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tony3d
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Crown Xti-2000 Hum

Just hooked up my Crown Xti-2000 to a Crown IC-150 pre-amp, and I have a lot of hum and some buzz. The IC-150 pre-amp outputs are going the Xti-2000 with an RCA to XLR cable. The hum is ridiculous. how do I solve this? I had and Onkyo M504 hooked up to the system just before I hooked up the Crown and there was no hum at all. Can I run the amp with nothing in the inputs just to see if it's the unbalanced leads going into a balanced inputs causing the problem?

jackfish
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Re: Crown Xti-2000 Hum

Ask DUP. Maybe you didn't get enough watts!

Jan Vigne
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Re: Crown Xti-2000 Hum

Yep, you can run an amplifier without a pre amplifier connected. Have the Crown electronics been used recently?

Jim Tavegia
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Re: Crown Xti-2000 Hum

You may have an improperly wired RCA to XLR cable. If you run the Crown preamp single-ended into another unbalance piece does it still hum?

tony3d
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Re: Crown Xti-2000 Hum

I found the ground loop problem! It was the cable box which goes into my 62" tv then the tv goes to my Crown IC-150. Pull those off the Crown and the buzz and hum are gone. I bought the Rolls he18 hum reducer and hooked it up between the tv out and Crown IC-150 and that took care of the hum in my system and doesn't effect the rest of the system. Sounds great plus I can't get the amp hot enough to run the fans. I'm very happy so far. I have no hum or buzz the amp is very quite.

Elk
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Re: Crown Xti-2000 Hum

Different set of priorities. Sound reinforcement amps are made with an emphasis on usability and reliability in the field, and for brute force. They are lightweight, rugged, powerful, versatile (it is not uncommon for them to have built in limiting, some EQ, etc.), lots of self-protection such as fans, circuit breakers, etc. Power rules over quality of sound.

Reinforcement amps are not used in recording and mastering studios for the same reasons that they are not favored by audiophiles; they gloss over subtleties, typically have a hard/glaring sound, etc.

There is nothing wrong with a PA amp, it just isn

Jan Vigne
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Re: Crown Xti-2000 Hum

Go buy a 69 cent ground lift at the hardware store. You can probably send the Rolls he18 hum reducer back for a refund.

tony3d
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Re: Crown Xti-2000 Hum

You mean one those cheater plugs that eliminates the ground lug? I thought thats a no no.

Jan Vigne
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Re: Crown Xti-2000 Hum

Ground lifts, i.e. cheater plugs, are not the best idea when you are in need of serious surge protection. Typically surge protectors of any sort shunt the spike to ground. If you use a ground lift, you will decrease the amount of protection your surge device provides but not totally eliminate the surge protection to that device.

But your problem is a ground loop. A ground lift is one way to deal with the problem very inexpensively. Depending upon the piece you bought, this might be all you really have at a higher price. The ground has to be broken/isolated somewhere for the noise to go away.

You can also call your cable company, they often have lifts they can provide since this is a typical problem with cable TV feeding a HT system.

If you haven't got a surge protector, buy one. 95% of the locations in the US can benefit from a surge protector. Spend some money to get a very good unit. $20 doesn't cut it on most systems. Look for RFI/EMI filtering on the supressor. Your system will sound better and your TV will look better.

If you use the ground lift, don't operate your sub while standing in a puddle of water (you or the sub).

If you have the sub and the cable box plugged into different AC outlets, try getting them on the same outlet/breaker before you make a further decision.

No matter what, use a surge protector. The cheapest I recommend is Panamax for around $120-150.

greenelec
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Re: Crown Xti-2000 Hum

Another issue with Pro PA amps is most are not full range. ie. Most reproduce signals from 40(or so) Hz to 18(or so) kHz. While most high quality Hi-Fi amps reproduce from 18-20Hz to 20-100 kHz. Getting that extra range at both ends of the sprectrum costs more money in design and execution.

tony3d
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Re: Crown Xti-2000 Hum

Well, I'll tell you compared to my Onkyo M504 power amp this amp simply reproduces music with the kind of muscle one associates with a live performance. I really notice no difference in the quality of sound other than a much improved low end over the Onkyo. I get much tighter, deep, dry bass. To be honest the top end seems a little more sterile, but hardly what I would call harsh. Maybe a better word would be analytical. All in all I see no reason to look at a very expensive consumer amp again. I was very skeptical before I bought this amp myself, and I posted on many boards before buying. I have listened to music including live music for many years. My brother was a jazz guitarist for 35 years. His very good friend Gene Palumbo went on to arrange, and conduct for Judy Garland for a couple years before her death. I believe I have a well trained ear, and what it hears is very neutral reproduction. I'm sure a lot of these $5000.00 amps are excellent and produce better specs, but to tell you the truth after hearing Krell, Threshold, and some H/K Citations over the years, this Crown stacks right up there with the best of them. Even the fan which I thought was going to be the big issue has not come on once that I can tell. I'm sure under laboratory listening conditions, these high end consumer amps may reveal more detail, but I listen in my living-room. So far I feel like I stole this amp for $699.00. I'll never run out of headroom, and it with probably outlast most consumer amps. In the past I personally owned a Phase Linear 400 series 2, H/K Citation 16, and an Onkyo M504. Each amp failed for one reason or another within a 8 years span. I know non of these where ultra high end, but they represented a good buy in their day, and were not exactly cheap. The only component I have from the very early 70's that has continued to perform with no maintenance at all is my Crown IC-150. If I get half the life out of this amp I should be in an old folks home by then. I'm not trying to sway anyone here, just presenting the facts as I see them.

CECE
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Re: Crown Xti-2000 Hum

Crown makes great stuff priced for reality...superb reliability sounds fine. I see Crown stuff in most live events, where the stuff is Cranking, in not so pristine enviorments. Since they sell quite a few, the price comes down. Pretty mass produced with high quality. The stuff in live events run day in day out, they can't be down, it costs money. Yeah, some high end amp that was recently reviewed in StereoPhile failed to meet it's advertised wattages...Yeah, that stuff is better, yup!!! Crown better meet specs, cus' they sell to the pro market, when setting up a pro system, if teh stuff don't do what is claimed, you can bet, the stuff is out, and won't return, and somehow Crown is used in a lot of pro live enviorments. They don't claim wattages they can't deliver. Now which brand was that really expensive, under performing "high end" amplifier. Can't go wrong with Crown. I've also seen QSC stuff just keep on going and going, moved every day bounced around in trucks, up stairs, down stairs, and it just keeps on working nite after nite, and sounds just fine. another mortally priced product, performance without teh nonsense attached to so many over priced "high end" stuff. Just think how much high end would sell, if the people setting the prices, came back to earth, and priced it for mortals. Remeber that $45K high distorion Cd only player...yupper, that's a real fine product, high priced, under performer. Reality says, over performer, underpriced...ther are brands out there that deliver....i can name a few....but i have so many times before...there are others

Elk
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Re: Crown Xti-2000 Hum


Quote:
Well, I'll tell you compared to my Onkyo M504 power amp this amp simply reproduces music with the kind of muscle one associates with a live performance.

....

To be honest the top end seems a little more sterile, but hardly what I would call harsh. Maybe a better word would be analytical.

...

I'm sure under laboratory listening conditions, these high end consumer amps may reveal more detail, but I listen in my living-room.

I think you answered your question as to why others prefer high-end amps and why high end amps are used in mixing and mastering studios.

If you mean the sound of live performance, meaning amplified live music, you will indeed get the same type of sound with your Crown - you are using the same kind of equipment to amplify the sound as you would hear in performance. Musicians playing through a PA system, no matter how good the reinforcment system, is a far cry from listening to acoustic instruments in a performance space.

It is quite easy to reproduce the sound of an amped performance at home - it just takes watts and sturdy speakers. It is much, much harder to reproduce the sound of acoustic instruments playing in a concert hall.

A delicate, airy, accurate high end is very hard to achive in an amp. This costs money in both RD and parts. A better amp will have a better high end. Performance costs money. Unfortunately.

Many people invovled in high end audio do listen in near laboratory conditions - dedicated rooms, acoustic treatments, etc. It is hard to hear the subtlties that excellent equipment can produce in the typical living room. Mastering studios are similarly set up to hear subtlties. Nothing wrong with listening in a living room however! Music should be part of your life.

The Crown is made to be knocked around by roadies and connected by ham-fisted techs. I doubt it will ever fail on you. If it does, Crown's customer service is very good and they will take care of you.

If you are happy with the sound, you bought a great amp for your purpose and saved a lot of money.

(DUP is right about one thing; there is never any excuse for poorly designed, badly made, unreliable equipment. At any price. Period.

Stereophile is doing a great service by reporting this type of nonsense to the potential buyer. Neither DUP nor the rest of us would know about these poor products without reading about them in Stereophile. Kudos to JA.)

tony3d
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Re: Crown Xti-2000 Hum


Quote:

Quote:
Well, I'll tell you compared to my Onkyo M504 power amp this amp simply reproduces music with the kind of muscle one associates with a live performance.

....
To be honest the top end seems a little more sterile, but hardly what I would call harsh. Maybe a better word would be analytical.

...

I'm sure under laboratory listening conditions, these high end consumer amps may reveal more detail, but I listen in my living-room.

I think you answered your question as to why others prefer high-end amps and why high end amps are used in mixing and mastering studios.

If you mean the sound of live performance, meaning amplified live music, you will indeed get the same type of sound with your Crown - you are using the same kind of equipment to amplify the sound as you would hear in performance. Musicians playing through a PA system, no matter how good the reinforcment system, is a far cry from listening to acoustic instruments in a performance space.

It is quite easy to reproduce the sound of an amped performance at home - it just takes watts and sturdy speakers. It is much, much harder to reproduce the sound of acoustic instruments playing in a concert hall.

A delicate, airy, accurate high end is very hard to achive in an amp. This costs money in both RD and parts. A better amp will have a better high end. Performance costs money. Unfortunately.

Many people invovled in high end audio do listen in near laboratory conditions - dedicated rooms, acoustic treatments, etc. It is hard to hear the subtlties that excellent equipment can produce in the typical living room. Mastering studios are similarly set up to hear subtlties. Nothing wrong with listening in a living room however! Music should be part of your life.

The Crown is made to be knocked around by roadies and connected by ham-fisted techs. I doubt it will ever fail on you. If it does, Crown's customer service is very good and they will take care of you.

If you are happy with the sound, you bought a great amp for your purpose and saved a lot of money.

(DUP is right about one thing; there is never any excuse for poorly designed, badly made, unreliable equipment. At any price. Period.

Stereophile is doing a great service by reporting this type of nonsense to the potential buyer. Neither DUP nor the rest of us would know about these poor products without reading about them in Stereophile. Kudos to JA.)

Elk, What you say makes some sense. Still as I said, compared to my Onkyo M504 the Crown is a better sounding amp especially on the low end. I listen to a lot of jazz, and some classical. So far I am very impressed with what I hear. When I said live music I meant just that. I use to go to many rehearsals where no amplification was used. I'm most familiar with guitar. I have listened to many of my old, mint condition barney Kessel recordings, and I must say the Crown handles them very well. I'm sure these super high end amps under extremely controlled listening conditions, may sound a bit better, but I personally can't justify the difference in cost verses performance. A lot of those high end amps really don't begin to put out enough power to replicate the dynamics found in a live performance. To me if it doesn't translate that impact then the experience is lacking. I guess music affects everyone differently. I suppose as long as the music stirs up your emotions it really doesn't matter how you achieve the end result. Just curious what amp are you using?

Elk
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Re: Crown Xti-2000 Hum

I agree completetly!; what matters is if your system connects you with the music.

I would expect the Crown to do pretty well. I always found a lot of the Hafler "pro" amps to sound good for the money also.

It is incredibly hard to recreate the dynamics of live music. I am a trumpet player (primarily classical) and have played in everything from small groups to full orchestras. No sudio system comes close to capturing what musicians can do live. I completely agree that a lot of amps cannot do this and headroom has its place. Most, if not all, speakers also compress the sound. Frustrating stuff.

I am currently listening to a Cary V12R F1 with some modifications. This is a somewhat complex tube amp - I find tubes are great with harmonic structure/timbre and the natural decay of instruments. They tend to lack in slam factor however. It depends on what is most important to you as listener.

I also have a McCormack 225, a 225 watt solid state amp. Very nice as well, but with different strengths. It's probably time to swap amps again just for fun.

tony3d
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Re: Crown Xti-2000 Hum

Elk I don't know if your interested, but I do 3d computer modeling and animation. I modeled the Cary Cad 805 in 3d by eye. Check it out at www.digitalcanvas3d.com. Everything on the site is computer generated, and photo-realistic. Let me know what you think.

Elk
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Re: Crown Xti-2000 Hum

Very Cool!

I also found a Onkyo M-504 Power Amp. Could this be a coincidence?

tony3d
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Re: Crown Xti-2000 Hum


Quote:
Very Cool!

I also found a Onkyo M-504 Power Amp. Could this be a coincidence?


That was a decent amp. Tell me about amp burn in. Is there something to it or not?

Elk
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Re: Crown Xti-2000 Hum


Quote:
Tell me about amp burn in. Is there something to it or not?

In my experience it depends on the equipment. Some seem to need some tiem to settle although I have never heard huge changes. Solid state does seem to like being left on however and often needs a good long time to completely warm up and stabilize if turned off. Tube amps appear to warm up more quickly (for example, my Cary is happy after a half hour or so). The McCormick sounds its best after a day or so of being left on. This is why many leave their SS equipment on all the time.

I think this is so dependent on equipment that it is hard to generalize.

Others think that there is no such thing as break-in and that once the amp is on it is going to sound the same throughout its working life. As the critters are physical components I have trouble accepting the idea that they don't change at all with time, temperature, etc. Everything changes.

CECE
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Re: Crown Xti-2000 Hum

Properly designed audio equipment, using quality parts, ain't doing no change, or break in. If you have equipment that changes between runs, it's got a real defect. If you can hear a difference, it's got a bad component. Todays electronic parts are super stable, reliable. How would a GPS module work, in a car which is hot cold, damp etc, if it was subjected to stuff so called high end stuff suffers from...if it's that unstable, that ain't high end, it crapola. No matter what ya paid for it. How come a cars computer modules run when it's 100 degrees or 0 degrees? How come those parts don't need breaking in? Why would a $5K amplifier have such poor parts, that it drifts while there is a temp change? Audio myths are amazing. Pieces of wire don't break in either.

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