crap.

The SAZ amps are Korean built.

Chris being my official repair center of course sees any amp that is blown for any reason - I'm sure Stetsom has a repair center as well.

 

[njaykaplan 10+ year member]

About a year and a half ago, I believe Alex (DBDesignsElite) did a lot of testing on the stetsom and warned me (about my 2k6D from years ago) that the mosfets were working to their limits, and that it most likely would burn up rather quickly.. But i tested it on half ohm daily for a week, and didn't heat up too much, although I had used reducers to fit 0 gauge into the 4 gauge terminal.. Never cut out on me, and sounded louder to the ear than a pair of mtx 81001s strapped into an incredibly low load.. I sold the amplifier because i believe his experience with amps, as he does repairs as well, and I tend to abuse amplifiers, so i'd prefer to stick to sundown which enjoys it :-D.