how much current ?

kappclark

I know how good a high current amp can sound, but how much current ?

I am wondering, bec I have a pair of Polk monitor 60's. Have 20+ year old Parasound HCA 500 power amp...right ch beg to flake out, so looking for high current replacement (maybe just another parasound)..

No need to do the grocery shopping with a 2 ton truck when a light pickup will do..(IOW, do I need high current with the Monotor 60's, or is it just a good design to have)

THX

cfrizz

Get a Parasound 1500A on Audiogon & you will be a happy camper. Welcome to Club Polk!

jinjuku

Most likely your biggest SQ improvement will be moving on up from those 60's.

Conradicles

I just recently upgraded my amp for my LSi9's...now they are getting 120 amps of high current and the difference is amazing.

tonyb

The monitor 60's are very easy to drive. If you want to amp them up, go used, Adcom,Parasound, B&K, Carver, and a cast of others which can be found under 5 benjamins on the used market.

dcmartinpc

cfrizz wrote: »

Get a Parasound 1500A on Audiogon & you will be a happy camper. Welcome to Club Polk!

I second the 1500a. It is an amazing amp for the price. And it has the guts to drive more difficult speakers when you upgrade without breaking the bank. I own 4 parasounds and love them all. My 1500a is used to drive either my LSi9s or my pair of CRS+ and it handles both very well.

Keep an eye on audiogon. The 1500a's pop up all the time and can usually be had for between $300 and $400.. Sometimes even cheaper, you just have to watch. Even the HCA-1200II would work well, it is basically the same amp but older and without the auto turn on feature, and it looks more industrial.

Don

newrival

I just so happen to have an HCA-1200 that I was going to put up for sale. Let me know if you're interested, Kap.

Schurkey

It's REAL easy to be misled by the "amps" spec of an amplifier.

There's no industry standard or legal requirement for the duration of the test burst. Therefore, the amplifier ampere output can be pretty much anything the company wants it to be...if the duration is short enough.

If the amplifier has individual rail fuses, you can figure out the ampere rating based on fuse size. For example, an Aragon 8008BB uses pairs of 10 amp fuses for each channel; it'll therefore throw 20 amps AC per channel "continuously" (to the point of overheating, which is of far longer duration than any musical peak).

I get VERY suspicious when I hear of outrageous claims for amperage output; it seems to be a game of ever-shorter bursts having no musical significance but it looks good in the brochure.

kappclark

Conradicles wrote: »

I just recently upgraded my amp for my LSi9's...now they are getting 120 amps of high current and the difference is amazing.

120 AMPS ?? Don't you mean watts ?

What amplifier do u use ?

Conradicles

Not watts...

Denon PMA-2000R and that thing is a beast!

kappclark

Conradicles wrote: »

Not watts...

Denon PMA-2000R and that thing is a beast!

Just looked at the reviews at Audioreview.com ...

YES - a beast ... everyone called it the sleeper amp .. I have had 1 Denon mid-fi amp before (forget model #), but this one takes the cake, clearly. The dual power supply design reminds me of a NAD 3150 I had way back when...we could never get the priotection circuitry to kick in !

LuSh

Conradicles Not watts...

Denon PMA-2000R and that thing is a beast!



With respect you're not getting 120 but closer in 6-9 during peak output.

Schurkey

I looked up the specs for that amp, and the manufacturer is claiming 120 amps "peak"; but predictably, there is no mention of what test procedure was used to achieve 120 amps.

http://usa.denon.com/us/downloads/pages/instructionmanual.aspx
I checked the "search by text" box, and then entered "PMA 2000R"

Then you download the .pdf document.

PMA-2000R has adopted a high-current UHC-MOS amplification
device capable of delivering a peak current of 120A to
the output stage, as much as 3~10 times greater than that of
conventional MOS-FET devices.

LuSh

Simple math makes it impossible. Ohms law would have wattage output at 57,600 watts if amperage really was at 120 and the impedance of the LSi was 4 ohm. Your wall plug even if a dedicated line will not let 2k through. And the denon would have melted long before this could even happen.

kappclark

LuSh wrote: »

Conradicles Not watts...

Denon PMA-2000R and that thing is a beast!



With respect you're not getting 120 but closer in 6-9 during peak output.

My little Parasound HCA 500 is rated at 10 Amps peak..One of Parasound's flagship amps, the Halo A21 is rated at 60 AMPS peak per channel (WOW!)

http://www.parasound.com/halo/a21.php

If the Denon is capable of 120A, then I would have to upgrade my electrical service (I only have 100A panel) In fact, I would probably need to pull out the 14-2 house wire and replace with 10-2 ! Do they want me to run a 120 amp breaker ?

I am sure the amp sounds fabulous, but seems like a bit of hucksterism here...maybe like the guy on the lunatic fringe who claims a stereo sounded better in Oregon then in NYC because the electricity was generated with hydroelectric making the power cleaner..

Schurkey

Years and years ago, a buddy of mine was very impressed with some piece of Harmon-Kardon gear. Might have been the Citation Twenty??? I kinda forget.

The rep said it put out some fantastic amount of peak amps. My buddy asked what the current draw from the wall socket was at that instant. The salesman only smiled.

I suspect the same sort of misleading test procedure--the "peak" is of such infinitely short duration--and probably into a dead short--that the amperage is coming from the power supply capacitors and not so much from the wall socket. There isn't time for the transistors to overheat. Published figures for power consumption wouldn't be an accurate gauge of amplifier output...if the "peak" duration is short enough, and into a nearly-zero-ohm load. (i.e., NOT MUSICALLY RELEVANT)

Until the Federal Trade Commission stops shilling for the corporations and begins to work for the citizens, we'll never know. I'm not holding my breath.

renowilliams

+1 on some great amps out there that can be had cheap. I recently bought a Rotel RB-870BX for $200.00 and it performs very well driving my SDA2A which are 4 ohm speakers.

tonyb

Guys, think about how an amp works. It doesn't just continuously draw current from the wall, it stores it, for those transient burst of power it may need. An amp rated say at 100 amps, isn't drawing that all at once. Mind you, there are some amps out there that practically need a dedicated power company to run them.
Regardless, amps and watts are two different animals, but it's watt ratings that sell product...because most don't understand current,amperage, and thats what speakers like. If your speakers could talk, they'd say screw the watt ratings, how much current are you gonna feed me.

reeltrouble1

my fellow morons they are talking about extremly short term bursts of stored energy on pk to pk...milliseconds, is it true, hell if I know as I have neither the time nor inclination, but the sun will come up and the rabbit hole goes down, like the individual attention span of the peanuts shucking their shells their is a difference in SQ. Of course the day here will come when some CP sam of seed will prove current does not exist despite Ohm's law fundamental statements.

damm tony, you beat me to it...

RT1

Schurkey

LuSh wrote: »

Simple math makes it impossible. Ohms law would have wattage output at 57,600 watts if amperage really was at 120 and the impedance of the LSi was 4 ohm. Your wall plug even if a dedicated line will not let 2k through. And the denon would have melted long before this could even happen.

I suppose there is a way to resolve this mathematically...but it's WAY beyond me.

An Aragon 8008BB has an FTC rating of 200 watts into 8 ohms. The power supply rail voltage is 80 volts, reduced from the expected 115 volts at the wall socket by the transformers. There is 140,000 uf of storage capacitance. I use this as an example because I'm familiar with the specs. If we scale down those specs to suit an amplifier of 40% of the FTC rating...

Given an "80 watt into 8 ohm" spec plus some additional "safety factor", I'm thinking that the Denon maybe has 40 volt power supply rails? Is that a safe presumption?

40 volts into how many ohms is 120 amps?

If the Denon has 60,000uf of storage capacitance, how long can the amplifier sustain a 120 ampere drain? Of course, the capacitors are being recharged by the wall socket, at 60 cycles per second--my hunch is that a 60hz recharge is going to turn out to be irrelevant, but what the hell do I know?

IF (big IF) this is a valid approach--using actual specs, or "best guess" of the actual spec for rail voltage and supply capacitance; along with a presumed nearly-zero-ohm load--the math for impulse duration can be worked for the Halo A21, or any other amp that has some incredible (as in not credible) ampere specification.

But it'll take a better man than I to work the math; or, for that matter, to spot holes in this theory. This is the best I can do.

I have NOT trusted ampere specifications for amplifiers since the experience with the Citation XX salesman.

FTGV

tonyb wrote: »

An amp rated say at 100 amps, isn't drawing that all at once.

Except in the case of pure Class A,the inefficient beasts that they are can have a continuous draw of more than twice their rated output.Most of that gets pissed away in the form of heat dissipated from the heatsinks.Class D on the other hand with it's 90ish % efficiency will deliver most of it's consumption to the load.It's operation can be thought of as a very fast on off switch.

if speakers could talk, they'd say screw the watt ratings, how much current are you gonna feed me.

Sure and as impedance decreases current demand increases,if the amp can't deliver enough current to drive the load then the wattage will decrease.

megasat16

FTGV wrote: »

Except in the case of pure Class A,the inefficient beasts that they are can have a continuous draw of more than twice their rated output.Most of that gets pissed away in the form of heat dissipated from the heatsinks.

Not really! What is lost in one is gained by another. In this case, the pissed away heat is warming up your igloo nicely. :biggrin:

reeltrouble1

sand in an ice room....cant be a good thing....

RT1