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Posted: Tue Dec 05, 2006 2:17 pm
by SQBubble
SQBubble wrote:I have been told that sometime some compagnies put on some fake fuse to make it look like it has alot and make alot of power... how can you know if an amplifier has fake fuses?

anyone can explain/clarify this?

Posted: Tue Dec 05, 2006 2:25 pm
You could ohm them with a meter and make sure all the fuses are in parallel. If they are, then I really do not see a way around the values adding up.

I can tell you from experience they are not fake in the MD3D. . . .


Posted: Tue Dec 05, 2006 3:17 pm
by SQBubble
BKOLFO4 wrote:You could ohm them with a meter and make sure all the fuses are in parallel. If they are, then I really do not see a way around the values adding up.

I can tell you from experience they are not fake in the MD3D. . . .


alright cool!!

thx alot man

Posted: Tue Dec 05, 2006 6:15 pm
by KU40
i've never heard of fake fuses. can you provide a link to an amp with them?

seems to me that while, granted, some companies do all they can to beef up the theoretical and marketable power of their amps, seems to me fake fuses are just silly. The people who buy the overhype don't seem to be the kind who would understand fuse ratings and their relation to output, and the kind who would know also know other ways to distinguish a good performer from a bad other than just fuse ratings, which would cross it off their lists as well.

Posted: Thu Jan 18, 2007 4:54 am
by miztahsparklez
check i think is the website for updates on bad circuit components not only on motherboards, but on other hardware too. im not affiliated with them, but they did provide me with some good insight on why alot of the stuff i have around the house/car breaks.. and every item i reinspected was bad because of crappy capacitors. lol

Posted: Thu Feb 22, 2007 2:26 pm
by jrlutor
eezip wrote:SQBubble, first of all, 3 fuses at 40A each and a generous 14.4V isn't even 1800W so it can't do 2400W. It might put out 2400W dynamic [peak].

BTW, the measurement for Watts in intrinsically RMS. If Watts is to be expressed in any other form than RMS, like dynamic [peak], it should be specified but the unit WRMS is redundant. Anyway...

There are some things that look good about the amp - the general power flow looks fine. I can't figure out why there are 4 big toroids around the output stage. I assume this is a class D amp, but even if it's a full bridge there should only be 2 inductors or 2 if the inductors are wound on a common core in a 2nd stage filter. They could be using some topology I'm not familiar with. Or the output filter could be more than 2nd stage. In this day and age, I find absolutely no reason to use more than 2nd order output filters and that's in agreement with some well respected engineers. Class D amps with second order filters can perform amazingly well [see Hypex/UcD, IR's demo amps, and many others out there] and it's much easier to close a loop around a 2nd order filter. Then you have the parts savings, board space savings, and less tolerance stack up in 2nd order filter's favor as well. But back to the subject; I don't really know what I'm looking at. The pictures aren't detailed enough to make a very good judgment so take everything I've said with a grain of salt. Sorry, but it's not easy to render a verdict with very little information.

The amp has (6) 40 amp fuses. In order to use the same cutting tool as the md2 (3) 40 amp fuses are internal. And yes, we call our open ended D- topology class DE. [No 4080 chips used.]

Posted: Thu Feb 22, 2007 11:03 pm
by eezip
jrlutor wrote:And yes, we call our open ended D- topology class DE. [No 4080 chips used.]

Is it 2 parallel full bridges? 4 parallel half bridges? 4-phase interleaved? What makes class DE special? Why do you call the amp 'open ended'? Can you provide any other details: clocked or self oscillating, prefilter or postfilter feedback, output filter order, etc.

One notable tidbit: I don't see any zobel capacitor, so I'm guessing there's no zobel network. There's only one topology I'm aware of that doesn't require a zobel network and it's patented and goes by a name other than class DE.

Posted: Sat Feb 24, 2007 3:17 am
by Kippo
how about Ampman Audio Revolution D1500 amplifier? Is the internal made of robust components to stand SPL burp in dbdrag or it is only suitable for daily use?

plus what can you modify with this amp?

Posted: Sat Feb 24, 2007 11:06 am
by eezip
Where are some pics of this amp? As I've said, it's impossible to really give a good impression on an amp without seeing it in person and having it to put on the bench, but I'll take a look at it.

There are lots of things you can modify on any amplifier. The most common things might be: bypassing unneeded circuitry [filters, phase switch, etc.], adding desired circuitry, changing op amps, biasing op amps into class A, adjusting SOA/OC limit. More than that and you need to know the amp which either means you have a schematic or it takes some time to get familiar with the design. And a lot of times changes more in-depth that what I listed get to be infeasible, prohibitively difficult, and wrought with peril.

Also, many times, it would seem the decisions made by the designer/engineer(s) have relegated the amp to mediocrity at best. I could spend a lot of time trying to spin yarn into gold, but I'd rather be working on something that was productive.

Posted: Mon Feb 26, 2007 2:56 pm
by Kippo
hi eezip,
the amp internals can be seen here :

it seems that modding an amp needs more technical knowledge/experience and not easy.