Quiet PA amps

kipman725

Member
Paid Member
2007-06-10 12:41 pm
Warrington
I use my PA system as my home HI-FI and so have an interest in any PA amps that are close to silent. Also in many situations even in PA very noisy fans can be audible for some music genres. I thought it might be informative to share a list of amps that are both powerful and do not make excessive noise. An amplifier can be classified as quiet as long as the fan noise is not audible from 2m away during light usage. I'm not very keen on modifying amplifier cooling unless airflow capability is retained.

Not Quiet:
Behringer Inuke
Cloud VTX series.
Ecler pam 1400 power amplifier
Powersoft Duecanali 5204
Crown XTI series.
QSC RMX
Peavey IPR1600
MC2 amps (not sure on specific models)
Classic crown Macrotec MA5002VZ ETC. (Macro-Tech 3600VZ notable mention)
BSS EPC780
Crown I-tech 5000
Nady XA-900
Gisen K21x4 (and probably Soundgear Saturn 16 as it looks identical)

Not a total racket:
Powersoft Duecanali 1604
Samson S2000 2*[email protected] ohms 2*[email protected] ohms, 2000W bridge
MC2 MC series
Crest CLh5000 (2*1470 watts 4 ohms (tested to far more on single channel))
Crest CA9 (the CA2, CA4 and CA6 should be about the same in this regard)
QSC Powerlight 2 series.

Quiet fan:
Peavey CS800s
Yamaha Triple E series of amps(P, PC-1N, XP) E.G Yamaha PC9501N ~2*1500W 4 ohm
Yamaha P7000s (fan does not spin normaly, 2*1100W 4ohm - conservative rating)
Lab Gruppen E-series (2*200W 2/4/8/16 ohm)
Carver PM700 [email protected] ohms [email protected] ohms (fan inside unit)
Samson SX-2800, 2*[email protected] ohms, 2*[email protected] 4 ohms, 2000W bridge
QSC USA 700, 2*240W @ 8 ohms, [email protected] 4 ohms, Bridged 900W
IMG STAGELINE: STA-2000D/STA1000D (fan does not turn on in normal use) (upto 4*500W, 4ohm)
Speaker Power SP2-12000-DP (2*6000W, 2ohms)
Crown XLS DriveCore 2 Series (up to 2*775, 4Ω (XLS2502 )) (fan does not turn on in normal use, multiple reports)
Dynacord SL Series (up to 2*1200W @ 4Ω (SL 2400))
Crown CTS4200 (4*260W 4ohm), (fans don't spin on my unit at idle - others report differently there may be firmware differences)
the t.amp TSA 4-300 4*550W (4ohm)
lab Gruppen C series (passive under low load)
Crown CDi1000 (2*968W 4ohm, fan does not spin under light load however once fan spins its quite noisy)
QSC EX800 does not run its fan until it gets hot (2*325W into 4ohm)
MC2 Delta 20 (4*350W 4 ohms - unit can have internal link changed to force fan to run at low speed but may thermal power limit as a result)
Powersoft Mezzo 6 series (up to 2*300W 4 ohms)
the t.amp Quadro 500 DSP (4x 500 W at 4 Ohm, 4x 250 W at 8 Ohm)

Fanless:
Apart audio champ 2, 2*(180W 4 ohm, 120W 8 ohm)
Apart audio PA2120, 2*(120W 2/4/8 ohm, Small amount of mains transformer mechanical hum audible in silent room)
Stewart world 600 (2*190W 4 ohm)
Stewart world 1.2 (2*350W 4ohm)
Behringer A500 (~2*200W 4ohm)
Behringer A800 (2*250W 4ohm)
Crown K1/K2 (upto 2*1250W 2 ohm)
QSC 3500 (2*560W 4ohm, 2*700W 2ohm, possible transformer hum)
Samson Servo 550 (2*275W 4 ohms, 1*550 watts into 8 ohms (bridged mono mode) , runs hot when pushed)
3e Audio EAUMT-0140-2-A (TPA3251 based) (2*128W 4ohm)
Powersoft Mezzo 3 series (upto 2*160 W 4 ohms)
QSC SPA series (upto 1*400w into 4/8ohms in 1/2 rack space)
 
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conanski

Member
2013-03-31 3:53 am
All of the Yamaha Tripple E series of amps(P, PC-1N, XP) are dead silent at low to medium output levels, these amps don't generate much waste heat and the fans are thermostatically controlled and don't run at all unless heatsink temps get too high. My experience with the P series is the fans don't run at all with 8 ohm loads as the amp never gets hot enough, and no these are not class D amplifiers the output section is class AB.
 
Until recently I used the FOH amp racks from my “A-rig” (6 Crown XLS2502s with 2x DriveRack 360 DSP) to run my 4 way large format monitors when I’m back in my rehearsal/mixdown/play space. I found that the fans never came on unless I was doing something so absurd that the fan noise was inconsequential. YMMV, as this system was pretty under-stressed.

I recently re-amped that PA with 3x Powersoft 1U amps and a single 4x8 Symetrix dsp to save space. The 2 channel 5204s that run the subs and mid-bass make an absolute racket even at idle. The fan in the newer-generation 4 channel 1604 that runs the mids and tweeters stays quiet at idle and doesn’t ramp up much in use, but it is seeing a very light (and very friendly) load.

Between the weight, noise, and gain structure issues, I’ve given up on using that rack in the (second floor!) studio... although a long set of speaker cables would save the first two problems. I’ve started to build a dedicated rack with used Lab Gruppen E-series amps for the bottom channels and my last remaining Stewart World 600 (fan-less!) amp for the tweeters. That stack stays quiet at idle, but I haven’t used it in anger yet... still waiting/waffling on which DSP to use before wiring it up.

I will let you know how the new rack works out, noise-wise, if it is of interest.
 

kipman725

Member
Paid Member
2007-06-10 12:41 pm
Warrington
Great info, even older amps are interesting as its not like I can afford anything high end and new for hobby.

Not amp related. The Symetrix 8x8 DSP has a tiny 40 mm fan that make more noise than almost all amps while not moving any air. I ended up cutting a large mesh window in the top of mine, putting it at the top of the rack case where there is a small space (~1/2 1U) then installing a 4*80mm fan, 2U back panel with eBay fan temperature controller. This means that heat buildup in the top of the rack is extracted. Judging by the front panel temperature of the DSP this is far more effective than the stock cooling.
 
If you are compiling a list that includes a category for amps that are not very quiet, I would add the Crown XTI series. The 6 XLS 2502 amps mentioned earlier used to be 4 XTI2002 and a pair of XTI1002s. This array was reasonably quiet at idle, but the amps driving the subs and midbass would get pretty audible when playing loudly. The noise was proportional enough to the load that I never felt self conscious about it at gigs, or even when using them when mixing in the studio, but it did come into play with recreational listening.

FWIW, a vendor once sent me a Behringer NU3000DSP amp by mistake... I was trying to buy a MeanWell 500 watt 12v power supply, and wound up with an amp instead. Not the kind of thing I’d put into my rig, but it was so cheap I kept it and used it to drive the subs in my hot tub room’s sound system. Pretty good bang-for-the-buck (and better DSP than the Crown XLS 2 series), but obtrusive fan noise even at idle. I recently sold it to a budget- and weight-conscious client to drive some side fill monitors in their system. I’ve seen various fan and passive cooling mods published for that amp that address the noise issue, but I can’t really imagine gigging with it.
 

kipman725

Member
Paid Member
2007-06-10 12:41 pm
Warrington
I have looked at the INuke schematics and construction and the fan mods are ill advised it needs those high airflow fans and for the 6000 the air has to go under the PCB. Also they should only be used on subs due to poor HF damping and hum from sensitive speakers. The fan control also appears to be designed to do a smooth linear ramp but due to design mistakes the gain of the slope is too high and it just fluctuates between low (6V) and high (12V). You have to spend a lot or have a massive rack to get more sustained LF power though.
 
I use a Crown for mid bass (it's quiet fan wise - it's variable speed and for loads I drive it never kicks in - JBL 2220 15 " drivers on horns that are 110dB/W efficient. 90-300Hz duty.
It does suffer a little earth loop hum though!
Better SQ then a Behringer inuke!

On tapped horn duty I use a Cerwin Vega beast.
These use Eminence kappa pro LFII drivers and are 105dB/W efficient. 20-90Hz duty.
I modded the fans to run the at 6v (simply put them in series) rather than the full 12v feed each they came with.
Nice and quiet but keep their cool.
Absolutely no hum from this amp.
 
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Dead quiet Carver PM700 240 watts at 8 ohms 325 at 4 ohms, pretty sure there is no fan
Fairly quiet Samson S2000, great for home use because it is a boat anchor, no one wants to move this beast. 650 watts at 8 ohms 1k watts at 4 ohms per side, 2000 watts bridged
Samson SX-2800 class H design 700 watts at 8 ohms x2, 1000watts at 4 ohms x2 or 2000 watts bridge
I drive rock and country bands mains and subs with this amp and it just idles along, I doubt the fan even kicks on unless it is outside.
QSC USA 700 240watts @ 8 ohms stereo 4500 watts at 4 ohms, Bridged 900 at 8 450 at 16 ohms
Has limit switches for low freq cut off, off, 50hz or 30 hz, plus limiting.
You can find all of those amps for around $100 (maybe not the Carver but I only paid $200 for mine)
All of these will run circles around more popular power amps and at home levels the fans will not even be needed.
 

kipman725

Member
Paid Member
2007-06-10 12:41 pm
Warrington
I'm already running Apart PA2120s on my tops (2*120W), kind of in the market for something for my subs, perhaps more power for the tops as well. Need to offload a lot of amps I have fixed before I get more though. Hence looking for info on noise levels as I'm just generally in the market if good deals come up. Running different amps doesn't appeal to me because of the additional setup time as my racks are internally wired with external connector panels.
 
Another amp for the “not quiet” column... the QSC RMX. I had an RMX 1450 (original version) running sidefills until a few years ago. Sold it last year. Nice enough amp, but its fan was so loud, even with no load, I didn’t want to hear it during rehearsals. It was loud enough to be obtrusive in some of the smaller venues I was mixing in.

And to you OT comment earlier... thanks for the heads up re: the noisy fan inside the Symetrix DSP. You’re right! I left it (a Radius) running for a few hours earlier today. I just went and checked, and after shutting off the Powersofts, the Symetrix was indeed making almost as much noise as the 1604 amp, but nowhere near as much as the 5204s. I could hear it from 10 feet away.

If the Jupiter tuns out to be that loud, I will consider modifying the cooling as you described. Or locating the rack elsewhere.
 
I find my Peavey IPR1600 aren't all that quiet either. They stay quiet for a while but then the fan ramps up even at background levels. Louder levels the music drowns them out quite easily, even if the fan is working hard for lots of sub bass. For films though I'd be better off with my convection cooled Acoustic Solutions SP101 or the SMSL SA 98E amps I have. Just a pain to build speakon to speaker terminal adaptors. I did find the SMSL a little bit lacking in definition in the highs (not as bad a a Lepai) though compared to the Acoustic Solutions amp, though surprisingly more powerful considering it's barely bigger than the big match boxes compared to my Acoustic Solutions that is a big as a Peavey and is heavier despite being only 35 wpc (but still very loud through an Omnitop 12).
The idle power use of a Peavey IPR1600 is about 40 watts so wondering if that's too much heat build up if a fan switch was installed.