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Topping Pre90 Review (preamplifier)

bsas

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This sounds like the individual channel was set to XLR + RCA which shouldn't be possible. I've measured the channel balance across my two units and its picture perfect.

I agree that shouldn't be possible. I tried to change all multiple times and it never reset it. But then, when I did a factory reset it fixed it. Like I said, now it is perfect after the factory reset. But how in the hell it got to the unbalanced state???
 

RETSELDRIB

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Where? Mine has just the following options:
"1. Display | M (A, L, M, H)"
"2. Remote | ON (ON, OFF)"
"3. Vol Memory | IN (IN, OUT)"
"4. Safe Vol Mode | OFF (ON, OFF)"
"5. Safe Vol | -20dB"
"6. Save and exit"
"7. Factory reset"

Are you not getting confused with the D90?

Sorry its taken a while to get back; i checked today and indeed was getting confused with the D90!
 

mhhd

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Hi,
I am a newbie here. I would like to built a custom length extender cable Pre90 <=> Ext90. Does anyone know the exact spec. of the 8 pin connector and maybe even where to obtain? The describtion of Topping as 'aviation connector' was not really helpful. I am located in Europe.
Thanks a lot!
Rgds :)
 

da Choge

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Hi,
I am a newbie here. I would like to built a custom length extender cable Pre90 <=> Ext90. Does anyone know the exact spec. of the 8 pin connector and maybe even where to obtain? The describtion of Topping as 'aviation connector' was not really helpful. I am located in Europe.
Thanks a lot!
Rgds :)
I possibly want to do this also, as I want my Pre90 and Ext90 in a side-by-side setup and not one on top of the other. I looked into this a while back and found some connectors, but have lost track of where. If I have time, I'll try to find them again. I found that the included cable might just be long enough to place the units side-by-side, but it may put a little strain on the cable.
 

Kal Rubinson

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I am a newbie here. I would like to built a custom length extender cable Pre90 <=> Ext90. Does anyone know the exact spec. of the 8 pin connector and maybe even where to obtain? The describtion of Topping as 'aviation connector' was not really helpful. I am located in Europe.
I looked into this a while back and found some connectors, but have lost track of where. If I have time, I'll try to find them again.
Well, you could cut the standard cable in two and insert a link of appropriate length or just cannibalize it for the connectors. :rolleyes:
 

nagster

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Jan 24, 2021
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Hi,
I am a newbie here. I would like to built a custom length extender cable Pre90 <=> Ext90. Does anyone know the exact spec. of the 8 pin connector and maybe even where to obtain? The describtion of Topping as 'aviation connector' was not really helpful. I am located in Europe.
Thanks a lot!
Rgds :)
These may be helpful...
 

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Peternz

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Just a note on this, I am using it as a headphone amp from the RCA outputs and it is simply outstanding as such.
 

WeekendWarrior

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Been an interested spectator of ASR for ages, but this is my first post.

I'm intrigued to find out if this relatively cheap but good measuring equipment sounds as good as my relatively expensive Naim separates system (whose measurements are unknown, although noting the poor review the Atom HE got on here recently). So I'm looking to get a home demo of the Topping D90LE, Pre90 and LA90 which is probably less than a fifth the cost of what I am listening to now.

I do have a question though and that is what the Pre90 brings to the party in this setup as both the LE and LA have volume control/ preamp capabilities. I will be running the LE directly from my server via it's USB connection and using Roon; I have no other music sources and only listen through loudspeakers. In this case, does the Pre90 improve the performance in any way, or is it an unnecessary piece of kit.
 

nagster

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In this case, does the Pre90 improve the performance in any way, or is it an unnecessary piece of kit.
About SINAD There is a measurement comparing D90SE (variable mode) and D90SE (fixed mode) + Pre90.
It seems that the branch point is around -4dBFS.
If there are no other conditions, it would be rational to use only D90LE (fixed mode) and LA90 and change the volume with the knob of LA90.
 

mhhd

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Hi,

This is the information I received from Toppings support department:
"M12, 8-pin, With shield, Male to Female Direct Connect.
That is, the two ends are wired 1 to 1, 2 to 2, .... .8 to 8. Then the shielding wires at both ends are to be connected to the metal terminals at both ends."

I hope this helps everybody interested :)
 

SlothRock

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Hi all - I have a DAC I’m using as the source for a solid state and tube amp. It has a higher output than the standard, with 5.8Vrms for XLR and 2.9Vrms for RCA. It does not have its own preamp.

I recently was messing around in Equalizer APO for one of my headphones but noticed that without any EQ applied, my computer indicated that things were getting clipped. Nothing that was audible, though. I did apply a software-based buffer and reduced gain by 5 and it seemed to clear it all up.

Is there any technical benefit to using a hardware preamp like this in between the DAC and my amps as opposed to continuing the use of the software buffer?
 

nagster

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Hi,

This is the information I received from Toppings support department:
"M12, 8-pin, With shield, Male to Female Direct Connect.
That is, the two ends are wired 1 to 1, 2 to 2, .... .8 to 8. Then the shielding wires at both ends are to be connected to the metal terminals at both ends."

I hope this helps everybody interested :)
Thank you.
 

maudio

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Hi,
I just bought an amp with 10K ohm input impedance (Nelson Pass design). Would Pre90 be a good match for it if my source has around 900 ohm output?
 

maudio

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I'm concerned because according to Stereophile review Pre90 has "only" 2 kOhm input impedance and my DAC has 750 Ohms output pure resistive output impedance at 1.4 or 2 Vrms (i think it might be the former), and there have been some reports of impedance mismatch: "A lot of sources will have a hard time driving the Pre 90 input. The source’s distortion will inevitably go up as it try to drive a much harder load."

I am used to integrated amps with 47 kOhm input impedance, and now this :D

But according to my DAC-manufacturer, "when the load is "too low" as 10 Ohms ... 2K, you only get a smaller output signal, sound quality remains exactly the same because the DAC's output impedance is pure resistive".

So no worries - or only in case it has 1.4Vrms output, which is below standard, could be an issue?
 
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maudio

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I ordered Pre90 after i read on the net that "DACs that have a lower voltage output will benefit the most out of Pre90", and this should be exactly my DAC. Hope there will be no impedance mismatch.
 

Veri

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I ordered Pre90 after i read on the net that "DACs that have a lower voltage output will benefit the most out of Pre90", and this should be exactly my DAC. Hope there will be no impedance mismatch.
I really think your amp input impedance + your DAC's sub-kΩ output impedance will all play along just fine.
 

Peternz

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I just wanted to share my experience since I have had the pre90 in my system for quite some time. I can not really praise it enough, it is probably the best audio component I have ever owned, in terms of sound quality, form and function. I use an L30 headphone amp downstream from it and turn it's volume control to the max and use the pre90 with it's remote control to control the volume. The sound this combo makes is simply beyond reproach.
 
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I got my Pre90 on Friday and something seems to be wrong. A have an Audiophonics Purifi power amp and an SMSL SU-9n DAC and my plan was to add the Pre90 for analog volume control and an additional analog input. Until now I was using digital volume control (Roon) and it sounded phenomenal. Reading the measurements and reviews for the Pre90 I thought this would be perfect for me, better usability with no sound quality penalty.

I got the thing out of the box and connected everything using XLR cables. I just started listening to my music as usual and didn't even think about "the sound" of the Pre90 because we all know how it measures... I just noticed that I really wasn't feeling it and thought I just had a bad day, happens, go to sleep.
The next day I fired up the stereo again and still, it didn't do anything for me and didn't sound the way I was used to. Something was wrong. Since the only thing that changed in my setup was the Preamp I just plugged the DAC straight into the amp again and boom, everything is normal again. A good three hours of switiching back and forth and thinking about biases and how it should be technically impossible to hear a difference and yadda yadda yadda I'm sending that thing back.

The only thing I could really measure (because I wanted to match the volume) was the output of the preamp vs the output of the DAC and it seems like I'm losing about 3 dB when the preamp is connected. (XLR in, XLR out) Shouldn't the Pre90 add 4db of gain? What is going on? Could it be a severe impedance mismatch between the SU-9n and the Pre90?

The reason for this long winded story, and I know, how everybody hates that, is: Do you think I was shipped a faulty unit and should I try again with a new one?
 

maudio

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I got my Pre90 on Friday and something seems to be wrong. A have an Audiophonics Purifi power amp and an SMSL SU-9n DAC and my plan was to add the Pre90 for analog volume control and an additional analog input. Until now I was using digital volume control (Roon) and it sounded phenomenal. Reading the measurements and reviews for the Pre90 I thought this would be perfect for me, better usability with no sound quality penalty.

I got the thing out of the box and connected everything using XLR cables. I just started listening to my music as usual and didn't even think about "the sound" of the Pre90 because we all know how it measures... I just noticed that I really wasn't feeling it and thought I just had a bad day, happens, go to sleep.
The next day I fired up the stereo again and still, it didn't do anything for me and didn't sound the way I was used to. Something was wrong. Since the only thing that changed in my setup was the Preamp I just plugged the DAC straight into the amp again and boom, everything is normal again. A good three hours of switiching back and forth and thinking about biases and how it should be technically impossible to hear a difference and yadda yadda yadda I'm sending that thing back.

The only thing I could really measure (because I wanted to match the volume) was the output of the preamp vs the output of the DAC and it seems like I'm losing about 3 dB when the preamp is connected. (XLR in, XLR out) Shouldn't the Pre90 add 4db of gain? What is going on? Could it be a severe impedance mismatch between the SU-9n and the Pre90?

The reason for this long winded story, and I know, how everybody hates that, is: Do you think I was shipped a faulty unit and should I try again with a new one?
Not a a faulty unit if the sound is without distorsions.

It can well be impedance mismatch, you would not be the 1st to encounter it. That's probly the reason for the preamp's relative low price. It is great but it can't cover the many combinations on the market like some more pricier preamps e.g. from Benchmark does. It is a bit sad Amir does not mention this fact, not sure if it is mentioned in Stereophile, but it is very plausible for someone who has some experience with preamps and amp.
And many on the Internet do mention it. Either it works great, when impedance and voltage are so that the Pre90 "likes" it, or it is returned because users lose some dynamics, bass or something else.

I should be getting mine today, till tomorrow the amp should come too. In the meantime i will test it with KingRex T20U amp.
 
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