High S/N ratio amps - Page 2 - AVS Forum
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post #31 of 33 Old 09-30-2013, 09:17 PM - Thread Starter
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I tried the Dayton t amp that I had on hand but it wasn't any quieter than my NAD integrated amp or my Sure 4x50w amp. Keep in mind that all of these amps are silent and sound great with nearly any other speaker but the sensitivity of the BMS makes the signal to them critical.
I just bought a MiniDSP and an ATI AT602 amp. This amp has a signal/noise ratio of over 120db at rated power. It only puts out 60w into 8 ohms so perhaps 45w into my 16 ohm cd's. I sure hope this settles them down. smile.gif
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post #32 of 33 Old 10-01-2013, 10:59 PM
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Quote:
Originally Posted by tsloms View Post

What would be the best type of resistor to use for this? They will need to dissipate quite a bit of wattage to attenuate that much.

Before you go and spend the time and money to build this high power attenuator, why don't you try a quick experiment to see if 20 dB is enough to reduce the hiss to an acceptable level.

Try adding a 1/4 Watt, 144 Ohm resistor in series with your tweeter (150 Ohms is close enough) but don't play any music with it hooked up, just listen for an acceptable reduction of hiss.
If your tweeter actually presents a 16 Ohm load then you should get about 20dB of attenuation with that value resistor and easily determine whether 20dB is enough or not.

And finally, for a really radical idea, why don't you think about using a 10:1 transformer to attenuate your tweeter by 20dB instead of using an L-Pad?
A transformer doesn't have any of the power dissipation issues that L-Pads have, and I've never heard of any complaints about the "sound" of transformers from the dedicated tube amplifier lovers.
(Transformers can be quite linear for the frequency range you're interested in, if you get a decent one)

Maybe others can suggest a good source for a high quality transformer.
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post #33 of 33 Old 10-02-2013, 06:48 AM - Thread Starter
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Quote:
Originally Posted by stereo2.0 View Post

Before you go and spend the time and money to build this high power attenuator, why don't you try a quick experiment to see if 20 dB is enough to reduce the hiss to an acceptable level.

Try adding a 1/4 Watt, 144 Ohm resistor in series with your tweeter (150 Ohms is close enough) but don't play any music with it hooked up, just listen for an acceptable reduction of hiss.
If your tweeter actually presents a 16 Ohm load then you should get about 20dB of attenuation with that value resistor and easily determine whether 20dB is enough or not.

And finally, for a really radical idea, why don't you think about using a 10:1 transformer to attenuate your tweeter by 20dB instead of using an L-Pad?
A transformer doesn't have any of the power dissipation issues that L-Pads have, and I've never heard of any complaints about the "sound" of transformers from the dedicated tube amplifier lovers.
(Transformers can be quite linear for the frequency range you're interested in, if you get a decent one)

Maybe others can suggest a good source for a high quality transformer.
I have tried to make up a simple lpad a couple of days ago but it wasn't enough. I made up about an 11.5 lpad with a 10 ohm in parallel and a 10 ohm in series. It did quiet the cd down about 3db but it was still pretty noticeable and will be even worse once I bring these speakers into my house. I did order a much quieter and lower power amp which should help dramatically.
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