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.
Disconnect everything and use headphones to narrow your elimination circle
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.
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..
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.
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:
An official release not being released is quite a stretch
www.l7audiolab.com
www.l7audiolab.com
Different devices, different measuring instruments, different people performing the measurements, different deviations, different contact resistances of the measuring cables, etc.Can anyone provide clarification on this?
SNR@50mV
ASR --------------------- L50 ( 95 dB) > L70 (93 dB)
L7Auidolab-------------- L70 ( 97 dB) > L50 (95 dB)
Measurements of Topping L70 HeadphoneAmp - L7Audiolab
台式设备 话说前几天住院去了，导致更新速度下降……家里堆着一大堆待测设备……本想着昨天偷偷溜回家先把Topping E/L70给测了……结果低估了工作量……加上我得到的医嘱是不能久坐使得工作效率下降了不少。因此到现在才搞完。那么，就让我们来先来看看 Topping L70 这台耳放Measurements of Topping L50 HeadphoneAmp - L7Audiolab
台式设备 前两天发布了拓品E50解码的测量，熟悉拓品产品策略的人一定猜到了，和E50一起推出的配套耳放 Topping L50 也已经在路上。没错！家人们！其实我早就拿到了Topping L50的工程样机。而且非常幸运的是，工程样机和最终零售版之间“没有区别”
Variations by unit?
it's 92.987 - 93.015 https://www.audiosciencereview.com/...plifier-snr-balanced-measurements-png.247905/
It's different topic.
Pretty in line with chatgpt answer:
Great question — and this is a perfect example of why measurements can vary between reputable sources like ASR (Audio Science Review) and L7Audiolab, even when testing the same device.
Here's how to explain the SNR@50mV discrepancies between L50 and L70:
What the numbers say
So ASR says L50 > L70, while L7Audiolab says L70 > L50 — why?
Source L50 (SNR @ 50mV) L70 (SNR @ 50mV) ASR 95 dB 93 dB L7Audiolab 95 dB 97 dB
Why these differences happen
1. Measurement Methodology
- Different analyzers: ASR uses Audio Precision APx555, as does L7Audiolab — but exact test procedures and setup may vary slightly (calibration, filtering, grounding).
- Bandwidth filtering: Some measurements may apply A-weighting filters, others may not, which can easily cause ±1–3 dB differences in low-level SNR tests.
- Volume setting / gain mode: Even a slight variation in volume control level affects noise floor, especially at 50 mV where amplifier gain can be high.
- Channel tested: Some devices have slightly better Ch1 or Ch2 performance; some reviewers average them, others report the worst.
2. Device Sample Variation
- Unit-to-unit variance is real, even for Topping gear. SNR differences of 1–2 dB between production samples are entirely normal.
- If ASR and L7 measured different units, they could show reversed results.
3. Environmental Noise
- Electromagnetic or USB power noise in the lab environment can pollute low-level SNR readings, especially at 50 mV output.
- L7Audiolab often uses LNA (Low Noise Adapter) for precision low-level measurements, which can give more favorable SNR numbers than standard APx555 setup.
What does it mean in practice?
- Both the L50 and L70 have excellent low-level SNR — anything over 90 dB @ 50 mV is already far beyond human audibility.
- A 2–4 dB swing in these SNR readings is not meaningful for real-world listening, especially with transparent DACs and low-noise sources.
- In real use with IEMs, both amps are dead silent unless you use ultra-sensitive BA IEMs — and even then, hiss is unlikely.
Summary
So while L7Audiolab shows L70 slightly better than L50, and ASR shows the opposite, both are within margin of error and should be considered functionally equivalent at 50 mV for most practical listening.
Reason for difference Explanation Test setup variations Filters, gain levels, cables, analyzer settings differ Sample differences Slight performance variance across units Environment / grounding Lab noise and interference can skew low-signal readings Analyzer precision L7 may use LNA adapter, ASR may not
L7 uses the APx555's high performance mode whereas Amir doesn't for consistency reasons.Can anyone provide clarification on this?
SNR@50mV
ASR --------------------- L50 ( 95 dB) > L70 (93 dB)
L7Auidolab-------------- L70 ( 97 dB) > L50 (95 dB)
Measurements of Topping L70 HeadphoneAmp - L7Audiolab
台式设备 话说前几天住院去了，导致更新速度下降……家里堆着一大堆待测设备……本想着昨天偷偷溜回家先把Topping E/L70给测了……结果低估了工作量……加上我得到的医嘱是不能久坐使得工作效率下降了不少。因此到现在才搞完。那么，就让我们来先来看看 Topping L70 这台耳放Measurements of Topping L50 HeadphoneAmp - L7Audiolab
台式设备 前两天发布了拓品E50解码的测量，熟悉拓品产品策略的人一定猜到了，和E50一起推出的配套耳放 Topping L50 也已经在路上。没错！家人们！其实我早就拿到了Topping L50的工程样机。而且非常幸运的是，工程样机和最终零售版之间“没有区别”
Variations by unit?
