Flatline 8.5k?

[Guest]

fosgate uses witchcraft

[CJ18]

fosgate uses witchcraft

Agreed

[IH8PunkRok]

Honestly if I was flat line id keep quiet. They have something new and different. If the amps make power good for them. I love seeing progress but other companies need to figure it out themselves

[8ight]

The Flatline is what I like to call a China amp, because that's what it is. You may get 8.5k @ 16v and like 5% THD on a test tone. Flatline, Addictive Audio, Popcorn Sounds, and RD (3250 v2) have all tried marketing big Chinese power like this.

[Wicks]

Lets do some math!

Regardless of the technology in the amp, its still restricted by its input.

With dual inputs, the amp is realistically limited to 600A of input (300A for each input).

If its truly rated at 16V then the amp is capable of inputting 16V*600A = 9600W.

If the amp can output 8500W then its efficiency would have to be = 8500/9600 = 88.5%.

If that's at 1ohm, then that's a pretty impressive efficiency.

The only amp I know of that is an exception would be the Fosgate T15K which actually has soo much internal capacitance that it actually can support itself for brief amounts of time.

Therefore it can rely on less input current.

All other amps operate in real time and only filter the current through it.

The only other thing I could think of would be Fosgate's "Boosted Rail" technology which increases efficiency, but as you've seen from Fosgate's smaller sized amps, has some limitations, at least at the moment.

Example from wikipedia:

Class-H amplifiers take the idea of class G one step further creating an infinitely variable supply rail. This is done by modulating the supply rails so that the rails are only a few volts larger than the output signal at any given time. The output stage operates at its maximum efficiency all the time. Switched-mode power supplies can be used to create the tracking rails. Significant efficiency gains can be achieved but with the drawback of more complicated supply design and reduced THD performance. In common designs, a voltage drop of about 10V is maintained over the output transistors in Class H circuits. The picture above shows positive supply voltage of the output stage and the voltage at the speaker output. The boost of the supply voltage is shown for a real music signal.

The voltage signal shown is thus a larger version of the input, but has been changed in sign (inverted) by the amplification. Other arrangements of amplifying device are possible, but that given (that is, common emitter, common source or common cathode) is the easiest to understand and employ in practice. If the amplifying element is linear, then the output will be faithful copy of the input, only larger and inverted. In practice, transistors are not linear, and the output will only approximate the input. nonlinearity from any of several sources is the origin of distortion within an amplifier. Which class of amplifier (A, B, AB or C) depends on how the amplifying device is biased – in the diagrams the bias circuits are omitted for clarity.

Any real amplifier is an imperfect realization of an ideal amplifier. One important limitation of a real amplifier is that the output it can generate is ultimately limited by the power available from the power supply. An amplifier will saturate and clip the output if the input signal becomes too large for the amplifier to reproduce or if operational limits for a device are exceeded.

[I.V]

fosgate uses witchcraft

maybe flatline too idk its hard to say, its better to wait

[reelfish92]

The Flatline 8.5k will play from 10v to 16v. I run my FL1 "2k" on a 12v set up and am very pleased with my results as have others who have run the other models on their 12v electrical. You may come over to where Flatline is a vendor and talk to the owners there in threads or the chatroom. I believe CJ posted a link to splbassx. You will be able to see a handful of Flatline powered vehicles at Spring Break Nationals March 2nd-3rd. Hope to see some of you there.

[Wicks]

The major differences that I see are the FL8.5k has less of the large copper coils, but more of the little silver topped things(dont know what they are, resistors maybe?)

The 8.5k also has less of the big black cylinders, i think they are caps. This is the part that I would like explained. What each part is and what it does. I have tried looking around online and just get more confused. Just need an amplifiers for dummies 101 course.

The little silver topped things are the "12V" input caps for the power supply. They are directly connected to your battery/alternator(s).

They filter the input current (ripple current) into the power supply of the amp.

I can't tell the actual values, but a larger amount of PSU capacitance would mean it has to filter a large amount of input current.

The large black cylinders are the voltage rail caps. They filter the rail voltage after the PSU has raised the voltage from ~12-14V up the rail voltage of the amp (Ex: 100VDC).

Again, more capacitance means its filtering more output current.

As Ray mentioned, with a much higher output voltage, a lesser output current is need, hence less capacitance...

Thank you for that. Now what about the copper coils? One has more than the other, how does that effect the amplifiers output?

The toroids (copper coils) on the side of the amp near the power inputs are in the amp's PSU.

Your 12V battery voltage is pulsed through them which boosts the 12V up to the rail voltage.

The more toroids, then I would expect the PSU to be able to output more current.

The toroids at the other end of the amp (output) are to filter the switching noise from the output signal, at least in Class D amps which most mono amps are.

Class D amps are soo efficient because they RAPIDLY pulse the output FETs as opposed to Class A/B amps where the FETs turn on with the output signal.

All that switching causes a lot of noise which needs to be filtered at the output.

[8ight]

Before wondering about what is what in an amp please read these papers:

This one is by Robert Zeff who is now part of Arc Audio, he used to be part of Zapco

http://www.caraudio-forum.com/forum/topic/4255-anatomy-of-the-power-amplifier-by-robert-zeff/

This one was published by Crown who makes lots of pro audio amps so it regards 120VAC amps but same concept

http://www.qscaudio.com/support/library/papers/amptalk.pdf

An important note: a good indication of power is the number and size of power supply and output fets. Big chunky fets with large legs are higher current models often found in high-end or high-output amplifiers. Of course it is not true that two amps with the same amount of fets are going to make the same amount of power but its an OK reference point when you have nothing else.

[TeamHT]

Have you clamped your amp? If so, any internal shots? More out of curiosity, the prices seem a bit high to spark my interest.