Review and Measurements of PS Audio Sprout100

[amirm]

It is fair to test the unit as a standalone D/A converter while at the same time driving the power amplifiers hard enough to cause it to frequently shutdown during your test?

I retested without the amp loaded down and results were the same.

 

[amirm]

So the line out was variable, what was the maximum output, and was 2.0V near the upper end or lower end of the preamplifier section's capability? Did S/N improve or get worse at higher output levels?

It has already been too long for me to remember such detail.

 

[jkahlon]

This is a review and detailed measurements of the PS Audio Sprout100 integrated DAC, headphone and power amplifier. It is on kind loan from a member. The Sprout100 is an upgrade over the original Sprout and costs USD $599.

I remember the first time I saw the Sprout at an audio show. I thought it was utterly cute! It is small and handsome little package with a ton of functionality:

View attachment 23669

As you see, in addition to functions I mentioned, it even has Bluetooth included. And moving magnet turntable input. It is a dream product for a frustrated marketing guy in a high-end audio company like PS Audio, wanting mass market product that appeals to the "younger audience."

The volume control is a rotary encoder with a built-in switch that powers the unit on and off. If you hold the button down, the LED color changes from purple to white, indicating bass boost is on. The rotary encoder is poorly programmed to have linear and slow response, making it very, very slow to change volume. To go from low to high volume you may have to turn it seven or eight times! We live in a digital age with music that is fast to access and comes at all levels. Having the ability to quickly change volume is important.

Input selection is old school mechanical selector. I like the clear labels.

The backside shows how much is crammed in there:

View attachment 23670​

I did not test sub out but it has sensor that automatically activates that output (and rolls off the mains?).

In addition to USB input, we also have toslink optical which is nice in case of ground loops.

The nicest bit is included power supply in such a small package. Kudos for managing to fit that in there and reduce clutter.

There is protection circuit for both power amplifier and headphone. During testing I found it to frequently activate which simply turns off the unit. It caused a lot of head scratching until I discovered the latter action.

It is also I think underdesigned from cooling perspective. When I started my DAC testing, I had the dummy load connected to the unit as well. After a few minutes of testing I noticed the signal went away. Then I realized per above it had shut down. Went to touch the power button and it was hot as heck. As was the rest of the enclosure which was super hot. Even the top "wood" panel was hot to touch. I would not rely on the 100 watt rating into 4 ohm to be a continuous rating for any length of time.

The Sprout100 is rated at 100 watts into 4 ohm and according to PS Audio uses ICEPower modules.

I should tell you that I hate testing multi-function devices like this. Every subsystem takes as much time as reviewing another product with just that functionality. In the interest of getting the review done, I did not bother to test the Vinyl input. I also did not touch the sub out or toslink.

DAC Measurements
The inclusion of line out allows us to test the DAC subsystem independently so let's start with our dashboard there:

View attachment 23671

The output was variable so I adjusted it to 2 volt. Per my review notes above, the power amplifier was on and was whaling away into the dummy load at the same time.

PS Audio rates Sprout100 as having less than 0.01% THD+N distortion from line out. We are beating that although that is such a low bar. Equivalent rating in SINAD (signal over noise and distortion) puts the Sprout100 in our bottom quarter of DACs reviewed:

View attachment 23672

Not a good place to be although probably fits the performance target they created for themselves for "lifestyle product" like this.

Back to our THD+N rating, we can separate the components of distortion and noise and get this ratio:
View attachment 23673

They are both contributing to the final THD+N but the noise is a bit more dominant. Likely in this small enclosure the could not get enough isolation for the DAC subsystem to reduce noise levels.

The high noise level makes the jitter graph "pretty" with almost no spikes visible but that is because the noise floor is so elevated:
View attachment 23674

Best in class DACs put that noise floor down to the bottom of the graph.

Same noise problem manifests itself hugely in linearity test:
View attachment 23675

That smooth, exponential rise indicates random noise polluting the voltage reading at each level. Noise-free performance then stops around 80 dB or 13 bits -- quit a bit shy of 16 bit performance of CD. In this day and age, I like any DAC to at least do justice to CD format, bringing fully transparency to 96 dB.

Intermodulation test shows similar higher noise floor but also pretty early rising of distortion levels:

View attachment 23676

Similar story for THD+N versus frequency:
View attachment 23677

Dynamic range of the DAC is as spec'd:

View attachment 23678

Speaker Amplifier Measurements
Note: all amplifier testing except when noted, is with an AUX-0040 Audio Precision filter in place to reduce high frequency components given the fact that this is a switching amplifier design.

As usual, for amplifiers I test with 5 watt output. The trick is to know what to use for input level and volume control. With digital input that was easy as I set the level to 0 dBFS. But then I thought we want to know the performance of the amp alone so we better test with analog input and here is what I got:

View attachment 23679

With digital input I could get over 80 dB by the way. But no combination of input and volume level could get us there with analog input. In some sense then the amplifier is good enough for the performance of the DAC.

Frequency response showed different response in each channel:
View attachment 23680

I swapped my loads and the curve did not change, indicating that the variation is due to the amplifier (filter) design, not differences in my loads. Clearly the channel in blue is resonating around 50 kHz, causing that large boost of nearly 20 dB! What you get with your speaker load and its wiring is unknown. The red channel is more behaved. We saw the same discrepancy between channels in the SINAD in the dashboard.

Poking our noise into the design using high-bandwidth spectrum (FFT) analysis, we see this:
View attachment 23681

Note that this is a raw test with the external filter removed. We clearly see the switching frequency around 600 kHz peaking up to almost -20 dB. You can have your own AM station if you like. We have an early rise in noise before 100 kHz which is due to some kind of noise shaping. There are a lot of other spikes which one could examine to see what is going on but I am too lazy to do so. Regardless, these amplifiers are not pretty to look at as far as performance above audible band. It is the price you pay for having 100 watt/channel amplifier squeezed into a little box.

Speaking of power, let's measure that into 4 ohm load:

View attachment 23682

We get 82 watts with both channels driven which is shy of the 100 watt specification. Noise and distortion is lower than Topping TP60 ($200) amplifier. And there is more power.

Signal to noise ratio is "OK":
View attachment 23683

Headphone Amplifier Measurements
Let's jump right in with power versus distortion and noise at 300 ohms:
View attachment 23684

We have competent level of power but much more noise and distortion than our reference Topping DX3 Pro ($220 when not on sale). I like to see at least 100 milliwatts here and the Sprout100 delivers.

Here is the picture at 33 ohm:
View attachment 23685

We have 420 milliwatts of power until the Sprout100 shuts down causing the graph to shoot back to the left. In other words, the unit is distortionless until it shuts down.

Output impedance is a bit high at 5.7 ohms:
View attachment 23686

Headphone Listening Test
I started my testing with Sennheiser HD-650. There was enough power there for a very good experience. I could not detect any onset of distortion.

Switching to Hifiman HE-400i, I got a bit more power and again, clarity and power until the end.

Dedicated headphone amplifiers will produce more power but there was enough here with either headphone to give a bit of tingling to my ear lobes during bass so I was happy.

I could not get the Sprout100 to shut down with the HE-400i so in practice this may not be a serious problem.

Conclusion
The reviews I read prior to testing the Sprout100 all point to how great it is that a "high-end" company like PS Audio has produced such a mass market product. And that this association must be translating into excellent sound. Our objective measurements show that this is not the case. Performance of such subsystem as the DAC and headphone amplifier is nothing to write home about.

Subjective aspects though are good: lots of power from the headphone amp and to some extent, from the power amplifier.

The miss from usability is the super slow to change volume control. In many cases I could move it a notch and nothing would happen to the output in my analyzer let alone the ears.

So where do we land? From objective performance I can't say that the Sprout100 lives up to the promise of the brand. From full functionality point of view at $599 it seems to be there though although I have yet to test many products in this category. For this reason, I am going to withhold giving or holding back a recommendation. Let the data guide you in that regard.

------------
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Just bought a Sprout 100 yesterday - my hearing impression is completely different, sound is extremely crisp and clear, it may be musical but clarity is there. Replaced a receiver which had seen better days and the improvement is clearly noticeable. However I would not want to compare a hearing experience with hard data. Hoping you had a good unit.

 

[confucius_zero]

@amirm why don't you do subjective listening with speakers on speaker amplifiers but do it with headphones?

 

[amirm]

@amirm why don't you do subjective listening with speakers on speaker amplifiers but do it with headphones?

My lab is in a loft on top of the living room. I will be booted out of the house on the third test of this kind.

Seriously, I do plan on doing some testing. I just don't have the room in short term to put speakers in my lab area for this use (I have powered monitors I use for listening to music). No, I won't take any risks with using my Revels in the main listening room.

 

[SEKLEM]

Probably not the best amp to use with a filterless NOS DAC, if you care about not frying your tweeters anyway.

What would cause that? Is this something implicit with this particular ICEpower amp module?

 

[firedog]

Just bought a Sprout 100 yesterday - my hearing impression is completely different, sound is extremely crisp and clear, it may be musical but clarity is there. Replaced a receiver which had seen better days and the improvement is clearly noticeable. However I would not want to compare a hearing experience with hard data. Hoping you had a good unit.

I think this makes sense. Nothing against the measurements, but again, let's put this in prespective: its an amp/dac/phono pre/head amp in a small box. An And looks good - which lots of inexpensive doesn't. An all in one designed for young people who have small living spaces and don't want lots of boxes. Hook up speakers and a source - done. I
'm sure it subjectively sounds fine and fits many peoples needs in terms of features and lifestyle. Nothing wrong with that. Probably a good buy for the money.

 

[molecules]

I had a PS 5.6 preamp with a passive phono preamp, which was wonderful. It's gone, so I was hoping the Sprout would be a great thing. I have a couple of questions:
1) How is the phono stage ? I know the reviewer did not test it, but this is a big part of the whole idea of this unit.
2) I missed the link on how the digital measurements affect sound (I read these type of specs are all so low vs analogue that they don't matter).
3) I was worried that the review implied the Sprout did not meet the published power specs, until someone mentioned that it did.

These questions are serious, if anyone has a useful answer: I am not trying to be a wise guy, I had a situation and sold my best gear, and am trying to build a system, and am looking at the usual suspects, Cambridge, NAD, Rotel.

I loved that phono stage on the 5.6, i could kick myself for selling it.
Dave

 

[GTsmokeya84]

Just bought a Sprout 100 yesterday - my hearing impression is completely different, sound is extremely crisp and clear, it may be musical but clarity is there. Replaced a receiver which had seen better days and the improvement is clearly noticeable. However I would not want to compare a hearing experience with hard data. Hoping you had a good unit.

I also purchased one out of curiosity and I am pleasantly surprised. Its clean and clear, I dont blast it or anything but at reasonable volume its nice. I am running some Kef Ls50's and when i play CD's i run it through an Arist R2R dac from massdrop. After a few burn in hours on the dac wow it sounds so nice. Again my ears I am no pro, just a hobbyist.

 

[JJB70]

The Sprout 100 looks and feels nice, it's very well featured and it's audible performance is fine. For the price, if you like the look then I'd say go for it as regardless of measurements it will be pretty much perform like any other amp of that rating. That said, the Yamaha WXA50 is another nice looking (well IMO) amp also well featured and which can be found (here at least) for about half the price of the Sprout. I've also found the TEAC AI503 (it's got VU meters) which is another amp cum DAC cum wireless connectivity centre which has excellent industrial design and feel for less than the Sprout despite a much higher nominal SRP. I've seen a couple of decent deals on the Cyrus One HD, again on paper should cost a lot more, doing pretty much the same thing as the Sprout but with a nice form factor and feel. ELAC make a lovely looking amp which again is doing pretty much the same thing as the Sprout.

I suspect none of these amplifiers will be that impressive if measured, but all of them will be perfectly good audibly. Their DACs appear to be well implemented and transparent (I honestly think it is harder to find one that isn't) and amplifiers aren't DACs. No, the measurements aren't anywhere near what we expect from a DAC but even cheap Behringer power amps sound fine whatever the measurements might say. I think there is a danger in becoming too focused on measurements, at the risk of sounding like an advocate of "good enough" once a component achieves the necessary performance to perform in a way which does not introduce audible degradation then it has achieved its purpose and the part of the chain that really needs thought is the speaker and how it is positioned and set up.

I will admit that I have been considering all of the above amps to drive a pair of KEF LS50s or maybe Technics SB-C700s this week. The money saved compared to the KEF LS50W would pay for a restoration of my beloved Sony ES gear and although I haven't heard the Technics or Sprout yet I have demo'd the Yamaha, TEAC and Cyrus One HD with the passive LS50 and subjective impressions were excellent (i.e. I was happy) and any differences with the LS50W marginal at best.

 

[Bruce Morgen]

The question of price-performance ratio -- AKA "bang for the buck" -- comes up here. A combination of a sub-$100 Behringer "U-Phoria" unit as the DAC and many a sub-$100 Chinese-made Class D "chip amp" (given enough "B+" juice, of course -- but adequate generic SMPS units are dirt-cheap) would meet the same overall criterion of "its audible performance is fine" for about a third of what PS Audio is asking, albeit without the elegant, decor-friendly looks and multiple-source inputs of the Sprout 100 or that Teac you mentioned. Going by the same laid-back subjective criterion, one wonders why the McGowans went with that IcePower module rather than one of the (surprisingly good IMO) Class D chips TI has been cranking out by the lorry load over the past few years -- my suspicion is that a single reviewer cracking open the case to a reveal mass-produced IC at the heart of a "high-end" maker's product would far too clearly reveal "The Emperor's New Clothes."

 

[JJB70]

I think you can get good audible performance for peanuts, and in the case of DACs an Apple dongle costing $9 is excellent.

In the case of amplifiers, amplifier design seems to be increasingly about implementing OEM Class D modules, not that there is anything wrong with that. However, buying audio gear isn't just about the audible quality. Things like industrial design, build quality, tactile feel, feature set, confidence in aftersales support all matter. And sometimes, well, people just like something.

In the case of the Sprout (or indeed similar amplifiers from Elac, TEAC, Cyrus, Yamaha etc) yes you can do it cheaper, and if you just want minimum cost do it cheaper. However they're not especially expensive as hifi goes, and are offer good industrial design, features and probably better aftersales support than cheap generic amplifiers from Ali etc.

 

[Soniclife]

In the case of amplifiers, amplifier design seems to be increasingly about implementing OEM Class D modules, not that there is anything wrong with that.

Not only isn't there anything wing with it, it would be really good if the competition continues until we are in a similar place to DAC chips.
We don't need 1000s of amp designers copying basic circuits from old books with limited depth of knowledge, we need a handful of really bright well resourced teams engaged in long term projects to make these modules and chips better, more powerful, more efficient and cheaper.

 

[Willem]

At the budget end a Yamaha AS 501, AS 701 or AS 801 is a no brainer, with really excellent measurements, a fair amount of power and in their current incarnation also digital inputs. They also look pretty classy, though a bit bulky. Those who want to spend more for more power can get real value for money with an RME ADI-2 DAC and the various Hypex power amps. The Hypex amps can be tucked out of sight.

 

[Bruce Morgen]

I think you can get good audible performance for peanuts, and in the case of DACs an Apple dongle costing $9 is excellent.

In the case of amplifiers, amplifier design seems to be increasingly about implementing OEM Class D modules, not that there is anything wrong with that. However, buying audio gear isn't just about the audible quality. Things like industrial design, build quality, tactile feel, feature set, confidence in aftersales support all matter. And sometimes, well, people just like something.

In the case of the Sprout (or indeed similar amplifiers from Elac, TEAC, Cyrus, Yamaha etc) yes you can do it cheaper, and if you just want minimum cost do it cheaper. However they're not especially expensive as hifi goes, and are offer good industrial design, features and probably better aftersales support than cheap generic amplifiers from Ali etc.

Well, as seen from here "aftersales support" for a sub-$100 "good audible performance" product simply means easy availability of an equivalent or better replacement unit (gratis if it's DOA or still under warranty, of course) -- it's not like you're going ship one of those remarkable Behringer gadgets or a generic chip amp out for a professional repair job or need some sort of deep tech support for that sort of purchase. I think what's emerging with this cheap and (for most folks) entirely adequate IC-based audio gear that the definition of "what's expensive as hifi goes" is sliding rapidly downhill in price, at least when it comes to electronics.

 

[JJB70]

Well, as seen from here "aftersales support" for a sub-$100 "good audible performance" product simply means easy availability of an equivalent or better replacement unit (gratis if it's DOA or still under warranty, of course) -- it's not like you're going ship one of those remarkable Behringer gadgets or a generic chip amp out for a professional repair job or need some sort of deep tech support for that sort of purchase. I think what's emerging with this cheap and (for most folks) entirely adequate IC-based audio gear that the definition of "what's expensive as hifi goes" is sliding rapidly downhill in price, at least when it comes to electronics.

I wouldn't disagree with any of that, and personally I'm not sure I'd go above the price point of the amps being discussed in this thread for a new item. That is partly because I think they offer all the performance I need and it is better to put money into speakers and room set up than an amp (or DAC), and partly because I think most modern gear will be fix by replacement. If I was to spend $$$$$$$$$s on an amplifier I'd rather go for a classic and have it professionally renewed, but that is because of an entirely subjective preference for the build of classic gear and nothing to do with sound quality.
However, even if looking at fix by replacement, I'd rather buy something I'd have some confidence in as a $500-1000 is still more than I'd be willing to treat as a truly throwaway item (well, throwaway after a few years, but not within a warranty period). And in some ways this is less about the manufacturer than the seller. To take the Sprout, I wouldn't buy one from PS in the US direct. This is not about being anti-US or questioning their customer care, but sending stuff back overseas is a PITA and expensive (keeping in mind many companies require you to pay shipping upfront and then may or may not reimburse the cost, and if you're not happy with things what are you going to do, really? I'd feel the same about buying TEAC from Japan or Shanling from China. If I buy from a local dealer (and I'm not going to look at local dealers through rose tinted glasses) I can just take it back to the shop and if it goes wrong I know the various mechanisms available to seek redress. A lesson I'm reminded of with a pair of expensive headphones I bought from the UK direct sales channel of the manufacturer.

 

[Bruce Morgen]

I wouldn't disagree with any of that, and personally I'm not sure I'd go above the price point of the amps being discussed in this thread for a new item. That is partly because I think they offer all the performance I need and it is better to put money into speakers and room set up than an amp (or DAC), and partly because I think most modern gear will be fix by replacement. If I was to spend $$$$$$$$$s on an amplifier I'd rather go for a classic and have it professionally renewed, but that is because of an entirely subjective preference for the build of classic gear and nothing to do with sound quality.
However, even if looking at fix by replacement, I'd rather buy something I'd have some confidence in as a $500-1000 is still more than I'd be willing to treat as a truly throwaway item (well, throwaway after a few years, but not within a warranty period). And in some ways this is less about the manufacturer than the seller. To take the Sprout, I wouldn't buy one from PS in the US direct. This is not about being anti-US or questioning their customer care, but sending stuff back overseas is a PITA and expensive (keeping in mind many companies require you to pay shipping upfront and then may or may not reimburse the cost, and if you're not happy with things what are you going to do, really? I'd feel the same about buying TEAC from Japan or Shanling from China. If I buy from a local dealer (and I'm not going to look at local dealers through rose tinted glasses) I can just take it back to the shop and if it goes wrong I know the various mechanisms available to seek redress. A lesson I'm reminded of with a pair of expensive headphones I bought from the UK direct sales channel of the manufacturer.

I understand your priorities and preferences completely -- and I certainly agree with your emphasis on speaker selection and room acoustics rather than obsessing on tiny differences in electronics performance, especially given the vagaries of human hearing. Don't get me wrong, I have enormous respect for the technical prowess of the folks behind Benchmark, Purifi, Hypex et al, but I have neither the budget nor the listening space to seriously consider their products. Given a sizable lottery payout, I'd probably go for something like a Kii Three system and be done with it -- but for now, I'm enjoying the process of getting an immensely enjoyable and credibly "hi-fi" listening experience for the proverbial "next to nothing."

 

[Juwieh]

I had not seen the Stereophile Sprout Review, but it is very unusual for Stereophile amp reviews to have no measurements.

Well, I reckon this is because the measurements of the previously tested original Sprout were so horrible:

View attachment 18916

https://www.stereophile.com/content/ps-audio-sprout-integrated-amplifier-measurements

 

[E_Majluf]

Hello Amirn,
I bought a PS Audio Sprout100 in February as a small system for my stay in Iquique, Chile, for work (I'm missing a couple of years). which consists of the Sporut100, an ASUS i5 PC of the year 2013. A hard disk of 4 Teras, A pair of B&W 603 speakers from the latest edition.

The sound is nice, transparent and sharp; It has enough power to enjoy in a small environment. I have left it running for hours at moderate volumes and it is always warm, no hot.

The only problem is the postsale, since in the manual, brochures, specs, even in Reviews of magazines on the internet ... it is reported that you can listen to PCM files of 24 bits 354 KHz and personally I have not been able to do it function. I have the FOOBAR2000 player and a couple of albums on DXD plus other 2L free songs. I have never had problems with my other DACs IFI nano iDSD Original and a Bryston BDA-3 (I wish you could review it, Amirn) to listen on DXD.

I have claimed both by email and the support of PS Audio, without any specific response.

 

[confucius_zero]

Well... sprout100's a Vshaped amp with strong midbass, laaaaaaaid back mids and some headache inducing treble -_- ack. Just something about that treble... I dunno man mah head T_T