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Conference napalm::commusic_v1

Title:* * Computer Music, MIDI, and Related Topics * *
Notice:Conference has been write-locked. Use new version.
Moderator:DYPSS1::SCHAFER
Created:Thu Feb 20 1986
Last Modified:Mon Aug 29 1994
Last Successful Update:Fri Jun 06 1997
Number of topics:2852
Total number of notes:33157

2184.0. "Power Amps - Digital or Analog?" by COGVAX::LABAK () Tue Nov 28 1989 13:54

     I started looking towards putting together a PA system for the
    band I'm in and I thought I would ask what you Commusic Noters
    thought about Digital VS Analog power amps. After visiting 2 music
    stores it looks like this..
    
    	CARVER PM350  450 watts per channel into 4 ohms. 21 lbs 
    
    		$760.00  at  Unions in Worcester
    		$640.00  through  Sam Ash                   
    
    	PV CS800 400 watts per channel into 4 ohms  54 lbs
    
    		$640.00 at Unions in Worcester.
    		$670.00 at Daddy's in Shewsbury.
    		Sam Ash won't quote PV prices.
                                               
     I want to be able to drive the mains and monitors from one power
    amp. That's why I'm leaning towards at least 400 watts per channel.
    The saleman have been telling me things like...
    
    	- The analog power amps holdup better and can drive lower impedance
          loads better. Is this true?
    
    	- The digital amps are cleaner.
    
    	- There is a different in sound between the digital and analog.
          I guess it's just a matter of taste.
                                              
     I like the idea of a 21Lb power amp  VS a 54Lb power amp if it
    can do the same job, the cost is the same.  But will it be just as
    powerful?  Anybody have any experience with the CARVER's or the
    PV's. Any thoughts or suggestions...  I started looking at
    mixers,effects and Eq's but I'll save that for later.
    
    Thanks
    Rick L.                                                  
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2184.1AnalogWEFXEM::COTEThere, but for the fins, go I...Tue Nov 28 1989 14:3714
    The Peavy CS series is a real workhorse. Built like tanks and pretty
    easy to service. Of that 54 lbs., what ain't transformer is heat sink.
    
    Carver gear kinda scares me, especially for commercial applications.
    He comes up with some real innovative products at decent prices, but
    so does Alesis...
    
    Given these 2 choices, *I* would go with the CS. 
    
    For a rock band PA system, I'd stick with the meat and potatoes amp and
    leave the Carver caviar to the audiophiles. (No wait, I think they'd
    throw it back...)
    
    Edd
2184.2other topics of interest - FYIDYO780::SCHAFERBrad - boycott hell.Tue Nov 28 1989 14:5520
Keyword: AMPLIFIER

Number  Repl   Title
------  ----   -----------------------------------------------------
  251     22   Recommendation: Amplifier for Synth Gear
  275     4    Amp suggestions?
  356     11   Looking for SMALL Amp/Speakers for Home Studio
  828     27   Connecting Pro Synth Equipment to Home Stereo
  875     15   Roland Juno Sounds Thin w/ Gorilla Amp
 1120     13   Recommendation - Powered Keyboard Monitor for Gigs
 1676     6    TOA Keyboard Amps
 1684     6    AB Power Amps?
 1797     1    Peavey DECA 528 Power Amp?
 1872     6    Power Amp: "Pro" vs. "Home"
 1922     5    Rackmount (1 Space) Power Amplifiers
 2039     8    Peavey KB300 Amp - Compression Light?
 2092     6    RAMSA Sound Equipment?
 2093     4    Help - Music Man Guitar Amp Buzzing
 2096     17   Micro PA Systems?
    
2184.3got any 100W nand gates????HPSTEK::RENELIFE -- It's a juggle out thereTue Nov 28 1989 16:0326
    I'm not sure what is meant by a DIGITAL or ANALOG power amp, but dam it
    all power amps are really Analog no????? I haven't seen too many
    digital logic devices that will drive hundreds of watts.  The reason
    Carver amps are much lighter than say the Peavey CS (and a lot of other
    power amps) is the power supply. Most power amps (and I'll go as far to
    say most consumer electronics [except maybe some computers]) have 
    LINEAR power supplies. They are relativesly simple to design/require few 
    parts and have been around lots longer than other types of power supplies
    (switchers). Linears have two disadvantages where switchers have the
    advantage...1) they weigh a lot (large 60hz xfmr) and 2) have low
    efficiencies (usually less than 50% of the power taken from the wall
    socket ever makes it to the load). Therefore they get HOT, needing
    large (heavy) heat sinks as Edd pointed out. Carver uses a rather 
    unique switcher in thier power supply designs. They dynamicly change
    taps on a multi-tap transformer depending on what the amp is doing
    at that moment. I imagine the control circuitry for this arrangement is
    rather complex, as it can be in most switching power supplies. This
    multi-tap transformer arrangement can process MUCH more power per unit
    volume than a simple 60hz transformer used in linears. As far as
    reliability (as Edd was gracefully hinting towards), a switcher can be
    designed to be very reliable. I've known at least one band that swears
    by (not at) them and have used them for years.
    
           to each his/her/its own....
    
                Frank
2184.4Carver PM-100FGVAXX::LAINGSoft-Core Cuddler*Jim Laing*282-1476Wed Nov 29 1989 00:266
    Though I'm not using it in heavy-duty "rock" applications, I have
    had no problems with a Carver PM-100 ... it may be smaller than
    you need (.0) - it's 12 lbs., 1 rack space, I think it's 150 w/ch
    into 4 ohms ...
    
    -Jim
2184.5STROKR::DEHAHNWed Nov 29 1989 08:5221
    
    No such monster as a digital power amp...yet. Switching supply amps,
    yes. Peavey DECA, Carver are two.
    
    Carvers are in wide use and have gotten mature enough in their design
    to hold up fairly well. For GB work I think they would be ok. But for
    hard driving rock or especially dance music I don't like them at all,
    they're too harsh and don't have enough punch in the bottom end. Your
    ears may differ.
    
    The Peavey isn't the greatest sounding Class AB amp either but you're
    on a budget so it's probably the most powerful reliable amp you'll get
    *new* for that kind of money. Remember the 400W/ch is at 4 ohms. Make
    sure you're comparing apples to apples.
    
    If used is a consideration then you have a lot more choices.
    
    CdH
    
    
    
2184.6HAMER::COCCOLImonitoring reality.........Thu Nov 30 1989 08:5110
    
    
       Go with the Peavey. You(or a roadie) can drop it off the roof
     and it'll still work. *^]
       Also, a friend of mine mentioned that there is some kind of plug
    in tube or module that will turn the CS series into 2 mono amps
    w/built in crossover for Bi-amping?. Can anyone confirm?.
    
                                        Rich
                     
2184.7MOSFET ampsTALLIS::PALMERColonel ModeMon Dec 04 1989 11:018
    I suggest you stay with a MOSFET amp like those offered by Hafler. They
    provide excellent dynamic headroom, frequency response and most
    importantly, they sound better than the other amps. I would stay away
    from Peavey, I think their amps are about the worst in the business.
    They may be roadworthy but they have all the sonic subtlety of a
    bulldozer with a failing transmission.
    
    Chris
2184.8Add It UpOTOO01::ELLACOTTFreddie's RevengeWed Dec 06 1989 10:1719
    1. Check your watts/dollar (my highest priority)
                                                    
    2. Check your watts/lb (in my case its watts/Kg...Canada you know)
    
    3. Is it a good brand (ie Peavy,Bryston,BGW,Roland,Your_own_fav_brand_here)
    
    4. Add up your points and you got your answer.
    
    Re -.1
    	I agree about Peavey, they also over rate their power output
    specs, most of their amps will not deliver stated power o/p at the
    stated THD or IMD.
    
    	I owned a Roland for 8+ years 120w/ch never had problem with
    it. It was clean up to 150 watts (I checked it). Also check the
    new line from Yorkville Sound (traynor), Beta series I think good 
    bang/buck
     	                           
    FJE
2184.9combo amps, maybe, but power amps?NRPUR::DEATONWed Dec 06 1989 10:2511
RE < Note 2184.8 by OTOO01::ELLACOTT "Freddie's Revenge" >

>    3. Is it a good brand (ie Peavy,Bryston,BGW,Roland,Your_own_fav_brand_here)
    
>    	I owned a Roland for 8+ years 120w/ch never had problem with
>    it. It was clean up to 150 watts (I checked it). 

	Roland makes/made a power amp?

	Dan

2184.10All Heat SinkOTOA01::ELLACOTTFreddie&#039;s RevengeWed Dec 06 1989 14:125
    Yeap... They sure do SPA120 and SPA240 are some of the model numbers..
    I think... They're bridgable and take two rack spaces. Mine put
    out better than 400 watts mono..
    FJE
    
2184.11Have you checked out the Ashley amps?TALLIS::PALMERColonel ModeThu Dec 14 1989 10:214
    How about the Ashley FET-2000M? It's 500W into 4 Ohms, 300W into 8 Ohms
    and is a solid, sweet MOSFET amp. Its slew rate is > 50 Volts/uSec, the
    damping factor is > 100 and the bandwidth is 100 kHz.
                                                              
2184.12Another Carvorite.GUESS::YERAZUNISThere&#039;s no force like brute force!Fri Dec 22 1989 09:3218
    I've had the little Carver (M-200t) as my home amplifier for about 
    seven years now.  Except for an out-of-the-box fault that the
    dealer wouldn't/couldn't service (going-out-of-business sale), the
    Carver has performed faultlessly for seven years.
    
    I don't find them harsh at all; having all of that headroom really
    does help.  
    
    I once bench-tested the Carver into a dummy load.  The Carver barely
    got above "stone-cold" while the dummy load was smoking hot.  We
    were monitoring the output on an HP distortion analyzer and the 
    Carver kept everything nice and clean...
    
    -----
    
    Some prosound outfits prefer Macintosh; who am I to judge ?
    
    	-Bill