AK4395/4396 ultrasonic noise spectrum graphic - diyAudio
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Old 31st January 2009, 07:03 PM   #1
sendler is offline sendler  United States
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Default AK4395/4396 ultrasonic noise spectrum graphic

Here is an interesting graphic that you may not have seen. The AKM dacs feature a 2v voltage output and super low ultrasonic noise floor which enables them to run their analog output direct out to the output connector with no analog filters or buffers, still providing plenty of power to drive passive stepped attenuators. No active circuitry of any kind following them. This provides the purest, most detailed sound that I have heard. The direct out mod is very cheap to put into a DEQ2496 or various sound cards that use the AKM dacs needing only a high quality coupling cap to block the dc offset. Interestingly, I find that the sound of the 4395 has better fine resolution but the 4396 has a beautifully focused and powerful presentation.
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Old 31st January 2009, 07:57 PM   #2
sendler is offline sendler  United States
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Default better pic

I worked the photo to make it easier to see.
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Old 1st February 2009, 03:51 AM   #3
jwb is offline jwb  United States
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What kind of test signal is used?
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Old 1st February 2009, 03:59 AM   #4
sendler is offline sendler  United States
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Default signal

looks like narrow band noise centered on 1k. The image is from the AKM site.
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Old 1st February 2009, 05:47 AM   #5
Pano is offline Pano  United States
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Thanks Scott, very nice!

You seem to be not alone in your preference for the '95 over the '96.

I have found that good chips like these need only a transformer and a resistor on the outputs for spectacular results.
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Old 1st February 2009, 07:09 AM   #6
SunRa is offline SunRa  Romania
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Hello, nice graph...

Quote:
I have found that good chips like these need only a transformer and a resistor on the outputs for spectacular results.

Do you have any examples of such transformers?
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Old 1st February 2009, 04:22 PM   #7
sendler is offline sendler  United States
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Default Direct through caps

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Originally posted by panomaniac
I have found that good chips like these need only a transformer and a resistor on the outputs for spectacular results.
I tried some nice Sowter transformers but found that I like the sound direct out from the dacs through Dayton foil caps the best. The trannies did have a nice liquid midrange though.
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Old 1st February 2009, 05:07 PM   #8
SunRa is offline SunRa  Romania
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yes I have heard of sowter being used in this position with akm parts. I was wondering about some less expensive transformers..
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Old 1st February 2009, 06:32 PM   #9
Pan is offline Pan  Sweden
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Quote:
Originally posted by jwb
What kind of test signal is used?
To me it looks like 1kHz sine at -60dBFS and the measurement done with few FFT points or possibly a window choosed for truer represenatation of noise rather than static signals.

/Peter
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Old 1st February 2009, 06:40 PM   #10
sendler is offline sendler  United States
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Default Sowters are the cheap trannies

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Originally posted by SunRa
yes I have heard of sowter being used in this position with akm parts. I was wondering about some less expensive transformers..
The Sowters ARE one of the value leaders at $120.00. Other high end transformers go way up from there. $200, $300 each! That's why I like the cap coupling method. With the right caps, Dayton foil, it sounds better and they only cost $15.00
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