Topping A70 Pro HP & Preamp Review

[LeChef86]

Guys, respect. I'm still green, so sorry for the "noob" question.

I just got A70pro, and as I rotate the volume knob, which is stepped, it makes distinctive clicking sounds at every step. I had A30 pro before, it didn't use to make any sounds when manipulating the volume control knob. Still did not plug in my headphones, clicking sounds are perceivable outside of sound reproduction. It is easily audible from 2 meters, and they slightly change in intensity and tonality every 2-3 steps.

I appreciate any knowledge you are willing to share with me.

Radan

 

[oleg87]

Guys, respect. I'm still green, so sorry for the "noob" question.

I just got A70pro, and as I rotate the volume knob, which is stepped, it makes distinctive clicking sounds at every step. I had A30 pro before, it didn't use to make any sounds when manipulating the volume control knob. Still did not plug in my headphones, clicking sounds are perceivable outside of sound reproduction. It is easily audible from 2 meters, and they slightly change in intensity and tonality every 2-3 steps.

I appreciate any knowledge you are willing to share with me.

Radan

That's the relay stepped volume control. Relays make clicks when they actuate.

 

[LeChef86]

Thank you for your quick reply, @oleg87. I appreciate it.

I see. Well, hopefully, it will not cause any disruptions in music. What worries me a bit is the intensity of clicks. Amir says: "While you hear the mechanical relays if you get close to the unit...". Mine is much more audible than that. I want to react before my return window closes.

Radan

 

[formdissolve]

Thank you for your quick reply, @oleg87. I appreciate it.

I see. Well, hopefully, it will not cause any disruptions in music. What worries me a bit is the intensity of clicks. Amir says: "While you hear the mechanical relays if you get close to the unit...". Mine is much more audible than that. I want to react before my return window closes.

Radan

I can hear the clicks from about 5 meters away. Only every now and then it cuts music for a quarter of a second or less when you hold the volume up or down on the remote (which is normal from all the relay volume preamps I've used)

 

[LeChef86]

Thanks for the reply.

What is the reason behind this design choice? Clicking is, clearly, a trade-off. What did they gain by implementing a stepped attenuator?

 

[formdissolve]

Thanks for the reply.

What is the reason behind this design choice? Clicking is, clearly, a trade-off. What did they gain by implementing a stepped attenuator?

If you look at the first page, it shows a very balanced volume channel match all the way down to low levels. If you used a volume potentiometer, you can get a large channel mismatch at low levels.

 

[LeChef86]

Thanks. I understand.
I can't wait to plug LCD-5 into it. Hopefully, it will provide enough juice considering those cans need equalization.
I wonder, are there any other LCD-5 users with A70pro on this forum?

Radan

 

[mike7877]

Thanks. I understand.
I can't wait to plug LCD-5 into it. Hopefully, it will provide enough juice considering those cans need equalization.
I wonder, are there any other LCD-5 users with A70pro on this forum?

Radan

I drive a pair of ATC SCM20 Pro PSL Mk2 studio monitors with mine when I listen at lower levels. They're 85dB/w and in a 12x10ft room with 8 foot ceiling (4x3.3m with normal ceiling), and they can reach decent listening levels. It'd be perfect if there was another 3dB headroom, but it's not far off (some songs with a lot of bass energy tend to trip the protection).

Like you, I also equalize. The absolutely amazing thing you can do with sealed designs using simple EQ is extend their LF extension by an entire octave like this:

Where's the 1.07 Q from? That's the woofer's Q in its enclosure.
Where'd the 56Hz come from? That's the speaker's -6dB point.
Where'd the 12dB come from? Sealed speakers roll off at 12dB/oct.

I'm going to make a tutorial thread about this in the future with more supporting info, but basically, right now I'm showing you this to demonstrate that I equalize too (and it's SPEAKERS that I'm equalizing...), and the speakers(!!!) play at moderate levels, driven directly from the 4 pin XLR headphone out on the front of the A70 Pro itself, filling a small-small-medium sized room with nominal SPL (small-small-medium like north-north-west lol - it's not a small room, but it's definitely not medium!)

edit: if anyone's wondering, I do have an amplifier for them lol - it's also Topping, an LA90 Discrete, actually. I'm thinking of bridging the one I've got and buying another, possibly two. Why two? Bi-amping for more power and additional clarity at higher volume levels (if the bass clips a bit, none of that distortion can affect things >2kHz, making the point at which distortion becomes obvious a couple dB higher.. free headroom! (even if it's a bit of a lie lol)

 

[Volikovvv]

Guys, respect. I'm still green, so sorry for the "noob" question.

I just got A70pro, and as I rotate the volume knob, which is stepped, it makes distinctive clicking sounds at every step. I had A30 pro before, it didn't use to make any sounds when manipulating the volume control knob. Still did not plug in my headphones, clicking sounds are perceivable outside of sound reproduction. It is easily audible from 2 meters, and they slightly change in intensity and tonality every 2-3 steps.

I appreciate any knowledge you are willing to share with me.

Radan

Hi! I'm currently using Topping A30 pro amplifier for a long time, is it worth to upgrade to A70pro? Is it sounds more pleasant to your ears?

 

[Human Bass]

Hi! I'm currently using Topping A30 pro amplifier for a long time, is it worth to upgrade to A70pro? Is it sounds more pleasant to your ears?

No. The A70 has a high failure rate. Tok risky.

 

[Roland68]

Hi! I'm currently using Topping A30 pro amplifier for a long time, is it worth to upgrade to A70pro? Is it sounds more pleasant to your ears?

For me, the A70 Pro is one of the best HPAs and in my opinion it also beats the A30 Pro.
But buy it through Amazon or a dealer in your country so that you have security, just in case...

 

[Gggggas]

I will have to agree, some will say that I am one of the lucky ones but I never had a single issue. Yesterday I had a HE1000SE and an Arya Stealth plugged in simultaneously on the XLR and 4.4mm outputs on High Gain working perfectly fine for hours.

 

[Roland68]

I will have to agree, some will say that I am one of the lucky ones but I never had a single issue. Yesterday I had a HE1000SE and an Arya Stealth plugged in simultaneously on the XLR and 4.4mm outputs on High Gain working perfectly fine for hours.

Why shouldn't that work? The A70 Pro is made for something like that.

The problems with the A70 Pro don't come from poor development or bad components. It is solely the result of the potting compound used for the modules combined with a lack of knowledge and inexperience. The joke is that Topping only did this to protect the circuit layout, which hasn't worked at all so far.

 

[DouglasteR]

Maybe an already asked question but, would this give more power than a DX7 Pro ?

HP is a HE6seV2 balanced.

Thanks.

 

[staticV3]

Maybe an already asked question but, would this give more power than a DX3 Pro ?

HP is a HE6seV2 balanced.

Thanks.

Definitely.

If you'd like to know how much more power, please tell me if you're using the original DX3 Pro or the newer DX3 Pro+.

 

[DouglasteR]

Definitely.

If you'd like to know how much more power, please tell me if you're using the original DX3 Pro or the newer DX3 Pro+.

Sorry, i meant the DX7 Pro (silver ed).

I was using the L70 (IIRC was even you that suggested it) combo and the R5 error is driving me nuts !

Thanks !

 

[staticV3]

Sorry, i meant the DX7 Pro (silver ed).

The old one? https://www.audiosciencereview.com/...-dx7-pro-dac-and-headphone-amp-reviewed.9446/

 

[DouglasteR]

The old one? https://www.audiosciencereview.com/...-dx7-pro-dac-and-headphone-amp-reviewed.9446/

Yep, the old square one

 

[Dunring]

Definitely.

If you'd like to know how much more power, please tell me if you're using the original DX3 Pro or the newer DX3 Pro+.

The original DX7 Pro will run out of power in high gain using an Autoeq profile for it and a song like Tonight, Tonight, Tonight by Genesis during the quiet parts. The A70Pro doesn't. Even stock with the He6se you can get it very loud and still be at -17db worth of headroom without equalizing. This is using a 5.2 volt DAC (SMSL DO300EX) with the A70Pro.

 

[DouglasteR]

The original DX7 Pro will run out of power in high gain using an Autoeq profile for it and a song like Tonight, Tonight, Tonight by Genesis during the quiet parts. The A70Pro doesn't. Even stock with the He6se you can get it very loud and still be at -17db worth of headroom without equalizing. This is using a 5.2 volt DAC (SMSL DO300EX) with the A70Pro.

View attachment 369342

I use Amir´s EQ profile and stacked with the L70, the DX7 pro could reach high volumes while maintaining the sweet bass.

But since jan/24, the L70 displays the error code "R5" and stutters heavily. Pausing the audio source (my pc) solves it till i hit play again (so, obviously an amp related problem, probably DC surge etc)

Back to just the DX7 pro, the volume is mid to mid high and it´s enough for now, but if the source´s volume is low = problem.

So i was wondering in selling the DX7 Pro and upgrading to the A70, if it´s capable to drive the He6seV2.

Thanks for the help guys.