• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Topping Pre90 Review (preamplifier)

Veri

Master Contributor
Joined
Feb 6, 2018
Messages
9,596
Likes
12,036
Great performance but expensive for what it is.
The HPA-4 is $2999. This Topping comes pretty close, at $599 without the extender. That's not particularly bad. Someone with speakers that needs a world-class pre is probably willing to pay that. If you want a pre in a headphone set-up, perhaps the Schiit pre's are better value.
 

kopczas

Active Member
Joined
Oct 6, 2020
Messages
260
Likes
154
So, except relay ladder and remote, what is the difference between A90 and Pre90?
 

YSC

Major Contributor
Joined
Dec 31, 2019
Messages
3,194
Likes
2,570
The source impedance in DACs is usually a couple of resistors and likely won't have a frequency dependent component to matter in audio band. So all you are left with is voltage drop which is what I tested for.
right, thanks for the info, but just in the name of knowledge, I think in some rare cases for dacs, say for some R2R discrete DACs or tube output stage dacs where some ppl do like, will this make it bass shy for that? just kind of interesting to know about the potential impact of unusual low input impedance for this spectacular preamp
 

soundwave76

Addicted to Fun and Learning
Forum Donor
Joined
Dec 28, 2018
Messages
730
Likes
1,365
Location
Finland
One can build a pretty awesome and good looking stack now with the Topping products. <slow clap>
 

nobody

Member
Joined
May 26, 2020
Messages
27
Likes
41
@amirm Thank you, for this extensive review. Would it be possible to add Topping A90 measurments in preamp mode for Crosstalk, Intermodulation distortion and SINAD vs frequency. So anyone can compare it directly to Pre90?
 

bungle

Active Member
Joined
Dec 11, 2020
Messages
179
Likes
122
Would it be crazy to ask topping to make a SOTA phono stage in the same form factor?
Excellent, now we need a power amp to match this ability @JohnYang1997

What I would love is a HDMI-Ext that you could put in that chain. Pre/Ext solves the analog switching and volume control side, D90 solves the ADC side (for other than HDMI), but nothing solves the HDMI problem (where things still are usable through a single remote).
 

YSC

Major Contributor
Joined
Dec 31, 2019
Messages
3,194
Likes
2,570
well, that makes it not much universal device.
That's my feeling, when I choose a preamp myself I can easily know what my chain is, but if for recommending to friends who might change front end often it would halt my recommendation, so that's why I kind of hope Amirm can also test the FR change with output impedance of the AP set higher to see the effect
 

kopczas

Active Member
Joined
Oct 6, 2020
Messages
260
Likes
154
I kind of hope Amirm can also test the FR change with output impedance of the AP set higher to see the effect

This would be nice. Maybe there is nothing to be worry about.
 

YSC

Major Contributor
Joined
Dec 31, 2019
Messages
3,194
Likes
2,570
This would be nice. Maybe there is nothing to be worry about.
sure, and for most modern dacs it probably just as Amirm said it won't matter a hair, but it's always know that it can be full transparent even improperly used for say very low SINAD vintage device or even computer on board sound card.

To me it's not about the absolute SINAD value above 100db, but for amp and pres it sounds more logical that we can use them anywhere without altering the sound signature so that in case I somehow prefer vintage effect boxes they will sound like the good old days
 

pma

Major Contributor
Joined
Feb 23, 2019
Messages
4,592
Likes
10,728
Location
Prague
What is the value of input impedance? There is no data on that.

There is no data because it would not look nice on the paper. Based on @amirm measurement, voltage drop from 4V to 3.6V when AP output impedance changed from 40 ohm to 200 ohm - results in Topping input impedance of 1.44 kohm - simple circuit maths.

This is very small input impedance. I would recommend nothing below 10 kohm. It affects distortion, and the low frequency corner, if the sound source has output coupling capacitor, which is very usual.

In my designs, I use 47 kohm or 100 kohm input impedance, very rarely 10 kohm.
 

Matias

Master Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
5,031
Likes
10,806
Location
São Paulo, Brazil
Crosstalk and input impedance could be better but still an awesome performance for a very good price (as far as high end pre-amplifiers go).

Congrats Topping for another great product launch!
 

YSC

Major Contributor
Joined
Dec 31, 2019
Messages
3,194
Likes
2,570
There is no data because it would not look nice on the paper. Based on @amirm measurement, voltage drop from 4V to 3.6V when AP output impedance changed from 40 ohm to 200 ohm - results in Topping input impedance of 1.44 kohm - simple circuit maths.

This is very small input impedance. I would recommend nothing below 10 kohm. It affects distortion, and the low frequency corner, if the sound source has output coupling capacitor, which is very usual.

In my designs, I use 47 kohm or 100 kohm input impedance, very rarely 10 kohm.
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?
 

DSJR

Major Contributor
Joined
Jan 27, 2020
Messages
3,314
Likes
4,427
Location
Suffolk Coastal, UK
A shame it's mostly balanced - I'm talking domestic use here. We unwashed audio peeps still use tuners with single ended output, some use tape decks too and what about the 'legions' of vinyl lovers with phono stages which are mostly single ended RCA outputs?

I know, 'we' need to come into the twenty first century and maybe some properly wired adaptor cables could be put to good use? As and when I need to replace my forty five year old preamps when the old controls finally give out, I'm still going to have to look to the used market I suspect (probably a Meridian 502 or similar although I'd love to try a Crown PSL2).
 

Matias

Master Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
5,031
Likes
10,806
Location
São Paulo, Brazil
Top Bottom