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Low distortion attenuator for building a passive pre-amp?

dualazmak

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The comment above about source impedance* is, of course, really important.
Sometimes folks need gain, drive, and/or impedance matching -- and in those cases, a passive just ain't a gonna cut it.

For passive attenuation, from my perspective, it is hard if not impossible to beat a tapped transformer or autoformer, since it allows attenuation at constant impedance. It does require wide bandwidth, so they ain't cheap, but any constant-impedance stepped attenuator ain't a-gonna be cheap, even if it just uses resistors.
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* I.e., and more generally, the importance of complementary source output and load imput impedances. :)

Hi mhardy6647,

Your nice comment is fully supporting my recent "attenuator bypass wiring" which fully cancels all of attenuation while the amplifier still can "see" the 8 Ohm attenuators with the total impedance maintained. The improvement of the sound cleanliness, transparency and resolution are more than expected, while the total "sound characteristics" remain unchanged.

The digital software crossover's channel gain on PC, in my case EKIO's gain settings, is now perfectly simulating the attenuator settings even for single-DAC + single-amplifier + LC network (no attenuation at all) system.

BTW, in your photo, I also like the simple DIY(?) audio rack. I am considering to build my rack like yours...
 
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restorer-john

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dualazmak

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restorer-john

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Thank you for the info... I believe I can purchase all of the parts at nearby big "Home Center Shop" with reasonable cost!

Please post a picture of your equipment rack when you have completed it. Many other people may get inspiration to do the same. :)
 

dualazmak

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Please post a picture of your equipment rack when you have completed it. Many other people may get inspiration to do the same. :)

You can see my current setup here in my thread. After I would fully decide four (4) stereo multichannel power amplifier(s), I will need a new audio rack at the left-hand side of the current still nice and rigid "side board cabinet". I will share my new equipment rack when completed, hopefully in the near future...
 
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Harmonie

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Just sharing my own experience. Sometime ago I had similar purist consideration feeding my mono amps in the shortest possible way. I used 2 DIY stepped attenuators, one a few inches directly behind each amp. That means using what, 50 cm ? HP cable.
Audiosynthesis Passion.jpg

Today, I'm happier using a DAC feeding directly the amp.
 
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