Sorting the good bad and ugly

[spkrman]

the nine.1 is NOT that good of an amp.

That annoying cooling fan, why?

Not regulated... when other amps in the price range are - vital for most situations.

I see no reason to buy this amp unless you are getting it for the low 200's.

Other than that, hifonics has come out with some really *really* sweet amps as of late.

[GlassWolf]

in case you don't know regulated from unregulated power supplies, here's a crash course on what splrman mentioned above, without going into too much detail on things like tight and loose regulation, PWM topology, and so forth.

Regulated Power Supplies
Most early audio amplifiers contained unregulated power supplies. Regulated supplies require very high quality filter capacitors (called "low ESR" capacitors), output chokes, and an optically isolated voltage feedback circuit. Regulation occurs by controlling the switching pulse width from 0 - 100% to compensate for changes in the battery and rail voltage. The same action occurs when the audio level increases. As the amplifier draws more power from the supply, the rail voltage drops. Again, the regulator circuitry senses this drop and responds with an increased pulse width.

The high frequency PWM (pulse width modulation) waveform is rectified (converted to DC) and applied to the output filter choke and capacitors. This output of this circuit is the + and - DC rails that feed the power amplifier.

Unregulated Power Supplies
Unregulated power supplies are less expensive than regulated supplies. They do not require an output choke, voltage sense or isolation circuitry. Because the duty cycle is nearly 100%, capacitor ripple current is much lower in unregulated supplies. Lower ripple current requires less expensive capacitors throughout.

Often we hear that unregulated designs have more "headroom". That means that the amplifier will produce extra power during transients. Most home audio amplifiers employ unregulated power supplies. The power supplies in these amplifiers run at 60 Hz, thus the filter capacitors must be 200-500 times larger than those used in high frequency switchers. The extra capacitance in home audio amplifiers results in extra headroom. Headroom for anything other than very short transients simply doesn't exist in the unregulated designs. The following is an example of specifications for an unregulated vs. regulated amplifiers.

Unregulated designs have a higher supply voltage at low power, causing higher voltage on the output transistors. This reduces the amplifier's efficiency.

Small amplifiers (less than 100 watts) cannot justify the extra cost of the regulation circuitry, so we often see unregulated supplies in these amplifiers.

[Fishy]

Hey kiki.

Is there ever a problem with level matching an unregulated and regulated amp in the same system? The way you describe it the output gain would actually change with an unregulated design depending on the amount of input voltage applied(power being produced). If I understand what you're saying it seems an unregulated amp is less efficient(less gain?) at lower volumes, or do you just mean more energy is wasted as heat?

I know that probably didn't make much sense, but I'm a bit confused.

-Fishy

[spkrman]

Hey kiki.

Is there ever a problem with level matching an unregulated and regulated amp in the same system? The way you describe it the output gain would actually change with an unregulated design depending on the amount of input voltage applied(power being produced). If I understand what you're saying it seems an unregulated amp is less efficient(less gain?) at lower volumes, or do you just mean more energy is wasted as heat?

I'm confused.

-Fishy

The levels could be the same so long as you could maintain the exact same battery voltage... but once voltage drops, power dips on the unregulated amp, while the regulated amp keeps chuggin. But you could match them at *any* voltage, so long as the voltage stayed the same.

[sinister audio]

id like to add if i could

Decks
Panasonic MXE , not too many companys have a deck with 3 pres out at 5volts for about 200 bucks list. i havent had any problems with the decks i have installed and i even put one in a tractor for a guy hows that for a test run. their SQ isnt as good as Eclipse but id rate it up there pretty high

Subs
Bravox, not many of you guys have heard of them, id recommend them( not highly recommend but just recommend) great subs for the money lots of differnt subs and VC configs almost dual2 and dual 4 for every model, asome customer service when you call them up you talk to the US Rep and if you have any problem at all he will straighten it out with ease and hes a great guy to work with. 3 year warranty too

Speakers:
Bravox coaxs, great speaker for the money 60-85 bucks list depending on size. great sound great mids and they play pretty low too ( i had a set of 6X9"s that had the same amount of bass as 2 RF p2's 15") sound great unamped and amped also 3 year warranty. they have 3 differnt models too. Recommend

Comps
Bravox 3 differnt sets, the diamond and kevlar i highly recommend. they have awsome sound the diamonds have silk tweeters. lots of midbass with out distorting great SQ with out hurting ears (MB Quarts) they have blowen alot of other comps out of the water, middle model Inifins, couple model up MBs and others i forgot about. im sure you guys would love them i sure do.

[GlassWolf]

yeah output of an unregulated power supply amp will vary directly related to teh input voltage, which is why amps like the orions put out more power at 14.4VDC than they do at 12VDC (example 1000wRMS vs 1280wRMS for the 2250SX going from 12 to 14.4VDC) however unregulated power supply amplifiers don't generally double their power at half the load as a regulated supply with a variable duty cycle will, so it's just a trade off. as for matching the amplifiers, I just match amplifier gain to one voltage, and if the voltage changes, the amplifier is slightly under-driven which isn't a big deal.

in my case, looking at using two Orion 2250SX amps on subs (unreg'ed) and an A1200.2 PPI for front stage, the subs would get a bit louder going from 12 to 14.4 volts, but the PPI won't.
that's not a big issue since above idle, the engine gets louder anyway so you'll never notice a big change.

[Fishy]

Yeah I understand the more voltage more output thing, but what I don't get is the lack of efficiency, i.e. higher voltage rails at lower power, or is this assuming a certain supply voltage drop at higher output(more current draw)?

Otherwise it seems like there would a problem even if the supply voltage remained constant.

-Fishy

[spkrman]

yeah output of an unregulated power supply amp will vary directly related to teh input voltage, which is why amps like the orions put out more power at 14.4VDC than they do at 12VDC (example 1000wRMS vs 1280wRMS for the 2250SX going from 12 to 14.4VDC) however unregulated power supply amplifiers don't generally double their power at half the load as a regulated supply with a variable duty cycle will, so it's just a trade off. as for matching the amplifiers, I just match amplifier gain to one voltage, and if the voltage changes, the amplifier is slightly under-driven which isn't a big deal.

in my case, looking at using two Orion 2250SX amps on subs (unreg'ed) and an A1200.2 PPI for front stage, the subs would get a bit louder going from 12 to 14.4 volts, but the PPI won't.
that's not a big issue since above idle, the engine gets louder anyway so you'll never notice a big change.

just to clarify

the newer orion amps are regulated

[GlassWolf]

yes, assuming the voltage drop, not only from the increased current, but increased losses to heat as well. I have more detailed info here on unregulated power supplies but it gets a little deep.. and that seems to annoy a lot of folks so I was trying to keep things as simple as I could and still get the differences across just for a basic conceptual understanding of the two topologies when looking at amplifiers.

yeah I think everything from DEI uses regulated power supplies now.
Back in the day, in the late 1980s, the differences in schools of thought on power supply design is what brought about the beginning of PPI as a company, when some of the founders left Orion on rather sour terms to start their own company about two years after the start of Orion. This is where the name "PrecisionPower" came from in fact.. one of the first applications of a regulated power supply in a mobile audio amplifier, versus the unregulated supplies used in the Orion amplifiers, Rockford Fosgates, and everybody elses'.

[spkrman]

actually, it appears only the orion and PPI sub amps are regulated.

Everything else DEI is unregulated.

I can definitely say for sure the viper 2500d likes voltage