Pro Amplifier recommendations

[jliedeka]

They GX-3 and GX-5 have 3 input connectors per channel, 1 RCA, 1 TRS and 1 XLR.

J

 

[WmAx]

Does anyone have any experience with the QSC amps? I was looking at the GX-3 and GX-5 on Parts Express. The 3 is class B and the 5 is class H. One thing that appeals to me is they have RCA inputs along with balanced XLRs.

Jim

These new budget amps from QSC; I do not know anything about their real performance. I find it odd they say it is class B and not class AB. It must be some kind of marketing promotion. I am not aware of any straight up class B audio amps - and I would not want one to be honest if it really is pure class B. I'm betting this is a standard class AB amplifier. Class H is fine; this is a class AB amplifier with a secondary/high voltage supply rail mode that kicks in at higher power ranges; this scheme allows the amplifier to operate at lower temperatures/higher efficiency.

The fans on these are still audible - and I am not sure what to swap them with in this example. You may be able to get by if you placed it in an audio cabinet with a door, though. The fans are not as loud as the Behringer EP or QSC RMX fans. We know what to replace the QSC RMX and Behringer EP fans with to get a silent amplifier; but these new amps may use different size fan/voltage; meaning you will have to do a fan search and experiment to find one that is low enough in noise for your application.

Midnight: these do indeed have RCA inputs. A local pro audio joint carries these new models and I did notice RCA inputs on the rear.

-Chris

 

[jliedeka]

Thanks, Chris.

Both of these amps have way more power than I need and the GX-5 is the same price as the Yamaha P2500S which is still way more power than I need.

OTOH, with the Yamaha, I'll either need to buy 3 Clean Boxes or build a 5 channel XLR driver. There's a fairly simple circuit that uses one Analog Devices SSM2142 chip per channel. However, I don't have any experience building electronic things.

Jim

 

[jliedeka]

Chris,

One more question. In another thread you quoted measurements for the Behringer A500. Are there other sources you can point me to, either on-line or print, that have credible measurements of some of these amplifiers under discussion?

Jim

 

[WmAx]

Thanks, Chris.

Both of these amps have way more power than I need and the GX-5 is the same price as the Yamaha P2500S which is still way more power than I need.

OTOH, with the Yamaha, I'll either need to buy 3 Clean Boxes or build a 5 channel XLR driver. There's a fairly simple circuit that uses one Analog Devices SSM2142 chip per channel. However, I don't have any experience building electronic things.

Jim

Well, another option is to get an electronics student to make it for you. They could just make say an 8 channel one and you would be set for any current or future uses. You can get some great deals this way. I have a dude that I pay to make custom circuits for me when I need them. If you are interested, PM me and I'll discuss details with you. BTW, the custom circuit would be cheaper and superior to the ART CleanBoxes; the ART rolls off the lowest octave.

Personally, if it came down to it, I would never pick the QSC budget amp over the Yamaha. The Yamaha has no fan noise, has a better chassis and I would wager has better build internally compared to the budget QSC. Now, the regular QSCs are superb, such as from the RMX line. But they are also costly and have very loud fans you must swap out just like the Behringer Ep2500.

-Chris

 

[tcarcio]

As for Crown, since you mention them, I don't recommend them for value. You do not get anywhere near the build quality that you get from the Behringer gear dollar for dollar. Not even close. I do use some Crowns .... but I found out this information the hard way... by buying them. LOL. They work fine - never had a problem. Just, they do not have the beefy well designed and executed robust build of the Behringers. beyond IME.

-Chris

Which Crowns did you own? I have used and still have both crown and behringer amps and I have been in and out of them and found no significant difference in quality. Crown has one of the best warrantees in the business and CS is fantastic. I like my ep-2500 but I have found Crowns as good if not better and have had zero issues. Just wondering what you had and how you came to that conclusion. As for price I would agree that you will pay more for thr higher end Crowns but the ones you would use for your home theater such as the Xls series are competitive in price and if you don't mind buying from ebay you can get some great deals as I have.

 

[WmAx]

Which Crowns did you own? I have used and still have both crown and behringer amps and I have been in and out of them and found no significant difference in quality. Crown has one of the best warrantees in the business and CS is fantastic. I like my ep-2500 but I have found Crowns as good if not better and have had zero issues. Just wondering what you had and how you came to that conclusion. As for price I would agree that you will pay more for thr higher end Crowns but the ones you would use for your home theater such as the Xls series are competitive in price and if you don't mind buying from ebay you can get some great deals as I have.

I have two of the XLS series. The most recent, 'D' type. I have analyzed the internal design.

Compared to the Behringer Ep2500, the Crown XlS cons are:

-PCB is inferior - standard single trace phenolic compared to glass expoxy double trace/redudant mil spec on the EP

-Heatsinks are very poorly designed/integrated. They actually pose a risk on the XLS - relative large metal mass attached to PCB, not frame: allowing a physical shock to potentially cause cracks/damage to the PCB easily.

-Heatsinks do not have efficient design in respect to air through put to maximize effectiveness of fan; the EP2500 has a well designed method here.

-Chassis is not as robust.

-Speaker binding posts are inferior quality and can not even accept large gauge wire (16 AWG) is about the maximum size the binding posts will accept. You have to use banana connectors or spades.

-Less output devices/less current capability. The EP can safely and efficiently power 2 Ohm stereo loads and 4 Ohm bridged loads. The XLS can not.

The EP is far superior in these ways. No comparision. XLS does is not comparable.

The XLS, however, is fine for home use, and the 202D model I do recommend when it fits the bill.

Used within their limitations, the XLS will be a transparent amplifier.

-Chris

 

[tcarcio]

Looks like you have gone through the Xls and I guess I am thinking more along the lines of the Cts series as far as what I have owned and used. Strange though that when a friend of mine that is in the repair business wen't through my Cts 600's he didn't have anything bad to say so do you think they just dropped the ball on the Xls as far as build or have you found this to be a fairly common thing?

 

[anda08]

Sorry to barge in into this conversation, but i was wondering could someone give me some recommendation in driving Monitor Audio GS20 full power.

At the moment i have Yamaha RX-V2700 which power amp would give me the power to get everything out of my speakers, my set up will be full GS later, but atm i can see that my AV receiver is not driving them at what they are capable off.

Would the power amp go with my Yamaha RX-V2700?

Please someone help me out

 

[jliedeka]

Pretty much everything in this thread could be applied to your situation. I assume the RX V2700 has pre-outs for the channels you want to amplify. (It does, I just checked.)

You need to determine how much power you need for your room and speakers and you need a away to interface your receiver to whichever amp you choose. Your receiver should have more than ample power for most normal listening. If you want a little more power for transients, any of the amps discussed would suit you.

Jim

 

[Soundman]

If you don't mind swapping the fan, the Behringer Ep2500 is perfect for you. If you don't want to open it up and bother with the $8 plus shipping fan exchange then Yamaha P5000S will output 500 x 2 into 8 Ohm, both channels driven and has no fan noise. As a benefit, it's rack mount ears come off if you don't like those to be present. The Yamaha will also have a longer/better warranty. Do keep in mind the Yamaha is not 4 Ohm stable bridged, and not 2 ohm stable stereo. It is 4 Ohm stable stereo. Output into 4 Ohms, both channels driven, is about 700 watts, 20Hz-20,000Hz. On the downside.... the Yamaha is nearly 2x the cost of the Behringer EP2500....

As for Crown, since you mention them, I don't recommend them for value. You do not get anywhere near the build quality that you get from the Behringer gear dollar for dollar. Not even close. I do use some Crowns .... but I found out this information the hard way... by buying them. LOL. They work fine - never had a problem. Just, they do not have the beefy well designed and executed robust build of the Behringers. The nice Crowns are not a good value. I only recommend some specific Crows, for example, if they happen to fit the budget and precise power range the user is looking for. Say for example the user wants an inexpensive high quality 200 watt x 2 into 8 ohm, 300 watt into 4 Ohm, stereo amplifier? The Crown XLS202D can be found for good prices and it is a great amp for this specific set of requirements. If the user will pay 300-350 though, I recommend the Yamaha P2500S instead of the Crown, for this approx. 200 watt range. I have had people want only 200-250 watts and thought that the extra power an EP2500 produces is too much and they specifically DO NOT want that much power, and have a tight budget. You can get the XLS202D for about 200-230 shipped range from a reputable online retailer if you do a price match request against a super discount retailer. I recommend zzounds.com as the actual retailer to buy from and get to price match. They offer superb customer service - above and beyond IME.

-Chris

What is the EP2500 8 ohm power rating? As far as the Yamaha goes, I was thinking about this one, if I did go with a Yamaha: http://pro-audio.musiciansfriend.com/product?sku=480827V This should be more then enough power where I will probably never need to bridge it anyway. I do like that with the Yamaha's I won't have to worry about fan noise and that the rack mount ears come off. Let me know what you think.

 

[anda08]

Pretty much everything in this thread could be applied to your situation. I assume the RX V2700 has pre-outs for the channels you want to amplify. (It does, I just checked.)

You need to determine how much power you need for your room and speakers and you need a away to interface your receiver to whichever amp you choose. Your receiver should have more than ample power for most normal listening. If you want a little more power for transients, any of the amps discussed would suit you.

Jim

Hi, well as i mentioned the power amp would be there just for my front speakers, the MA GS20 are 150w speakers, and i can see my RX-V2700 only has one output for fronts RCA, so how much power amp would i need to drive those speakers at full power? And which amp would produce best quality sound? I am kinda new to all of this...

Also how much does Yamaha P2500S achieve at 6ohms because it doesn't seem to state anywhere...

Yeah the 2700 has a lot of power, but it struggles to achieve good performance after 0dB or maybe its the speakers ? i dont know

P.S: can someone provide me a link to a cable which i would need to hook up the power amp onto the 2700.

Thanks

 

[jliedeka]

The Yamaha puts out 250Wpc at 8 ohms and will put out more at 6 ohms. That should be plenty for your MA GS20s. I've never gone to 0dB on my receiver but I'm running some really sensitive Klipsch speakers.

As for interfacing, your best bet would be to get an ART Clean Box (not the Clean Box II), some RCA cables to go from the receiver to the Clean Box and some XLR cables to go from the Clean Box to the amp.

You could try to buy or make some RCA to XLR cables and avoid the clean box. That might not be the best solution because your receiver's output level will probably not be high enough to make the most out of the amplifier. You could get a higher noise floor if you turn the gain all the way up on the amp.

Jim

 

[MidnightSensi]

Interesting on the new QSC budget line, I must be thinking of another amplifier with the TRS connections.

Just fyi, Comprehensive makes XLR to RCA connectors that work well and are built sturdy.

 

[WmAx]

Hi, well as i mentioned the power amp would be there just for my front speakers, the MA GS20 are 150w speakers, and i can see my RX-V2700 only has one output for fronts RCA, so how much power amp would i need to drive those speakers at full power? And which amp would produce best quality sound? I am kinda new to all of this...

Also how much does Yamaha P2500S achieve at 6ohms because it doesn't seem to state anywhere...

Around 280 watts per channel at 6 ohms, based on the 4 Ohm and 8 Ohm levels.

-Chris

P.S: can someone provide me a link to a cable which i would need to hook up the power amp onto the 2700.

RCA female to XLR MALE.

This place has a large assortment of adapters:
http://www.audiogear.com/Audio-Adapters-IM.html

*Note: in some cases, a ground loop may occur between consumer unbalanced and balanced consumer gear. In that case, use an ART DTI unit. This also negates need for adapter, as it has all type of inputs/outputs. You would use a standard RCA cable to connect to the ART DTI input side. Then use a stanard XLR female to XLR male patch cord from the DTI to amplifier.

**Note: consumer amplifiers may not produce enough output voltage to feed pro amps. It varies between products and you really won't know until you try the particular combo you have. If there is a voltage mismatch, then you woudl have to turn up the amp gain too high, resulting in audible hiss. The solution is to use an active converter box like the Art CleanBox Original. It is similar to the ART DTI box, but it is active instead of passive. The active circuitry allows you to adjust the signal strength to match the devices ideally.

 

[WmAx]

What is the EP2500 8 ohm power rating? As far as the Yamaha goes, I was thinking about this one, if I did go with a Yamaha: http://pro-audio.musiciansfriend.com/product?sku=480827V This should be more then enough power where I will probably never need to bridge it anyway. I do like that with the Yamaha's I won't have to worry about fan noise and that the rack mount ears come off. Let me know what you think.

Once again: 450 x 2 at 8 Ohms.

As far as the Yamaha goes, that's 700 x 2 at 8 Ohms, and almost 1kw x 2 at 4 Ohms. The Yamaha can power most sub drivers easily. It will certainly power just about any main speaker in existence without effort. The only exception being some very rare exotic ribbon speakers that have 1-1.5 Ohm impedance - which is too low for most any amplifier.

-Chris

 

[Soundman]

Once again: 450 x 2 at 8 Ohms.

Sorry Chris. I must have missed that somehow.

As far as the Yamaha goes, that's 700 x 2 at 8 Ohms, and almost 1kw x 2 at 4 Ohms. The Yamaha can power most sub drivers easily. It will certainly power just about any main speaker in existence without effort. The only exception being some very rare exotic ribbon speakers that have 1-1.5 Ohm impedance - which is too low for most any amplifier.

-Chris

I thought that $599.00 for the Yamaha P7000S was a good price. Anything else in that price range you would recommend? Or possibly bridge and get 2 lower priced amps? What's the better way to go in your opinion?

 

[WmAx]

Sorry Chris. I must have missed that somehow.


I thought that $599.00 for the Yamaha P7000S was a good price. Anything else in that price range you would recommend? Or possibly bridge and get 2 lower priced amps? What's the better way to go in your opinion?

The Yamaha is excellent. It's just that... rarely does anyone use that level of power for the mains. I would have suggested the P3500S or P5000S at the very most unless your mains have super low efficiency: for example, if your mains have an efficiency in the 80-83db/watt/1 Meter range, then the P7000S could definitely be a great choice. But with an 86-88db/watt/1 Meter range efficiency, the P3500S would be fine. 350 watts per channel - and keep in mind - that is the 20Hz-20,000Hz rating. Most amps use a 1kHz rating, and in that case, it's a 390 x 2 into 8 Ohms amplifier.

Keep in mind, that the larger the amplifier, the more gain is produces. At a certain point, if your speakers are too efficient for a given power range, then the speakers may cause the noise floor/hiss to become audible. So you should base the amplifier you choose partially on the sensitivity of your speakers. I have no idea what your speaker sensitivity may be....

-Chris

 

[Soundman]

The Yamaha is excellent. It's just that... rarely does anyone use that level of power for the mains. I would have suggested the P3500S or P5000S at the very most unless your mains have super low efficiency: for example, if your mains have an efficiency in the 80-83db/watt/1 Meter range, then the P7000S could definitely be a great choice. But with an 86-88db/watt/1 Meter range efficiency, the P3500S would be fine. 350 watts per channel - and keep in mind - that is the 20Hz-20,000Hz rating. Most amps use a 1kHz rating, and in that case, it's a 390 x 2 into 8 Ohms amplifier.

Keep in mind, that the larger the amplifier, the more gain is produces. At a certain point, if your speakers are too efficient for a given power range, then the speakers may cause the noise floor/hiss to become audible. So you should base the amplifier you choose partially on the sensitivity of your speakers. I have no idea what your speaker sensitivity may be....

-Chris

Oh, well my speakers are fairly sensitive: Mains- 91.5db, center- 89db, surrounds- 87db. I don't want there to be a hiss problem, but I want plenty of headroom with plenty of power so I won't need to upgrade later. Other users using these same speakers have used 500wpc amps, these speakers, from the accounts I'm hearing about sound better, the more power you give 'em. Many have said that they really open up when you give them more power and you aren't doing these speakers justice until you do.

 

[WmAx]

Oh, well my speakers are fairly sensitive: Mains- 91.5db, center- 89db, surrounds- 87db. I don't want there to be a hiss problem, but I want plenty of headroom with plenty of power so I won't need to upgrade later. Other users using these same speakers have used 500wpc amps, these speakers, from the accounts I'm hearing about sound better, the more power you give 'em. Many have said that they really open up when you give them more power and you aren't doing these speakers justice until you do.

Well, then go for it. LOL.

I am not really one to talk about reasonable power, I guess... as my 3 way computer stereo speakers...

I have two dedicated 20A circuits to my computer and I use 1050 watts RMS per stereo channel..... so.....

-Chris