Topping L70 Headphone Amp Review

[vintagelove]

The bass boost with headphones is quite real at high volumes. Alas, it is quite loud by the time it gets there. I wish hearing damage did not occur or I would always listen at that level. It is very enjoyable for a few seconds I crank it up that loud....

Hi, I hate to bother you, but did you by any chance determine what the maximum input level before clipping the input stage was (in low gain mode)?

Btw, thanks for all the work you do.

 

[staticV3]

Nice attempt. I'm afraid it is a bit too much though.
You are suggesting here that a HD650 would become extremely muddy and dark at higher levels.
I suggest to listen to the HD650 at your background listening level and at high SPL.
There will be more 'grunt' and you will hear more deep bass.
Humans don't determine loudness at 1kHz but over a larger range from upper bass to lower treble.

Then apply the red trace in EQ to the HD650 (it sounds awful and muffled) and tell me if you think the tonal balance is similar than without EQ at very loud levels.

I'm afraid I'm not crazy enough to push my HD600 and my ears to 100dB AVG, 115dB peak. My regular listening volume is about 65dB AVG, 80dB peak, so that'd be an 11.5x volume increase over normal.

However, I've successfully applied ISO 226 to +10/+20dB boost and -10/-20dB reduction and my hearing very much follows the curves.
I adjust the volume, levels go down/up, but certain frequencies moreso than others -> tonality shifts.
I enable the loudness correction -> tonal balance is restored to normal.

Hence, I'm reasonably confident in the ISO and that graph I posted.
But +40dB is just bonkers loud and therefore more of a theoretical exercise.

If you'd like to try the loudness correction I've created yourself, hit me up and I'll send you the files!

 

[solderdude]

65dB average is late evening background level listening.
For 65dB to 80dB correction you would need
20Hz +10dB
50Hz +10dB
100Hz +8dB
200Hz +7dB
500Hz + 1dB

for 80 to 100 you would get
20Hz +10dB but HD600 needs + 12dB to Harman so would be -2dB opposite Harman
50Hz +8dB but is -5dB opposite Harman so +3dB bassier than Harman.
100Hz +8dB would be +8dB so a lot more 'punch'.
200Hz +5dB
500Hz +1dB

So not Harman type of bass.

 

[MRC01]

Model	SE	BAL
Topping A90	10k Ohms	2.0k Ohms
Topping A90D	10k Ohms	2.0k Ohms
Topping Pre90	10k Ohms	2.2k Ohms
Topping L30	2.5k Ohms	N/A
Topping L70	2.0k Ohms	2.0k Ohms

Source: the other thread.

2 kOhm is pretty low. I assume they're doing this to reduce noise / improve SNR. If you want a safe 10:1 impedance ratio from the source device, it must have < 200 ohm output impedance. Most solid state sources do, but not all. I'd prefer to see them all at least 10 kOhm. Far less likely to have impedance matching issues, with negligible impact on noise / SNR. Looks like chasing paper specs at the cost of compatibility.

Also, I wonder why have different input impedances for SE & Balanced?

 

[Veri]

2 kOhm is pretty low. I assume they're doing this to reduce noise / improve SNR. If you want a safe 10:1 impedance ratio from the source device, it must have < 200 ohm output impedance. Most solid state sources do, but not all. I'd prefer to see them all at least 10 kOhm. Far less likely to have impedance matching issues, with negligible impact on noise / SNR. Looks like chasing paper specs at the cost of compatibility.

I wonder if the support rep isn't just plain wrong, though. I'd expect the BAL input impedance to be at least twice the SE one, i.e. >= 4.0k Ohms...
Maybe @JohnYang1997 can chime in if he's ever got a moment to spare on the forum here

 

[Robbo99999]

Forget the tones and equal loudness contours.
Do your experiments with real music and known SPL (you know how to determine that)
Consider that music spectrum is not 'white noise' type which basically is what equal loudness contours is about.
Subbass does really lift a bit at higher levels (use your HD600) but you will need to reach really (and for you uncomfortable) loud levels to get a somewhat similar-ish tonal balance feel as you would at your preferred listening level with Harman EQ applied.

Amplifiers such as the L70 (and many others that can supply a similar voltage with low THD) can get you there with the HD600. It needs to be 'clean' power though and don't do this for longer than a few seconds of sheer 'enjoyment of oodles of power'.
The Sennheisers will already be distorting a lot in the bass so you don't want clipping or extra 'tube amp percentage' added to that of the headphone.

(I'm assuming you were talking to me). When I said "I can't even imagine cranking it up to 100dB for 1kHz", I wasn't referring to listening to sine tones, instead I was referring to listening to music at the same volume pot position that gives me 100dB at 1kHz for a 0dBFS sine tone - that's the context of the numbers I was talking about in my previous post.

I understand what you mean in your post though - but I'm not gonna blast my ears re a phenomenon that I'm already aware of (in some sense, when I've momentarily upped volume to what I think are insane levels - it's just not a way I could ever enjoy music, not even for one track).

 

[Robbo99999]

I'm afraid I'm not crazy enough to push my HD600 and my ears to 100dB AVG, 115dB peak. My regular listening volume is about 65dB AVG, 80dB peak, so that'd be an 11.5x volume increase over normal.

However, I've successfully applied ISO 226 to +10/+20dB boost and -10/-20dB reduction and my hearing very much follows the curves.
I adjust the volume, levels go down/up, but certain frequencies moreso than others -> tonality shifts.
I enable the loudness correction -> tonal balance is restored to normal.

Hence, I'm reasonably confident in the ISO and that graph I posted.
But +40dB is just bonkers loud and therefore more of a theoretical exercise.

If you'd like to try the loudness correction I've created yourself, hit me up and I'll send you the files!

What programs and "instructions within those programs" do you use to implement your loudness corrections?

 

[staticV3]

What programs and "instructions within those programs" do you use to implement your loudness corrections?

Here'y my simple EQApo setup:

and a closer look at the -20dB equal loudness correction curve:

 

[kencreten]

Same same, but different, but still the same.

So DAC manufacturers have gotten into the yearly release cycle like smartphones. Well, who's to blame them as long as it sells and there are actually people who ugprade their DAC every year.

Soon we'll be battling over tiny fractions of a db. I guess we already are.

 

[Robbo99999]

Here'y my simple EQApo setup:
View attachment 248609
and a closer look at the -20dB equal loudness correction curve:
View attachment 248610

Where's the information that tells it how to change the EQ based on the output SPL? How do you set that up? One drawback (unless there is a workaround) is that it only knows your digital output rather than your input from twiddling the volume knob on your headphone amp (EDIT: and I guess it wouldn't know the recording level of your music either which is another variable?). Am I right in thinking you'd leave the volume knob of the headphone amp at an optimal position and then use digital volume control around that - well the program would have to in order for it to know how to change the loudness EQ?

 

[staticV3]

@Robbo99999 we're straying pretty far off topic tbh. I'll DM you the details.

 

[Ziroz]

Does anyone know what code r3 means? Couldn't find error codes in the manual.

Also got this error code r3 today, has topping reached back to you?

 

[Chagall]

Also got this error code r3 today, has topping reached back to you?

They have, but nothing helpful.

Thank you for contacting TOPPING support. We are happy to assist.
Disconnect all the inputs and outputs of L70, if it still show r3 after rebooting?
Best Regards

So I asked again what does the code stand for and is it safe to use.
Waiting on that

 

[SiamXIII]

Is there any reason to grab A90D over this for preamp usage?

 

[Ziroz]

They have, but nothing helpful.

Thank you for contacting TOPPING support. We are happy to assist.
Disconnect all the inputs and outputs of L70, if it still show r3 after rebooting?
Best Regards

So I asked again what does the code stand for and is it safe to use.
Waiting on that

I got a similar reply from them saying r3 has something to do with the protection voltage, it should be fine to just restart the device and keep using it.
I then inquired about whether there is a list of error codes for the L70, which they replied with "no".

 

[Chagall]

I got a similar reply from them saying r3 has something to do with the protection voltage, it should be fine to just restart the device and keep using it.
I then inquired about whether there is a list of error codes for the L70, which they replied with "no".

Thanks for the info!

My E70 was set to wake up on input signal and that's when I got the code on L70 (turned it on with remote - no trigger cable).
I've since disabled E70 to turn on/off and didn't get the code again.
Don't know if that has anything to do with it.

 

[Adaboy4z]

Just received the L70 today listening with HD6XX and HE400se connected via RCA to a Samsung tablet. First impression it looks sharp in all black and red accent on the volume knob. What can I say it sounds good to me with plenty of power. I really like that big display and It didn't take long to familiarize myself with the remote. I didn't realize having both headphones connected is such a convenience, just hit the programmed buttons to switch headphones. Waiting on E70 to arrive in a couple of days.

 

[Labjr]

You really won't need anything else, the DAC and amp are endgame items IMO. Great decision if you ever want to move up the headphone chain too. Enjoy!

Endgame is about two weeks around here.

 

[Adaboy4z]

Endgame is about two weeks around here.

True to that

 

[okok]

2 kOhm is pretty low.

2k ohm input impedance on all inputs? this is really really bad design, mismatch will reduce tons of performances, many got 50k or 100k input impedance

oh boy