Topping Pre90 Review (preamplifier)

[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.

 

[ZestClub]

This may be true for audiophools, not for engineers.

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.

We all hear differently - that may depend on your genetic ancestry how your brain processes sound - some people can't hear the difference between a 1970's NE5532 and others can clearly hear the muffled top end. I only listen to very recent recordings so no 5532's in my chain thanks!

 

[LTig]

We all hear differently - that may depend on your genetic ancestry how you process sound - some people can't hear the difference between a 1970's NE5532 and others can clearly hear the muffled top end.

This is no prove. How did those people came to hear the claimed difference? Level controlled? Blind listening? Multiple times? If any of these questions is answered with no the claims are not valid, as has been proven by science.

Alternatively measure the frequency response using NE5532 and "better" opamps and show the difference between 5 and 20 kHz. If this is below 0.1 dB there can be no muffled top end.

I only listen to very recent recordings so no 5532's in my chain thanks!

How do you know which opamps have been used in the recording chain?

 

[ZestClub]

So now we have switched from denying that the Topping Pre 90 uses, lets just say average level components, to saying well it doesn't really matter because no one can really hear the difference anyway

 

[himey]

So now we have switched from denying that the Topping Pre 90 uses, lets just say average level components, to saying well it doesn't really matter because no one can really hear the difference anyway

You are obviously confused and may need to read the posts again much slower.

 

[ZestClub]

You are obviously confused and may need to read the posts again much slower.

I can read thanks - Anyway, I will get back to you guys soon and let you know the outcome of my opamp rolling on the Pre90.
I will also record the sound for you as well so you can be the judge.

 

[LTig]

I can read thanks - Anyway, I will get back to you guys soon and let you know the outcome of my opamp rolling on the Pre90.
I will also record the sound for you as well so you can be the judge.

Use the best ADC available for those recordings, like @amirm's AP, otherwise the differences will be swamped by noise and distortion of the ADC. And people listening to the recordings must use a playback chain which is better than the Pre90 regarding noise and distortion, for the same reason.

 

[ZestClub]

Use the best ADC available for those recordings, like @amirm's AP, otherwise the differences will be swamped by noise and distortion of the ADC. And people listening to the recordings must use a playback chain which is better than the Pre90 regarding noise and distortion, for the same reason.

I agree, and I am aware of that problem - low ball ADC and opamps in cheap Audio Interfaces.

 

[Pulkass]

Use the best ADC available for those recordings, like @amirm's AP, otherwise the differences will be swamped by noise and distortion of the ADC. And people listening to the recordings must use a playback chain which is better than the Pre90 regarding noise and distortion, for the same reason.

What is ADC ?