Topping A90 Discrete Review (Headphone Amp & Preamp)

[Palladium]

Head-Fi seems to be a gathering of a rare type of people who like the sound of distortion in their music.

To them (yes, they've used all these adjectives):

Lack of distortion = bright, sharp, fatiguing, cheap, painful, clinical, and sterile

Distortion = powerful, rich, euphonic, wide, musical, dancing, live, relaxing, syrupy, smooth, and authoritative

The moment anyone suggests they prefer distortion or dare say they like a flaw of the amplifier, they start by defending their own character "I'm a good guy because I think everyone is entitled to like whatever they want" then proceed to attack the character of the other person, calling them an "ASR fanboy", insinuating that measurements have made them blind to the truth, saying that they can't hear, or even that they're just trolling. They will then appeal to others on the forum for support, like "can you believe this troll?", "thank God for the ignore button, amirite?", "your posts belong on ASR, not here", "everyone just mute them", etc.

And every new IEM has lifts so many veils versus the one released a week ago.

 

[Bow_Wazoo]

How does the volume button feel?
Like on the predecessor?
Including slip?

 

[PointyFox]

you don't have any issue on the single end? for sure?

you go check it, first.

It has nothing to do with the cable

Just checked mine and no issue with the SE out. Took it up to about 85 volume on low.

How does the volume button feel?
Like on the predecessor?
Including slip?

Feels the same as on my A90. My A90 didn't have any slip or squishiness either. The person I sold it to was also surprised with the quality of the volume knob.

 

[WhyNotHad]

Just checked mine and no issue with the SE out. Took it up to about 85 volume on low.


Feels the same as on my A90. My A90 didn't have any slip or squishiness either. The person I sold it to was also surprised with the quality of the volume knob.

That's right. The issue of SE OUT does not occur in low gain.

After changing to high gain, try to connect the cable to the SE OUT terminal and disconnect it.
Then you'll know about this problem.

Every single function counts. Using SE out in high gain is no exception.

 

[PointyFox]

That's right. The issue of SE OUT does not occur in low gain.

After changing to high gain, try to connect the cable to the SE OUT terminal and disconnect it.
Then you'll know about this problem.

Every single function counts. Using SE out in high gain is no exception.

Yep, high gain does it. Causes static in the left channel and the amp to change to low gain.

 

[Haruko]

Yep, high gain does it. Causes static in the left channel and the amp to change to low gain.

thank god i got golden sample then ... i have problems with D90LE tho... so i really understand your frustration with topping guys

if it's obvious that the unit contains a defect in several cases it should be declared in the measurement imho... so people can reconsider purchase before it's too late

 

[PointyFox]

Changing the firmware from 2.3 to 2.4 fixes the gain change, but the static is still there. I unplugged/replugged a few times and one of the unpluggings caused it to throw a "-2" error code until I powered it off/on.

As a side note, I was just insulted for having a small amp on Head-fi.

 

[kenexcelon]

How big of an issue(s) are the problems you are running into? I was "THIS" close to purchasing a combo, but I'm now having second thoughts.

 

[PointyFox]

It's only a problem if you use the 1/4" jack on high gain and disconnect the headphone cable while the amp is on. Then it produces some noise in the left channel for like 1/4 of a second and occasionally throws a "-2" error, causing you to need to toggle the power off and on.

So it's not an issue unless you do that specific thing.

 

[carlcamper]

Just updated my firmware to V2.4 ( link ). I don't notice any changes, but at least the restarting issue on the 6.35mm unbalanced ports is still fixed, meaning it now shows -5 for a short time, then keeps working.

 

[eyecent]

Just updated my firmware to V2.4 ( link ). I don't notice any changes, but at least the restarting issue on the 6.35mm unbalanced ports is still fixed, meaning it now shows -5 for a short time, then keeps working.

Many users, including myself, have the same problem since the 2.4 firmware was uploaded. In 2.3 it turned into a low gain with pop noise. At 2.4, the power is turned off.

After a long conversation on a Korean website, I am disappointed to hear that the machine should be sent to China, so I write to Asr.

 

[eyecent]

It's only a problem if you use the 1/4" jack on high gain and disconnect the headphone cable while the amp is on. Then it produces some noise in the left channel for like 1/4 of a second and occasionally throws a "-2" error, causing you to need to toggle the power off and on.

So it's not an issue unless you do that specific thing.

l50 or a90 does not turn off when unplugged the high gain. This is an obvious design error.

 

[dartinbout]

To all of the A90D owners who are unhappy, I would be happy to trade you my A90. I only use balanced connections (XLR in, out and HP) so these horrible deficiencies wouldn't affect me. I want to use the EXT and run the A90D as an amp and a switching pre. I'm sure we could work out a deal. Send me a DM.

 

[Ryche]

I'm new to this forum so, Hi everyone!

I have just received my A90D and started to listen to it a couple of hours ago.

And found it to have a very low volume compared to my previous SMSL SH-9.

It is something like, 60% of the volume, to the point I had to enable the High Gain and put it on the MAX setting.

This setup goes like this: DAC is the SMSL DO200, XLRs Balanced connections, Sennheiser HD800 (XLR)

Yes the volume increases when changing from LOW to HIGH gain settings.
No the Volume Limiter isn't turned on.
Voltage Here is around 120V (kinda high at this time of the day (20:00h)

When playing high resolution content (above 44-16) things are considerably "worse", Jazz @176-24 I have to go to a very quiet room to listen.

Comparing the DO200 Paired with the SH-9 I can never go above 80-85 on volume even using LOW Gain.

But changing the SH-9 to the A90D I had to switch to HIGH GAIN and MAX Volume to reach what is something like 60 on the SH-9 with LOW Gain.

Thing is, I am considering a return of this unit, because it is of no use as is.

Just sharing my XP with it.

regards

 

[carlcamper]

I'm new to this forum so, Hi everyone!

I have just received my A90D and started to listen to it a couple of hours ago.

And found it to have a very low volume compared to my previous SMSL SH-9.

It is something like, 60% of the volume, to the point I had to enable the High Gain and put it on the MAX setting.

This setup goes like this: DAC is the SMSL DO200, XLRs Balanced connections, Sennheiser HD800 (XLR)

Yes the volume increases when changing from LOW to HIGH gain settings.
No the Volume Limiter isn't turned on.
Voltage Here is around 120V (kinda high at this time of the day (20:00h)

When playing high resolution content (above 44-16) things are considerably "worse", Jazz @176-24 I have to go to a very quiet room to listen.

Comparing the DO200 Paired with the SH-9 I can never go above 80-85 on volume even using LOW Gain.

But changing the SH-9 to the A90D I had to switch to HIGH GAIN and MAX Volume to reach what is something like 60 on the SH-9 with LOW Gain.

Thing is, I am considering a return of this unit, because it is of no use as is.

Just sharing my XP with it.

regards

Check if your SMSL DAC is in fixed volume preamp mode ( for my SMSL D-6, this is Pr1)

 

[raif71]

I'm new to this forum so, Hi everyone!

I have just received my A90D and started to listen to it a couple of hours ago.

And found it to have a very low volume compared to my previous SMSL SH-9.

It is something like, 60% of the volume, to the point I had to enable the High Gain and put it on the MAX setting.

This setup goes like this: DAC is the SMSL DO200, XLRs Balanced connections, Sennheiser HD800 (XLR)

Yes the volume increases when changing from LOW to HIGH gain settings.
No the Volume Limiter isn't turned on.
Voltage Here is around 120V (kinda high at this time of the day (20:00h)

When playing high resolution content (above 44-16) things are considerably "worse", Jazz @176-24 I have to go to a very quiet room to listen.

Comparing the DO200 Paired with the SH-9 I can never go above 80-85 on volume even using LOW Gain.

But changing the SH-9 to the A90D I had to switch to HIGH GAIN and MAX Volume to reach what is something like 60 on the SH-9 with LOW Gain.

Thing is, I am considering a return of this unit, because it is of no use as is.

Just sharing my XP with it.

regards

Hmm could this be an impedance mismatch phenomena ie the ratio of output impedance of the DAC to input impedance of the AMP is not >1:8 ? Do you use rca or xlr for the connection of the do200 and a90d ?

 

[jannytaylor]

How do they compare, for XLR out ?

 

[Ryche]

Check if your SMSL DAC is in fixed volume preamp mode ( for my SMSL D-6, this is Pr1)

Thanks, It is in Fixed volume, but I have tried the variable option with no avail.

Hmm could this be an impedance mismatch phenomena ie the ratio of output impedance of the DAC to input impedance of the AMP is not >1:8 ? Do you use rca or xlr for the connection of the do200 and a90d ?

The impedance is a good bet, I can see on the DO200 the output impedance is 100_Ohm and 4V (XLR), and the A90D Input sensitivity is 3Vrms (Gain=High, XLR), the SH-9 don't have the input specifications besides a 47_Ohm impedance.

 

[raif71]

Thanks, It is in Fixed volume, but I have tried the variable option with no avail.

The impedance is a good bet, I can see on the DO200 the output impedance is 100_Ohm and 4V (XLR), and the A90D Input sensitivity is 3Vrms (Gain=High, XLR), the SH-9 don't have the input specifications besides a 47_Ohm impedance.

100 ohm is quite low...if A90D input impedance is more than 1K...this should meet the 1:8 ratio so perhaps it is not a mismatch of impedance. Anyway, A90 input impedance is found here, and it is stated for balanced, it is 2K and 10K for unbalanced. If this is the same too for A90d, then there shouldn't be an issue of impedance mismatching.

 

[4udio]

Thanks, It is in Fixed volume, but I have tried the variable option with no avail.

The impedance is a good bet, I can see on the DO200 the output impedance is 100_Ohm and 4V (XLR), and the A90D Input sensitivity is 3Vrms (Gain=High, XLR), the SH-9 don't have the input specifications besides a 47_Ohm impedance.

try another DAC in combination with A90D and, if volume problem remains, return it.