Topping A90 Headphone Amplifier Review

[AdamG]

Hi - thanks for this info. Is CSI an authorized Indonesian distributor?

Unfortunately no. I bought it from an individual seller on one of Indonesia's online marketplace. It seems my seller bought it directly from a Chinese reseller online and was able to ship it to Indonesia with a lower customs cost (compared to if I buy directly from shenzenaudio.com for example).

Welcome Aboard @gpardede.

 

[bahamot]

Hi - thanks for this info. Is CSI an authorized Indonesian distributor?

Unfortunately no. I bought it from an individual seller on one of Indonesia's online marketplace. It seems my seller bought it directly from a Chinese reseller online and was able to ship it to Indonesia with a lower customs cost (compared to if I buy directly from shenzenaudio.com for example).

Yes, AFAIK, CSI is the authorised Topping distributor in Indonesia. Well at least they communicate directly with Topping.

 

[gpardede]

Welcome Aboard @gpardede.

Thanks, AdamG247.

 

[gpardede]

Yes, AFAIK, CSI is the authorised Topping distributor in Indonesia. Well at least they communicate directly with Topping.

Good to know this, thanks.

After googling I believe the complete name is CSI-Zone? I'm surprised they weren't on my radar for the Topping stack when I bought my Topping A&D90 back in January. Could it be they just gotten authorized recently? I'm kicking myself for poor diligence work. This is an expensive hobby (per my standards) and I should've checked for the best possible vendor.

 

[bahamot]

Good to know this, thanks.

After googling I believe the complete name is CSI-Zone? I'm surprised they weren't on my radar for the Topping stack when I bought my Topping A&D90 back in January. Could it be they just gotten authorized recently? I'm kicking myself for poor diligence work. This is an expensive hobby (per my standards) and I should've checked for the best possible vendor.

Yes, they are listed as Csi-zone in Tokopedia. Not sure since when, but I bought my A90 last year from CSI.

 

[Rantenti]

ifi has the iDefender+ for breaking ground loops at the USB. At a price of around USD50, it looks worth a try if breaking the ground loop at any point will be effective. Otherwise, they have the GND defender for power input too but it costs double.

Bought the iDefender+ (their latest version).
The buzz and static-like noise that waxed and waned with GPU/CPU usage is gone.

But after removing this layer of noise, I can hear ~1khz background high-pitched whining when I start play music with Foobar or play videos (with volume turned to zero). This is much softer than those buzz and cracking static, but it is becoming obvious now that the buzzing is gone.

Is this EMI radiating from CPU or Graphics card? Thanks for suggestions!

 

[mariachideath]

Anyone know if the 4.4mm headphone output is TRS or TRRS? A90 is to be paired Aeon RT cans to be delivered shortly. I ordered them originally with the 3.5mm cable because I was to order the A30Pro. Then I decided on the A90, so I asked Dan Clark's store for a change to XLR cable. I was told maybe (they would try, but maybe not possible). Cans in transit and I am not sure what I am going to get.

 

[Rantenti]

Anyone know if the 4.4mm headphone output is TRS or TRRS? A90 is to be paired Aeon RT cans to be delivered shortly. I ordered them originally with the 3.5mm cable because I was to order the A30Pro. Then I decided on the A90, so I asked Dan Clark's store for a change to XLR cable. I was told maybe (they would try, but maybe not possible). Cans in transit and I am not sure what I am going to get.

The 4.4mm on the A90 is a balanced output. I guess it should be TRRS. Please correct me if I am in error.

I'm using a 4-core balanced cable with ungrounded TRRRS plug without problem.

 

[Jackhifi]

Whenever I use my Topping A90 with Campfire Solaris 2020, I get this weird clicking noise in the right earbud. It doesn't change with volume change but does get louder when switching between the 3 different gain levels. It goes away if I use IEMatch. I thought the noise floor is supposed to be pretty low here so I was a bit surprised but it's also not a constant noise. It's this weird clicking static.

Did I receive a bad unit?

 

[aandres_gm]

I'm in the market for a new headphone stack that will at some point also include a turntable, and I believe the A90 is the only product that meets my requirements. I need at least two inputs (check, for the A90), enough power to drive anything under the sun (check) and, ideally, the ability to function as a preamp for future use with speakers (also check). As for creature comforts, I'd also like the unit's on/off switch to be on the front, which made me discard the Gustard H16.

Question, am I missing anything, or is the A90 really the only product that fits the bill? I don't necessarily need XLR + RCA inputs, by the way. Two RCA would suffice.

One other thing, is there any specific thing I should look for when purchasing a second hand A90? Any known issues I should test for? Thanks!

 

[Wegi76]

Question, am I missing anything, or is the A90 really the only product that fits the bill?

The features you listed are all present, yes. But it`s for sure not the only one. See "Singxer SA-1" for example or SMSL SP400 seems to be comparable (not sure about "Power Off" on the front, but there`s a button on the remote at least....)

Be aware that the A90 does not have a remote control.

 

[foxxx0]

Be advised, the SP400 will always drive the headphone out, there is no way to switch between pre-amp mode and hp-amp mode, both outputs are always driven. That is quite unfortunate and would have been an easy and cheap feature to implement, but it is not there.

 

[aandres_gm]

The features you listed are all present, yes. But it`s for sure not the only one. See "Singxer SA-1" for example or SMSL SP400 seems to be comparable (not sure about "Power Off" on the front, but there`s a button on the remote at least....)

Be aware that the A90 does not have a remote control.

Thanks for the suggestion. The Singxer appears to offer basically the same funtionality as the Topping, even the price is the same. The SMSL appears to also offer the same functionality, but a higher price.

 

[TurdiesBirdies]

I haven't really since this point addressed anywhere I have been able to see. But how is the volume attenuated? I see on other DACs like the H16 and SH-9 having stepped resistor relays. But don't see anything like this on the A90 PCB.

How is the volume of the A90 attenuated? Is it just a potentiometer? What potentiometer is used?

 

[bahamot]

I haven't really since this point addressed anywhere I have been able to see. But how is the volume attenuated? I see on other DACs like the H16 and SH-9 having stepped resistor relays. But don't see anything like this on the A90 PCB.

How is the volume of the A90 attenuated? Is it just a potentiometer? What potentiometer is used?

Potentio info is available on the early pages of this thread.

 

[TurdiesBirdies]

Potentio info is available on the early pages of this thread.

Yeah I ended up seeing that reading through the thread. Is this to be any issue for long term channel stability?

Seems like not a good option when SH-9 and H16 have resistor relays?

 

[RHO]

Yeah I ended up seeing that reading through the thread. Is this to be any issue for long term channel stability?

Seems like not a good option when SH-9 and H16 have resistor relays?

Relays can develop contact issues too.

 

[TurdiesBirdies]

Relays can develop contact issues too.

But then you can always change to new volume position to use a new circuit?

I still ordered the A90. Shipping soon. But wish there was more info on this pot.

 

[fendy323]

hiii, want to ask sir,
can someone give me some advice for setup a90+d90 with my hd800s?
i mean like volume d90 and a90 sparately ?

 

[Wegi76]

Stupid question with regards to the preamp output from me: I`m really getting confused by all the different units...

Base question is: How should I set the A90 to have the cleanest amplification in the following setup:

I connected the A90 as a preamp via XLR to a pair of active speakers. The speakers offer an analogue gain setting (0db or +6db) and the manual states the following regarding input voltages: Max input: 4,5Vrms, Input sensitivity 1V (+6db gain setting), 2V (0db gain setting). Also the speakers have a digital volume control and a remote contol. So I could use them comfortably to control my playback volume.

Input to the A90 is balanced XLR from my RME ADI2DAC with +9db, so "full power".

The A90 manual says that the output level in preamp mode is 49Vpp in Medium and High gain. I found this formula to convert Vpp in Vrms:
Vrms = 0.3535 * Vpp. So, 49Vpp would be > 17Vrms according to the formula :-o This sounds like it will potentially kill the speakers, when comparing to the Max Input of 4,5Vrms. Even in Low Gain the A90 produces 18Vpp (6,4Vrms). Lets say my 4year old son "plays" with the volume knob and cranks it up to the max. Could this cause damage to the speakers input?

I have to confess that I really don`t have a good understanding of these numbers, units, conversion, so again sorry for the stupid question but how should I set things ideally & safe in my configuration?

Thanks for any advise.
Markus