Kolatratar
New Member
- Joined
- Mar 8, 2025
- Messages
- 1
- Likes
- 0
The input impedance of Topping LA90/LA90discrete balanced input is 20kOhms:
www.audiosciencereview.com
The input impedance of the Topping Pre90 balanced input is 2kOhms:
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?

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. ;))

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...

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?