Seperate amps. low watt Tubes vs high watt solid state?

[michael hurd]

Thanks, but until I see some better power tests, I would not rely on faith. The HI-FI market I was referring to was the glowing glass klub.

Regardless, you may find these tests interesting.

http://home.pacbell.net/lordpk/bink/bink.jpg

QSC PL9.0 PFC amp came pretty close to it's advertised power at 20 hz. Check out what it was able to output at 20 khz!

Crest 8002 was also a good choice. Sagging power ( real world ) a non-issue.

QSC PL6.0II ( rating close to LAB Gruppen ) delivered 2,853 watts at 20 khz while the lab struggled at UH...718 watts. ( at AC sag test )

The LAB Gruppen had a superior S/N ratio, compared to most all in the shootout.

Crown K2 fine, strong HF output, but lacking down low with sagging A/C service.

More tests here...

http://www.avsforum.com/avs-vb/showthread.php?t=855865

These tests ( AVS forum link ) used a variac to keep voltage stable while the device was under test

Too bad they are only driving resistors, but it is an apples to apples comparison. I would like to see what most would do with a real reactive load. I bet about 1/4 of them would fall flat on their face.

[michael hurd]

Another interesting note about a "popular" amp that appears to be a copy of another company's design down to the silk screening and chassis, but with a lighter power supply ( hey they had to cheat somewhere to sell for so cheap ! )

http://www.avsforum.com/avs-vb/showthread.php?t=976075

( Copy and paste )

Keep in mind that the EP2500's are not a solid amplifier. The may work well for Ib use where they are only called to deliver lower amounts of power, but not when you need them to produce serious levels. We had 6 of them for this installation originally.

http://www.aespeakers.com/phpbb2/viewtopic.php?t=644

Out of the box, 4 of them didn't work right. Three had a problem with not powering up when you turned them on. You had to flip the switch multiple times to bring the amp out of protect mode. The 4th had a broken power switch that couldn't turn off. We used a bridged EP2500 to power each of 4 LABsubs. This is a 4ohm nominal load. After a short period of time we noticed the amps clipping quite badly while playing at the same level they had 20minutes earlier with no signs of clipping. We brought the level down 3db and still clipping, 6dB and still clipping, then 10dB and still clipping. The club was open so we had to continue anyway. Soon 3 out of the 4 woofers in a pair of lab subs stopped playing. The coils physically burnt up. Upon examining things, the amps were putting out a huge amount of DC current. This is what burnt up the drivers, and the reason for clipping at low levels. We replaced the 12" drivers and replaced the amps with QSC PLX3402's bridged. Much more power available and never had the issue again.

The EP2500 is supposedly a copy of the other QSC RMX 2450, but has much less power supply. Unfortunately the power supply is not something you can cheap on if you want a reliable amp. Here are pics of the inside.

http://www.tomhole.com/Behringer%20E...RMX%202450.htm

John

[jacksonbart]

Captain Caveman!!!!!!!!!!

[mas]

We were listing the cheapest and smallest to be considered for serious use by forum folks for their biggest bang for the buck (ROI) factor only to be challenged on the basis that there are bigger more expensive amps?[][]

Sure, but why compare old dusty and discontinued models of one camp to the latest from another camp?

There are a small group of really high quality high powered amps and QSC is definitely among them, but they are by no means alone!.

The Crown ITech IT8000, with 200volts output.

And while QSC is great (you'll get no argument from me there!), they will shut down with a dead short, and they cost more...

And you are going to be hard pressed to even get general consumer info on the high end Lab Gruppen amps as they simply do not live there. And what they are doing goes far beyond what anyone else is doing with their coupling in the form of modular powered systems (re their PLM 10000Q).

But you might start with the FP 13000 - conservatively rated at 2 channels at 6500W each...and still less than 27 pounds in 2U. Of course, their Nomadlink remote control access system allows you to connect up to 960 of these units....almost enough to handle the typical forum user's needs.

Or there is the Lab Gruppen FP10000Q/BP - 4 channels at 1300W each at 8 ohms. That should work for a modest HT setup combined with another FP13000 for center channel and sub use...

And where else are you going to find a dealer supported certified used amp marketplace listing for certified used amps listed by owners with a waiting list? Lab Gruppen does. []

On the other hand, you can buy a 3W wannabe.... Chihuahuas are cute too, what with their bug eyes and always shivering from the cold...even on 100 degree days...[]

[michael hurd]

"We were listing the cheapest and smallest to be considered for serious
use by forum folks for their biggest bang for the buck (ROI) factor
only to be challenged on the basis that there are bigger more expensive
amps?"

Maybe you were saying no need to spend $ 500. My rebuttal is that there are folks spending multi-kilobucks to buy some perty glowing globes.

"Sure, but why compare old dusty and discontinued models of one camp to the latest from another camp?"

I wasn't, I was comparing some models in the chart. Regardless, my point is that I don't rely on faith. Maybe you have some inside / backyard tests on the Lab Gruppen, but I don't.

"

The Crown ITech IT8000, with 200volts output.

And while QSC is great (you'll get no argument from me there!), they will shut down with a dead short, and they cost more..."

Shut down, sure it should with a dead short to protect itself. As far as costing more, the Itech 8000 is $ 7,762.00 retail according to the Crown audio website. The QSC PL380 is $ 4400 and change, retail here in Canada. And that is after import fees by distributor, etc. I imagine street prices on both would be definately lower.

Not worried about modular systems....

"But you might start with the FP 13000 - conservatively rated at 2
channels at 6500W each...and still less than 27 pounds in 2U. Of
course, their Nomadlink remote control access system allows you to
connect up to 960 of these units....almost enough to handle the typical forum user's needs."

Rated yes, independant tests? ANYwhere? Faith?

QSC has dataport for daisy chaining and remote control, Crown has their Hi-Q Net.

[mas]

I am not quite sure how or why the thread took the tact of exploring Megawatt amps, as while configurations are certainly available, they have no practical purpuse in the home environment. (I think only the car aaudio folks need them)

When shorted, the high end Crowns will weld instead of shutting down, and their ability to handle obtuse loads (as evidenced by their ability to be used to weld) is legendary and WELL EARNED. - that is also why the MacroTechs require a 30 amp service even though they never draw this is ordinary circumstances! It is simply required to accommodate their function in a dead short. . And when the fault is corrected, you can place them right back into service.

Faith? Huh? Well, do you mean do I rely on an AV forums opinion or their tests, No. There are PLENTY of industrial and production rigs in the real world that depend on these things everyday under conditions no forum is going to present, and which are routinely subjected to rougher handling than anyone individual is going to give them and forced to perform in more hostile industrial electrical environments than I suspect anyone has ever encountered..

And the modular systems are pro SR rigs, as the industry is quickly heading towards integrated powered systems - a trend first begun by Meyer over 25 years ago. But not all models have networking capabilities. Those I mentioned do.

After years of verification and proven performance, only the exceptional aberrant device has failed to live up to the stated claims. When that changes, i will start conducting weekend verification sessions. And at least in many pro environments, Crown with cross ship a unit in order to keep you up and running in the rare event that a unit does go down. I suspect QSC and LG may indeed do the same, given their excellent customer service and no questions asked warranties. And I know for a fact that this even oincludes units that have fallen from flown distro racks (ok, I have only experienced that first hand with Crown, but I would wager that QSC and LG are similar in this regard.

As for Crown, there specs are guaranteed minimums. Their maximums are simply bonuses and insurance.

As for Lab Gruppen, i only wish I had the opportunity and the means to buy them! Their used prices remain higher than the competitions new prices! With literally a waiting list.

And faith? After dealing with them for decades, I don't feel the need to run out and verfiy every unit - unlike some brands where I would be amazed if the exceptional unit actually performed near the stated claims.

My general point is not to debate one brand versus another,but rather to
mention that the competiton within this market space is robust, and
that you would not be making a mistake to purchase any of these
manufacturers higher end units.

My specific point was that there is no need for anyone in the home market to spend more than $500 for a very well performing high powered unit with the bonus of having a very nice integrated DSP capability {and network control if you want to take advantage of that! ;-) }.

And while they are certainly available, one needn't buy a Terex truck to drive to Kroger or to work. But on the other hand, they don't have to spend exhorbitant amounts of money to simply buy a moped either, as many are so want to do. Of course someone may buy any model for whatever reason they choose, but they need not exceed the $500 unless they simply want to.

[michael hurd]

Not sure how or why? Look at the title: Seperate amps. low watt Tubes vs high watt solid state.

"When shorted, the high end Crowns will weld instead of shutting down,
and their ability to handle obtuse loads (as evidenced by their ability
to be used to weld) is legendary and WELL EARNED. - that is also why
the MacroTechs require a 30 amp service even though they never draw
this is ordinary circumstances! It is simply required to accommodate
their function in a dead short. . And when the fault is corrected, you
can place them right back into service."

If I want to weld, I would break out the leathers and fire up the 450 amp Miller and grab a handfull of 7018's and my helmet.

Dead short = fire. With current supplied to a cabinet that has a dead short, you are ensuring that the fire department is definately going to earn their keep. Maybe Crown should partner with Square D, and offer breakers for the home, that continue to supply current even over safe loads for the wiring. I bet that would be the next best trend... never have to worry about that block heater cord that keeps popping the breaker, get a Crown breaker.... no problem, just plug it in.... good to go.

"There are PLENTY of industrial and production rigs in the real world
that depend on these things everyday under conditions no forum is going
to present, and which are routinely subjected to rougher handling than
anyone individual is going to give them and forced to perform in more
hostile industrial electrical environments than I suspect anyone has
ever encountered.."

I am sure that DUH-L, OOPS, and FED-UP not to mention UShouldaPaidSomeone handles them just as rough as anyone in the field, from a 4G impact on a conveyor belt flying at 60 MPH in a distribution center compared to a rack falling off a truck. [:^)] As far as hostile industrial electrical environments..... really.... a 200 amp distro is not going to sag as bad as a home electrical system>? Let's face it, in a small gig, you aren't going to bring in a rack of Macrotech's for the subs. Scale back the equipment, most venues have enough power for anything, unless you are playing in some small backwoods bar / club built in 1940, where you tap into the panel and hope and pray the service entrance wires hold up.

"And while they are certainly available, one needn't buy a Terex
truck to drive to Kroger or to work. But on the other hand, they don't
have to spend exhorbitant amounts of money to simply buy a moped
either, as many are so want to do. Of course someone may buy any model
for whatever reason they choose, but they need not exceed the $500
unless they simply want to."

IF you did buy a Terex Titan, it would certainly ease parking problems in the parking lot of the store, simply DRIVE to the door, over whatever is in the way...[] I agree, if someone wants to spend more than that, fine, I just won't spend it on a moped.... I would spend the same to buy a Honda.

[mas]

Like I said, the topic was comparing low power tube to higher power SS.

My point was that a $500 XTi should be sufficient to run anything in the home they require.

You were the one bringing up the 'megawatt' QSCs - and in the space they have plenty of quality competitiion.

And while I very much admire QSC, they do not offer the same ROI as Crown in the $500 price range.

And when we get in to low impedance capabilities, Crown excels. And while QSC does fine, that is not QSC's forte. And the higher end Crowns do indeed survive a dead short. Complain, buy a welder, do whatever. The Crown's survive undamaged. I've seem it demonstrated by Crown and I can even take credit for inadvertently having a hot banana plug fall onto a metal bench while we were bench tweaking a monitor. ...Scared the #$@%& out of everyone in the building!

And large venues do not have problems?! ...Especially as they are normally located in the middle of commercial/industrial areas???? You have obviously never been to the Grand Palace in Branson, where even the seats and toilets have ground loop hum! Even the staff hums. I know folks who refuse to go out with Mike W. - 'Ski' (I will provide more names and detail via a PM!) as he insisted on going the extra 10 miles and staying up all night in an attempt to identify and correct (at least to try and identify the main sources) and isolate the FOH from the incredible amounts of hum! (Oh, and the guys who won't go out - it was because the thought of work, let alone excellence, scares them...) And regulated voltage? I have news for you.Especially on a service supplying the entire complex with the wacko reactive lighting and environmental processing loads! Talk about switching transients!?!?!?! Yup, pure sinewave! NOT! And that is just from the internal loads! It ignores the industrial demands and interference nearby! That is precisely one of the factors that the higher end pro amps provide - a greater ability to deal with and to survive such nonsense.

And then you have the innumerable festivals and fairs and various other shows with the powerfactor corrected and regulated (sorry, I just had to toss that fantasy in!) power sources!

I would much rather deal with a small club with 3 pro SR amps and a few instrument amps rather than a concert venue running 60-80KW SR rig, not to mention the myriad super Troopers, arc and stage lighting (no interference there!), not to mention the incredibly variable environmental loads.

But as I said, the topic was low power tubes versus higher power SS for home and home theater use. And I will stand by my suggestion that the $500 Crown XTI is a best buy that should adequately handle any load with which they are faced, in addition to having an integrated top shelf DSP section. There is no need to spend any more nor a reason to move to a higher powered unit. {But hey, if you want one of the higher power Crown, QSC or Lab Gruppens, enjoy!!!! (BTW, he Mackies are getting good reviews from the critics and from a few friends who have used them - but I admit to having no hands-on experience with them.)}

The topic was not supplying the Meadowlands or Red Rock.or the SilverDome. But with enough of those amps, you could certainly address the needs of the larger venues as well.

But we can have fun debating this further if you like - even though i think we are agreeing! []

[TheSoundBroker]

The generally accepted rule of thumb is 1.5 to 2X RMS power in the amp to the speakers for live sound.You can translate this over to home audio to 1.5X RMS and be safe. This translates to 375/ch into the RF-7s. If you require more than 1.5X RMS to maintain the output in the space without clipping, you need a larger speaker system with more output and higher efficiency.

In my listening experience...since I have and sell a number of the different amps being talked about here...the Crown vs QSC debate will depend on which line you are looking at. Crown Macrotech's are excellent but are discontinued. I-Tech's (the replacement) don't sound as good, though the crews love them because they weight nothing in comparison and they are a lot more efficient. In the $500 price range, you have the Crown XTi and the QSC PLX-2. Of them, I prefer the XTi. Neither of them is as good as the Face Audio TS series. I also sell the Behringer's but wouldn't use them as a mid/top end amp. To be fair to Behringer, we've only had one failure in all the amps we've sold and Behringer had a replacement shipped the same day. Oh, and the EP-2500 was modeled after the QSC RMX-2400...the 2450 is the newer version. It is a decent subwoofer amp, but compared to the bigger iron, doesn't have the sheer grunt down below and it loses output power as the frequencies go down and the power supply runs out of oomph. Putting a single channel of one of the large 30 amp required beasts vs a bridged EP-2500, it isn't even close.

On the mega amps, the big QSC's aren't the best sounding in my experience. The Crown Macrotech's are excellent amps, but I'd put the Face F-2000TX up against them. They brought that line out after Crown went to all switch mod power supplies in their new amps (the F-2000TX is a classic old school Class AB amp with a stupidly enormous power supply). I have two of them in my room, each with 30 amp dedicated lines to them and they are more transparent than the Macrotech's in side by side comparisons.

[plissken99]

Well the Crown XTi series amps are very impressive! I could get the XTi 2000 for $450, and get 475w per channel! That should be an elegant sufficiency to power my speakers. But keep the talk going, I've got lots of time before I'm ready to pull a trigger on anything.

[mas]

The MacroTech line is still a production unit, but they are not intended, nor are they really realistic for a home market with their 30 amp service. And they are not necessary to drive any speaker worth having. They are simply overkill for home use.And I speak not only from 25 years of hands on use, but from home use as well. Their design features which distinguish them will never be realized in home use.

For home use, there is no need to move above the Crown XTi or the QSC PLX2.

And if I did, of the current production lines it would be to either the Crown CTs or to Lab Gruppen. (if, that is, I decide I absolutely need a Porshe GT3)

[SWL]

Well the Crown XTi series amps are very impressive! I could get the XTi 2000 for $450, and get 475w per channel! That should be an elegant sufficiency to power my speakers. But keep the talk going, I've got lots of time before I'm ready to pull a trigger on anything.

Where can you get an XTI 2000 for $450?

[mas]

Well the Crown XTi series amps are very impressive! I could get the XTi 2000 for $450, and get 475w per channel! That should be an elegant sufficiency to power my speakers. But keep the talk going, I've got lots of time before I'm ready to pull a trigger on anything.

Where can you get an XTI 2000 for $450?

My guess, unless it is used, is that he may mean the XTi 1000.

[SWL]

Well the Crown XTi series amps are very impressive! I could get the XTi 2000 for $450, and get 475w per channel! That should be an elegant sufficiency to power my speakers. But keep the talk going, I've got lots of time before I'm ready to pull a trigger on anything.

Where can you get an XTI 2000 for $450?

My guess, unless it is used, is that he may mean the XTi 1000.

Yeah, I got my 2000's for $625 each. The best deal I found locally by $80.00. Trading in my XLS's to get two more..........never ends.(insert smily face)

[michael hurd]

"And large venues do not have problems?! ...Especially as they are
normally located in the middle of commercial/industrial areas???? You
have obviously never been to the Grand Palace in Branson, where even
the seats and toilets have ground loop hum! Even the staff hums. I know
folks who refuse to go out with Mike W. - 'Ski' (I will provide more
names and detail via a PM!) as he insisted on going the extra 10 miles
and staying up all night in an attempt to identify and correct (at
least to try and identify the main sources) and isolate the FOH from
the incredible amounts of hum! (Oh, and the guys who won't go out - it
was because the thought of work, let alone excellence, scares them...)
And regulated voltage? I have news for you.Especially on a service
supplying the entire complex with the wacko reactive lighting and
environmental processing loads! Talk about switching transients!?!?!?!
Yup, pure sinewave! NOT! And that is just from the internal loads! It
ignores the industrial demands and interference nearby! That is
precisely one of the factors that the higher end pro amps provide - a
greater ability to deal with and to survive such nonsense."

I don't know about you, maybe you didn't read, I mentioned voltage SAG. Nothing about hum, ground loops and so on. Low input voltage to a power amp is very bad for it, the power supply has to work overtime to keep up. This is particularly bad in SMPS amps, not as much in regular linear amps with large, heavy transformers. Besides... what power amps DON'T rectify to DC and smooth with caps..... in the power supply.... for DC to supply the rails...[:S]

And no, I haven't been to the Grand Palace in Branson..... [:^)]

But if you ever find your way to Northwestern Ontario, I will suggest you should take a look at the Thunder Bay Community Auditorium. Converts from regular performance hall to a band clamshell with variable acoustics.

http://www.tbca.com/article/auditorium-135.asp

http://www.tbca.com/article/performance-sound-systems-176.asp

http://www.tbca.com/article/performance-lighting-system-177.asp

At an outdoor festival, you may have no choice other than generator power. Unless you are playing Woodstock, or some other very large festival, you wouldn't be needing that exotic a setup. ( delay towers, etc ) Again, scale to the event.

We do agree to some extent yes, buy why would you buy a more powerful amp.... headroom is the answer. If people can spend $ 4 kilobucks on a couple of microphonic glowing gems, then I would prefer to spend $ 4 kilobucks on a pair of high powered solid scrape ( also called KLUB ) amps. Why drive a yugo when you can drive a Freightliner>?[]

[Islander]

So these XTi amps are powerful, inexpensive and dependable, all important and good things. In a home setting, do they sound as good as a more typical "hi-fi" amp, in terms of transparency, clarity and low noise floor, among other things?

[DrWho]

If you guys go with the XTi, I would recommend the 1000 and not the larger versions....simply because the gain is less, which will help you get more resolution outta the DSP on the amp. It's only 3dB difference between the 1000 and 2000, but that might make the difference between audible digital noise in a very quiet room. If your noise floor isn't uber low, then there's no sense in worrying about it.

[mas]

If people can spend $ 4 kilobucks on a couple of microphonic glowing gems, then I would prefer to spend $ 4 kilobucks on a pair of high powered solid scrape ( also called KLUB ) amps. Why drive a yugo when you can drive a Freightliner>?

Given the lack of a restriction on finances?

OK! Now we agree! []

Sure, i say buy the amp(s0 and we can run over and listen to it in my new Porsche GT3! [] (in addition to a new diesel 4 wheel drive!)

I was focused on a real world where funds may not be unlimited and one wants the best ROI in a home setting. But hey, headroom is nice! And its not hard to twist my arm! Besides, you never know when you may feel and itch to weld in your listening room![]

[damonrpayne]

[6]It is a proven and universally accepted fact that you should go with solid state over tubes.[6]

[mas]

It is a proven and universally accepted fact that you should go with solid state over tubes.

If you want to use tubes, that certainly doesn't bother me. I have no problem with either topology that is well designed. But there are other considerations to think about as well.

But if you want a higher power amp, you can go with tubes, although speaking from personal experience, I might suggest the SS route if for no other reason than the initial cost as well as the cost of the care and feeding of such amps. - as it just cost me about $600 to retube my amp. - easily enough to BUY a new Crown XTi.

And for a home theater where you are looking at at least 5 channels, that can quickly get pretty pricey.