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The New Hypex Fusion Plate amps
The New Hypex Fusion Plate amps
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Old 19th March 2019, 05:05 PM   #1291
dirkwright is offline dirkwright  United States
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Default miniDSP vs. Hypex?

I have used the miniDSP plate amps and they do work great, except for some noise. I am using them with a high sensitivity loudspeaker (99dB) and there is some really strange noise coming out of the tweeters. I have tried various ways to solve the problem but it appears to be the PowerICE amps themselves that are making the noise. I was wondering if the Hypex amps were more quiet? The data they provide doesn't look that great to me (miniDSP appears to have better numbers?). Has anyone tested these Hypex plate amps? I'm used to the software on the miniDSP but I suppose I can learn something new if the Hypex is really much better. Thanks.
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Old 19th March 2019, 05:37 PM   #1292
Windforce85 is offline Windforce85  Poland
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You will hear the hiss from 99dB sensitivity driver for sure. Bare NCore amplifier with stock buffer and switched mode power supply is very quiet. Equipped with any kind of DSP - not. 99 dB is a challenge for going active in silent domestic environment. Resistive padding of excessively sensitive channel can solve the problem.

Last edited by Windforce85; 19th March 2019 at 05:42 PM.
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Old 19th March 2019, 08:26 PM   #1293
denibeni is offline denibeni
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I can't hear any strange noise from Fusionamp with a 93 dB speaker.
I have to get close enough to hear that little noise, which I think is quite normal from any amplifier.
I cannot hear anything from the listening position (2m) when the amplifier is resting.
+6dB speaker sensitivity would it matter so much?
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Old 19th March 2019, 10:21 PM   #1294
Windforce85 is offline Windforce85  Poland
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Quote:
Originally Posted by denibeni View Post
+6dB speaker sensitivity would it matter so much?

Yes, this is 2x more acoustical output. Much depends on listener's environment and experience. Mostly, I found that this is inacceptable for listener when compression driver is directly paired with contemporary DSP without resistive padding and the listener is listening to music in calm, domestic fashion. When you want to pair 99dB sensitive speaker with DSP for large venue sound reinforcement it is acceptable.
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Old 20th March 2019, 01:00 AM   #1295
dirkwright is offline dirkwright  United States
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Quote:
Originally Posted by Windforce85 View Post
Yes, this is 2x more acoustical output. Much depends on listener's environment and experience. Mostly, I found that this is inacceptable for listener when compression driver is directly paired with contemporary DSP without resistive padding and the listener is listening to music in calm, domestic fashion. When you want to pair 99dB sensitive speaker with DSP for large venue sound reinforcement it is acceptable.
Thanks so much! yeah, I was wondering if I should install a pad between the amp and the compression driver. I turned the channel for that driver down by 6 dB (from 105 to 99) in the DSP software but it's still noisy. I can try a normal loudspeaker L pad instead.
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Old 20th March 2019, 09:09 AM   #1296
hugo stiglitz is offline hugo stiglitz  Germany
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Quote:
Originally Posted by denibeni View Post
I can't hear any strange noise from Fusionamp with a 93 dB speaker.
I have to get close enough to hear that little noise, which I think is quite normal from any amplifier.
I cannot hear anything from the listening position (2m) when the amplifier is resting.
+6dB speaker sensitivity would it matter so much?
I will say that this is normal.
Hypex FA amps have some issues with some shielding. You should hear some digital-kinda noise.
If you go some pages back you will find lots of people complaining about this.
Hypex has done nothing to solve this.
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Old 20th March 2019, 09:22 AM   #1297
denibeni is offline denibeni
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Quote:
Originally Posted by hugo stiglitz View Post
I will say that this is normal.
Hypex FA amps have some issues with some shielding. You should hear some digital-kinda noise.
If you go some pages back you will find lots of people complaining about this.
Hypex has done nothing to solve this.
Huh?? I don't complain about noise. It's very quiet for me, i just want to refer to this exactly.
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Old 20th March 2019, 09:33 AM   #1298
triode_al is offline triode_al  Netherlands
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Quote:
Originally Posted by hugo stiglitz View Post
I will say that this is normal.
Hypex FA amps have some issues with some shielding. You should hear some digital-kinda noise.
If you go some pages back you will find lots of people complaining about this.
Hypex has done nothing to solve this.
There was a reaction to some noise mentioned. Possible culprit: the signal cable that bends too close to the power pot.

Remedy: insert a piece of foam to inch it away, there is slack enough. I did that. It moved outwards by 3 cm.
I have no sound issue; I did it preventive (so did not listen without the piece of foam).
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Pass buffer -->300B SE + DN2540 CCS/Buffer; --> 165GMF in TQWT; working on a HYPEXed sub.
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Old 20th March 2019, 09:36 AM   #1299
chebum is offline chebum  Poland
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The New Hypex Fusion Plate amps
Quote:
Originally Posted by dirkwright View Post
I can try a normal loudspeaker L pad instead.
I have a 15dB L pad and I feel it reduces dynamics a bit. Probably, this effect will be less pronounced with a 6dB L pad.
I asked why is that happening here on forum. People say a serial resistor increases Qes which means amp damps driver movements less.
I'd try the suggestion above and avoid L pad.
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Old 20th March 2019, 12:28 PM   #1300
dirkwright is offline dirkwright  United States
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Quote:
Originally Posted by chebum View Post
I have a 15dB L pad and I feel it reduces dynamics a bit. Probably, this effect will be less pronounced with a 6dB L pad.
I asked why is that happening here on forum. People say a serial resistor increases Qes which means amp damps driver movements less.
I'd try the suggestion above and avoid L pad.
Yes, that is true as far as I know. The noise I have is from the miniDSP plate amp. I've discussed it with them and they just say "we never expected anyone to use our amps with high sensitivity drivers".... haha. Ok, well, what's needed in the field is a super low noise DSP plate amp. I have no clue how to make that happen, but a lot of horn loudspeaker guys would benefit from them, that's for sure.

The noise is still present when the input volume control is turned all the way down, so the noise is coming from the device itself. As someone noted above, it's most likely from the DSP electronics. MiniDSP suggested that I used the L pad they provide between the DSP and the power amp. I think I tried that with no result, besides the fact that adding series resistance will add noise anyway.... sigh. I looked at some of the chips they used for the DSP boards and I don't see any name brand (TI, et al.) op amps on there. Looks like no name or oem I guess?

Oh well, with music playing, I can't hear any noise, and others can't either, so it's not a huge issue. I am concerned though because I want to make a home theater system using all DSP plate amps. That's a lot of plate amps!

I hooked up a DE250 + horn to the 250 watt miniDSP plate amp and just got a really mild hiss. So, maybe the 125 plate amps use cheaper parts that make more noise? I dunno. I'll have to ask them about that. (the idea of powering a DE250 with a 250 watt plate amp is absurd on it's face, but i was just curious).
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