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Posted by Gordon McLeod (Member # 33) on 06-23-2002, 01:43 PM:
 
Was wondering which make and model of amplifier most people are installing these days for both budget and highend theatres
Until its discontiouance I used the QSC USA amp the most with the DCA for high end
Now it seems to by ISA's

For Budget theatres we have been using a amp made in China and sold under the Pryamid name (1000watts bridged mono)


 

Posted by Paul G. Thompson (Member # 655) on 06-23-2002, 01:47 PM:
 
I sill use QSC's. They are competitive in price.
 
Posted by Richard Fowler (Member # 893) on 06-23-2002, 02:22 PM:
 
The QSC ISA are made in China ( same as RMX / designed by QSC ). Most of our projects use DCA or ISA based on the client and our audio harnesses are designed to work with both types of amplifiers. The Harmon Group ( JBL and a million other companies they own ) has taken over Crown;there are some new options from that manufacturer. For home theatres and small screening rooms we have used Sherbourn multi-channel amplifiers.
Richard Fowler
TVP-Theatre & Video Products Inc. www.tvpmiami.com
 
Posted by Mark Gulbrandsen (Member # 72) on 06-23-2002, 03:29 PM:
 
I use the RMX QSC series the most. They are great and very cheap. Its essentially the same circuit as the QSC 1400 amp. In quantities they are VERY cheap and ultra cost effective. Have not lost a single unit in well over a year now. My second choice would most likeley be Crown Amps as they too are high quality and somewhat cost effective. Both QSC and Crown are very good sounding....not like Krell, or Pass Labs stuff, but very decent. For X-overs on two way systems I am switching to the Component Engineering THX replacement card, used either in a used 3417, or my own main frame. Second choice, and for three way would be either the digital, or analog JBL x-overs. I've gotten excellent results with them in past jobs.
Mark @ GTS
 
Posted by Pete Naples (Member # 761) on 06-23-2002, 04:26 PM:
 
QSC is king in these parts pretty much too. The USA has given way to the RMX, but I do like the DCA too, although reliability has been a bit of a problem, like a lot of US made kit, it's rated for the 220v supply that US makers seem to think we have here in Europe, feed it the 240 upwards supply that we have in reality and those SMPSUs go out with a BANG sometimes.

Middle of the road jobs I've been using HFA amplifiers made by a UK company called BK Electronics, and for the budget concious there's the OMP series from the same stable. Cheap they may be but they are surprisingly good for the £££

In the past Rauch and Quad Electroacoustic were popular, but I've nto seen any new ones of eitehr make for some time now.
 

Posted by Steve Guttag (Member # 268) on 06-23-2002, 08:55 PM:
 
QSC here. DCA, ISA and MXa series. The bulk have been DCA amps though.

Mark, watch out on the Crowns (CE, CL, CH series)...they do not ground their inputs (despite the symbol the silk-screen on the panel). Also, they have a quirk in that the SPI indicator is on the input, pre-attenuator.

Steve

------------------
"Old projectionists never die, they just changeover!"
 

Posted by Don Sneed (Member # 955) on 06-23-2002, 11:00 PM:
 
we use QSC DCA, & Crown CL series amps....I perfer the QSC anyday !!
 
Posted by Manny Knowles (Member # 1171) on 06-24-2002, 02:59 AM:
 
I haven't done that many installations (about 20 screens total). I had good experience with QSC 1400 (which is out of production now) and so I just kept using that model wherever possible. I was striving for uniformity from theatre to theatre in this chain I work for. Sometimes it wasn't possible to find that many used 1400s...

One of the theatres (a 3-plex) uses the USA type by QSC.

Another one (5-plex) uses Ashley amps. I think their subs are driven by Crown amps.

I'm always on a budget, so I got nearly all of my amps used and they are in great condition. I only had to return one and that was because the rack was set up for 220V and the amp in question was 110V only (or vice-versa).


 

Posted by Aaron Sisemore (Member # 145) on 06-24-2002, 12:11 PM:
 
QSC 1x00 series, USA series and MX series. I have also recently installed Hafler and Crown in a couple locations, but mainly QSC for me

-Aaron

 

Posted by Bernard Tonks (Member # 809) on 06-24-2002, 01:30 PM:
 
quote:
Pete said:
Middle of the road jobs I've been using HFA amplifiers made by a UK company called BK Electronics, and for the budget concious there's the OMP series from the same stable. Cheap they may be but they are surprisingly good for the £££

As I installed stereo for monitoring in the projection room and to be able to enjoy a film from the large viewing port, I used BK Electronics OMP amplifiers which you can also get in module form only. Well built and rated at 100 watts rms, also included in the same price is a very meaty Toroidal power supply for a mere UK £39 including UK VAT plus £10 to include loudspeaker protection. Excellent value and service with a very little price increase today.

www.bkelec.com/
B.K Modules & Hybrids page.

The main amps with the Dolby CP55 were Quad make.


 

Posted by John Gordon (Member # 523) on 06-24-2002, 02:45 PM:
 
Hello all,
Thanks for the support.
Our DCA and ISA models are our current cinema amps--as well as the MX series. For those who want the best, the DCA is the amp. For those on a budget, the ISA series is the choice.
I would highly discourage theaters from using the RMX as a cinema amplifier. It does not have the right features for cinema use, rather the RMX is intended for the DJ and MI markets. We do not authorize RMX amps to our cinema dealers. If you are on a budget, the ISA is the amp to use. The price is very similar to the RMX as well.
My personal favorite is the DCA--I use these at home as well. Great amp. And , I will put the DCA amps up against your Krell or Pass Labs any day

------------------
John Gordon
QSC Audio Products, Inc.
1675 MacArthur Blvd.
Costa Mesa, CA 92626
(714) 957-7100
john_gordon@qscaudio.com
http://www.qscaudio.com
 

Posted by John Gordon (Member # 523) on 06-24-2002, 07:23 PM:
 
Hello Pete,
I’m at a little bit of a loss regarding the failures you mention with the DCAs. Do you have an actual count of the number of amps that have gone down? We do not have a record of consistent failures.
But for your concern, and others in Europe, all of our amps for countries running on 240V power are indeed capable of 240V—our European amps are the exact double that of the US 120V—we just label them as 230V. It is true though that a switching supply can go out with a “bang.” I’m not trying to divert blame or anything, but is it possible the theaters have unstable power and pushing it well above 240V? We have 120V amps running in Mexico just fine on a nominal 127V, with lots of fluctuation too.

------------------
John Gordon
QSC Audio Products, Inc.
1675 MacArthur Blvd.
Costa Mesa, CA 92626
(714) 957-7100
john_gordon@qscaudio.com
http://www.qscaudio.com
 

Posted by Scott Norwood (Member # 30) on 06-24-2002, 08:33 PM:
 
I haven't seen the DCA models--what features do they have that makes them appropriate for cinema use?

The places where I've worked have almost all had QSC MX and USA series, which seem to be very reliable. And I use an MX-1500a at home, though it is completely the wrong amp for my smallish apartment...it sounds good, though, so I'm keeping it.


 

Posted by Gordon McLeod (Member # 33) on 06-24-2002, 10:36 PM:
 
THe DCA is the best amp I have used
The worst are the Crown CE serries
 
Posted by Mark Gulbrandsen (Member # 72) on 06-25-2002, 12:08 AM:
 
Steve,
I just completed a re-install of over 40 CE2000's at the Isis Theatre in Aspen, CO. All went very well and they sound great!! Speakers here are EAW, but not by my choice. I don't care for their HF sections much, you have to run the hf through a passive flter to bring them in line for THX, or for that matter just to get rid of the rising hf response so you can eq them properly. I always hate running through any sort of additional filter network on the hf end of things!! Not a single problem with the CE2000's though......
Mark @ GTS
 
Posted by Phil Hill (Member # 371) on 06-25-2002, 04:22 AM:
 
After many failures and DOAs with Crown and JBL, I switched to QSC about 10 years ago when "brand recognition" was the most important thing to our "Marketing" department. It was not a pleasent political fight...so I just did it. Never have been sorry. I've used many 100's of QSC amps over the years with 99.9% reliability and great sound/performance. I think the DCA series is hands-down the best ever cinema amp.

>>> Phil


 

Posted by Ron Lacheur (Member # 1126) on 06-25-2002, 01:23 PM:
 
aren't JBL amps manufactured by QSC?
 
Posted by Richard Fowler (Member # 893) on 06-25-2002, 02:52 PM:
 
JBL phased out their amplifier arm when their parent - Harmon - bought Crown last year.
Richard Fowler
TVP-Theatre & Video Products Inc. www.tvpmiami.com

 
Posted by Ben Wales (Member # 92) on 06-25-2002, 06:30 PM:
 
But for your concern, and others in Europe, all of our amps for countries running on 240V power are indeed capable of 240V—our European amps.

Gordon @ QSC

Are the European PSU rated for 240v 10% +/- ?, We have in the UK in some parts of the country high voltage as high as 250v in some citys
 

Posted by John Gordon (Member # 523) on 06-27-2002, 12:52 PM:
 
Scott N,
Features on the DCA:
Input connectors: XLR; ¼” TRS; terminal block (Euro connector); and our DataPort connector.
Output connectors: Speakon and safety-shrouded barrier strip, including monitor output.
Gain controls have a security cover that prevents the unwanted hands from playing with them. The RMX line has knobs on the front that cannot be locked out, which is not desirable.
And of course all seven models are THX approved.

Ron L,
Yes, at one point we manufactured amps for JBL, but no longer.

Regarding the 240V issue. We qualify all amps to withstand 25% high line for relatively brief periods without failing. Based on the 500V rating of the gate driver chip, the supply should briefly withstand about 47% high line. At this voltage the filter caps are 25% overstressed and will overheat fairly quickly.

btw, as for reliability, I've personnally installed over 1,000 DCAs (new and used) without a single failure.

------------------
John Gordon
QSC Audio Products, Inc.
1675 MacArthur Blvd.
Costa Mesa, CA 92626
(714) 957-7100
john_gordon@qscaudio.com http://www.qscaudio.com


 

Posted by System Notices (Member # 2357) on 06-02-2010, 08:49 PM:
 

It has been 2897 days since the last post.


 
Posted by Mike Frese (Member # 4361) on 06-02-2010, 08:49 PM:
 
Are the QSC DCA's still one of the top choices? What about the QSC ISA's?
 
Posted by Danial Simmonds (Member # 4638) on 06-02-2010, 10:51 PM:
 
Yup here im installing 11 screens 2 halls are using the DCA Amps the rest is using ISA amps due to budget...

DCA's are smaller, lighter easy to install... have installed more than hundreds of these amps all over the place :-) its a personal favorite.

Regards
Danial
 
Posted by Demetris Thoupis (Member # 833) on 06-03-2010, 06:06 AM:
 
I believe this perception of QSC DCA amps as the best is just something that has been planted in our brains throughout the years. I do not say that QSC are not great. They are excellent and I used RMX series in a multiplex in 2001 and DCA in a multiplex in 2007 and so far not a single failure in either of these locations. I find though the overlove on the QSC to be something which cannot be explained. What really makes them the best? I can name a few other companies with better feature amplifiers like for example the Crown DSi Series. Not only they are excellent amps, budget friendly but they also incorporate very nice features like built in crossover network and some parametric eq minimizing the need for an external crossover network. I have not used these amps but I find this feature very interesting. Also the Crown XLS series are the most budget conservative amps. Still I am not saying that QSC are not excellent but I don't like the idea of everyone considering them the BEST because there are other excellent brands as well.
Demetris
 
Posted by Steve Guttag (Member # 268) on 06-03-2010, 06:50 AM:
 
Crown burned their bridges with NUMEROUS failures. Having built-in crossovers and other "features" in the amplifier also means those functions fail when the amp fails or have to be replaced when the amp is replaced...etc.

There ARE other amplifiers out there...even better ones than QSC... Lab Gruppen comes to mind but look at the QSC feature set, bang for the buck, form factor...and reliability and also support. They still sit VERY high on the list.

They have their ISA line for the budget conscious people that don't mind a HEAVY amp made in China that has higher distortion numbers and higher noise than the DCA line. The DCA line is also pretty decent on the electricity front too...no big surge at turn on...just cool clean power.

As for crossovers...rather than having them built in...they have them attach, if you desire (XC-3) and they will work on the ISA or DCA...need to swap an amp (I haven't) ...three screws, the crossover can move to the replacement without calibration.

Though I don't condone it...they have their DATAPORT for amazingly fast installation of the amp by most anybody. Simply plug a premade cable between their (or others now) monitor and the amp and you are wired for both input and speaker level MONITOR output. Even other amp companies, like Crown, copied them on that one.

Are there better amps (sounding, power...etc) yes...but when you put all of the factors of cost, reliability, performance, feature set, support....etc...they continue to simply be the best choice for the cinema market place.

Steve
 
Posted by Stephen Furley (Member # 1277) on 06-03-2010, 11:09 AM:
 
quote:
Are the European PSU rated for 240v 10% +/- ?, We have in the UK in some parts of the country high voltage as high as 250v in some citys
The highest you should see in the UK, phase to neutral is 230 V + 10% i.e. 253 V, close to the old limit of 240 V + 6%, i.e. 254.4 V. It's the lower limit which has been considerably lowered in recent years.

In our main building at work it's always below 230, sometimes well below, but we are overloaded. EDF are trying to find a route to get a new HV feeder into our substation at the moment. Phase 2 is always the worst, and phase 3 the best, or at least the least bad. Our load is also badly out of balance.

In another building which we have, just a few tens of metres away I'm seeing 247.2 V on one phase at the moment, and overnight I've been seeing over 253 V, I think 254.8 is the highest I've seen so far.

While we're talking of matters electrical, I wonder if anybody here can answer a question for me. As some of you may know, I collect lamps and lighting equipment. I have an unusual American lamp which I'd like to run up to see what the light from it is like. I have the correct ballast for it, tapped for 120, 208, 240 and 277 V, but of course, it's intended for 60 Hz. I can get 60 Hz. at various Voltages but only up to 200 VA, which isn't enough to run this lamp. Does anybody know what the effect of trying to run it with about 240 V 50 Hz into the 277 V tap would be? The lower frequency should increase the lamp current, it's a conventional magnetic ballast, but would the reduced Voltage bring the current down to a safe value? I only want to run it for a few minutes, but it's a metal halide lamp, so I'm inclined to be a bit cautious with it.
 
Posted by Jonathan Althaus (Member # 5042) on 06-03-2010, 11:41 AM:
 
We've gone from the old style Peaveys to QSC and now Crowns. I hated the Peaveys, they always seemed to be needed to be replaced and compared to the QSC's and Crown's were insanely heavy. I like the Crowns a lot, slim, light, and give off a nice blue glow.
 
Posted by Gordon Bachlund (Member # 124) on 06-03-2010, 12:42 PM:
 
Stephen, since the 60 Hz ballast is magnetic, it will operate hotter at 50 Hz. However, since you plan to operate it for only short periods of time you should have no problems with 240V 50 Hz into the ballast's 240V winding.

When I worked overseas years ago I experienced shortened 60 Hz ballast life when wired to 50 Hz, but no catastrophic problems.
 
Posted by Robert Minichino (Member # 3495) on 06-03-2010, 12:58 PM:
 
Since the ballast is working as an inductor and not a transformer (the ignition winding is a saturated high voltage tap, but that's unaffected), the current at 60Hz is the same as the current at 50Hz if you apply sqrt(50/60)=0.91 times the voltage. So 252V to the 277V tap should be perfectly safe. If it won't start with your line voltage into the 277V tap, you should be perfectly safe at the 240V tap for a short period of time. Make sure to use an appropriately-sized fuse.
 
Posted by Stephen Furley (Member # 1277) on 06-03-2010, 03:41 PM:
 
I ran it up, from a safe distance, and the lamp current was a bit high, but only by a few percent. The colour was rather poor by modern standards, with a rather nasty greenish tinge to it. It's a very early 2 kW metal halide lamp; metal halide technoogy has come a long way in recent years. The ballast is huge, and heavy.

Most lamp types will operate on simple inductive ballasts on 240 V over here. A few large ones run on 415 V across two phases for things like sports stadium lighting.

High-pressure mercury of any size will run on a simple ballast on 240 V, but 415 V ballasts are available for the largest sizes.

Low pressure sodium (SOX) lamps will work on an inductive ballast with a low-Voltage (~700 V) parallel ignitor; only the longest (180 W) ones need a leak transformer these days.

High pressure sodium Normally use a simple inductive ballast with a high-Voltage (2.4 - 5 kV) superimposed ignitor, and most metal halide lamps use the same gear as SON. Some older style probe start type metal halide lamps use a mercury ballast with a low Voltage ignitor.

Most fluorescent lamps tend to use high-frequency electronic gear these days.

Neon signs and cold cathode tubes use either transformers or electronic gear. We seldom see the sort of ballasts which are common over there. In most cases ours tend to be considerably cheaper.
 
Posted by Tony Bandiera Jr (Member # 2365) on 06-03-2010, 11:06 PM:
 
Back on topic (but thanks for the info on lamps and ballasts guys!!) it has always been QSC only for me.

Starting way back in the mid-late 80's when I worked for Knott's Berry Farm and we were switching from Altec (not bad but parts were getting hard to come by and they were underpowered) and Yamaha (Great motorcycles but crappy amps) I have been a huge fan of QSC.

True story: Set up sound on the roof of Calico Saloon for Halloween Haunt's sound efx. Used one Yamaha amp and one QSC 1400. Both were powered up overnight and got rained (heavily) on. Guess which one survived? The 1400 was still on and working but the Yamaha was dead. Never could get it working even after extensive drying time.

Another: One USA series amp at UC Irvine failed. No drama, just came in one day and it was dead. Took it to QSC Service which is local to UCI, dropped it off for repair. Despite the fact it was out of warranty (5 years old) QSC repaired it for free and even shipped it back to me at no charge. After 13 years that has been the only breakdown of the 7 MXa series and 3 USA series amps in that room. Oh, the amps stay powered up 24/7.

Another selling point for me is the integration of QSC's hardware now for cinema use..The DCM monitors, DCA amps and the speaker systems which work extremely well together. My new install at UCI gets rave reviews for sound quality and it was at a great price point.

As for Crown, I have been generally satisfied with the sound, but the reliability and often violent failure modes has made me stay away from them. I have seen too many Crown amps go down with lots of sparks and flames and impress the full DC power supply voltage to the speakers. In fact IIRC it was a Crown amp that caught fire and caused an evacuation and shutdown of a ride at Disney's California Adventure park.

BGW amps were once popular here in So Cal but have been replaced over time with QSC. The BGW's were generally quite good, but the combination power switch/circuit breaker was a weak link.

So for sound quality, ease of installation, integration from processor output to speakers, reliability and outstanding service support at a great price point, QSC wins hands down.

quote: Demetris Thoupis
I believe this perception of QSC DCA amps as the best is just something that has been planted in our brains throughout the years. I do not say that QSC are not great. They are excellent and I used RMX series in a multiplex in 2001 and DCA in a multiplex in 2007 and so far not a single failure in either of these locations. I find though the overlove on the QSC to be something which cannot be explained. What really makes them the best? I can name a few other companies with better feature amplifiers like for example the Crown DSi Series. Not only they are excellent amps, budget friendly but they also incorporate very nice features like built in crossover network and some parametric eq minimizing the need for an external crossover network. I have not used these amps but I find this feature very interesting. Also the Crown XLS series are the most budget conservative amps. Still I am not saying that QSC are not excellent but I don't like the idea of everyone considering them the BEST because there are other excellent brands as well.
Demetris
LOL Demetris, now who's taking the piss out of someone like you said to me in another thread? [Big Grin] [Big Grin] (I'm just havin fun with you, please don't get mad.)

To answer your question, the points I summarized above the quote are what makes QSC the best, so far. No one else has come close to matching them in all the categories I mentioned.

That is generally the criteria for determining the best in a given situation.
 
Posted by Michael Voiland (Member # 5386) on 06-03-2010, 11:29 PM:
 
Anyone ever hear of ashly?
 
Posted by Jeremy Weigel (Member # 4208) on 06-04-2010, 12:15 AM:
 
All of our amps are QSC's Mxa1500 & 2000's and RMX 1450's. I've only had 2 of them die. Both were MXa2000's and they died violently. Sparks and smoke shot out the front. Luckily they didn't damage the speakers. I still have one of them and have been debating whether it is worth trying to fix it.
 
Posted by Stephen Furley (Member # 1277) on 06-04-2010, 04:50 AM:
 
The people who don't like Crown amps, what was it about them that you didn't like?
 
Posted by Steve Guttag (Member # 268) on 06-04-2010, 06:28 AM:
 
Ashleys suck...they have been the primary cause of recones for me aside from foam rot! When an Ashley goes, it will cook the voice coil...they LOVE to do that. They are hot amps and are often undercooled. To top it off, I don't like how they sound.

As to Crowns...their reliability leaves a lot to be desired. Crown designs often have parts operating close to their maximum...with little thought as to varying line voltages that might push that part over its maximum rating. When Crowns fail, they are often violent and self-destruct. ....the list goes on and on. Now, as some have said, they have SOME amps that sound quite good, I just don't trust them anymore (and I used to be a Crown fan...back in the '70s and '80s).
 
Posted by Sam D. Chavez (Member # 1841) on 06-04-2010, 10:43 AM:
 
What Steve said.
 
Posted by Scott Norwood (Member # 30) on 06-04-2010, 10:52 AM:
 
Out of curiousity, what is the expected lifetime of a quality amplifier?

I finally heard of a QSC that failed--it is an MX2000a that was installed in 1998 or so. (I don't know the details of the failure mode, but it didn't take out the speakers. It is in the process of being repaired and I hope to find out later what went wrong.)

Is this an anomaly, or are all of the other amps of that vintage in that venue about to need service? These have all been powered off at night (and on every day) since the installation.

This is the first time that I have seen any issues with QSC, and pretty much all of the recent (post-mid-1990s) installations in this area use them. The only other issue that I have had is noisy pots in MX-1500a units, which were easily and cheaply replaced (I think that the part is something like $3 from QSC).

(Does anyone use Crest amplifiers in cinemas? Crown and Crest seem to be popular with the stage theater crowd, but they (almost?) never show up in cinemas.)
 
Posted by Tony Bandiera Jr (Member # 2365) on 06-04-2010, 12:44 PM:
 
quote: Jeremy Weigel
I've only had 2 of them die. Both were MXa2000's and they died violently. Sparks and smoke shot out the front. Luckily they didn't damage the speakers. I still have one of them and have been debating whether it is worth trying to fix it.
Jeremy, there was a bad run of MXa's that had a problem with the power switch and associated wiring. When it let go the forced air from the fan in concert with the natural dust build-up made for quite a show.

Contact QSC's service department with the amp's serial number, it is quite possible they will fix it at no charge if it was one of the affected lot. Even if not a warranty issue, their repair rates are very reasonable and I doubt the repair cost would exceed $300. A great deal for a fresh amp. (They check EVERYTHING when doing a repair and reset bias, etc. and replace any questionable parts.)

Stephen, I listed some points about Crown in my previous post and Steve and Sam pretty well recapped it. Crown, in terms of reliability and speaker protection when failing, sucks.

Scott, I would feel that 20-25 years is a good benchmark for amplifier life, but there are plenty of amps out there that are 30-40 years old and still running.

Main failure modes for older amps are the electrolytic caps which can dry out and fail after many years, sometimes bridge rectifiers go bad, level pots are the most common failure (and cheap to fix) but a bigger issue with really old amps is non-availability of semiconductors.

Never saw any Crest amps in cinemas, had one screening room with them, but they've been replaced with QSC's.
[Big Grin]
 
Posted by Demetris Thoupis (Member # 833) on 06-04-2010, 02:11 PM:
 
In the 90's unfortunately QSC had no direct dealer in Cyprus so we used the CrestAudio Multiplex series for some cinemas via the local CrestAudio dealer (hey we are in the middle of nowhere in a sense). They don't like to sit unworking that is for sure. Also leaking capacitors was a common problem to them. Then we changed over the JBL amps the MPX series again from the local dealer and from those we never had a failure. I used Crown at a college cinema and have not had any problems yet and everything else so far was QSC but pricing down here is quite hefty compared to Crown although we have used QSC so far in our projects from 2001 till today simply for the mind planting QSC are the best. In a funny way, I had a call for a failed RMX unit today [Big Grin] . Sods law!

Demetris

PS. And I don't compare testing an amp in the rain a test which validates which amp is best or not! They are not supposed to get wet. (although definately not saying that Yamaha amps are worth installing in cinema applications)
 
Posted by Phil Hill (Member # 371) on 06-04-2010, 02:35 PM:
 
Having installed over 3000 power amps in large screen and simulator ride cinemas, the worst of the bunch were JBL 6290 (usually failed on power-up - although the 6260 was good) and, as Steve said, ANY Crown amp. When the Crowns failed, they usually take the speaker with them...shitty design that applies the DC rail to the VC when kaput...avoid!

The best (IMHO) is the QSC DCA series and I've had good luck with the MX series.
 
Posted by Marco Giustini (Member # 4544) on 06-04-2010, 04:25 PM:
 
My personal experience with DCA's amps is awesome. 68 DCA's installed in the theatre I used to work. Two failures in 6 years, one of which a few weeks after the opening.
 
Posted by Gordon McLeod (Member # 33) on 06-04-2010, 05:36 PM:
 
I always remember being told that the crown DC300 amps earned there name well they alway would go DC on the speaker terminals
ALso had a lot of grief form latter Hafler Amps
I liked the AB International Amps
 
Posted by Bobby Henderson (Member # 840) on 06-04-2010, 09:05 PM:
 
Wow. No mention of Peavey?
[Razz]

I'm just throwing that in to possibly piss off some Cinemark folks. Heh heh.
 
Posted by Louis Bornwasser (Member # 3063) on 06-04-2010, 09:38 PM:
 
Started with old Crown (DC300 & D150), went to Hafler back when David Hafler owned the company. Then bought Ashly from Kelmar.

Stayed with Ashly for 25 years. I only bought the FET500/FET2000/FTX2001 series. Sold over 7000 of them. Reliable, powerful, rated at 2 ohm (will work at .6 ohm)Really sweet sound. Distortion at or below rated output is .003% below 9k. Widely used in the UK in cinemas and studios. All National Amusement cinemas, many Goodrich Theatres, and all of my independents.

Would still be selling them, but no longer made. Substantial inventory still available since I had 2 runs made after the factory dropped the model.

No replacement in sight at a correct price. Louis
 
Posted by Jonathan Althaus (Member # 5042) on 06-04-2010, 10:18 PM:
 
Peavey CS 400, still have 22 in use, and 11 CS 800 X's. Haven't replaced one in months (knock on wood).
 
Posted by James Westbrook (Member # 3690) on 06-04-2010, 10:58 PM:
 
The key word here is "months."
 
Posted by Demetris Thoupis (Member # 833) on 06-05-2010, 03:58 AM:
 
I have also two cinemas with Peavey amps that were originaly installed from a foreign dealer. Only had one failure and that was excessive dry joins.
Dem
 
Posted by Stephen Furley (Member # 1277) on 06-05-2010, 04:42 AM:
 
During the time that I was projecting at Croydon the original amps, I can't remember what they were now, were replaced by Crown; it's the only place I've actually seen them. This was around the time when digital went in, and various other upgrades were made.

Didn't really have enough experience of them to form an opinion, good or bad. I turned them on at the start of the day, and they worked. Didn't sound better or worse than similar amps, at least not to my ear.
 
Posted by Mark Gulbrandsen (Member # 72) on 06-05-2010, 10:54 PM:
 
Back when I entered this biz in the Chicago area it was McGhoan Electronics. I mainly found McGhoan PA amplifiers... even in stereo systems. Now McGhoan had a ong history of building record players for Montgomery Wards and branded amplifiers for the Chicago area Hi-Fi chain Musicraft. I'm sure that Sam has run into these in past years when he was installing Dolby gear around the Chicago area. I always figured they had some union connection of some sort and I can vouch that these amps were taken right out of the pages of the RCA Semiconductor book! Reliable they were... cheaply built they were but they did work. Hopefully most have been retired by now however I can imagine that a few have survived.

Oh, and today I install only QSC amplifiers... model dependent on the jobs budget r the existing equipment at the site. I also rebuild gobs of series 1 amplifiers

Mark
 
Posted by Marco Giustini (Member # 4544) on 06-06-2010, 12:51 PM:
 
I have experience with Crowns amps dying in a smoky cloud passing DC to the speakers...

One of the QSC's that failed did so in a smoky cloud, though, but no DC to the speaker.
 
Posted by Martin Brooks (Member # 1269) on 06-06-2010, 10:44 PM:
 
quote: Steve Guttag
Crown burned their bridges with NUMEROUS failures. Having built-in crossovers and other "features" in the amplifier also means those functions fail when the amp fails or have to be replaced when the amp is replaced...etc.
That's too bad. I have a Crown D75 that's been in operation in my system at home for something like 33 years with absolutely not a single problem.
 
Posted by Mark Gulbrandsen (Member # 72) on 06-07-2010, 08:13 AM:
 
Martin... If you replace it you will finally hear the music! It's an ancient design with many audible issues including very high transient intermod distortion. There were even better sounding amps in those days. Basically the same circuit as the D-150 and DC-300 just scaled down. Very slow high distortion input I.C. And Quasi complementary output stage with all the inherent problems of old school semiconductors.
 
Posted by Joe Elliott (Member # 4006) on 06-07-2010, 10:10 AM:
 
We have about 70 Crown amps in the building with a fail rate of about 6 in the past two years. Now granted these amps are only 8 years old, but that doesn't seam too bad. However, I have experienced the DC hum to the speakers, and it generally travels through all the channels, and you have to disconnect the offending amp. That has happened twice out of the 6 amps that failed.
 
Posted by Steve Guttag (Member # 268) on 06-07-2010, 11:56 AM:
 
6 in the past two years? That is about 8.5%. Care to know how many DCAs I've sent back in the past decade out of the hundreds we've sold? Of those that got into service...I think it is either zero or 1. I've had one or two DOAs (needing just a quick fix...still frustrating though).

Steve
 
Posted by Martin Brooks (Member # 1269) on 06-07-2010, 04:21 PM:
 
quote: Mark Gulbrandsen
Martin... If you replace it you will finally hear the music! It's an ancient design with many audible issues including very high transient intermod distortion. There were even better sounding amps in those days. Basically the same circuit as the D-150 and DC-300 just scaled down. Very slow high distortion input I.C. And Quasi complementary output stage with all the inherent problems of old school semiconductors.
A bit off topic, but: before that Crown, I had a Fisher 500c receiver. It was definitely warmer but had more limited frequency response and a bit of hum on the bottom. I'm actually in the market for new equipment, but I have to say that I have been notoriously unimpressed by anything I've heard at retail that's reasonably priced. I actually hope that whatever I get to replace the Crown does sound a lot better so I won't regret the investment.
 
Posted by Louis Bornwasser (Member # 3063) on 06-07-2010, 09:58 PM:
 
We once sold an Ashly to a guy for home use. He tried 3 units in a row, complaining that they weren't loud enough. At 300 watts/channel, I rejected that as just wrong.

We sold him a D75 Crown. He was very happy. He asociated distortion with loudness.At full output distortion was over 40%. Louis
 
Posted by Mark Gulbrandsen (Member # 72) on 06-07-2010, 10:31 PM:
 
Louis,
I completely believe that!
 
Posted by Tony Bandiera Jr (Member # 2365) on 06-08-2010, 02:01 PM:
 
quote: Demetris Thoupis
PS. And I don't compare testing an amp in the rain a test which validates which amp is best or not! They are not supposed to get wet. (although definately not saying that Yamaha amps are worth installing in cinema applications)
LOL I do. I have tested various amps by heat, cold, water and dropping from a height of three feet onto a carpeted concrete floor. So far only QSC's have survived the worst I could throw at them. Another good torture test is to feed it a square wave signal at about 4khz at full rated power. A lot of amps don't survive that test. [evil]

Bobby/Jonathan: I installed a pair of Peavey CS400's for two center/surround setups for Laemmle Theatres way back in the late 80's. One amp finally quit after about ten years and as far as I know the other one is still there. Small rooms so they don't have to work very hard. One thing I did notice and did not like about the Peaveys is how hot the transformer got even at idle. Since the houses used Cervin-Vega disco speakers behind the screen I have no opinion on how good/bad those amps sounded.

quote: Louis Bornwasser
We sold him a D75 Crown. He was very happy. He asociated distortion with loudness.At full output distortion was over 40%. Louis
I'll bet he's the same guy who equates the numbers on the fader with watts output too. [Roll Eyes]
 
Posted by Jonathan Althaus (Member # 5042) on 06-30-2010, 01:41 PM:
 
Replaced a Peavey 800 last week, probably the first time in over a year.

About 2 years ago, we had 12 crowns installed, and other than the one we were trying to push double the load of what it could handle, did not have any go out. We get a premade rack last week (all Crown) for a digital install, and 2 have gone out in a 5 day span. Turns out these amps were made in China, whereas all our others were American made. After talking to Crown, they admitted they had a huge batch of amps with bad transducers.
 
Posted by Jeremy Weigel (Member # 4208) on 12-27-2010, 10:35 PM:
 
quote: Jeremy Weigel
I still have one of them and have been debating whether it is worth trying to fix it.
quote: Tony Bandiera Jr
Jeremy, there was a bad run of MXa's that had a problem with the power switch and associated wiring. When it let go the forced air from the fan in concert with the natural dust build-up made for quite a show.

Contact QSC's service department with the amp's serial number, it is quite possible they will fix it at no charge if it was one of the affected lot. Even if not a warranty issue, their repair rates are very reasonable and I doubt the repair cost would exceed $300. A great deal for a fresh amp. (They check EVERYTHING when doing a repair and reset bias, etc. and replace any questionable parts.)
I finally dug this amp out of the storage corner and opened it up. One of the large caps blew its top. You can see where flame shot out of it. The remaining large caps on that particular board are all slightly bulging. I see no other visibly burnt components.

I sent QSC an email last week asking if they still repair these units since they don't list any parts available for them. Still haven't heard back. If they don't, does any else here repair these or know someone who does?
 
Posted by Tony Bandiera Jr (Member # 2365) on 12-27-2010, 11:33 PM:
 
Jeremy, I am 99.9997% sure that they can/will still service it.

Forget email, call them instead. They may even send you a proper shipping box for it.

In case they don't repair it, chances are I can.

OT: I haven't forgotten your CAT64 extender project, but can't find the 32-position edge connector anywhere. I do Have an old CP200 backplane somewhere and once I locate it I'll steal the connector off of it. [Smile]
 
Posted by Steve Guttag (Member # 268) on 12-28-2010, 06:21 AM:
 
QSC used to have "renew" kits available. I'd check with Sam Hynds to see if they still do. They have the items that age...including the capacitors. Change out everything in the kit and you essentially have a new amplifier (from an aging standpoint).

-Steve
 
Posted by Jeremy Weigel (Member # 4208) on 12-29-2010, 10:35 PM:
 
Thanks Tony and Steve. I'll give them a call on Monday.
 




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