Specifications are not always correct, and the impedance is rarely flat versus frequency --> changes can affect the pass-through frequency response. However, these ratios make imagination the most likely difference...then again again the buffering circuitry could quite conceivably affect the sound.
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Audiophonics HPA-S400ET Review (Stereo Amplifier)
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Could you better explain this? Affect the sound in what aspect? Frequency response?
I’m also curious about your question, I had a similar feeling when i tried a Pre90 to the HPA-S400ET on buffer-bypass mode. I also thought that the “matching” impedances between them were fine, so in theory it should have worked fine. However i returned the HPA to medium gain buffer and kept it the ever since because it felt more right to my ears (or expectations)
Me the same. I ended up with the buffer ON and the gain set to 20dB.
My only concern was if the output voltage from the Topping A90 (8V) could be a little too high for the input sensivity of the amp at this settings (4V).
But in the end I think that 8V output voltage has to be considered at full 100% volume pot and anything around 70% should be much less than 8V. I'm right?
My only concern was if the output voltage from the Topping A90 (8V) could be a little too high for the input sensivity of the amp at this settings (4V).
But in the end I think that 8V output voltage has to be considered at full 100% volume pot and anything around 70% should be much less than 8V. I'm right?
No worries. You will hear your amplifier clipping long before you happen to feed it with 8Vrms.
Do you use any adaptive loudness? The gain offsets your loudness curve and may reduce bass if your reference level is different.
Why don't you just connect the D90 to the Audiophonics and sell the preamp? You are adding unnecessary stuff in the middle. If you use A90 for headphones, you could connect it to D90 via RCA and use XLR for the Audiophonics, or use a simple XLR selector as an alternative
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Sorry to say, i would focus more on loudspeakers here, B&W have a quite "idiosyncratic measured behavior" as stereophile says...
Check Amir's reviews of Kef R11 or Revel 208 (similar price range of your B&Ws towers) to have an example of a correct frequency response. Don't hate me now ;-) I was a victim as well of sexy British manufacturers (PMC) with poor objective performance
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There is nothing wrong with using Purifi amps with the high gain option selected. You will never hear any distortion at normal listening levels and you may experience a bit more bass kick in some systems. While the 3 position gain switch is nice in an academic sense for measurement testing it really doesn't add anything to the sound of my setup by running in low gain even with the RME ADI-2. After trying all the settings on my Boxem 4215/E2 over an extended period the high setting is my final preference. I have yet to hear increased distortion. The higher gain option is good. Don't be afraid of it Skywalker.
Very much agree with this. I have a pair of MPA-M400ET monos and my plan was to use them in bypass since, as you note, driving them should be no sweat for a Pre90. Compared to medium (or high) gain, however, bypass just sounded kind of muted and "colorless". Took me a while to give in and change them back to buffered since I didn't think what I was hearing made sense.
It’s ok to use the digital volume control? Any loss?
I don’t hate you because my B&W are yet on eBay and my next purchase is Revel M16
Same identical thing for me
Yes, and no.
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If You compared level adjusted and ABX-ed ...
You lose ≈1dB SNR per dB of volume attenuation.
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Are you saying at -40dB on the DAC you are looking at approx. 80dB SNR or right around the level of a decent AVR?
I remember hundreds of discussions about this, one of them is https://www.audiosciencereview.com/...olume-control-vs-analog-volume-control.20512/
Try to put everything at max volume while playing nothing. Would you hear any noise? It is true that you might loose something in terms of sound/noise ratio, but with topping dac and purifi amp the noise is irrelevant in absolute value, and still the environment will give you most of background noise.
AND, most importantly, would you hear any difference compared to your current setup?
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nemesis.ie
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Regarding buffered/not buffered "issues":
Are you measuring for comparison or is this just "by ear"? Can it be adjusted via EQ?
I run unbuffered to remove tweeter hiss and have room EQ in place and certainly don't find anything muted/missing. Bass from the speakers (80 Hz XO to subs) is punch and powerful. Both with my previous Emotiva speakers (C2+, C3+, B1+, A1+) and current Fyne Audio F500s, F500Cs and F502Cis.
They sound the same as the level matched Topping PA7+ (driving 2 Emotiva A1+s) after EQ too.
No noticeable bass difference versus the previous Emotiva UPA-1 nor HC-1 amps in this respect either. The Audiophonics units take up much less space and run cooler (more efficiently) of course which is the big + along with SN/R/lack of tweeter hiss due to the low gain setting.
IMO EQ is important.
Are you measuring for comparison or is this just "by ear"? Can it be adjusted via EQ?
I run unbuffered to remove tweeter hiss and have room EQ in place and certainly don't find anything muted/missing. Bass from the speakers (80 Hz XO to subs) is punch and powerful. Both with my previous Emotiva speakers (C2+, C3+, B1+, A1+) and current Fyne Audio F500s, F500Cs and F502Cis.
They sound the same as the level matched Topping PA7+ (driving 2 Emotiva A1+s) after EQ too.
No noticeable bass difference versus the previous Emotiva UPA-1 nor HC-1 amps in this respect either. The Audiophonics units take up much less space and run cooler (more efficiently) of course which is the big + along with SN/R/lack of tweeter hiss due to the low gain setting.
IMO EQ is important.
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