Topping Pre90 Review (preamplifier)

[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 ?

 

[phoenixsong]

What is ADC ?

Analogue to digital converter. It's for when you're trying to capture raw sound with microphones into your laptop, for example. So it does the opposite of what DACs do

 

[MaxwellsEq]

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

That's not how electronic circuits work.

 

[Arci66]

Thanks for the great review and for the huge discussion.
I am evaluating to give a try to this preamp.
My chain is a Eversolo A8->Marantz MM7025-> SF Sonetto I
The preamp of the eversolo A8 doesen't look so energic; to have a sound level of about 80-85 dB the volume has to reach -20 dB at -50dB sound level is very weak.
The XLR output level of the eversolo A8 is 4.2 V
Marantz MM7025 XLR Input sensitivity/impedence: 2.4V/30KOhm

Do you think putting the Topping Pre90 in the chain can improve the performances of my system?
Thanks in advance for your time

 

[MaxwellsEq]

The preamp of the eversolo A8 doesen't look so energic; to have a sound level of about 80-85 dB the volume has to reach -20 dB at -50dB sound level is very weak

Those numbers sound fine to me. The numbers such as "-20dB" only means something if you have a calibrated end-to-end chain. If you turn the volume up to full I assume it's too loud...

 

[Arci66]

Those numbers sound fine to me. The numbers such as "-20dB" only means something if you have a calibrated end-to-end chain. If you turn the volume up to full I assume it's too loud...

Yes, my wife come shouting
So you mean there is no point to add a Topping Pre90?
Somebody measured the output impedence of eversolo A8 : The output impedance was usefully low across the audioband, at 101 ohms, balanced, and 51 ohms, unbalanced.
So on XLR 101 ohms the maratz has a input impedence of 30 kohm

 

[Veri]

The circuit is not "discrete" either its all based on the Texas Instruments (tpa6120a2) chip.
Do you people even own a screwdriver?

It is designed as the equivalent of a composite amplifier with nested feedback loops done entirely in a discrete way. You should read read mocenigo's post again, really..
Do you even have some electronic design credentials? Or just an enthusiastic DIY'er?

 

[ZestClub]

It is designed as the equivalent of a composite amplifier with nested feedback loops done entirely in a discrete way. You should read read mocenigo's post again, really..
Do you even have some electronic design credentials? Or just an enthusiastic DIY'er?

We were talking about the TI tpa6120a2 headphone amplifier chips function in the Pre90 at the time - and its not very "discrete" is it!

 

[ZestClub]

But all that "nested feedback loops done entirely in a discrete way" technology doesn't come cheap like you might think/
Those 20 year old headphone amp chips are way pricey you know.
Way way up there at the $2 mark - I mean, I am just amazed that Topping would put something so expensive in one of their preamps,

 

[DSJR]

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!

MUFFLED TOP END???

Sorry to shout above, but my mental processes always regarded the 5532 as being 'stripped out' and 'bare' sounding That is, until I forgot what I was listening to and 'thought' it was something else. More modern chips in older circuits can apparently oscillate, I gather.

Anyway, I hear sometimes significant differences in musical productions, a delightful soundfield between and behind the speakers if there in the recordings and no longer ever feel the need to 'listen' to the gear and all this, from a preamp with a 5532 per channel with a volume pot in front of it. Recent times have changed my hearing in any case, so have to admit I'm so glad I'm no longer an 'audiophile/audiophool' as such.

 

[misterdog]

But all that "nested feedback loops done entirely in a discrete way" technology doesn't come cheap like you might think/
Those 20 year old headphone amp chips are way pricey you know.
Way way up there at the $2 mark.

Proven test data shows it to be more than adequate, and a bargain at it's price.

Maybe once you've built your preamp you can send it to Amir and show us how superior it is ?
Until such times all this 'I think' is just noise on the internet.

 

[ZestClub]

Proven test data shows it to be more than adequate, and a bargain at it's price.

Maybe once you've built your preamp you can send it to Amir and show us how superior it is ?
Until such times all this 'I think' is just noise on the internet.

So with 4 x OPA1612's and 2 x tpa6120a2 we are now at $16 of parts - not sure where the other hundreds of dollars go though...
Perhaps the volume knob was machined out of solid Palladium or something?

 

[staticV3]

@ZestClub I think it's about time you form a coherent and factual point of criticism if you want to actually contribute.

You've just been jumping from one easily debunked misconception to the next.

Complaining that some of the chips inside the Pre90 cost way less than the final MSRP does not help your case. It just comes across as you trolling for trolling's sake.