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Topping 8-Channel Preamp: New Product Request

dped90

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Some time ago Topping's R & D staff thanked me for requesting this new product-what I'm sure would be the best MCH answer to their highly successful Pre90 preamp. https://www.stereophile.com/content/topping-pre90-line-preamplifier

Indeed, I am facing the exact same dilemma as did KR here where the otherwise very effective DIRAC Live 3 room correction inflicted a gain loss of almost 20db on his 5.3 system. As his Exasound s88 DAC's balanced outputs apparently could not provide output voltage to drive the amplifiers and/or using the DAC's remote for attenuation would result in resolution loss, perhaps especially at lower listening levels, KR mentioned that he purchased three of these preamps to solve the problem.

True, Fig. 3 here shows the superbly low distortion which continues to virtually decline all the way to 17v.
https://www.stereophile.com/content/topping-pre90-line-preamplifier-measurements And for many users the price certainly allows purchasing multiple Pre90.

But having to contend with a stack of them is unappealing to many and as KR found that controlling system volume-especially with the Pre90's badly engineered remote-can't be the most effortless thing in the world.

Meanwhile, I've spent half nearly this month hunting for the handful of custom amplifier designers who might build for me an 8 channel preamp with balanced inputs/outputs, ~ 15v output/channel, a stereo balance control to set the levels between the front and side/rear speakers of the 5.3 system I want to build and a volume/mute remote to master control the output of all 8 channels by digitally controlling an analog potentiometer.

But after all of that hunting, emailing and web chatting, no luck, of course.

An 8-channel version of the Topping Pre90 preamp would be a godsend for users of MCH channel DACs like the Exasound S88 and the Okto DAC 8 Pro. And it would be the perfect opportunity for Topping to make good on offering a well designed bug free volume/mute remote.

AND for adding a front/rear speaker pair stereo balance control.

Let's go Topping, make this 8-channel preamp happen in 2023!
 

Kal Rubinson

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Yeah. I thought I heard that the 8-channel dac they put out was not selling despite many requests. Probably hearsay, but not far from the truth.
I think it would sell much better with two changes:
1. Replace the 8xTRS jacks with 8xRCA+DB25(with 8xbal outs).
2. Replace the up/down volume buttons with a large knob.
 

somebodyelse

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On the DM-7, the "don't use it single ended" issue comes up a lot. It's also priced uncomfortably close to the MOTU Ultralite Mk5 which doesn't measure much worse, doesn't have warnings about single ended use, has a boatload more capabilities, and has a more reassuring warranty support system for many of us.
 

bloodshoteyed

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I think it would sell much better with two changes:
1. Replace the 8xTRS jacks with 8xRCA+DB25(with 8xbal outs).
2. Replace the up/down volume buttons with a large knob.
if i may, i'd add my wet dream scenario...
a decent piece of SW with at least the capability of setting x-overs on the different outputs (if not anything more in the likes of time-delay, PEQ and other things, being able to upload them into the HW piece of equipment)
 

somebodyelse

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if i may, i'd add my wet dream scenario...
a decent piece of SW with at least the capability of setting x-overs on the different outputs (if not anything more in the likes of time-delay, PEQ and other things, being able to upload them into the HW piece of equipment)
That sounds suspiciously like the now discontinued Hypex DLCP, something from MiniDSP or (if they can restart production) the Auverdion Aurora.
 

Kal Rubinson

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if i may, i'd add my wet dream scenario...
a decent piece of SW with at least the capability of setting x-overs on the different outputs (if not anything more in the likes of time-delay, PEQ and other things, being able to upload them into the HW piece of equipment)
Yes but I was proposing a modification, not a new device. It requires the addition of new circuit hardware to support the additional processing whether the crossovers are implemented in analog or digital form.
 

wjp007

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Some time ago Topping's R & D staff thanked me for requesting this new product-what I'm sure would be the best MCH answer to their highly successful Pre90 preamp. https://www.stereophile.com/content/topping-pre90-line-preamplifier

Indeed, I am facing the exact same dilemma as did KR here where the otherwise very effective DIRAC Live 3 room correction inflicted a gain loss of almost 20db on his 5.3 system. As his Exasound s88 DAC's balanced outputs apparently could not provide output voltage to drive the amplifiers and/or using the DAC's remote for attenuation would result in resolution loss, perhaps especially at lower listening levels, KR mentioned that he purchased three of these preamps to solve the problem.

True, Fig. 3 here shows the superbly low distortion which continues to virtually decline all the way to 17v.
https://www.stereophile.com/content/topping-pre90-line-preamplifier-measurements And for many users the price certainly allows purchasing multiple Pre90.

But having to contend with a stack of them is unappealing to many and as KR found that controlling system volume-especially with the Pre90's badly engineered remote-can't be the most effortless thing in the world.

Meanwhile, I've spent half nearly this month hunting for the handful of custom amplifier designers who might build for me an 8 channel preamp with balanced inputs/outputs, ~ 15v output/channel, a stereo balance control to set the levels between the front and side/rear speakers of the 5.3 system I want to build and a volume/mute remote to master control the output of all 8 channels by digitally controlling an analog potentiometer.

But after all of that hunting, emailing and web chatting, no luck, of course.

An 8-channel version of the Topping Pre90 preamp would be a godsend for users of MCH channel DACs like the Exasound S88 and the Okto DAC 8 Pro. And it would be the perfect opportunity for Topping to make good on offering a well designed bug free volume/mute remote.

AND for adding a front/rear speaker pair stereo balance control.

Let's go Topping, make this 8-channel preamp happen in 2023!
Agreed. This is exactly the same issue I ran into. One of the issues with Dirac is it does put significant attenuation into the system. I'm sure I could have solved it with a Power AMP that has some input gain control like Parasound, but that just was way beyond my budget.
 

bloodshoteyed

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That sounds suspiciously like the now discontinued Hypex DLCP, something from MiniDSP or (if they can restart production) the Auverdion Aurora.
exactly, except i'd like more than a single choice
 

mdsimon2

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I am showing my own ignorance as I am not a Dirac user but I don't understand when people say that Dirac removes gain from their system. Maybe someone can help me understand?

If Dirac is cutting across the entire frequency spectrum can you not increase the level across the board with DSP?

Or is it a situation where Dirac is boosting your low end and cutting midrange? So you can't increase the level without clipping the low end? If this is the case I don't really see how a preamp helps you get any gain back as you will just clip your amplifier. Although I do admit I prefer amplifier clipping to DSP clipping.

Seems to me that the simple solution is to have a DAC that has a bit more output voltage than your amplifiers. If you are starting with one of the many 4 V output voltage DACs and using typical input sensitivity amplifiers (< 2 V) it seems that should give you plenty of flexibility. What am I missing?

Michael
 
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dped90

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I am showing my own ignorance as I am not a Dirac user but I don't understand when people say that Dirac removes gain from their system. Maybe someone can help me understand?

If Dirac is cutting across the entire frequency spectrum can you not increase the level across the board with DSP?

Or is it a situation where Dirac is boosting your low end and cutting midrange? So you can't increase the level without clipping the low end? If this is the case I don't really see how a preamp helps you get any gain back as you will just clip your amplifier. Although I do admit I prefer amplifier clipping to DSP clipping.

Seems to me that the simple solution is to have a DAC that has a bit more output voltage than your amplifiers. If you are starting with one of the many 4 V output voltage DACs and using typical input sensitivity amplifiers (< 2 V) it seems that should give you plenty of flexibility. What am I missing?

Michael
Depending on how much DIRAC is asked to correct the room, 4 v balanced out, translates to 15db gain might be sufficient to overcome such and average gain loss.
https://www.sowter.co.uk/decibels.php Thus, 4v might be sufficient IF you don't ask DIRAC to over correct the room and/or fail to FIRST make as many acoustical room corrections before applying DIRAC. ths61's post #39 cautions likewise here. https://gearspace.com/board/high-end/1255435-okto-research-dac8-pro-2.html

But then I'm sure Kal Rubinson had done at least some acoustically physical improvements to his room prior to putting DIRAC online.

I see you're using Camilla DSP. Any problems with the learning curve for general room correction?

ths61's seem quite expert at it; he also uses it to quad amp his speakers.
 
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dped90

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Depending on how much DIRAC is asked to correct the room, 4 v balanced out, translates to 15db gain might be sufficient to overcome such and average gain loss.
https://www.sowter.co.uk/decibels.php Thus, 4v might be sufficient IF you don't ask DIRAC to over correct the room and/or fail to FIRST make as many acoustical room corrections before applying DIRAC. ths61's post #39 cautions likewise here. https://gearspace.com/board/high-end/1255435-okto-research-dac8-pro-2.html

But then I'm sure Kal Rubinson had done at least some acoustically physical improvements to his room prior to putting DIRAC online.

I see you're using Camilla DSP. Any problems with the learning curve for general room correction?

ths61's seem quite expert at it; he also uses it to quad amp his speakers.
Yes but I was proposing a modification, not a new device. It requires the addition of new circuit hardware to support the additional processing whether the crossovers are implemented in analog or digital form.
Kindly reply.
 

HooStat

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Depending on how much DIRAC is asked to correct the room, 4 v balanced out, translates to 15db gain might be sufficient to overcome such and average gain loss.
https://www.sowter.co.uk/decibels.php Thus, 4v might be sufficient IF you don't ask DIRAC to over correct the room and/or fail to FIRST make as many acoustical room corrections before applying DIRAC. ths61's post #39 cautions likewise here. https://gearspace.com/board/high-end/1255435-okto-research-dac8-pro-2.html

But then I'm sure Kal Rubinson had done at least some acoustically physical improvements to his room prior to putting DIRAC online.

I see you're using Camilla DSP. Any problems with the learning curve for general room correction?

ths61's seem quite expert at it; he also uses it to quad amp his speakers.
I don't understand this answer about how and why Dirac cuts headroom. Whatever the solution is, it starts with explaining the problem clearly.
 

Kal Rubinson

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I don't understand this answer about how and why Dirac cuts headroom. Whatever the solution is, it starts with explaining the problem clearly.
One reason is due to the fact that there is finite dynamic range with 0dB at the top limit for digital signals, any boosts used for EQ are generally implemented by lowering the level of everything else.
 

chelgrian

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One reason is due to the fact that there is finite dynamic range with 0dB at the top limit for digital signals, any boosts used for EQ are generally implemented by lowering the level of everything else.
You can can overcome the digital problem by converting to 32 (or more) bit float format internally before processing.

However if you do that to give yourself more headroom than you could ever make use of in the digital realm you are still going to need to reduce the overall level to prevent problems when converting the signal back to analogue to feed in to an amplifier.
 

mdsimon2

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I see you're using Camilla DSP. Any problems with the learning curve for general room correction?

CamillaDSP is just a tool, it is not automated in anyway so what you do with is up to you. It is very powerful and flexible and I like it more than the miniDSPs I've used in the past from a usability standpoint.

Michael
 
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dped90

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I'll display my ignorance too of Camilla but this discussion is interesting and informative in the use of alternate flavors of room correction software.

And it's encouraging to see how one user is endeavoring to improve the sound of his BD movies, played on JRiver, once better room correcting solutions are found.
 

boXem

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One reason is due to the fact that there is finite dynamic range with 0dB at the top limit for digital signals, any boosts used for EQ are generally implemented by lowering the level of everything else.
Sure, but one should also keep in mind that amplifiers have a finite input range and a finite power capability. I am not sure that OP realises this.
 
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dped90

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Sure, but one should also keep in mind that amplifiers have a finite input range and a finite power capability. I am not sure that OP realises this.
I'm sure that I do, though more importantly does Kal, who apparently found that the Topping Pre90's output range perfectly loads the inputs of his power amps; offsetting the gain loss from DIRAC Live 3.

Frankly, the primary reason for this thread was to, however unlikely, induce Topping to design and issue an
8-channel version of the Pre90-and with the added features and bug fixes, discussed below. And I reasoned that those who read Kal's Pre90 review and were using the Exasound, Okto or Topping's own 8 channel DAC-and DIRAC or similar DRC to build their MCH systems and correct their rooms-would want an 8 channel version of this preamp-given how well it obviates DIRAC gain losses, as shown in Fig. 3.
https://www.stereophile.com/content/topping-pre90-line-preamplifier-measurements

Thus, perhaps more besides me might email Topping to request an 8-channel version of the Pre90.

I thought it was worth a shot.
 
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