Topping Pre90 Review (preamplifier)

[da Choge]

Any single-ended to balanced conversion (or vice-a-versa) like with the Schiit Freya S (discontinued)? I suspect not, but just asking.

[This is an additional post from an edit of my previous post; deleted it from there and split it off to this new post]

 

[JohnYang1997]

Any single-ended to balanced conversion (or vice-a-versa) like with the Schiit Freya S (discontinued)? I suspect not, but just asking.

[This is an additional post from an edit of my previous post; deleted it from there and split it off to this new post]

It does.

 

[xema]

Possibly odd question: but is there a major difference between this and a microphone preamp? (Besides no phantom power) For example could you plug in a ribbon or dynamic mic into to this and then into an AD converter? (I've plugged ribbons/dynamics straight into a lynx hilo in the past and it worked fine except with some quiet sources, the noise floor would be a bit too high when you turned it up)

This is a hifi/consumer audio preamp, witch should be called "Monitor Controller" in pro audio

 

[617]

Interesting design choice. Making two products (one for someone with 2 sources maybe a dac and a phono) and one for someone with a big traditional hifi (tape, vcr, phono, cd, tuner) is a good idea.

I assume the d90 is the same case size?

Would it be crazy to ask topping to make a SOTA phono stage in the same form factor?

 

[da Choge]

It does.

(single-ended to balanced conversion)

This seems to be the tomBOMBadil of small-form factor preamps! Maybe a tad expensive with the add-on unit, but glad to see the add-on has lots of balanced inputs -- and still quite affordable. I think this may be the Schiit of modest preamps. I'm liking what I see so far.

 

[PeteL]

Other than Benchmark HPA4, I don't think it has an equal no matter how much money you spend.

The Schiit Freya S?
I didn,t go and toroughly compared each measurments, In term of SINAD and feature they look "Equal" but maybe I am missing something obvious.

 

[amirm]

The Schiit Freya S?
I didn,t go and toroughly compared each measurments, In term of SINAD and feature they look "Equal" but maybe I am missing something obvious.

I didn't show it but in THD+N vs Frequency the distortion is fair bit less than Freya S.

 

[phoenixsong]

Nice, but I was hoping for one more XLR output (phono pre and balanced dac in, balanced headamp and active speakers out). Also if volume control isn't needed the Nobsound Little Bear series will probably do just fine

 

[zenmastering]

This is a hifi/consumer audio preamp, witch should be called "Monitor Controller" in pro audio

Except the unfortunate choice to only allow 'previous/next' input selection disqualifies this for much pro use...

 

[ririt]

@JohnYang1997, how to find the manual of this device? some possible interesting features are highlighted for this preamp (selection of 2 complete dedicated set-up through C1 and C2 buttons of the remote, determine a fixed volume for inputs/outputs). I would like to know how it really works....

 

[Eetu]

@JohnYang1997, how to find the manual of this device? some possible interesting features are highlighted for this preamp (selection of 2 complete dedicated set-up through C1 and C2 buttons of the remote, determine a fixed volume for inputs/outputs). I would like to know how it really works....

Manual available here:
http://www.tphifi.net/drivers/pre90_ext90_manual.zip

 

[Veri]

@JohnYang1997, how to find the manual of this device? some possible interesting features are highlighted for this preamp (selection of 2 complete dedicated set-up through C1 and C2 buttons of the remote, determine a fixed volume for inputs/outputs). I would like to know how it really works....

It was already linked on page 1

 

[pma]

Distortion is whopping -25 dB lower than best case threshold of hearing. Combined noise+distortion as represented by SINAD is 5 dB better than said threshold. And this includes the noise from my analyzer. Likely the actual performance is fair bit better.

Suspecting some of the good noise figure comes at the expense of lower than normal input impedance, I jacked up the default 40 ohm output impedance of my Audio Precision analyzer to 200 ohm. The result was that the output from the Pre90 dropped down to 3.6 volts (instead of 4). One click on the volume control compensated for that nicely and give me the same good performance just as well:

So there is really no penalty to the lower input impedance.

/

Distortion is whopping -25 dB lower than best case threshold of hearing. Combined noise+distortion as represented by SINAD is 5 dB better than said threshold.

Threshold of hearing of nonlinear distortion is much higher, in tens of dB. This SINAD race is pointless.

Suspecting some of the good noise figure comes at the expense of lower than normal input impedance, I jacked up the default 40 ohm output impedance of my Audio Precision analyzer to 200 ohm. The result was that the output from the Pre90 dropped down to 3.6 volts (instead of 4).

This makes 1440 ohm input impedance of the Topping, right? This is extremely low and will increase distortion of many sound sources. So the "advantage" of the highest SINAD is lost, as we need to evaluate the complete chain and not the single components. All this (like low input imp) is done to get the best numbers on paper and it has no practical importance.

 

[amirm]

Threshold of hearing of nonlinear distortion is much higher, in tens of dB. This SINAD race is pointless.

You are making a generic statement, I am making an absolute statement. Yours has a lot of strings attached, mine does not. Provable dynamic range of our hearing is about 115 dB. So if your noise floor is higher then you could hear such level. Anything above this becomes shades of gray, not absolute.

 

[Rja4000]

@JohnYang1997
What noise amplifier are you using for measurements ?
And what SINAD value do you measure @5mV ?

 

[MrOtto]

Compared to legacy Hifi, incredably results for the price, but considering the competition now just two inputs and no headphone amp? $849 if you want more than two inputs? Is the form factor that important to keep not to add more inputs?

 

[Veri]

@JohnYang1997
What noise amplifier are you using for measurements ?

You can see (an example of) it here:
https://www.audiosciencereview.com/...f-topping-a90-headphone-amp.11946/post-347130

 

[ririt]

Manual available here:
http://www.tphifi.net/drivers/pre90_ext90_manual.zip

Thank you

 

[preload]

Thanks for this review Amir. Btw I didn't see your usual L-R channel level mismatch vs volume setting measurements. There's bound to be some given the use of a resistor network.

 

[daftcombo]

Great performance but expensive for what it is.