Topping L70 Headphone Amp Review

[jkim]

I was doubting it as well but ground lift doesn't help, L70 has the switch to eliminate it on the back. The buzz changes the channel when I change the cables from left to right and vice versa. It's also present when I disconnect the dac (E30II Lite). It disappears when I shut down the L70 but leave the power amp on. Hard to believe the reason would be anywhere else than in the L70. All the equipment are connected to the same power strip.

I also own both the L70 and A70 Pro. I measured both using my E1DA Cosmos stack. Except for the fancier display (and higher output power I won't need) of the A70 Pro, there's nothing I prefer less about the L70 to the A70 Pro. I also love its relatively small form factor for its output power.

Sometimes it's not easy to troubleshoot noise issues. But it is also likely that you have a defective unit. Have you replaced the L70 with another preamp in the same setup?

 

[redeyes]

hmm, changes from left to right with cables.. have you tried different ones?

 

[Burns]

I was doubting it as well but ground lift doesn't help, L70 has the switch to eliminate it on the back. The buzz changes the channel when I change the cables from left to right and vice versa. It's also present when I disconnect the dac (E30II Lite). It disappears when I shut down the L70 but leave the power amp on. Hard to believe the reason would be anywhere else than in the L70. All the equipment are connected to the same power strip.

Disconnect everything and use headphones to narrow your elimination circle

 

[Yersinia Bestmate]

Disconnect everything and use headphones to narrow your elimination circle

Hp outputs are clean - no buzzing whatsoever. It is only in the line-out right channel and only via the XLR output.

 

[jkim]

Hp outputs are clean - no buzzing whatsoever. It is only in the line-out right channel and only via the XLR output.

That is strange. I just remeasured both the L70 and A70 Pro's XLR line outputs at volume knob levels from -0 to -10 dB. Both preamps are extremely transparent for either channel.

Here are my L70's XLR L/R lineouts' 1 kHz sinusoid FFTs @ -10 dB volume setting:


It only contains slight harmonic products, most of which (higher-order ones, in particular) are from the DAC---Topping D50 III---used as a signal generator. Essentially, my L70 adds little to no THD+N to the DAC output.

 

[Yersinia Bestmate]

That is strange. I just remeasured both the L70 and A70 Pro's XLR line outputs at volume knob levels from -0 to -10 dB. Both preamps are extremely transparent for either channel.

Here are my L70's XLR L/R lineouts' 1 kHz sinusoid FFTs @ -10 dB volume setting:
View attachment 447425View attachment 447426

It only contains slight harmonic products, most of which (higher-order ones, in particular) are from the DAC---Topping D50 III---used as a signal generator. Essentially, my L70 adds little to no THD+N to the DAC output.

Strange indeed but then again products can be defective. Unfortunately that's what I got.

Going to return the L70 and get something else instead, maybe I'll replace it with Audiophonics AP310-Preamp as I really do not need HP outputs.

 

[Burns]

Strange indeed but then again products can be defective. Unfortunately that's what I got.

Going to return the L70 and get something else instead, maybe I'll replace it with Audiophonics AP310-Preamp as I really do not need HP outputs.

hasty conclusion after one copy. Exchange L70 for another L70, you will know if you were unlucky or if your audio track has a problem. You can also return the second L70 even if it is technically efficient. I give more percentage for problems with your audio track, L70 is a very nice device in terms of quality to price ratio, It is worth giving L70 a second chance. Return the first one without giving a reason to one seller, buy another L70 device from another seller, at most you will also return it without giving a reason from the right..

 

[Yersinia Bestmate]

hasty conclusion after one copy. Exchange L70 for another L70, you will know if you were unlucky or if your audio track has a problem. You can also return the second L70 even if it is technically efficient. I give more percentage for problems with your audio track, L70 is a very nice device in terms of quality to price ratio, It is worth giving L70 a second chance. Return the first one without giving a reason to one seller, buy another L70 device from another seller, at most you will also return it without giving a reason from the right..

I am not quite sure what you mean by "audio track", signal chain perhaps? Maybe I was not clear enough in my previous posts, I'm sorry for that. Anyway, I'll try to summarise what I've tried and why I think I have a faulty unit:

* The buzzing can be heard when there's no input signal to the L70 but it is powered on and connected to a power amp via XLR cables.
* The power amp I'm using is an Audiophonics MPA-S250NC, and there's no buzzing when I disconnect L70 from the amp but leave the amp powered on so it is not the source of the problem.
* There's no buzz either when connecting the dac I'm using in that particular set atm (a Topping E30II lite) directly to the power amp with rca-to-XLR cables nor when I connect the preamp of and old NAD c720bee to the power amp.
* Now I've also tried different interconnects, different speakers (Elac FS217, Magnat Quantum 757, Dali Concept 6), different speaker cables and even different power outlet. The problem persist whenever L70 is in the signal chain and disappears when it is either turned off or replaced with a different device, as stated before. Ground lift doesn't help either.

Anyhow, I am not motivated enough to buy another one and go through all the hassle. I'll just get something else instead and probably return the one I bought. It's not a big deal after all, just a piece of equipment altough a nice one, especially considering the looks, price and the performance. I think I've not made a hasty conclusion considering everything I've tried. Moreover, the remote volume control of L70 is frustrating and I want something that acts faster and smoother. The AP 310 preamp ticks all the boxer for me atm.

Thanks for the advices everyone, my L70 is getting a comfy ride back to the shop I bought it from.

edit: a couple of typos

 

[sansenri]

regarding Topping's error codes, the L70 FAQs mention the following

It would have been better to show clearer differences between r2 and r3, but I hope useful

 

[Yersinia Bestmate]

regarding Topping's error codes, the L70 FAQs mention the following
View attachment 449688
It would have been better to show clearer differences between r2 and r3, but I hope useful

There were no error codes in my case.

 

[sansenri]

There were no error codes in my case.

good to know, however, if you read the entire thread, several people encountered r2, r3 and r5 error codes and were wondering what they meant. The FAQ is on the Topping site, however somewhat not immediately evident, so I hope useful.

 

[Jeff Dennis]

I got an r3 error when I wanted to check the firmware version and the usb cable was not appropriate (probably only charging and no data transmission). I bought it recently and it had firmware version 1.15 installed.

 

[starence]

Hmm, I thought 1.14 was the newest firmware, it seems to be the only version you can download from Topping.

 

[Jeff Dennis]

Hmm, I thought 1.14 was the newest firmware, it seems to be the only version you can download from Topping.

Strange but true. In this thread 1.15 was already mentioned in March of this year. It’s unclear what the changes in this version are and why it’s not available for download yet. My (first) dedicated HPA L70 is still on 1.14 (bought it in 2024); this one is a dedicated Pre-amp.

 

[wowin21]

Strange but true. In this thread 1.15 was already mentioned in March of this year. It’s unclear what the changes in this version are and why it’s not available for download yet. My (first) dedicated HPA L70 is still on 1.14 (bought it in 2024); this one is a dedicated Pre-amp.

I also saw VER115.TXT, so I sent an email to Topping and received the following response:

Don’t worry, version V1.15 is also an official release. It only fixes a minor display error, so you can use it with confidence. ^.^

 

[BeeKay]

Don’t worry, version V1.15 is also an official release. It only fixes a minor display error, so you can use it with confidence

An official release not being released is quite a stretch