Topping Pre90 Review (preamplifier)

[-Matt-]

Sorry for not trawling the previous 49 pages for answers but...

Would the Topping Pre90 be suitable in an AV bypass role?

I.e. Connect the AVR pre out for L and R channels to the rca inputs of the Pre90. Connect a balanced dac to the xlr inputs. Connect the xlr outputs to a balanced power amp such as hypex.

Would it then be possible to switch between the AVR and dac as though they were two sources just by changing the input? Can you do this via a remote, or better yet, can commands to do this perhaps be sent via usb serial port?

Could a fixed volume be specified on the rca input, whilst allowing volume adjustment on the xlr input used by the dac (for stereo listening).

Any problem with gain structure in the setup proposed above?

Any better/cheaper alternatives?

 

[Kal Rubinson]

I.e. Connect the AVR pre out for L and R channels to the rca inputs of the Pre90. Connect a balanced dac to the xlr inputs. Connect the xlr outputs to a balanced power amp such as hypex.

Yes.

Would it then be possible to switch between the AVR and dac as though they were two sources just by changing the input?

Yes.

Can you do this via a remote, or better yet, can commands to do this perhaps be sent via usb serial port?

Yes by remote or front panel button but not by any other method.

Could a fixed volume be specified on the rca input, whilst allowing volume adjustment on the xlr input used by the dac (for stereo listening).

No. They are both controlled by the same control. However, the gain is indicated by the display and you can easily and consistently set it to 0dB for A/V bypass via RCA while using it variably for the DAC. Unfortunately, there is no way to preclude user error.

Any problem with gain structure in the setup proposed above?

Nope. Just the control issue above.

 

[-Matt-]

Thanks for those answers Kal.

It sounds as though you may have tried using the Pre90 in this way. If so, can you offer any subjective comment on useability and whether you recommend it for this application?

 

[glc650]

Thanks for those answers Kal.

It sounds as though you may have tried using the Pre90 in this way. If so, can you offer any subjective comment on useability and whether you recommend it for this application?

I use my Pre90 in a similar fashion:

Pre90 input side:
D90SE > Pre90 via XLR
Marantz SR8012 pre-out > Pre90 via RCA

Pre90 output side:
tube amp/subs via RCA
solid state amp via XLR

(I also have a device in the chain that allows me to use the same L/R speakers with either amp).

This allows me to use either amp with my 2ch setup and my solid state amp with TV/movies (Marantz), although I could also use my tube amp for that.

I also have a U90 before my DAC:

U90 input:
USBridge > U90 via USB

U90 output:
coax #1 (for MQA) > D90SE
IIS (for high-res above 192/non-MQA) > D90SE
2nd coax > Marantz (so I can listen to music while TV is on in background by simply changing input on Marantz)

 

[Kal Rubinson]

It sounds as though you may have tried using the Pre90 in this way. If so, can you offer any subjective comment on useability and whether you recommend it for this application?

I do not. I have 3 Pre90s which are generally set at 0dB gain. They get XLR input from my 6-8channel XLR switcher (to select sources) and they feed my amps and subs via XLR. They are there because they drive the various outputs better than does the passive switcher and the sources. They are also there in case of the need for additional gain, on occasion.

 

[-Matt-]

Thank you glc650 and Kal for confirming that this approach is viable.

I'm not sure if I will do this yet. I'd prefer to keep my setup as simple as possible. (Currently using just an AVR for both video and music and want to keep using the same front speakers for both).

I tried to buy a receiver that would offer transparent dac performance, but since Denon changed the design and dac chips and the new models have not been tested I'm now unsure what level of performance my AVR is capable of. (My personal line in the sand was "SINAD somewhere near 100dB will do").

I don't like the fact that the adc and dac in the AVR potentially form a bottleneck for 2ch music. Hence the interest in AV bypass. However, correcting this seems to require purchase of an external dac, power amp and now possibly also a pre amp. It also probably means losing room eq.

Perhaps I'd be better off just waiting for the next generation of Denon AVRs with AK dacs and trading up?

 

[glc650]

I don't like the fact that the adc and dac in the AVR potentially form a bottleneck for 2ch music. Hence the interest in AV bypass. However, correcting this seems to require purchase of an external dac, power amp and now possibly also a pre amp. It also probably means losing room eq.

Some combination of direct/pure direct and/or not using bass management/EQ might get you there but it's tough to tell just what the AVR is doing. There's also the analogue inputs but you still need to have all DSP off otherwise the AVR will convert the analogue signal to digital. I went the separate DAC/pre/amp (well I was already using a separate amp with my AVR for L/R fronts) route to make sure I got what I wanted. As for EQ, I use HAF filters + xtalk correction with Roon and it at least sounds on par with what Audyssey does on my Marantz. You could also use a minDSP device w/DIRAC (I know, yet another device to add to a 2ch chain) if you don't use Roon for music.

 

[JohnnyNG]

Topping Pre90 line preamplifier

There has not been a conventional preamplifier in my main audio system for quite a while, because no multichannel preamp is available that's of high enough quality. Instead, I use the high-precision digital volume controls in my players and DACs and choose sources with a relay-based multichannel...

www.stereophile.com

 

[Veri]

Topping Pre90 line preamplifier

There has not been a conventional preamplifier in my main audio system for quite a while, because no multichannel preamp is available that's of high enough quality. Instead, I use the high-precision digital volume controls in my players and DACs and choose sources with a relay-based multichannel...

www.stereophile.com

Very nice! Congrats on the review and mention @JohnYang1997

 

[dtaylo1066]

The Pre90 preamplifier's measured performance is simply superb. The fact that that performance can be achieved in such a small chassis and for such a low price suggests that Topping has some serious audio engineering talent in-house.—John Atkinson

 

[Oilman]

Sorry for not trawling the previous 49 pages for answers but...

Would the Topping Pre90 be suitable in an AV bypass role?

I.e. Connect the AVR pre out for L and R channels to the rca inputs of the Pre90. Connect a balanced dac to the xlr inputs. Connect the xlr outputs to a balanced power amp such as hypex.

Would it then be possible to switch between the AVR and dac as though they were two sources just by changing the input? Can you do this via a remote, or better yet, can commands to do this perhaps be sent via usb serial port?

Could a fixed volume be specified on the rca input, whilst allowing volume adjustment on the xlr input used by the dac (for stereo listening).

Any problem with gain structure in the setup proposed above?

Any better/cheaper alternatives?

I do this using a Pre90, D90SE, and Lyngdorf MP50. Though I haven’t bothered to learn if the remote can do the input switching.

 

[Kal Rubinson]

I do this using a Pre90, D90SE, and Lyngdorf MP50. Though I haven’t bothered to learn if the remote can do the input switching.

Only if you are a good marksman.

 

[Oilman]

Only if you are a good marksman.

So true Kal. It’s the Pre90’s single, annoying flaw. Any idea on the cause - is it a wimpy remote IR diode, or perhaps Topping recessed the IR receiver too far into the case? If the former, perhaps a stronger universal remote should fix, if the latter, would need an IR repeater.

 

[nothingman]

Extremely helpful real world use case described in your review, thanks @Kal Rubinson! I’m basically in the same boat, miniDSP SHD capable of the usual 2V SE/4V Bal output, digital volume control, no gain available, and running Dirac, which means I could really use some gain and hifi volume control back in my system like you’re achieving with the triple-Pre90s.

As it is I don’t want to mess with dual Pre90 units and IR repeaters and such. If there were a four channel version of this I would be very hard pressed not to place it in my 2.1 (2.2 before long) system. Please consider offering this in multichannel @JohnYang1997 — a four and eight channel in this product specifically would find a lot of use.

 

[Kal Rubinson]

As it is I don’t want to mess with dual Pre90 units and IR repeaters and such. If there were a four channel version of this I would be very hard pressed not to place it in my 2.1 (2.2 before long) system. Please consider offering this in multichannel @JohnYang1997 — a four and eight channel in this product specifically would find a lot of use.

My fantasy is that Topping repurposes the EXT multipin connector to allow the daisy-chaining of multiple Pre90s. I know that is not possible with the current hardware.

 

[nagster]

I am using Pre90 / Ext90.
My hope is the next version (Pre90m?), With multiple syncs (input selection and volume) and the addition of master / slave selection capabilities. More versatile.

At the same time, if possible, if you can improve the following,,,
Remote control aim is too difficult
Remote control input direct selection
Volume knob instability / jump (similar to RME ADI2)

 

[bungle]

My fantasy is that Topping repurposes the EXT multipin connector to allow the daisy-chaining of multiple Pre90s. I know that is not possible with the current hardware.

For daisy chaining you would need two multipin connectors per unit?

 

[nagster]

When the Ext multi-connector hub(?) is released, it may be possible to make a star connection like LAN.
Or Y para cable or T type branch terminal
However, I don't think the volume control signal is flowing through the current Pre90 multi-connector...

 

[-Matt-]

Only if you are a good marksman.

I really dislike infrared remotes and try to eliminate them whenever possible. This is why I asked about a serial port via the usb (RS232 or ethernet would also be ok). I like to have my electronics in a cabinet, out of view, and send control commands from a pc running a webserver with remote control gui (accesible via my phone browser).

Obviously, for future versions of the Pre90 it would be nice to have such an interface. (With two-way comms so that you can poll the current volume etc).

 

[Digi]

Can I pair this Topping Pre90 preamplifier with a Parasound A21+ amplifier? Are there any issues that I need to be concerned of? Voltage, etc?