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SMSL M500 DAC and HP Amp Review

MediumRare

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I will take it as a possible theory. Do you own the M500 by the way? Do you own any other amps to compare them?

I should also underline, that M500 is the DAC used in one of the testing paths I have described, where using either an RCA out or XLR out from M500 going to the Logitech Z-2300 (old school TXH certified, class AB) active speaker setup with headphone out, I am getting much fuller (better sounding) low frequencies, compared to M500 headphone out.
I have a Topping DX7 Pro with a headphone amp. But we can rely on Amir's review of this unit. So the only alternative to the hypothesis above, IMO, is that yours is broken.
 

reddeath

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I have a Topping DX7 Pro with a headphone amp. But we can rely on Amir's review of this unit. So the only alternative to the hypothesis above, IMO, is that yours is broken.
How can I test the theory that the unit (or specifically the headphone amp in low frequencies) is broken?

As for the review itself, I am not sure I have ever read a review on the website of anything describing the perceived quality of music from the equipment. There is only focus on measurements, which IMO is not everything.
 

reddeath

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I have even thought about buying the M500 MK2, which was just announced. But what if the sound is the same thin in the low frequencies? That's a bit risky.
 

rooster.jorge

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Weird. Mine is “satisfying enough”. It is one of the best to listen to music. I am not sure whether is a personal preference or not. I have been using it for 2 years or more. No issues, but perhaps I like it more since I see different things over and over again. Are you sure it is not a personal preference?
 

reddeath

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Weird. Mine is “satisfying enough”. It is one of the best to listen to music. I am not sure whether is a personal preference or not. I have been using it for 2 years or more. No issues, but perhaps I like it more since I see different things over and over again. Are you sure it is not a personal preference?
Maybe it is a matter of comparison. If other amps sound more full, M500 sounds too thin by comparison. Maybe the situation is that M500 has a bit too little base and other amps have a bit too much. There must be a reason why M500 MK2 has a new headphone amp built-in, which has a different design and double the power. They tried to improve on many aspects and apparently thought that headphone amp needed an overhaul.
 

foxxx0

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On my M500 the headphone out is pretty much indistinguishable from my SP400 amp.
That applies to both low impedance IEMs and ~150 ohm HD660S.

The SP400 amp is connected through XLR to the M500.

Neither with IEMs nor with the HD660S can I perceive a *really* notable difference between the internal headphone amp of the M500 compared to the standalone SP400 amp.
(Which begs the question: Why did I buy it then? - Because I wanted to. :p It has a bit more headroom than the M500 internal amp, which can come in handy for higher impedance headphone and/or EQ)

So either something in your connections is broken or your actual M500 is defective.

For what it's worth: using a Logitech Z-2300 (THX certified or not) *does not* qualify as a good test in my book though.
 

reddeath

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On my M500 the headphone out is pretty much indistinguishable from my SP400 amp.
That applies to both low impedance IEMs and ~150 ohm HD660S.

The SP400 amp is connected through XLR to the M500.

Neither with IEMs nor with the HD660S can I perceive a *really* notable difference between the internal headphone amp of the M500 compared to the standalone SP400 amp.
(Which begs the question: Why did I buy it then? - Because I wanted to. :p It has a bit more headroom than the M500 internal amp, which can come in handy for higher impedance headphone and/or EQ)

So either something in your connections is broken or your actual M500 is defective.

For what it's worth: using a Logitech Z-2300 (THX certified or not) *does not* qualify as a good test in my book though.
Which version of the M500 do you have (SW, HW, date) ? And how do you connect balanced headphones to 6,3mm headphone port on M500?
 

USER

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Headphones tested (all around 50 ohm):
- Bose QC 35 II
- Sennheiser HD 599
- Sennheiser HD 558
A quick check of online measurements shows that the Sennheisers do not have much bass to begin with--they are roughly like the HD 600s in this way. The Bose QC 35 II does have bass and was reviewed here. I encourage you to take a look at it. Amir notes that impedance changes drastically when powered on and off. This could well affect your sound. See if turning it on and off changes things. Never rely on the single number the manufacturer gives you. It is often intentionally vague. Impedance can change throughout the frequency, especially with lower quality headphones. This is why the reviews here are useful. More, the Bose is less sensitive than you think.

Likely the cause is impedance and power mismatch. Since it is not great power-wise, Amir didn't really provide a thorough review of the M500 headphone section as he does with dedicated units so its hard to definitively see if an impedance mismatch could specifically affect the bass region. However, it was noted that the unit was underpowered. I'd just go with that. This idea of "tuning" a modern headphone amplifier to a specific sound just really isn't a thing. There's plenty of evidence in the reviews.
 
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foxxx0

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Which version of the M500 do you have (SW, HW, date) ? And how do you connect balanced headphones to 6,3mm headphone port on M500?
HW 1.2
SW 1.5

It's one of the earlier models and likely has the 3rd harmonic issue.
I've collected the flash tools, firmware files and what not, but I simply haven't found the time to open it, do some soldering and upgrade the firmware yet.

My HD660S are currently 6.3mm single ended and not balanced (yet).
I have some silicon wire, paracord and connectors here to make a custom balanced cable, but yet again - no free time yet, work has been crazy the last couple of weeks.
 

SMSL-Mandy

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HW 1.2
SW 1.5

It's one of the earlier models and likely has the 3rd harmonic issue.
I've collected the flash tools, firmware files and what not, but I simply haven't found the time to open it, do some soldering and upgrade the firmware yet.

My HD660S are currently 6.3mm single ended and not balanced (yet).
I have some silicon wire, paracord and connectors here to make a custom balanced cable, but yet again - no free time yet, work has been crazy the last couple of weeks.
HW 1.2
It needs to send back to china for a HW upgrade to 1.3
not only can be choose by the firmware.
Where you bought it? send me the email of your address.
Thanks
 

reddeath

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HW 1.2
It needs to send back to china for a HW upgrade to 1.3
not only can be choose by the firmware.
Where you bought it? send me the email of your address.
Thanks
Am I reading this correct? SMSL employee asks a random person on the forum, who mentioned he has M500 V1, to send it back for a replacement/upgrade to V2. This is essentially a "recall" request.
Since SMSL has all email addresses of the people who bought the products through their websites at least, why is the recall done selectively, by chance, instead of sending notification to all customers?
 

SMSL-Mandy

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Am I reading this correct? SMSL employee asks a random person on the forum, who mentioned he has M500 V1, to send it back for a replacement/upgrade to V2. This is essentially a "recall" request.
Since SMSL has all email addresses of the people who bought the products through their websites at least, why is the recall done selectively, by chance, instead of sending notification to all customers?
This is not a recall request, I just find the customer have a upgrade requirement and want to help him for the solve the probelm.

Thanks
 

reddeath

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This is not a recall request, I just find the customer have a upgrade requirement and want to help him for the solve the probelm.

Thanks
Could you please address my request few posts back regarding low frequencies lacking in the headphone amp on M500? Some forum users suggested hardware failure. How can this be verified, preferably without sending the unit anywhere?
 

foxxx0

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HW 1.2
It needs to send back to china for a HW upgrade to 1.3
not only can be choose by the firmware.
Where you bought it? send me the email of your address.
Thanks
Hi Mandy, I've sent you a private message with the details. Thanks for reaching out!
 

Veri

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Could you please address my request few posts back regarding low frequencies lacking in the headphone amp on M500?
I don't think SMSL can verify or help you without sending it in. Unless you can do measurements of your unit.
 

reddeath

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I just saw this video:

He also mentions the "thin" sound of M500 V2 comparing to V1. Although he talks about XLR output.
He asked the question what is the difference exactly between V1 and V2.
 
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amirm

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I just saw this video:

He also mentions the "thin" sound of M500 V2 comparing to V1. Although he talks about XLR output.
He asked the question what is the difference exactly between V1 and V2.
There is no such thing as "slow sound." Veil and such being there/removed is classical biased listening practices. He says the voltage output is different. He should buy a $20 meter and measure that and not speculate from listening tests. Audiophiles routinely report level differences with cables and such that are not there and can't possibly be there.

He is welcome to send me his new M500 and I will measure it.
 

reddeath

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There is no such thing as "slow sound." Veil and such being there/removed is classical biased listening practices. He says the voltage output is different. He should buy a $20 meter and measure that and not speculate from listening tests. Audiophiles routinely report level differences with cables and such that are not there and can't possibly be there.

He is welcome to send me his new M500 and I will measure it.
Wow, nice. I just doubt he will hear about the offer. I just shared his youtube video here.

And on another matter, regarding your review, which of the tests listed measures the frequency response of the headphone amplifier in M500? I have an impression that my M500 V2 has a "thin" low frequency, comparing to other amps I have available and tested with the same headphones. I would like to dig deeper into this area and understand the test results.
 
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