SMSL SH-9 THX Headphone Amplifier Review

[NexusOne]

Is there a next step From the SH9 with a remote or is there Nothing at the Moment because on the asr Ranking there is nothing with better measurements.

 

[mr.at]

Is there a next step From the SH9 with a remote or is there Nothing at the Moment because on the asr Ranking there is nothing with better measurements.

Doesn't a Topping L70 come with one? Also the extra outs for a speaker/another pre. Then yet relayed volume control. AND a screen yet still.
I have the SH-9 myself, but an L70 would just be ideal at this point.

 

[teashea]

This is a review and detailed measurements of the SMSL SH-9 THX headphone amplifier. Product was just released and will be available shortly. The sample I have was kindly sent to me by SHENZHENAUDIO and costs US $290.

The market for high performance headphone amplifiers has become quite crowded but SH-9 sets itself apart with a gorgeous digital display and volume control:

View attachment 93385

A 256-step attenuator using resistor ladder implements volume control which should result in perfect channel matching (see measurement later). Typical of these systems, the volume control changes a bit slow compared to analog counterparts. The chatter of relays controlling which resistors are being used is rather quiet which is a relief.

The back side shows that there is only input and no pass through/pre-amp mode:
View attachment 93386

As you will see in the measurements, the 4 pin XLR output is NOT balanced in the sense that it doesn't provide higher output level compared to 1/4 headphone jack. There is balanced input as you see which is important to keep possibility of ground loops low. As long as there is enough output, it does not matter whether there is or is not a balanced (properly called differential) output.

SMSL SH-9 Measurements
As usual, we measure the unity gain of the unit with feeding it 4 volts and getting 4 volts out. The low gain mode is 0 dB which makes this task easy:

View attachment 93387

This is superb performance and provably transparent to the source. Ranking is way up there:

View attachment 93388

Noise performance is excellent as well:

View attachment 93389

50 mv output which forces the output attenuation is good but not state of the art:

View attachment 93390

Frequency response is dead flat as we like to see:
View attachment 93391

Here is our power versus distortion starting at 300 ohm:

View attachment 93392

My threshold for desktop products here is 100 milliwatts and the SH-9 sails way past that to 226 milliwatts. So it should have no trouble driving high impedance headphones.

Switching to the other extreme at 33 ohm we get similarly excellent performance:

View attachment 93393

Using the XLR output with balanced load shows that there is no more output to be had:

View attachment 93395

As you see the drop THX amp in balanced mode can produce much more power. But SH-9 beats it in noise department and by good bit.

Finally, the key differentiation for SH-9: channel balance:

View attachment 93396

SMSL SH-9 Headphone Listening Test
I tested the SH-9 with my killer load: the Ether CX with its 25 ohm impedance and low efficiency. The SH-9 had no trouble whatsoever driving it with authority with no sign of distortion to any loudness level you wanted. Likewise it took the Sennheiser HD-650 headphone's neck and drove it to skull resonating levels with ease.

dfjk jkkk jdkfj kkkkk.... what ...

Oops, sorry about that. A screw had come loose inside my head as a result of the above testing. Tightened that and all is well now.

Conclusions
The SMSL SH-9 Joins other instrument grade, ultra-fidelity headphone camp. It mates nicely to its DAC sibling, the SMSL SU-9. It has an attractive, high contrast high resolution display with accurate digital volume control. The cost is also quite attractive. Misses are few which is lower power due to lack of balanced output, soft control buttons, and slow volume control.

I love differentiation without sacrificing performance which SMSL SH-9 brings. I am happy to put the SH-9 on my recommended list.

------------
As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Does this have a L/R balance control? There is a bal indicator on the panel

 

[mr.at]

Does this have a L/R balance control? There is a bal indicator on the panel

No, that is the indicator for the input. It switches from BAL (Balance input at the bank, dual XLR) or RCA (SE input via dual RCAs at the back). It's an input switcher.

 

[teashea]

No, that is the indicator for the input. It switches from BAL (Balance input at the bank, dual XLR) or RCA (SE input via dual RCAs at the back). It's an input switcher.

Thank you

 

[Dunring]

I've got one of these coming in next week. Has anyone heard an explanation why the measured output is about half the quoted specs? On paper it should test the same power as the SP200 but at 1.9 watts at 32 ohm it's actually much less.

 

[Jimbob54]

I've got one of these coming in next week. Has anyone heard an explanation why the measured output is about half the quoted specs? On paper it should test the same power as the SP200 but at 1.9 watts at 32 ohm it's actually much less.

Usually because Amir measures to the bend in the knee/ clipping point which in these amps is way below the usual quoted spec power @1% THD.

 

[staticV3]

On paper it should test the same power as the SP200 but at 1.9 watts at 32 ohm it's actually much less.

If you see this in the official specs, assume it is at 1% THD+N. That's the industry standard.

Now look at Amir's graph:

Exactly 3W at 33Ω, 1% THD+N, just like in the specs.

 

[Dunring]

Ok thanks, I've had the HO200 and a few SP200's so it'll be fun to hear how it sounds. I've got an A30Pro and really into amplifiers with the same power on all connectors. XLR is superior as a connector, but I get a lot of 600ohm Beyers and others I don't have balanced cables for, really flexible/consistent for testing headphones out since 3-5 different ones arrive each week. The equalizing bug and pre-volume war favorite songs really needs some extra headroom sometimes.

 

[Music1969]

This is a wonderfully priced headamp with great ladder resistor volume control - say goodbye to channel imbalance

If you need more headroom there is the bigger brother SMSL SP400

I have to admit - the Topping A90 Discrete aesthetic design is beautiful with its dot matrix volume indicator but firmware bugs reported by users and even YouTube reviewers, are a huge turnoff for me.

 

[Dunring]

I just got one of these in, does anyone know what that plug on the bottom is for? Can't seem to find any reference to it in the manual or web site.

 

[AdamG]

I just got one of these in, does anyone know what that plug on the bottom is for? Can't seem to find any reference to it in the manual or web site.


View attachment 278694

Just a guess. It’s a service port and/or firmware update port for Factory use.

 

[Jimster480]

I just got one of these in, does anyone know what that plug on the bottom is for? Can't seem to find any reference to it in the manual or web site.


View attachment 278694

It would be for updating the firmware. At least this is what it was for on other SMSL devices that have had a similar port somewhere.

 

[Dunring]

Well I got two of these and each is a different firmware version on each, here's what I can tell. 1.0/1.0 is the original one, the other I have is 1.0/1.11 and off the menu you can tell as well because it has a screen timeout setting, and the original one doesn't. I was testing both (volume matched using an app) and the 1.11 sounded better, only then I noticed on the one I liked more, the screen would shut off. If you buy one used, I'd highly recommend asking to make sure it's the 1.11 version. I like this one so much I'm keeping it as a daily driver. There's no firmware update on the SMSL site, going to contact them and see about the port on the bottom just out of curiosity about that port, doesn't look like any standard cable plug.

 

[Music1969]

There's no firmware update on the SMSL site, going to contact them and see about the port on the bottom just out of curiosity about that port, doesn't look like any standard cable plug.

Please keep us posted !

I wonder if my SP400 had a firwmare update for screen timeout too.

 

[mr.at]

Wow I'd love myself some screen timeout. Funny, I bought this quite late (2021 or so) after many reviews had come out, I guess I'm still with 1.0.
It sounds better too? Please elaborate on that.

That's two reasons now for us to figure something out to update this now.

Well I got two of these and each is a different firmware version on each, here's what I can tell. 1.0/1.0 is the original one, the other I have is 1.0/1.11 and off the menu you can tell as well because it has a screen timeout setting, and the original one doesn't. I was testing both (volume matched using an app) and the 1.11 sounded better, only then I noticed on the one I liked more, the screen would shut off. If you buy one used, I'd highly recommend asking to make sure it's the 1.11 version. I like this one so much I'm keeping it as a daily driver. There's no firmware update on the SMSL site, going to contact them and see about the port on the bottom just out of curiosity about that port, doesn't look like any standard cable plug.

 

[Vamp898]

This might sound like a strange question but...

S.M.S.L is telling on the Homepage that this amp does have an balanced output. Based on your measurements, it doesn't.

So it should be totally safe to sue them right? They are stating false claims on their official homepage. Did that happen? Or does just no one care?

 

[Jimbob54]

This might sound like a strange question but...

S.M.S.L is telling on the Homepage that this amp does have an balanced output. Based on your measurements, it doesn't.

So it should be totally safe to sue them right? They are stating false claims on their official homepage. Did that happen? Or does just no one care?

Speak to a lawyer. About litigating in China. When you've suffered no real loss or harm.

 

[Vamp898]

Speak to a lawyer. About litigating in China. When you've suffered no real loss or harm.

Oh, i am sorry, i should have marked the post as sarcasm^^

Balanced has nothing to do with having more output power. You are legally allowed to call your device balanced when it uses an balanced connection (completely unrelated to how much output power it has).

So you could (makes no sense, but is possible) design your device in a way that it has less output power on balanced than on single ended and it still would be an balanced connection.

The only requirement you have to fullfill to call your device 100% truly balanced is, to use an balanced connection.

The SH-9 uses an balanced connection, so it is allowed to call itself an balanced amp without any issues.

It is, on the other hand, illegal to claim that an company is lying about the capabilities of their products... so the better question is, why is S.M.S.L not suing^^

 

[Jimbob54]

Oh, i am sorry, i should have marked the post as sarcasm^^

Balanced has nothing to do with having more output power. You are legally allowed to call your device balanced when it uses an balanced connection (completely unrelated to how much output power it has).

So you could (makes no sense, but is possible) design your device in a way that it has less output power on balanced than on single ended and it still would be an balanced connection.

The only requirement you have to fullfill to call your device 100% truly balanced is, to use an balanced connection.

The SH-9 uses an balanced connection, so it is allowed to call itself an balanced amp without any issues.

It is, on the other hand, illegal to claim that an company is lying about the capabilities of their products... so the better question is, why is S.M.S.L not suing^^

It's probsbly better to quote the particular post you are referring to. And no, I doubt smsl really cares much about what people say about pruduct specifics on forums such as this.