Topping Pre90 Review (preamplifier)

[Dgob]

too much work, or rather, too many variables to explore which in the long run made me tired. I no longer listened to music, but I spent a lot of time adjusting, moving, changing, weighing...
The world of vinyl is beautiful and fascinating, but now with a good Dac and Roon at the monthly price of half an LP I listen to everything I want. above all, I discovered a myriad of artists, with Roon's radios, that I would never have listened to with vinyl or even with CD.

I hear you, although my views on vinyl are as above. Still,

Best Music for Equipment Reviews and Listening Pleasure

I have already thanked you on your relevant thread, but would just like to point out how magnificent it is - for anyone here or in search of excellent sampling music. To paraphrase Lawrence Oates: "I'm just going inside and may be some time!" So much to explore...

www.audiosciencereview.com

 

[mocenigo]

question to those who already own it: how do you think the gain of this preamp? do you have to stay close to zero to hear at a good volume? practical example: xlr-xlr, -10 already becomes an annoying volume or are you inclined to raise it further? thanks to those who want to share!

It depends on the output of your source(s), the gain of your power amp, the sensitivity of your speakers and your listening distance. There is no rule. It could be -40 as well as 0.

 

[staticV3]

I get you. All XLR in and out.

+10 is the top of the displayed output.

In any case, there is more than enough gain available.

Max volume should be +16:


If yours tops out at +10, then you may have enabled Safe volume in the menu, and set that to +10.

 

[Fred_B]

question to those who already own it: how do you think the gain of this preamp? do you have to stay close to zero to hear at a good volume? practical example: xlr-xlr, -10 already becomes an annoying volume or are you inclined to raise it further? thanks to those who want to share!

I just got my Pre90 today. A normal listening volume for me is -10 to -15 dB, but I have my amplifier set for low gain (3.9X). Everyone's amplifier may have different amounts of gain but it seems like the Pre90 has a wide range of gain which should work with most amps.

 

[Fred_B]

I have a couple of questions about the Pre90, for those of you that have one.

Has anybody confirmed the "below 1 mV" DC offset? Manual says "<1mVrms" but I assume they mean <1mV DC. My current preamp has 9mV of DC on one output and I'm trying to see if I can reduce that. My amplifier amplifies the DC at the input so I have it set to low gain (3.9X). Still I am getting about 25 mV DC on the worst channel.

And (I assume this is true) can you have a configuration where RCA input and XLR output is selected?

Edit: Never mind the second question, I see SE IN / BAL OUT is a listed configuration in the specifications.
Edit: Placed an order with Apos. Will measure DC offset when it arrives. Also ordered an $8.99 IR extender from Amazon.

Received my Pre90 today (Monday). Ordered it Thursday afternoon. I don't think it stopped moving for very long between China and Texas! Thanks to DHL for quick delivery, and Apos for free shipping.

First thing I did before connecting it to my system was to check the DC offset levels on both channels to see if it met the "less than 1 mV" spec. It certainly did, I measured 0.1 mV from + to ground and 0.0 mV from - to ground (XLR pins) on both Left and Right channels.

I had to use a $9 IR extender since I sit about 12 feet from the Pre90, but that works OK. Unfortunately, the display is just a bit too small for me to read the dB numbers from my chair, but I can HEAR the volume anyway.

Now I'm going through the process of comparing the Pre90 to my other preamp, a Schiit Kara. So far with about an hour of listening, I can't tell a difference. According to the specs for both preamps, they SHOULD sound the same.

 

[JohnnyNG]

Everyone's amplifier may have different amounts of gain but it seems like the Pre90 has a wide range of gain which should work with most amps.

Exactly. The volume I use for my phono stage, and its relatively low output voltage, is much higher than that for my DAC. The per-input volume memory comes in very handy. As do the audible/tactile relay clicks since my pre90 is to the side of and slightly behind my seat. I don't use the remote.

 

[eduardw]

My normal lissening volume is -35.

 

[Dgob]

My normal lissening volume is -35.

Mine too. In my room, that gives me around 70-85dB.

 

[BurntFinger]

Mea Culpa here. Totally forgot I had the output set to XLR + RCA as I was using the RCA outputs to feed subwoofers in a previous set-up.

 

[kolestonin]

95% of my listening is between -40db and -30db and that gives me a sound volume between 65db and 85db approximately.

I use mine with RCA IN and RCA+XLR OUT so I guess it is normal maximum allowed volume is +10db.

Saw your posts and tried for the first time the safe volume option setting it at -5db as I thought it could be a nice feature so to avoid frying my speakers.
Volume still goes till +10db though...

Does the setting work only when playing music? It is 23:00 here and I can't try it with music, but I was expecting it will not allow me to set anything above -5db no matter the state of the device.

 

[staticV3]

@kolestonin
That's how I thought Safe volume worked as well, but reading the manual again, it operates differently:

Note:
When switching input/output channels or powering on, if the memorized volume is higher than the safe volume, the volume will be automatically adjusted to the safe volume level.
If the memorized volume needs to be restored please press the OK button on the remote within 10 seconds.

Basically, If you ended your last listening session at -10, but set Safe volume to -30 in the menu, the next time you turn on the Pre90, volume will be bumped down to -30 automatically.
From there you can still increase volume to max manually.

Same thing happens when switching inputs/outputs.

 

[kolestonin]

I also saw that but I think it is something different.

What I say is when no music is playing I use the remote and can turn up the volume till max(+10db) no matter I set my safe volume to -5db.
I wonder if the safe volume is enabled only when the device gets an input signal.

(I will of course try tomorrow morning as now my neighbors and other household members are sleeping)

 

[staticV3]

I wonder if the safe volume is enabled only when the device gets an input signal.

No. The Pre90 has no concept of signal presence.

I also saw that but I think it is something different.

I think it is literally how Safe Volume operates.

 

[Null-Test]

I don’t know if this has been addressed already but I can now confirm that the IR remote issue on the Pre90 is indeed a design flaw which places the IR receiver sensor misaligned with its display window (see 1-3 from Pic1), to the point it gets partially blocked by the metal part of the case, next to the display, on the right hand side of the unit (when one is facing it). So, an external IR extender/repeater was needed from which I could place its emitter part directly aimed at the still visible part of the Pre90 IR sensor, over the display (see Pic 2 below).

Pic1 - Topping Pre90 front panel:

Pic 2 - IR repeater’s sensor above the volume knob and emitter directly over the display (note that the IR repeater’s emitter had to be tilted to cover as much of the Pre90 sensor’s exposed part as possible):

 

[kolestonin]

As I already mentioned in this thread, safe volume mode setting seems not to be working on my device.
I follow manual instructions, I set safe volume to -05db, but the volume will go higher when I use the remote or the volume knob.
I tried a factory reset but this did not help.
So I contaced Shenzhenaudio who replied the below:

We submitted your question to our engineers and they told us that the safety volume is detected only when you turn on the computer/switch inputs/switch outputs.Hope this helps you.Best regards.

Can you help me understand what they say? I will of course re-contact them, but I would like to try my luck here where people with knowledge might understand above explanation and communication is also more direct.

 

[Jim Creek]

I don’t know if this has been addressed already but I can now confirm that the IR remote issue on the Pre90 is indeed a design flaw which places the IR receiver sensor misaligned with its display window (see 1-3 from Pic1), to the point it gets partially blocked by the metal part of the case, next to the display, on the right hand side of the unit (when one is facing it). So, an external IR extender/repeater was needed from which I could place its emitter part directly aimed at the still visible part of the Pre90 IR sensor, over the display (see Pic 2 below).

Pic1 - Topping Pre90 front panel:
View attachment 378751

Pic 2 - IR repeater’s sensor above the volume knob and emitter directly over the display (note that the IR repeater’s emitter had to be tilted to cover as much of the Pre90 sensor’s exposed part as possible):

View attachment 378752

I found that when the Pre90 is located on my left I have a problem with the remote control connecting with the sensor. When I relocated the Pre90 to my right the remote works much much better. I have deduced that the volume-function knob blocks the IR from the remote because of the location of the sensor.

The IR sensor is too close, and just to the left of the volume knob. If your line of sight is to the right of the sensor, then the volume-function knob blocks the signal from the remote.

 

[glc650]

I don’t know if this has been addressed already but I can now confirm that the IR remote issue on the Pre90 is indeed a design flaw which places the IR receiver sensor misaligned with its display window (see 1-3 from Pic1), to the point it gets partially blocked by the metal part of the case, next to the display, on the right hand side of the unit (when one is facing it). So, an external IR extender/repeater was needed from which I could place its emitter part directly aimed at the still visible part of the Pre90 IR sensor, over the display (see Pic 2 below).

Pic1 - Topping Pre90 front panel:
View attachment 378751

Pic 2 - IR repeater’s sensor above the volume knob and emitter directly over the display (note that the IR repeater’s emitter had to be tilted to cover as much of the Pre90 sensor’s exposed part as possible):

View attachment 378752

I had to do something similar (only I have the extender mounted the other way with scotch tape - I'm surprised this works for you) with both of my Pre90s and both of my DM7s in order to get IR working consistently.

 

[Grael]

As I already mentioned in this thread, safe volume mode setting seems not to be working on my device.
I follow manual instructions, I set safe volume to -05db, but the volume will go higher when I use the remote or the volume knob.
I tried a factory reset but this did not help.
So I contaced Shenzhenaudio who replied the below:

We submitted your question to our engineers and they told us that the safety volume is detected only when you turn on the computer/switch inputs/switch outputs.Hope this helps you.Best regards.

Can you help me understand what they say? I will of course re-contact them, but I would like to try my luck here where people with knowledge might understand above explanation and communication is also more direct.

Safe volume is designed to be the maximum volume remembered and set WHEN you turn on the device or switch to the specific input. (or output)
But you still can push it higher afterwards if needed when you stay on this input. (or output)

 

[Null-Test]

I found that when the Pre90 is located on my left I have a problem with the remote control connecting with the sensor. When I relocated the Pre90 to my right the remote works much much better. I have deduced that the volume-function knob blocks the IR from the remote because of the location of the sensor.

The IR sensor is too close, and just to the left of the volume knob. If your line of sight is to the right of the sensor, then the volume-function knob blocks the signal from the remote.

It has nothing to do with the volume knob, which is far enough from the display in order to be able to shade the remote control receiver.

The only reason why the remote works much better, almost flawless, when aimed at an angle from the left hand side of the Pre90 unit has to do with the fact that only from that position the remote can “see” the IR receiver which is otherwise blocked by the metal around the display on its right.

That happens because the IR receiver is placed on the right hand side of the display (see picture above) and, due to a layout error on the PCB (Printed Circuit Board), where this IR receiver is soldered to, there is a misalignment between the little window on the display screen intended for the receiver and the receiver itself, the latter being placed too far to the right, sitting partially behind the metal of the case which can block any incoming IR signal depending on the remote position, as I’ve explained before.

 

[BurntFinger]

I have not opened mine up (yet), but this begs the question: how hard might it be to relocate the IR receiver?

My simple solution so far is to turn the Topping stack about 25 degrees counterclockwise as viewed from above in my audio rack.