XLR input impedance of Topping LA90/LA90d power amp is higher than its recommended preamp Pre90?!

[Kolatratar]

The input impedance of Topping LA90/LA90discrete balanced input is 20kOhms:

Topping LA90 Review (Integrated Amplifier)

I'd like to think Topping took inspiration from my Bryston x Topping mashup: And my Centered volume knobs thread: https://www.audiosciencereview.com/forum/index.php?threads/centered-volume-knobs.16751/ (They didn't, but I'd like to think so. ;))

www.audiosciencereview.com

The input impedance of the Topping Pre90 balanced input is 2kOhms:

Topping Pre90 Review (preamplifier)

for 10k ohm, do you think it will affect output capacitor coupled source with 200ohm output impedance? it seems quite some dacs are spec like that, and that for passive preamps the 10k ohm input impedance seems quite common? well, that makes it not much universal device...

www.audiosciencereview.com

I just purchased a Topping LA90 discrete. I'm quite impressed with its sound quality and I am considering the Pre90 - Topping's website recommends the LA90d to be paired with the Pre90 preamp.

However, the input impedance of the LA90d is 20kOhms while that of the Pre90 is 2kOhms!

Does anyone find it really strange that the input impedance of the preamp is lower than that of its power amp?! What's the point of having a preamp then?

 

[Jimbob54]

The input impedance of Topping LA90/LA90discrete balanced input is 20kOhms:

Topping LA90 Review (Integrated Amplifier)

I'd like to think Topping took inspiration from my Bryston x Topping mashup: And my Centered volume knobs thread: https://www.audiosciencereview.com/forum/index.php?threads/centered-volume-knobs.16751/ (They didn't, but I'd like to think so. ;))

www.audiosciencereview.com

The input impedance of the Topping Pre90 balanced input is 2kOhms:

Topping Pre90 Review (preamplifier)

for 10k ohm, do you think it will affect output capacitor coupled source with 200ohm output impedance? it seems quite some dacs are spec like that, and that for passive preamps the 10k ohm input impedance seems quite common? well, that makes it not much universal device...

www.audiosciencereview.com

I just purchased a Topping LA90 discrete. I'm quite impressed with its sound quality and I am considering the Pre90 - Topping's website recommends the LA90d to be paired with the Pre90 preamp.

However, the input impedance of the LA90d is 20kOhms while that of the Pre90 is 2kOhms!

Does anyone find it really strange that the input impedance of the preamp is lower than that of its power amp?! What's the point of having a preamp then?

Volume control, input selection. It's the output impedance of the pre90/input of the la90 you need to look at.

 

[staticV3]

Volume control, input selection. It's the output impedance of the pre90/input of the la90 you need to look at.

And the Pre90 input impedance to make sure that whatever sources you plug into it are comfortable at 2k load impedance.
Many vintage electronics may not be.

 

[babadono]

? what is the question? It is the output of a preamp that feeds a power amp. Output impedances are always lower than input of next stage in audio equipment. We want to transfer the maximum signal voltage possible. So a low output z feeds a high input z sometimes referred to bridging the load.

 

[pma]

However, the input impedance of the LA90d is 20kOhms while that of the Pre90 is 2kOhms!

They have very low input impedance of the Pre 90 for the reason to get lowest noise numbers on paper.

 

[Snoopy]

They have very low input impedance of the Pre 90 for the reason to get lowest noise numbers on paper.

Could be a nice name for the brand..
topping - the paper Tiger