Topping A70 Pro HP & Preamp Review

[DrCWO]

Got my second unit a couple days ago. I'm starting to hear crackling in the right ear now, even without a record on the table. Anyone know why?

I guess your phono preamp outputs a small DC voltage. Attach a voltmeter at its outputs and check.

 

[Antagron]

Does anyone know if I were to send my broken amp back to Topping in China, would it get tariffed on the way back into the US?

 

[flognuts]

I just got one of these largely based on this review as well as others.
What an excellent amp, hooked up to my OPPO Sonica I can't imagine anything sounding any better.

 

[Yersinia Bestmate]

Hi Folks!
I have a class d amplifier for my living room, feeding my passive speakers, I was thinking of using the Pre90 as a preamp, but I've seen the A70 pro which also has a headphone amp, I use headphones at night so I need a headphone amp, is it crazy to use the a70 as a preamp for the main amp in the living room? Will it perform just as well as the pre 90?

Ive used A70pro as a preamp in my no. 1 set for about half a year now and been very pleased with the performance. Xlr cables to hypex main amp and rca's to sub - works like a charm, looks good and is compact and one gets a state-of-the-art hp amp aswell.

 

[Chrise36]

Not at all


Yes.

What other hp amp/pre would you propose as a safer choice but with same features and specs?

 

[Tovarich007]

Why "safer" ? Is there anything unsafe in the A70 pro ?

 

[Chrise36]

Why "safer" ? Is there anything unsafe in the A70 pro ?

Reliability wise hp amps do not have the best record.

 

[Antagron]

Reliability wise hp amps do not have the best record.

I learned (the hard way) that the warranty for Topping amps is 2 years but headphone amps is 1 year. Plus you have to ship back to China for service and pay tariffs to reimport.

 

[Chrise36]

I learned (the hard way) that the warranty for Topping amps is 2 years but headphone amps is 1 year. Plus you have to ship back to China for service and pay tariffs to reimport.

If you are in the EU and buy inside the EU everything has 2 years guarantee. But for 500+ plus euro hp amp i would like something worry free

 

[Antagron]

If you are in the EU and buy inside the EU everything has 2 years guarantee. But for 500+ plus euro hp amp i would like something worry free

That is a comfort, but if it fails you will still have to ship it to China. :/

 

[BeeKay]

That is a comfort, but if it fails you will still have to ship it to China. :/

Not quite true. It’s on the dealer.

 

[Antagron]

Not quite true. It’s on the dealer.

That decides it, I’m moving to Europe!

 

[Chrise36]

That is a comfort, but if it fails you will still have to ship it to China. :/

No i send it to the shop in the EU. It is his obligation to send a new one.

 

[Antagron]

No i send it to the shop in the EU. It is his obligation to send a new one.

That decides it, I’m moving to Europe!

 

[Roland68]

If you are in the EU and buy inside the EU everything has 2 years guarantee. But for 500+ plus euro hp amp i would like something worry free

If you want a truly worry-free HPA, then buy a Violectric or Lake People.
I know of enough units that have been working flawlessly for at least 20-30 years (in daily studio use). Failures are virtually unheard of, and even if there is a problem, the manufacturer or a technician can repair the unit easily and inexpensively.
A used HPA V200 costs €400-500 and is on average 10 years old and should last at least another 20 years.

 

[Chrise36]

If you want a truly worry-free HPA, then buy a Violectric or Lake People.
I know of enough units that have been working flawlessly for at least 20-30 years (in daily studio use). Failures are virtually unheard of, and even if there is a problem, the manufacturer or a technician can repair the unit easily and inexpensively.
A used HPA V200 costs €400-500 and is on average 10 years old and should last at least another 20 years.

Good to know thanks!

 

[BeeKay]

Trigger question

I’m currently using the A70 Pro as HPA and Preamp. Is there a way to switch off downstream devices (power amps, subwoofer) by 12V trigger when I put it in HPA mode?
If not possible yet this would be a great option for Topping to include in an upcoming firmware version.

 

[mike7877]

Trigger question

I’m currently using the A70 Pro as HPA and Preamp. Is there a way to switch off downstream devices (power amps, subwoofer) by 12V trigger when I put it in HPA mode?
If not possible yet this would be a great option for Topping to include in an upcoming firmware version.

Not possible. I agree, that'd be a nice addition!

 

[mike7877]

When Topping designed this wonderful, powerful, beautiful headphone amp/preamp, they chose to use TI OPA1656 and OPA1612 op amps (pictured below)

Can anyone decipher (or does anyone know) how these op amps are configured internally?

I know the 1656 is good to use on inputs because it has really really really really low current noise, and the 1612 is really really good when driven from a low impedance:

(1612)

The 49.9 ohm resistors are a little confusing because the output impedance of the A70 Pro is 50/100 ohms (RCA/XLR), because also, here from the last stage (TPA6120A2) datasheet:

Any guesses?

 

[Roland68]

When Topping designed this wonderful, powerful, beautiful headphone amp/preamp, they chose to use TI OPA1656 and OPA1612 op amps (pictured below)

View attachment 454790

Can anyone decipher (or does anyone know) how these op amps are configured internally?

I know the 1656 is good to use on inputs because it has really really really really low current noise, and the 1612 is really really good when driven from a low impedance:
View attachment 454802
(1612)

The 49.9 ohm resistors are a little confusing because the output impedance of the A70 Pro is 50/100 ohms (RCA/XLR), because also, here from the last stage (TPA6120A2) datasheet:
View attachment 454803

Any guesses?

Have you ever measured whether the preamplifier outputs are powered by the op amps, the Tang-ku-la modules, or the output stage?