Stetsom Amp Guts?

[9teenD]

you can also stop clipping at the deck, before it even reaches the amp.

[Team_DC-Derrick]

the ONLY way to stop clipping is to o scope it... it doesnt matter how the settings on the head unit are once its o scoped, how ever your head unit settings are, it shouldnt clip unless you increase the bass/sub levels on the head unit

[9teenD]

i'm not saying that if you scope the h/u, the amp won't clip. i already said i haven't scoped the amp yet. yes scoping the amp will get out the clipping. i was just asking about the h/u because you were clipping lower than 1/4 gain.

[bass_4_ever]

What hes saying is that you don't need to be running an amp at max gain to get the "full potential" of the amp. What hes saying is tha many amps are different and the gain can be maxed out 1/4 1/2 3/4's gai. I know this doesn't stop clipping, but it helps to tune the amp... get a multi-meter, grab an RMS / ohms chart, put ur multi-meter on your amp outputs and see what your voltage is coming out of the amp. This way you can measure if your getting a crazy clipped signal. I'm running 2 Massive Audio DB3000.1's right now and the gain is maxed out at half way. I haven't o-scoped it but this is judging by the output voltage.

I figured I was going to get mixed emotions about Stetsom, or any brand I would ask about. I just wanted to get an idea of peoples experiences with them, good and bad. This way I could be aware of the possible crap that I could run into if i do decide to take one or two. I wanted to get reviews about them before I shell out money (since I'm in canada and there are no canadian dealers anymore, its going to cost more).

I like the SounDigital amps, but the websites in a whole different language and I've read mixed reviews about them as well.

Like I said, I'm just trying to get a feel for what I might be in for if i do buy a Stetsom. And I appreciate all good & bad comments alike since I can understand how Stetsom amps work and also what some of their flaws might be...

Cheers,

Andrew

[UnderLoK]

Few things... First off in some cases it takes the gain being maxed to get the full power out of an amp. It will be dirty as shit, but more power none the less. Obviously you're looking for the happy medium... The DMM thing is a myth and you might as well do it by ear, seriously... If you were to use a DMM on let's say a T2500 at 2500 watts it wouldn't be optimized (some put out 3200 clean)... If you did the same with let's say a Crunch 3k you will set it to 3000, but do you know for a fact that amp is spitting out 3k clean? No... How about my SS XXX 4000's?! Their site says 3300, the manual says 2800, and my current draw says none of the above... What then?! If you don't use an o-scope you might as well tune it by ear because you are still guessing as amps vary even within the same product line. Fact of the matter is most people lie their ass off on the internet and take their best guess. I can beat the hell out of mine and not smell coil which tells me I'm safe. Does that mean without a DOUBT that I'm not clipping? Nope, but at least I know I'm either under or on the hairy edge. I need it scoped, but unfortunately no one around me has one, so for now I play it as safe as possible until I can get it scoped (just reminded me to make a thread about that).

As far as Stetsom goes, Derrick and Aaron were beating the living shit out of that amp in 90 degree heat all day long. If that doesn't highlight a quality product I don't know what else would.

I've had bad experiences with a number of products, but I equate that to bad luck. Manufacturing isn't a perfect process especially in small batches. Amp companies aren't regulated like car manufactureres, home appliances, etc. so there is a much larger margin for error.

IMHO your best bet on an amp is to find a company that will help you when you need it and has a kick ass warranty. If you have to ship the thing across the planet to get fixed when it breaks (you have to assume that it will) that is no help unless you want to be without it for months on end. If it were me, while I would want an SD (their PSU's are killer), I would aim more for a company that a local shop carries. Why is that important? Because when the thing blows up a week or a month later that shop has pull with distributors who have pull with the company to get your shit fixed ASAP. Doing it on your own puts you at the ass end of the line (which is what happened to me with Soundstream). Also note that some companies will just send you a new referb amp or another new one when/if yours blows within 90 days (will vary). Soundstream does it, but unfortunately for me not with the XXX line... I should have bought 3400's instead...

Anyways good luck man and no matter who you go with you will be happy if you have good luck. If you don't then you won't... Happens with all of the amps out there from RF, SS, AQ, Stet, SD, Crunch, HF, PA, etc... Not every amp built is perfect when it comes off of the line and if you have bad luck, you will hate that company and that is about all there is to it.

[bass_4_ever]

does anyone have pics of the internals??

[R_Mac_1]

I've been reading some pretty interesting things on CACO about Stetsom. Getting past whether they suck or are amazing...if you blow one you may not be able to get them fixed. There is a worldwide shortage of electronic parts, including many specific to Stetsom. DB-R, who does their warranty repairs, says that if you have one that is out of warranty, you plain may not be able to get it fixed. Stetsom has the parts and will only give them out to do a warranty repair. A lot of parts used in other amps (like Zenon amps) are in short supply as well. Many have lead times of 30-50 weeks.

Okay, maybe go read this and I will explain some here, so those of you here who are savvy in electronics business can discuss, I am VERY interested to say the least to hear predictions, insight, etc.

http://www.edn.com/article/509652-Se...rt_supply_.php

As some of you may already know, there is a shortage of certain electrical components that go into your electronics, primarily your amplifiers. This has caused some companies (we won't name names) to not be able to get certain models from their build houses right now because the build houses cannot get the mosfets and/or other major components to complete the builds.

This is my opinion of what has happened/is happening, please add your input, and keep this a civil conversation:

1. In around Feb 2009, the economy in the US and others became a major concern and unemployment rates skyrocketed. Because demand for things like Power Mosfets was predicted to extremely drop, major semiconductor companies laid off tons of workers and shut down lots of production lines.

2. For a while, say for example, totally guessing, not factual here, that a company like International Rectifier, who makes most of the mosfets in your amps, normally runs 10 production lines of a certain mosfet, and then when the economy started to tank, they cut it back to 2 production lines and layed-off all those workers.... So there was still some product being put out there on the market, but not near as much as it was.

3. Demand picked up as the economy picked up. Now, orders are coming in like they used to for the power mosfets etc, but the company cannot produce nowhere near as many as before, they now have to re-hire workers and bring production lines back online. This process takes weeks-months.

4. Shelf stock diminishes. Orders for the parts that are in high demand have almost completely, in some cases completely, wiped out Shelf Stock. Lead times from the part manufacturers go from normal 12 weeks or so, to 20 weeks+.

5. Buyers get scared they won't be able to get the parts they need, so they start an ordering frenzy, signing agreements to buy X amount of parts per year or whatever, called "allocation". Future orders of these parts that are scheduled with 20 week+ lead time are now ALL on allocation already. So even when they come in stock in 20 weeks, you can't buy any if you didn't already have them on allocation. So you maybe faced with 50+ weeks lead times or even more at this point..... Smaller buyers cannot afford the allocation prices, some mosfets, for example, have gone from $0.90 each to $4.00+ each..... So what do they do? Nothing, they have to wait....

So what is this going to mean for the business? The business of manufacturing amplifiers, repairing amplifiers, etc?

One example is this. Stetsom amplifiers. They use High Current mosfets which are different than what you find in most Korean amplifiers, they are not as common, not as many are produced, and now the shelf stock has diminished. There simply are no more parts availible, and because they are not a "hot" item normally, their production is pushed back 50+ week lead times..... Ouch.

As of right now, if you own a Stetsom amplifier, (this may apply to Soundigital too, I do not know, Murillo can chime in) if you need repair, the parts may not be availible for 1 year+. This IS scary.

Discuss.

Consolidating info from various posts in this thread for first post, adding as we go:

Stetsom amp specific parts:

Power supply mosfets:

IRFP2907 - 0 stock, lead time 50 weeks

IRFP4004 - 0 stock, lead time 33 weeks

IRFB1404 - 0 stock, lead time 50 weeks

FDA8440 - 0 stock, lead time 34 weeks

Output mosfets:

IRFP4668 - 0 stock, lead time 33 weeks

IRFP4768 - 0 stock, lead time 33 weeks

IRFP90N20D - 0 stock, lead time 32 weeks

Rectifier Diodes:

FEP 16DT - 0 stock, lead time 18 - 43 weeks

FEP 16FT - 0 stock, lead time 18 - 43 weeks

Drivers:

IR4427 - stock in 2 digits, lead time 38 weeks

IR2184 - 0 stock, lead time 38 weeks

IRS2092 - 0 stock, lead time 38 weeks

IR2010 - 2-3 digit stock, lead time 38 weeks

IR2110 - 0 stock, lead time 38 weeks

Some commonly used parts stats:

RD D5, D9, SAZ-4500D, Cactus (newer), AQ 3500, many others Output Mosfet FDA24N40F manufacturered by Fairchild Semiconductor: Shelf stock in 3 digit range (100-999 on shelf) lead time 41 weeks.

RD D5 D9, SAZ (1500, 2500, 3000, 3500 and all other brands with similar/same boards), American Bass, Memphis 4K, Atomic, Cactus, and almost ALL amps with TO-247AC (big case style) mosfets in power supply IRFP064N made by international rectifier, Shelf Stock in the 4 digit range(1000-9999), lead time 32 weeks. Luckily we have these on allocation, and a good stock of them here at the shop already...

SAZ-2500, 3000D, 3500D, VFL 400.1, VFL 500.1 VFL 200.1, Atomic 3K, 5K, 7K, RD 3250.1(v1 older), 7500.1, and many others Output mosfet IRFP360LC made by international rectifier, Shelf Stock in 3 digit range (100-999) lead time 32 weeks....

Power supply mosfet that is going to be being used in alot of amps in the future to replace the IRFP064N mosfet, IRFP1405 mosfet Shelf Stock depleted entirely, lead time 50 weeks

IR21844S Mosfet Drive IC Half Bridge (made by International Rectifier): 0 Shelf Stock, 33 Week Lead Time

THIS ^^^ is the chip used on all the large Zenon type amps in the little drive card with the numbers scratched off. These almost always need replacement when the amps output sections fails, 90% of the time or better, it will need this part.....

TL494CN: Used in almost 99% of amps made in last 15 years to control the power supply. PWM controller, made by Texas Instruments and others: Shelf Stock in 4-5 digit ranges, Lead time 26 weeks.

4700uf 100V capacitors and similar sizes used as Rail voltage filter caps in almost all larger Korean made and other amplifiers: Shelf Stock nearly depleted, Lead time 106 days to 72 weeks.

Adding this Chart for Top 14 Semiconductor Manufacturer Lead Times as of 07/16/2010:

Since this was released, some of the Lead Times have been pushed out to 50 Weeks now.... Even though almost a month has gone by since this chart was made, the Lead Times are getting LONGER instead of SHORTER... Geeezzzussss...

From the mouth (well...fingers) of the owner of DB-R.

Some people may want to think twice about buying a used/out of warranty Stetsom. I think Murilo chimed in and said they (SounDigital) stocked up on a lot of parts they use. Jacob (sundownz) said they are in the process of buying up parts and making a massive amp purchase from his build house to stock up.

[sqsux]

[SounDigital]

What hes saying is that you don't need to be running an amp at max gain to get the "full potential" of the amp. What hes saying is tha many amps are different and the gain can be maxed out 1/4 1/2 3/4's gai. I know this doesn't stop clipping, but it helps to tune the amp... get a multi-meter, grab an RMS / ohms chart, put ur multi-meter on your amp outputs and see what your voltage is coming out of the amp. This way you can measure if your getting a crazy clipped signal. I'm running 2 Massive Audio DB3000.1's right now and the gain is maxed out at half way. I haven't o-scoped it but this is judging by the output voltage.

I figured I was going to get mixed emotions about Stetsom, or any brand I would ask about. I just wanted to get an idea of peoples experiences with them, good and bad. This way I could be aware of the possible crap that I could run into if i do decide to take one or two. I wanted to get reviews about them before I shell out money (since I'm in canada and there are no canadian dealers anymore, its going to cost more).

I like the SounDigital amps, but the websites in a whole different language and I've read mixed reviews about them as well.

Like I said, I'm just trying to get a feel for what I might be in for if i do buy a Stetsom. And I appreciate all good & bad comments alike since I can understand how Stetsom amps work and also what some of their flaws might be...

Cheers,

Andrew

Hello Andrew!

Yes you will get all kinds of answers... it's the brand wars.

Being a small company (less than 40 people at work) and being focused almost entirely on D class high-power amplifiers we were able to create a product that would fulfill our own expectations, considering the owner and managers themselves run the products since the creation of the company.

What I can say about our products is that they have a very well designed PWM power supply, they will work with any kind of battery supply, so from a single battery (street classes, voltage drops of 9V) to a 16V AGM bank at charge (almost 20V). This is not an easy task when you are at the 5kW+ power range...

We actually are so confident on the product we back it up with 5 years of warranty and a lifetime warranty for competitors (the guys that push the product to the limit).

[bass_4_ever]

thanks for the info all! and also thanks for the video!! I've got some time to think on what brand to go with. I've got a few in mind... I'm tying to get rid of my equipment first. So far stetsom seems to be a good candidate, as well as soundigital, and a few more. I appreciate all the feedback from everyone!

Murilo, I will be running 1 regular car battery up front, as well as 2 or more batteries in the back, with 1 260 amp alternator. I'm struggling for space in the car since its going behind the backseats in a golf GTI. Does SounDigital have any distributors in Canada?