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SMSL SH-9 THX Headphone Amplifier Review

peng

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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?

Based on what measurements? Amir's did not prove the output was not "balanced", though he may be right, that it wasn't truly balanced by the common definitions.

In order to be sure, one needs to see the schematics, or take other measurements than just the output voltage that is just one indicator. The lower than expected output could have been by design, for other reasons.

I would think the quickest way to find out, is to email smsl.
 

mr.at

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We're faulting SMSL more than we should here.
Everyone who's read a bit of more detailed info knows it's not a truly/fully balanced amp.
Neither is the Massdrop 789.
And then some.

On paper, all are balanced you see. Their can claim that their amp are balanced simply because they have balanced input and balanced output, so no arguments there.

They all call it a balanced amp. But in more detail you find out it's not fully balanced. All these amps talk about XLR input and output being there for convenience. I knew before buying it that it's not actually balanced. But THX has other advantages why it does matter a whole lot.

However, people who are looking for a true balanced amp will know better than to buy these.
So there. Not much of a misrepresentation, but rather a don't ask don't tell scenario.

Remember: For truly balanced amps, most to all companies insist on the fact a lot more, so that the reader is informed of the particular detail.
 
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Roland68

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Based on what measurements? Amir's did not prove the output was not "balanced", though he may be right, that it wasn't truly balanced by the common definitions.

In order to be sure, one needs to see the schematics, or take other measurements than just the output voltage that is just one indicator. The lower than expected output could have been by design, for other reasons.

I would think the quickest way to find out, is to email smsl.
It has long been established that the SH-9 (which I still think is very good) is not a balanced headphone amp. You don't have to measure anything for this.
The SH-9 has only 2 "amplifiers", i.e. 1 per channel. For a balanced output, 2 "power amplifiers" per channel are required.
The excellent relay-based volume control is also only stereo, so everything from the input is SE.
But as I said, there is no new information and you don't need any measuring equipment for it.

I also find it very strange that with SMSL, Sabaj, etc., you first have to look into the devices to know what is SE and what is balanced. Topping is at least honestly given in the technical data and comparison tables.
Especially for "non-technicians" it is very confusing to see through the sense and nonsense.

But the big manufacturers, such as Marantz, Yamaha, etc. are no better. Many, if not most, XLR connectors are fake or very cheaply wired. Often only the + and ground pin are connected internally (- to ground) and that's kidding the customer, because only SE. In other cases, the signal is converted in the cheapest way to SE at the input, or to balanced at the output.
This may be ok for cheap devices, but I'm talking about devices in the 4-digit range and often not with a "1" in front.
So what are you supposed to accuse SMSL of?
 

peng

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It has long been established that the SH-9 (which I still think is very good) is not a balanced headphone amp. You don't have to measure anything for this.
The SH-9 has only 2 "amplifiers", i.e. 1 per channel. For a balanced output, 2 "power amplifiers" per channel are required.
The excellent relay-based volume control is also only stereo, so everything from the input is SE.
But as I said, there is no new information and you don't need any measuring equipment for it.

I also find it very strange that with SMSL, Sabaj, etc., you first have to look into the devices to know what is SE and what is balanced. Topping is at least honestly given in the technical data and comparison tables.
Especially for "non-technicians" it is very confusing to see through the sense and nonsense.

But the big manufacturers, such as Marantz, Yamaha, etc. are no better. Many, if not most, XLR connectors are fake or very cheaply wired. Often only the + and ground pin are connected internally (- to ground) and that's kidding the customer, because only SE. In other cases, the signal is converted in the cheapest way to SE at the input, or to balanced at the output.
This may be ok for cheap devices, but I'm talking about devices in the 4-digit range and often not with a "1" in front.
So what are you supposed to accuse SMSL of?
You don't need to measure anything if you have the necessary information. It appears that you have the information so okay, thank you for sharing.

That being said, as others have alluded to, there are definition(s) for "balanced", and "fully balance". For preamps and prepros, very few (including some so called higher end ones such as Bryston and Parasound, just as an example, are not "fully (end to end) balanced", yet some relatively affordable ones are fully balanced. That's why I wasn't sure about the SH-9, and not want to base on just the output voltage/power measurements. Again, thanks for the additional information.
 

Roland68

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You don't need to measure anything if you have the necessary information. It appears that you have the information so okay, thank you for sharing.

That being said, as others have alluded to, there are definition(s) for "balanced", and "fully balance". For preamps and prepros, very few (including some so called higher end ones such as Bryston and Parasound, just as an example, are not "fully (end to end) balanced", yet some relatively affordable ones are fully balanced. That's why I wasn't sure about the SH-9, and not want to base on just the output voltage/power measurements. Again, thanks for the additional information.
This information was available to everyone from the start and was not secret. It was known that the SH-9 only has 2 THX chips and can therefore only do SE. The SP400 is the model with 4 of these chips and has a balanced output, but only a stereo volume control, so internally not fully balanced.
In most cases you can use the volume potentiometer to identify whether it is a fully balanced device or not, even with the devices you have mentioned. The required quad pot is twice as long as the stereo pot. The interior views can be found from almost all devices with Google image search.

You must also distinguish between HPA output, balanced small signal processing, and balanced small signal transmission over cable. That's three pairs of shoes and the advantage of one is the disadvantage of the other.

With an HPA you have two power amps per side, which can increase and at most double the power, but also the noise per power amp adds up. Disadvantage with sensitive headphones.

Symmetrical small-signal processing is very error-prone, very expensive (extremely precise components), very complex and development-intensive. The danger that parts of the signals cancel each other out is very high and that's exactly what we don't want. In many comparisons I could not "hear" any advantage with fully balanced devices, rather the opposite.

Symmetrical signal transmissions have the real advantage, since with correct and high-quality circuitry/electronics in the source and receiving devices, all interference signals en route are eliminated.
But, as written before, even in expensive high-end devices, there is saving or cheating, and we're really only talking about components for a few $, less than 10!
That's why I haven't bought any devices with an XLR connection for a long time without looking at the circuit documentation.
 

teashea

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No doubt that lawyers will be beathing down your door wanting to represent you. Just a small problem of the filing fee being more than the damages.
 

Roland68

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No doubt that lawyers will be beathing down your door wanting to represent you. Just a small problem of the filing fee being more than the damages.
If you mean me, I have no idea how you get that. I can't complain about anything.
All my gear has very good working real XLR connectors and I've never wasted my money on any pseudo gear.

On the contrary, I owe these manufacturers a debt of gratitude, because these machinations forced me to deal with and familiarize myself with this subject. This has brought me and my understanding of this topic much further and saved me a lot of money.
Because you learn most from your own mistakes, but the "mistakes" or non-optimal circuits of others are also very suitable for this.
My knowledge of balanced connections previously came from LVDS (Industry/IT) and some Studio Engineering/Pro Audio. Man, I was an idiot to believe that this topic in particular would be treated seriously in the hi-fi sector :facepalm:

If you spend a lot more money on a high-end device to have Balanced XLR connectors, and eventually find out that those outputs are only paralleled to the RCA outputs, wouldn't you feel cheated?
Large companies often charge a very tidy surcharge for devices with XLR connections. It's a pity for the buyers who then get such a device.

But it's actually about the SH-9, which I would prefer to many devices with a real balanced output, including the SP400.
 

peng

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This information was available to everyone from the start and was not secret. It was known that the SH-9 only has 2 THX chips and can therefore only do SE. The SP400 is the model with 4 of these chips and has a balanced output, but only a stereo volume control, so internally not fully balanced.
In most cases you can use the volume potentiometer to identify whether it is a fully balanced device or not, even with the devices you have mentioned. The required quad pot is twice as long as the stereo pot. The interior views can be found from almost all devices with Google image search.

You must also distinguish between HPA output, balanced small signal processing, and balanced small signal transmission over cable. That's three pairs of shoes and the advantage of one is the disadvantage of the other.

With an HPA you have two power amps per side, which can increase and at most double the power, but also the noise per power amp adds up. Disadvantage with sensitive headphones.

Symmetrical small-signal processing is very error-prone, very expensive (extremely precise components), very complex and development-intensive. The danger that parts of the signals cancel each other out is very high and that's exactly what we don't want. In many comparisons I could not "hear" any advantage with fully balanced devices, rather the opposite.

Symmetrical signal transmissions have the real advantage, since with correct and high-quality circuitry/electronics in the source and receiving devices, all interference signals en route are eliminated.
But, as written before, even in expensive high-end devices, there is saving or cheating, and we're really only talking about components for a few $, less than 10!
That's why I haven't bought any devices with an XLR connection for a long time without looking at the circuit documentation.
Not trying to argue or disagree with your points as you obviously are very knowlegeable in this, but it has no relevancy, not directly anyway, to my point that people should not draw their conclusion based on the xlr output not more than the other output as Amir alluded to. I just realize now, that Vamp898, post#339, made that same point. As to the additional information you cited, I did visit the smsl website before I posted, but somehow I must have missed some paragraphs, pages, or links.

If anyone, including Amir, had concluded that the SH-9's output is not truly balanced based on info you cited, I would not have posted at all.
 

Roland68

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Not trying to argue or disagree with your points as you obviously are very knowlegeable in this, but it has no relevancy, not directly anyway, to my point that people should not draw their conclusion based on the xlr output not more than the other output as Amir alluded to. I just realize now, that Vamp898, post#339, made that same point. As to the additional information you cited, I did visit the smsl website before I posted, but somehow I must have missed some paragraphs, pages, or links.

If anyone, including Amir, had concluded that the SH-9's output is not truly balanced based on info you cited, I would not have posted at all.
I definitely agree with you. You cannot rely on the manufacturer's information on this subject and for an audio fan it is very difficult to find out whether a device has a real balanced/differential output or whether it is only pseudo = single ended.
The easiest way to recognize the devices is the performance data. If there is only one per ohm, it's probably SE.
 

Sanlitun

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Just picked up one of these out of curiosity. Anyone else find it stays warm when switched off?
 

Roland68

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Just picked up one of these out of curiosity. Anyone else find it stays warm when switched off?
Unfortunately, the device does not have a real off switch, so the switched-mode power supply is always on. Use a power strip with a switch.
 

Music1969

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This is still a great buy by the way.

No channel imbalance issues with resistor ladder volume control.

I have its biggest brother (balanced out!) the SP400 but that extra power output is probably not important.
 

Sanlitun

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Unfortunately, the device does not have a real off switch, so the switched-mode power supply is always on. Use a power strip with a switch.
Of course not one of the reviews of the SH-9 mention that it is hot all the time while plugged in, or any of its other issues.
 
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ethanhallbeyer

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Is the SH-9 still the best bang for your buck HPA in 2023, or is there something else to consider now?
 

Doodski

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Is the SH-9 still the best bang for your buck HPA in 2023, or is there something else to consider now?
If you don't need balanced and single ended is fine then the Schiit Magni Heretic is a nice economical and powerful headphone amp. It's bare bones but has lots of power.
 
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Sak

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For almost 2 years, I've owned the SH9, and I want to say that it's one of the most successful amplifiers from SMSL (with a perfect channel balance and remote control) in terms of price, quality, and convenience. Recently, I bought the Topping A30 PRO at half price. Overall, I liked it a lot; it's a very good amplifier with many connectors, a power switch, and well-thought-out design. However, it's a pity it doesn't have remote, and the volume control is not very convenient. It also gets quite hot despite the well-designed technical openings all around it. In this regard, SMSL has room for improvement. It would be good to have such openings on the sides at least. Because the SH9 also heats up. Two small 5V fans completely solve this problem and are inexpensive. On the A30 PRO, you can place them more easily from any side, even from below or the side. On the SH9, I installed two fans at the back, which blow into the XLR jacks. The airflow isn't as good as on the A30 PRO, but the fans do their job. I no longer feel the heat, and the chassis stays cool.
If we talk about the sound in general, it's difficult to notice any objective difference when switching between them because the volume levels are different. Subjectively, the A30 PRO has slightly more noticeable low frequencies, while the SH9 has a slightly more neutral sound. But these are all based on personal preferences. Both amplifiers are wonderful.
Initially, I planned to keep the newer A30 PRO out of these two, but I still prefer the SH9 based on my personal preferences. I don't need more power, but the perfect channel balance (256-step attenuator using a resistor ladder and remote control) provides incredible convenience compared to the A30 PRO. Furthermore, as mentioned in previous messages, SMSL has updated the firmware to version 1.0/1.11 in the latest revisions of the amplifier. Finally, SMSL heard our prayers and made the screen switchable off! (They should have done this with the first-generation M500; it would have been great, and it's not a problem to flash it). You can set time intervals for turning off the screen, and they added a few more brightness adjustment levels and some menu options.
In general, after 2 years, I still love my SH9, and I haven't regretted this successful purchase. Before this, I had the SP200, and if it had a remote and a similar attenuator, it would have been a wonderful small and powerful amplifier. Maybe these brief comparisons will be helpful to someone.
I apologize for the machine translation.

 

Music1969

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SMSL has updated the firmware to version 1.0/1.11 in the latest revisions of the amplifier. Finally, SMSL heard our prayers and made the screen switchable off!
This is a classic amp. Reliable. How did you update firmware ?
 

Sak

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Как вы обновляли прошивку?
This is a newer version of the SH9, purchased recently.
I haven't personally flashed it, but it's possible if there are service tool available from the manufacturer.

For example, when I had the Sabaj D5, which I bought at the launch, there was some issue with it, I don't remember the specifics, but I contacted SMSL through their official website, and they sent me a tool like this, built on the STM32 microchip, and a program that allowed me to easily update the device, and the problem was resolved.


The SH9 has a similar service port, but it's slightly smaller. I think you should get in touch with SMSL, and they should be able to send you the firmware, the updating program, and this tool.

For example, with the M500, I manually soldered to the service connector and updated the firmware using an ST-Link. It's not difficult; for SH9 the problem is to find the program and firmware.
 

adrianlimkb

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I think i am able to get a used combo SU-9 + SH-9 at around 350 usd,would this be a good buy rather than a L30ii + a dac around 200usd?
Is this combo still relevant good for 2024 and maybe 2 year more to go...
 
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