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Ivaols

Quiet amp for active K-402

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I am experiencing a lot of hissing noise in the listening position. My setup is K-402 and K-69-A with Xilica XP4080 as electronic crossover. Amp is ATI AT3005 connected with XLR, amp gain is 28db. 

 

Most of the hissing noise is coming from the amp. 

 

What do you guys use with your active high sensitive horn systems? Have you found a low gain and low noise amp? 

 

Price is a concern and DIY is not an option. I am not a believer in huge sonic differences between amps working within their limits, I just need that amp to be quiet 🤫 

 

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I used to run Yamaha pro amps with my horns... to hear any hiss you needed to put your head at the horn. I think the amps were the P2500S amps. They were 259wpc, and you can pick them up used for a couple of hundred.


Sent from my SM-G935V using Tapatalk

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26 minutes ago, ellisr63 said:

I used to run Yamaha pro amps with my horns... to hear any hiss you needed to put your head at the horn. I think the amps were the P2500S amps. They were 259wpc, and you can pick them up used for a couple of hundred.


Sent from my SM-G935V using Tapatalk
 

Thank you ellisr63. Yamaha Pro amp is definitely something I will look into. 

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I’ve used many of the Yamahas p!!!!s series amps such as the p5000s and its little brother on most of my large horn setups and with all of my horn type subs. Either of these will show or putout any hissing or noise that’s in the chain of audio gear
I always use a very high sensitive horn driver as a test speaker for checking my amps in my audio chain for any sound that may be in it I would use like a large 20 pound JBL compression driver on a large wound horn that’s usually about 10 inches in diameter or larger to see if I can hear any hissing through it and I would also run some paint noise in white noise with using your pro Briette bass blocker or as simple as possible crossover in the chain. Whether it was active or passive type crossover so that I wouldn’t get any lower frequencies in it and I also will use and oscilloscope hooked to the speaker outputs and turn the volume up on everything and see if I could see any noise on my oscilloscope and try to trace down what frequency it is but I wish you luck and you will be very satisfied on buying a Yamaha P series and if you like I know someone who is selling one I can pass that information onto you just send me a message and I’ll give you his information he does have a P5000S amp for sale. I just forget how much she wants for it but it’s a very reasonable price but do you have to remember these two have some weight tune so shipping will cost a few dollars but they are very cool running amps and when I was running a dating audio 15 inch MK series two sub in a custom built tuba sub box and the amp would barely blink for the input sensitivity that’s how sensitive that sub box was and also these amps can be bridged a mono or Stereo or parallel mono
so it has a lot of options on how you can hook it up
but it only takes XLR balanced inputs or quarter-inch TSR unbalanced inputs
and I had no problem with either type
And it has 5 way binding speaker output jacks


Dollar for dollar Klipsch has no equals
Name one other speaker company that can build a speaker and keep working like new after 45 plus years of service. Answer NO ONE !!!!!!

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Click on here. This is the guy with the Yamaha p5000s amp

http://techtalk.parts-express.com/forum/free-classifieds/1406459-yamaha-p5000s-amplifier-with-no-fan-noise-500-700-1400-watts-at-8-4-ω-8-ω-mono


Dollar for dollar Klipsch has no equals
Name one other speaker company that can build a speaker and keep working like new after 45 plus years of service. Answer NO ONE !!!!!!

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1 hour ago, Ivaols said:

Most of the hissing noise is coming from the amp. 

So with no input connected to the amp you have hiss?  Basically just the amp and speaker and nothing else?

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I use a lowly Crown D75 in bridged mode one on each driver of the 402s. Picked up 5 of em for $140 and refurb'd em myself. If you turn your head 90 degrees at the mouth of the horn you can hear a little hiss. I chalk that up as normal. In my opinion you need an amp with gain controls so you can open up the Xilica and turn down the amp. That looks like a pretty pricey amp, sorry you are having trouble with it.

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17 hours ago, carlthess40 said:

Click on here. This is the guy with the Yamaha p5000s amp

http://techtalk.parts-express.com/forum/free-classifieds/1406459-yamaha-p5000s-amplifier-with-no-fan-noise-500-700-1400-watts-at-8-4-ω-8-ω-mono


Dollar for dollar Klipsch has no equals
Name one other speaker company that can build a speaker and keep working like new after 45 plus years of service. Answer NO ONE !!!!!!

Thank you for your two informative posts. I live in Norway and guess the fright will be substantial. Luckily I found the Yamaha P3500S at my favourite pro dealer. Gives me comfort when buying that two guys from this forum is recommending Yamaha pro amp. 

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17 hours ago, babadono said:

I use a lowly Crown D75 in bridged mode one on each driver of the 402s. Picked up 5 of em for $140 and refurb'd em myself. If you turn your head 90 degrees at the mouth of the horn you can hear a little hiss. I chalk that up as normal. In my opinion you need an amp with gain controls so you can open up the Xilica and turn down the amp. That looks like a pretty pricey amp, sorry you are having trouble with it.

I think you have a valid point. As of now I have to lower the gain by minus 9.5db in the Xilica for the K-402 output. If I can open it up to 0 dB and lower the gain on the amp side it will provide better s/n ratio. 

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On another note, sometimes when one adds more electronic gear into the chain, one can introduce hums and hisses. As an experiment, try putting a cheater plug on the amp and or the Xilica and see if the hiss goes away. 

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18 hours ago, CECAA850 said:

So with no input connected to the amp you have hiss?  Basically just the amp and speaker and nothing else?

If the Xilica is plugged in but turned of there's hardly any noise through K-402 when the amp is on. When I turn on the Xilica prosessor, even without a signal, the hiss is there. The hiss is not dependent on main volume, it is constant. 

 

I have read that high gain (28db in my case) is one factor that creates hiss. 

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2 minutes ago, Ivaols said:

If the Xilica is plugged in but turned of there's hardly any noise through K-402 when the amp is on. When I turn on the Xilica prosessor, even without a signal, the hiss is there. The hiss is not dependent on main volume, it is constant. 

 

I have read that high gain (28db in my case) is one factor that creates hiss. 

Then it doesn't appear to be an amp issue then rather a processor/gain problem.

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OK so you are using XLR(balanced)  to XLR from the Xilica to the amp? When you say there is hiss with the amp on and the Xilica on but no signal what is the input to the Xilica? To prove it is the Xilica causing the problem you need to put some balanced dummy plugs on the input to the Xilica

https://centralindianaaes.files.wordpress.com/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf

see page 116 and onward of linked document.

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14 minutes ago, CECAA850 said:

Then it doesn't appear to be an amp issue then rather a processor/gain problem.

I'm not sure. I bought the Xilica because it is known to be quiet. 

 

I use a Heresy III as center speaker. The signal from the receiver is going directly to the ATI AT3005, not via Xilica, and there is a high hiss sound. 

 

I am sure the noise is not coming from the receiver because unplugging it don't make any difference. 

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4 minutes ago, babadono said:

OK so you are using XLR(balanced)  to XLR from the Xilica to the amp? When you say there is hiss with the amp on and the Xilica on but no signal what is the input to the Xilica? To prove it is the Xilica causing the problem you need to put some balanced dummy plugs on the input to the Xilica

https://centralindianaaes.files.wordpress.com/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf

see page 116 and onward of linked document.

Yes, xlr to xlr from the Xilica to the amp. 

Input to the Xilica is front left, front right and LFE from the receiver. 

 

There is still one input without connection, and two outputs without connection.

 

If I do not have to buy a new amp that would be great! 

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If you unplug the input to the amp (rca's) hook the speakers up to the amp and turn the amp on is there a hiss?

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You might also put something like THIS on the unused inputs and see if it helps.

 

image.png.205b99a79afe05f2f9218948add8fcb4.png

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That is a quality amp with a very good noise floor.   I would bet a steak that your problem is anywhere but that unit.

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I'll send you an updated .xdat file that greatly increases the input channel gains.  It appears to be a gain staging issue.  I would bet it's your preamp (which you haven't identified here) not driving the signal chain with enough output.  The Xilicas have all been dead quiet quiescently in the setups that I've used them in.

 

Chris

 

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