Topping Pre90 Review (preamplifier)

[Pulkass]

I say it again : Topping pre 90 is breathtaking in the handling of the signal. The first time l operated it, it was clear. I dumped my balanced tube pre amp after that ,love at first hearing.

I won't ever thank Armin, and the wonderful people in this majestic community enough for such tests, !!!! Have l been flattering too much? Nooo c Mon. I m just a warm hearted ltalian of respectful 72 years, hooked to music since 1963. But my hearing is G O O D.

 

[mocenigo]

Thanks for clearing the argument!!!

He should have tried with vacuum tubes!

 

[MBO]

Я больше разочаровался в Topping Pre90 после того, как разобрал его и обнаружил, что он использует 20-летние чипы усилителей для наушников Texas Instruments (tpa6120a2) и очень средние Opamps OPA1612. В данный момент я катаю их и заметил еще один след TSOP (под площадью SOIC8 для OPA1612), поэтому мне интересно, для какого варианта это было? возможно, OPA828 (двойной OPA2828) Хм...
Теперь объясняется, что звук "в коробке" OPA1612 и низкий бас.
Вот и все, что для них является самым современным техническим (как в их литературе), с прозрачным звуком, который рекламировали в то время все так называемые аудиоэксперты.

I absolutely agree, I also took it apart, it is not at all as optimal in quality as it is advertised, it has a very hard colored sound. And also it is not quite stable in terms of the output stage circuit, I had problems with it.

 

[misterdog]

it is not quite stable in terms of the output stage circuit

?

 

[Pulkass]

https://www.stereophile.com/content/topping-pre90-line-preamplifier-page-2 I dont see any op amp inside.

Conclusions
The Pre90 is a simple, compact, analog stereo preamplifier with a transparent, noise-free sound. Signal selection, power on/off, muting, and volume adjustments are equally noise-free, save for the subtle ticks of the relays that accomplish those tasks.

Although it is small and inexpensive, the Topping preamp (with the Ext90 extension) has all the necessary features, with one exception. It lacks a channel-balance control, which may be critical to some users. Also, the effectiveness of the remote control could be improved.

Some people may summarily reject it because of its low cost, small size, limited warranty, Chinese manufacture, or the fact that it's only sold online. All those parameters must be weighed against its low price and outstanding performance. It fits my needs, and it fits my ears, so for me it's a great bargain.

 

[mocenigo]

I won't ever thank Armin, and the wonderful people in this majestic community enough for such tests, !!!! Have l been flattering too much? Nooo c Mon. I m just a warm hearted ltalian of respectful 72 years, hooked to music since 1963. But my hearing is G O O D.

I absolutely agree, I also took it apart, it is not at all as optimal in quality as it is advertised, it has a very hard colored sound. And also it is not quite stable in terms of the output stage circuit, I had problems with it.

Not quite stable. Care to elaborate?
Also “colored”, well… nope.

 

[mocenigo]

I've become more disappointed in the Topping Pre90 after taking it apart to find that it uses 20 year old Texas Instruments headphone amp chips (tpa6120a2) and the very average Opamps OPA1612's. I am rolling them at the moment and noticed another TSOP footprint (underneath the SOIC8 footprint for the OPA1612's), so I wonder what option that was for? possibly the OPA828 (OPA2828 dual) Hmm...
That "boxed in sound" of the OPA1612's and low bass is now explained.
So much for them being state of the art tech (as in their literature), with a transparent sound as touted at the time by all the so called audio pundits.

The circuit has a NE5532 at the input as inverter (for SE inputs, and it is perfect for those purposes), then two halves of a OPA1612 as its own input buffer. Then there is the amplification module proper, an entirely discrete circuit, which is designed as the equivalent of a composite amplifier with nested feedback loops, but done entirely in a discrete way (there are some realisations using two opamps, such as Tom Christiansen's excellent buffers). The OPA1612 is one of the least noisy components in the entire industry, and has virtually no distortion, so unless you are feeding it too strong a signal and saturate it, it cannot give a "boxy" sound.

 

[lordhumungous]

I've become more disappointed in the Topping Pre90 after taking it apart to find that it uses 20 year old Texas Instruments headphone amp chips (tpa6120a2) and the very average Opamps OPA1612's. I am rolling them at the moment and noticed another TSOP footprint (underneath the SOIC8 footprint for the OPA1612's), so I wonder what option that was for? possibly the OPA828 (OPA2828 dual) Hmm...
That "boxed in sound" of the OPA1612's and low bass is now explained.
So much for them being state of the art tech (as in their literature), with a transparent sound as touted at the time by all the so called audio pundits.

I'd be more worried about your Dac and speakers

 

[BDWoody]

Hmm...
That "boxed in sound" of the OPA1612's and low bass is now explained.

Uh huh.

So much for them being state of the art tech (as in their literature), with a transparent sound as touted at the time by all the so called audio pundits.

Where has it been demonstrated by anyone to not be transparent? You certainly haven't. You are just telling anecdotal stories.

 

[NicS]

I'm still enjoying my Pre90. Sounds great. Performs well. Terrible remote control.

 

[lordhumungous]

I'm still enjoying my Pre90. Sounds great. Performs well. Terrible remote control.

I had to resort to a IR blaster next to the Pre90 instead of the remote it is so unresponsive.

 

[drewdawg999]

I say it again : Topping pre 90 is breathtaking in the handling of the signal. The first time l operated it, it was clear. I dumped my balanced tube pre amp after that ,love at first hearing.

I wholeheartedly agree. Dumped my nice Rogue Pre with 6SN7 RCA grey glass, relegated to spare bedroom system. Still a nice piece but the Pre90 beats it handily. The clarity is crystal clear, as defined as I can hear. Both RCA and XLR inputs sound beautiful, great volume control. Thinking of springing for the EXT90 this time around, gonna need more inputs at some point. Have a working cassette player from the Shack, back in the day, playback only unit, in addition to a turntable and DAC. Use the RCA out for a sub, so I have full control over how much warmth to apply. As far as preamps go, it's the best I've ever had, has done everything I've asked of it exceptionally.

 

[ZestClub]

As far as trolling goes, this is a poor attempt.

But its all accurate though - the Topping Pre90 does use a 20 year old headphone chip amp (tpa6120a2) and OPA1612's which are Meh.
I am changing mine at the moment to a header so I can swap different Opamps in and out, so I will let you all know how it goes.
The extra (redundant) TSOP footprint under the OPA1612 (once its removed) can be seen in this photo as well.

 

[ZestClub]

It's the design of the circuit what counts, and the measurements do tell that the final result is state of the art. Remember that many recordings of the best sound quality have been produced by using lots of much older opamps (NE5534) in the mixing consoles and effect boxes.

The Pre90 is transparent as has been proven by @amirm's measurements. As long as you do not prove otherwise by multiple level controlled blind listening tests your statements are just biased opinions, as any member of ASR including you should know by now.

No its not - its just a standard TI circuit - when it came out and I bought into all the BS I remember all this talk about nested opamps within nested opamps within more nested opamps driving that distortion down to new lows - well there is only 2 x opamps (per circuit) so just how much nesting can really be going on ??

 

[ZestClub]

The circuit has a NE5532 at the input as inverter (for SE inputs, and it is perfect for those purposes), then two halves of a OPA1612 as its own input buffer. Then there is the amplification module proper, an entirely discrete circuit, which is designed as the equivalent of a composite amplifier with nested feedback loops, but done entirely in a discrete way (there are some realisations using two opamps, such as Tom Christiansen's excellent buffers). The OPA1612 is one of the least noisy components in the entire industry, and has virtually no distortion, so unless you are feeding it too strong a signal and saturate it, it cannot give a "boxy" sound.

I never heard anyone say "I am upgrading my gear to OPA1612's" - they are well known as being OKish but not great sounding.
That's reflected in the price of only $3.50 each, I doubt there is $100 of parts in the Pre 90 tops.

There aren't any NE5532's in the Pre-90 - and why would they use an even worse chip from the 1970's in their "state of the Art" design??
The circuit is not "discrete" either its all based on the Texas Instruments (tpa6120a2) chip.
Do you people even own a screwdriver?

 

[Kal Rubinson]

Let's get back to science. Does anyone dispute the measurements?

 

[LTig]

No its not - its just a standard TI circuit - when it came out and I bought into all the BS I remember all this talk about nested opamps within nested opamps within more nested opamps driving that distortion down to new lows - well there is only 2 x opamps (per circuit) so just how much nesting can really be going on ??

You're confusing the parts of the internal circuits with their final result. If the measurements tell us that a device is audibly transparent it doesn't matter how transparency has been achieved. As an engineer I rather praise the designers for achieving this without using hyper expensive parts. It keeps costs low.

 

[ZestClub]

You're confusing the parts of the internal circuits with their final result. If the measurements tell us that a device is audibly transparent it doesn't matter how transparency has been achieved. As an engineer I rather praise the designers for achieving this without using hyper expensive parts. It keeps costs low.

Well seeing as all the audio information has to pass through those chips the final sound quality can not be better than what's maximally achievable using them.

 

[LTig]

I never heard anyone say "I am upgrading my gear to OPA1612's" - they are well known as being OKish but not great sounding.

This may be true for audiophools, not for engineers.

here aren't any NE5532's in the Pre-90 - and why would they use an even worse chip from the 1970's in their "state of the Art" design??

The 5532 was SOTA until the 2000s, as Douglas Self has shown. And a lot of great sounding music went through dozens of them in the recording chain, so one more cannot do much harm after all.

 

[LTig]

Well seeing as all the audio information has to pass through those chips the final sound quality can not be better than what's maximally achievable using them.

Once again, maybe I was not clear enough: it's the result what counts, not how it is achieved.

If you disagree that the measurements prove audibly transparency then please show your prove.