Hello Everyone.
This is a review and detailed measurements of the SMSL H200 Preamplifier and HP Amplifier.
It was kindly sent to me by SMSL, on my request, and I received a very early production sample. Current price is below $400.
Presentation
The SMSL H200 is a pure analogue preamplifier, some sort of dinosaur in our digital world, and now addressing a niche market(?). It offers only two inputs (Balanced and Single Ended), with two rear outputs (XLR and RCA) as well as two front balanced and unbalanced outputs too for headphones.
Rear inputs must be selected from the menu, making it a 2 inputs preamplifier, again one being balanced and the other unbalanced. Both rear outputs will route the signal when they are active, else it goes to front output, meaning there too you have to chose between line or headphones outputs.
This device integrates well in the "200" series from SMSL where we find notably the PL200T, D200 or G1 that I already reviewed.
The back is as simple as it can get, but not the USB input for potential updates :
You can get more details about this device from SMSL themselves who announced the release of the H200 here on ASR.
User experience
The interface is simple, and serves to select the input (RCA or XLR), and outputs (rear or front). There's one addition and that is the gain which is selectable between High/Mid/Low and it impacts rear outputs too.
There is a remote control that repeats all functions available from the front knob, but I did not use it.
Basically, we have only two analogue inputs, one Balanced and one Single Ended. This is not much, but in a digital world, the DAC is likely to be the real source selector. No phono input here.
Looking at it from far away, it looks like you get only a volume knob, especially if you think about it as a preamplifier. But it is a little more than that. To start with, the analog volume is digitally controlled to offer perfect channel balance, and a significant part of a preamplifier’s performances rely on the quality of the volume knob.
What's interesting too is that we get 3 selectable gains that influence the rear outputs too. You are used to the "Low" gain setting which is useful for sensitive IEMs to increase the dynamic range by lowering the internal gain of the amplifier. It means you'll need to crank up the volume by several notches, and that's the purpose so as to increase the DR. I measured them (from XLR input) as is:
The reason I'm mentioning this, in the user experience section of the review, is because it is practical to get selectable gains at the output. Indeed, and similar to the IEM reasoning for wanting low gain, I do like to have high gain at the output so I can use older devices such as a Cassette Deck but also some older CD Players (HDCD ones are often limited to 1Vrms when not playing a HDCD disc). These older devices can go way below our standard 2Vrms output, let alone 4Vrms from XLR, but modern amplifiers are in demand of higher input voltages. So having a "high" 14dB (RCA) or 20dB (XLR) gain at the output of the preamp will help drive an amplifier to its max power with low output voltage sources.
On the contrary, having a "Medium Gain" choice helps with high output voltages sources and amplifiers that can be driven to full power with input voltages below 1Vrms. Again, the idea is the use the volume as close as possible to the max so the dynamic range is better. We'll see if that theory translates into measurable advantages.
The H200 gets warm rapidly and can run hot if outside temperature is too (no measurements, sorry).
The volume display does not show the standard attenuation in dB but a rather unusual % of maximum, from 0 to 99%. I could hear some light relay sound when going one level up or down.
SMSL H200 - Measurements (Preamplifier)
Preamble: Despite few functionalities, it was really long to test this device as I wanted to check XLR to XLR, RCA to RCA, XLR to RCA and RCA to XLR at the 3 gains. So, I have a ton of measurements! And be reassured that you'll get the most significant ones, not to make this review too long.
All measurements were performed with an E1DA Cosmos ADCiso (grade 0), and the Cosmos Scaler (100kohms from unbalanced input), for capturing analog outputs of the Accuphase. I used a high performance DAC, the SMSL DO400, as the generator with REW Software from a laptop. All these devices run on batteries, and the D50III was behind a USB isolator, to prevent as much as possible any ground loops.
Unless otherwise noted, all the below measurements where done with the SMSL DO400 acting as the generator, with the below parameters from XLR outputs (divide by two for RCA):
Both XLR and RCA outputs are non inverting and Left & Right channels are perfectly balanced at any volume (very good).
----
Time has come to start with the very standard SINAD measurement (or THD+N in my case) with 1kHz sine input at 4Vrms, with the H200 set at medium gain and volume at maximum (99%):
The above corresponds to what SMSL published (122dB SINAD) which is very good. Pushing it to 5Vrms input (the max I can get from the DO400) improved the SINAD by 2dB:
We get close to 124dB SINAD, which is crazy good.
But let's go back to some more reasonable / real life case, starting with unity gain at 4Vrms input/output (volume set to 92%):
Compared to the DO400 alone, we loose few dBs of SINAD and this is because the signal is attenuated, ie we lose resolution.
Let's try even more realistic case of 1Vrms input and 2Vrms output:
That is 12dB less output from the SMSL DO400, and at this attenuation, its performances are down to 116dB SINAD, so we lose 6dB by going through the H200, when its volume it set to maximum. More on that later.
What about RCA? Let's check:
This the best I got when pushing the input to 2.5Vrms and with unity gain. We lose a little compared to XLR (roughly 2dB) and besides a bit more Power supply related leakages, performances are very close.
I'll stop here for the SINAD calculations, as you got the point of excellence. From the above, you saw that the distortion generated by the H200 is always below -130dB, this is a very transparent device on harmonic distortion perspective. As a consequence, the limit is the noise floor and nothing else here (I let you read the Noise figures).
----
The reason why I shared so many measurements is because I wanted to show you a little more than usual, so to make you consider what happens when we lower the volume. And more on that immediately. The two below tables are inspired from the tests I performed with the SMSL D200 which has an excellent analog volume control.
What I did is that I compared lowering the volume from the SMSL DO400 (which has a digital volume attenuation via its high end ES9039MSPRO) and attenuating the same way via the H200. Here below are the results from XLR and RCA in/out (THD+N, THD and ENOB are provided):
As you can see, when the volume goes down, it is preferable to use the one of the H200 rather than the digital one of the DO400 (XLR). Since a preamplifier is almost always used to attenuate the signal rather than to increase the gain, I think the above is very good, and by the way a new level of excellence for what I measured previously with other items.
Note there's no advantage on RCA in/out though. But again, the DO400 is much higher resolved device, theoretically, and so seeing the H200 very close to it is good news.
The perfect level matching between the two channels at any output volume is also to be recognized.
----
I suppose you saw above that there is a little PS leakage that can be seen (50Hz and harmonics):
The above shows two cases, on at Low Gain and the other at High Gain, both XLR in/out, and at different voltages. At these high levels, the spuria are at or below -140dBr which is really nothing.
----
Since I'm here, let me add the 50Hz @0dBFS into 600ohms, for compatibility with Stereophile measurements:
This is similar to what I showed with other high-end DACs, meaning it is very good.
----
Let's accelerate a bit this review. The bandwidth is extremely flat (measured up to 80kHz):
This is from the RCA outputs with Volume set at 70% which is low. The two channels are perfectly matched, and if you get the impression there's only one channel represented here, there are two! It is the same perfection at any volume and with balanced in/out too.
----
Let's continue with the famous Multitone that a lot of you, including me, like so much:
This is a very good result, much better than what I measured from the old Accuphase C-280. The few spikes are coming from my interface, I get them from time to time. We have here well above 21bit distortion free range!
----
Oh, yes, another measurement that you can use to compare with other devices. It is the THD+N ratio vs frequency, with an extended bandwidth to capture all distortion and noise components up to 90kHz:
This is at unity gain. This is so good that I am at the limit of my measurement interface, both ends have distortion coming from the ADC, not from the H200. This is very low level of noise and of course distortion.
----
The below IMD SMPTE sweep vs input level is not comparable to the same test from Amir, because it is excluding noise:
I overlaid results at two volume settings, max gain or unity gain. The level of IMD is very low, only the best DACs can do better and note that here there is the IMD from the DO400 that adds on top of the H200, so my guess is that the H200 alone does a little better.
----
Considering the quality of the device I'm reviewing here, I though I'd add other IMD measurements that you don't get often, and for future reference:
The H200 has very low level of distortion, be it harmonic or non-harmonic. Let's see what other pre-amp can beat that.
----
Dynamic range measurement gave me a little headache. According to the AES standard, it should be measurement from a -60dB signal relative to max amplitude or say a 0dB level that we define.
So I initially went for 5Vrms input as the 0dB level, and reduced the input by -60dB, and here we go (max volume, Medium Gain):
This is below what SMSL published (132dB) and so I wondered, what if instead of reducing the source, I reduce the volume of the H200 by -60dB?
Wow, ok, respect.
----
Now I'm used to regroup all Inter Modulation tests as below, when I review DACs, and these are sourced from REW's results (IMD distortion and Total Distortion+Noise shown for each):
These are extremely low intermodulation distortion and noise. And from all of what I published so far, I state that this preamp is distortion free!
SMSL H200 - Measurements - Headphones
I got the exact same output voltages from the front outputs as from the back. And the measurements are equally excellent.
Let me add one from HPA Unbalanced output, with XLR input at 5Vrms, in High Gain mode, output volume set at 87%, into 32ohms load:
Far from max volume, we already get near 121dB SINAD. That means we get up to 1W of clean output power with unnecessary high SINAD. I could not go higher because it clips my ADC
Going Medium gain, again with 5Vrms input, volume at max 99%, still into 32ohm load, I can set my ADC to capture the full amplitude without clipping and in that case:
This time we get 123dB SINAD from unbalanced front output, this is impressive.
And let me jump directly to one that Amir always publishes and that's the SNR measured at 50mVrms output in low gain:
We get a very good 87.4dB SNR which puts this baby in the comfortable zone of @amirm's chart. As a matter of facts, it is funny to note that in "Medium Gain" it does a little better, reaching 88dB
Conclusion
That was a long review and it's because I truly enjoyed reviewing this preamplifier. I was not expecting anything special, considering the price, but when I first saw the excellent results, incredibly better than the very good old Accuphase C-280, I had to investigate more and create one review to serve as a master reference.
Of course, that means it's the best preamplifier I reviewed, and I am eager to test higher end versions from SMSL (@Kitty (S.M.S.L Marketing) if you hear me
).
On a HP Amp perspective, it is above average and beats the DO400 I used as the generator, on that perspective. I guess I (we) shall be happy.
The extreme quality of the analog volume control is to be noted. For when listening at low volume, it is the guarantee to get resolution difficult to equal from the best DACs. So, don't be afraid to insert it in your current set, it will not degrade the performances, on the contrary...
To be honest, when measuring this preamp, I reached several times the limits of what I can safely measure, especially at lower output volumes, good on the H200. And I saw many times people talking about fact that a preamplifier should be "a straight wire with gain". And I've seen many reviews giving that appraisal to preamplifiers far from delivering as this one does...
So, Ladies and Gentleman, here you go: a straight wire with gain. Well done to SMSL at that price point.
I hope you enjoyed this review!
Flo
This is a review and detailed measurements of the SMSL H200 Preamplifier and HP Amplifier.
It was kindly sent to me by SMSL, on my request, and I received a very early production sample. Current price is below $400.
Presentation
The SMSL H200 is a pure analogue preamplifier, some sort of dinosaur in our digital world, and now addressing a niche market(?). It offers only two inputs (Balanced and Single Ended), with two rear outputs (XLR and RCA) as well as two front balanced and unbalanced outputs too for headphones.
Rear inputs must be selected from the menu, making it a 2 inputs preamplifier, again one being balanced and the other unbalanced. Both rear outputs will route the signal when they are active, else it goes to front output, meaning there too you have to chose between line or headphones outputs.
This device integrates well in the "200" series from SMSL where we find notably the PL200T, D200 or G1 that I already reviewed.
The back is as simple as it can get, but not the USB input for potential updates :
You can get more details about this device from SMSL themselves who announced the release of the H200 here on ASR.
User experience
The interface is simple, and serves to select the input (RCA or XLR), and outputs (rear or front). There's one addition and that is the gain which is selectable between High/Mid/Low and it impacts rear outputs too.
There is a remote control that repeats all functions available from the front knob, but I did not use it.
Basically, we have only two analogue inputs, one Balanced and one Single Ended. This is not much, but in a digital world, the DAC is likely to be the real source selector. No phono input here.
Looking at it from far away, it looks like you get only a volume knob, especially if you think about it as a preamplifier. But it is a little more than that. To start with, the analog volume is digitally controlled to offer perfect channel balance, and a significant part of a preamplifier’s performances rely on the quality of the volume knob.
What's interesting too is that we get 3 selectable gains that influence the rear outputs too. You are used to the "Low" gain setting which is useful for sensitive IEMs to increase the dynamic range by lowering the internal gain of the amplifier. It means you'll need to crank up the volume by several notches, and that's the purpose so as to increase the DR. I measured them (from XLR input) as is:
- Low Gain : -3.8dB gain (claimed -3.8dB)
- Medium Gain : 5.5dB gain (claimed 6dB)
- High Gain : 19.13dB gain (claimed 19.7dB)
The reason I'm mentioning this, in the user experience section of the review, is because it is practical to get selectable gains at the output. Indeed, and similar to the IEM reasoning for wanting low gain, I do like to have high gain at the output so I can use older devices such as a Cassette Deck but also some older CD Players (HDCD ones are often limited to 1Vrms when not playing a HDCD disc). These older devices can go way below our standard 2Vrms output, let alone 4Vrms from XLR, but modern amplifiers are in demand of higher input voltages. So having a "high" 14dB (RCA) or 20dB (XLR) gain at the output of the preamp will help drive an amplifier to its max power with low output voltage sources.
On the contrary, having a "Medium Gain" choice helps with high output voltages sources and amplifiers that can be driven to full power with input voltages below 1Vrms. Again, the idea is the use the volume as close as possible to the max so the dynamic range is better. We'll see if that theory translates into measurable advantages.
The H200 gets warm rapidly and can run hot if outside temperature is too (no measurements, sorry).
The volume display does not show the standard attenuation in dB but a rather unusual % of maximum, from 0 to 99%. I could hear some light relay sound when going one level up or down.
SMSL H200 - Measurements (Preamplifier)
Preamble: Despite few functionalities, it was really long to test this device as I wanted to check XLR to XLR, RCA to RCA, XLR to RCA and RCA to XLR at the 3 gains. So, I have a ton of measurements! And be reassured that you'll get the most significant ones, not to make this review too long.
All measurements were performed with an E1DA Cosmos ADCiso (grade 0), and the Cosmos Scaler (100kohms from unbalanced input), for capturing analog outputs of the Accuphase. I used a high performance DAC, the SMSL DO400, as the generator with REW Software from a laptop. All these devices run on batteries, and the D50III was behind a USB isolator, to prevent as much as possible any ground loops.
Unless otherwise noted, all the below measurements where done with the SMSL DO400 acting as the generator, with the below parameters from XLR outputs (divide by two for RCA):
- When it was used as a source at +2dB output, its output was 5.243Vrms (16.6dBu)
- When it was used as a source at 0dB output, its output was 4.161Vrms (14.6dBu)
Both XLR and RCA outputs are non inverting and Left & Right channels are perfectly balanced at any volume (very good).
----
Time has come to start with the very standard SINAD measurement (or THD+N in my case) with 1kHz sine input at 4Vrms, with the H200 set at medium gain and volume at maximum (99%):
The above corresponds to what SMSL published (122dB SINAD) which is very good. Pushing it to 5Vrms input (the max I can get from the DO400) improved the SINAD by 2dB:
We get close to 124dB SINAD, which is crazy good.
But let's go back to some more reasonable / real life case, starting with unity gain at 4Vrms input/output (volume set to 92%):
Compared to the DO400 alone, we loose few dBs of SINAD and this is because the signal is attenuated, ie we lose resolution.
Let's try even more realistic case of 1Vrms input and 2Vrms output:
That is 12dB less output from the SMSL DO400, and at this attenuation, its performances are down to 116dB SINAD, so we lose 6dB by going through the H200, when its volume it set to maximum. More on that later.
What about RCA? Let's check:
This the best I got when pushing the input to 2.5Vrms and with unity gain. We lose a little compared to XLR (roughly 2dB) and besides a bit more Power supply related leakages, performances are very close.
I'll stop here for the SINAD calculations, as you got the point of excellence. From the above, you saw that the distortion generated by the H200 is always below -130dB, this is a very transparent device on harmonic distortion perspective. As a consequence, the limit is the noise floor and nothing else here (I let you read the Noise figures).
----
The reason why I shared so many measurements is because I wanted to show you a little more than usual, so to make you consider what happens when we lower the volume. And more on that immediately. The two below tables are inspired from the tests I performed with the SMSL D200 which has an excellent analog volume control.
What I did is that I compared lowering the volume from the SMSL DO400 (which has a digital volume attenuation via its high end ES9039MSPRO) and attenuating the same way via the H200. Here below are the results from XLR and RCA in/out (THD+N, THD and ENOB are provided):
As you can see, when the volume goes down, it is preferable to use the one of the H200 rather than the digital one of the DO400 (XLR). Since a preamplifier is almost always used to attenuate the signal rather than to increase the gain, I think the above is very good, and by the way a new level of excellence for what I measured previously with other items.
Note there's no advantage on RCA in/out though. But again, the DO400 is much higher resolved device, theoretically, and so seeing the H200 very close to it is good news.
The perfect level matching between the two channels at any output volume is also to be recognized.
----
I suppose you saw above that there is a little PS leakage that can be seen (50Hz and harmonics):
The above shows two cases, on at Low Gain and the other at High Gain, both XLR in/out, and at different voltages. At these high levels, the spuria are at or below -140dBr which is really nothing.
----
Since I'm here, let me add the 50Hz @0dBFS into 600ohms, for compatibility with Stereophile measurements:
This is similar to what I showed with other high-end DACs, meaning it is very good.
----
Let's accelerate a bit this review. The bandwidth is extremely flat (measured up to 80kHz):
This is from the RCA outputs with Volume set at 70% which is low. The two channels are perfectly matched, and if you get the impression there's only one channel represented here, there are two! It is the same perfection at any volume and with balanced in/out too.
----
Let's continue with the famous Multitone that a lot of you, including me, like so much:
This is a very good result, much better than what I measured from the old Accuphase C-280. The few spikes are coming from my interface, I get them from time to time. We have here well above 21bit distortion free range!
----
Oh, yes, another measurement that you can use to compare with other devices. It is the THD+N ratio vs frequency, with an extended bandwidth to capture all distortion and noise components up to 90kHz:
This is at unity gain. This is so good that I am at the limit of my measurement interface, both ends have distortion coming from the ADC, not from the H200. This is very low level of noise and of course distortion.
----
The below IMD SMPTE sweep vs input level is not comparable to the same test from Amir, because it is excluding noise:
I overlaid results at two volume settings, max gain or unity gain. The level of IMD is very low, only the best DACs can do better and note that here there is the IMD from the DO400 that adds on top of the H200, so my guess is that the H200 alone does a little better.
----
Considering the quality of the device I'm reviewing here, I though I'd add other IMD measurements that you don't get often, and for future reference:
The H200 has very low level of distortion, be it harmonic or non-harmonic. Let's see what other pre-amp can beat that.
----
Dynamic range measurement gave me a little headache. According to the AES standard, it should be measurement from a -60dB signal relative to max amplitude or say a 0dB level that we define.
So I initially went for 5Vrms input as the 0dB level, and reduced the input by -60dB, and here we go (max volume, Medium Gain):
This is below what SMSL published (132dB) and so I wondered, what if instead of reducing the source, I reduce the volume of the H200 by -60dB?
Wow, ok, respect.
----
Now I'm used to regroup all Inter Modulation tests as below, when I review DACs, and these are sourced from REW's results (IMD distortion and Total Distortion+Noise shown for each):
These are extremely low intermodulation distortion and noise. And from all of what I published so far, I state that this preamp is distortion free!
SMSL H200 - Measurements - Headphones
I got the exact same output voltages from the front outputs as from the back. And the measurements are equally excellent.
Let me add one from HPA Unbalanced output, with XLR input at 5Vrms, in High Gain mode, output volume set at 87%, into 32ohms load:
Far from max volume, we already get near 121dB SINAD. That means we get up to 1W of clean output power with unnecessary high SINAD. I could not go higher because it clips my ADC
Going Medium gain, again with 5Vrms input, volume at max 99%, still into 32ohm load, I can set my ADC to capture the full amplitude without clipping and in that case:
This time we get 123dB SINAD from unbalanced front output, this is impressive.
And let me jump directly to one that Amir always publishes and that's the SNR measured at 50mVrms output in low gain:
We get a very good 87.4dB SNR which puts this baby in the comfortable zone of @amirm's chart. As a matter of facts, it is funny to note that in "Medium Gain" it does a little better, reaching 88dB
Conclusion
That was a long review and it's because I truly enjoyed reviewing this preamplifier. I was not expecting anything special, considering the price, but when I first saw the excellent results, incredibly better than the very good old Accuphase C-280, I had to investigate more and create one review to serve as a master reference.
Of course, that means it's the best preamplifier I reviewed, and I am eager to test higher end versions from SMSL (@Kitty (S.M.S.L Marketing) if you hear me
).On a HP Amp perspective, it is above average and beats the DO400 I used as the generator, on that perspective. I guess I (we) shall be happy.
The extreme quality of the analog volume control is to be noted. For when listening at low volume, it is the guarantee to get resolution difficult to equal from the best DACs. So, don't be afraid to insert it in your current set, it will not degrade the performances, on the contrary...
To be honest, when measuring this preamp, I reached several times the limits of what I can safely measure, especially at lower output volumes, good on the H200. And I saw many times people talking about fact that a preamplifier should be "a straight wire with gain". And I've seen many reviews giving that appraisal to preamplifiers far from delivering as this one does...
So, Ladies and Gentleman, here you go: a straight wire with gain. Well done to SMSL at that price point.
I hope you enjoyed this review!
Flo
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