Some insights on the MiniDSP SHD

[AbsolutK]

I have been wanting to tame a few room anomalies for quite some years now. My source/amplification is a super-integrated DIY (Allo Katana DAC stack, 2 stereo amplifiers and all related power supply). I don't have very many options for DSP, let alone DIRAC. So when I saw the MiniDSP SHD, and amirm's measurements over at ASR, I was sold. It was icing on the cake to learn that Tom from Neurochrome had designed its output stages, whose amplifiers I'm using for my current build.

 

There's not much on the internet regarding this device, what's inside, what's good and bad. So I'll try to cover my observations in case they help someone else. Ask away, if you have any questions and I'll try my best to answer!

 

Competition

Based on this thread and Dirac's partner page, these are the SHD competitors.

• Anthem
  • STR Preamp …$4k!
  • Proprietary Room Correction (ARC) instead of Dirac. Has phono and 4 channel out. This is designed as a preamp (instead of a processor) and is closest to what I'd consider instead of the SHD. Nice official video as well as one by Audioholics on the STR product range.  
• NAD
  • C658 …$1600. This is the closest competitor, but is 2 channel only
  • M17 …$4k+!
• Arcam
  • None.
  • The AVR series are receivers, full with amplification.
• Datasat
  • R20i. No balanced out (perhaps there's a daughter-card) …$6k+!
• Emotiva
  • XMC-1 (now XMC-2) …$3k!
  • RMC-1 …$5k!
• Theta
  • Casablanca IV …$10k+!

 

Part 1 - Unboxing

The package is delivered in 2 boxes - a) the SHD alone and b) the accessories and the UMIK. It was nice to see a large (albeit flimsy) tripod included.

 

Some nits:

• There is no printed manual in the box. It is linked on the product page, but not under "Support", which is odd.
• Despite being called out on page 26 of the Manual ("A short Ethernet cable is provided with the unit"), there is no ethernet cable included. This is not a big deal.
• There are no batteries included for the remote. This is not a big deal either.
• The included large tripod is rather flimsy. But it's there and it's useful, so that's nice.

 

Part 2 - Physical, External

The chassis itself is quite sturdy. However, it is lacking weight - from the chassis itself, or from components inside. As a result, the box resonates quite a bit when you tap it. You may have to put damping weight on the top to make it not resonate.

 

I opted for the SHD (over the Studio) just for versatility. Having an on-board ADC and DAC allows me to use this device both as a Studio as well as, in a pinch, a full-fledged streamer. Notes on the DAC are below. I do not have use for the ADC section anytime soon. At least not until there's a Phono program included ;).

 

Starting from the left, the connectors are as below:

• Fused, switched IEC inlet. This connects to the SMPS power supply inside (more on that below)
• USB Host and Ethernet port. This connects directly to the streamer module inside. I have not used (and don't intend to use) the USB Host.
• SPDIF (RCA), Toslink and AES/EBU ports for digital input
• RCA and XLR connectors for Single Ended and Balanced analog inputs.
  • There are only two channels (L and R)
  • This goes to the ADC stage
• RCA and XLR connectors for Single Ended and Balanced analog outputs
  • There are four channels
  • Behind the scenes, the Single Ended conversion/output is from a secondary board.

 

Part 3 - Physical, Internal

• Main board
  • The first reaction to seeing inside is - wow, that is neat and clean!
  • The board is marked "DDRC44 main" "Ver 1.1" and the date "May 10, 2018". There is no DDRC44 product in their range, proving this is truly a custom design by MiniDSP rather than a bunch of existing products cobbled together
  • Lots of LDOs
  • Lots of isolators
• Streamer board
  • This SBC is rather small. Seems even smaller than a Raspberry Pi Zero
  • USB Host and Ethernet jacks go straight onto this SBC
  • There is no isolation on Eithernet, so you'd benefit from using FMCs
  • A micro SD card is inserted and kapton taped shut. Presumably this is where the Volumio build sits
  • An unused Micro USB port is to its left, presumably for diagnostics
  • There is a 7-wire harness that connects the streamer to the main board. Is this I2S perhaps?
• DAC
  • Yes, it uses the AKM4490, a ~5 year old DAC
  • Yes, there are two discrete DAC chips
  • Power seems to be well thought out. The caps can likely be upgraded.
• Power Supply
  • The IEC inlet links to a switching mode power supply
  • Uncooled (which this is), it seems to be rated at 84W (24v, 3.5A)
  • The harness from the PSU to the main board uses two pairs of wires. Why, I'm not sure. The output measures 24v on the harness.
  • This is being stepped down on the main board to provide 5v to the streamer section via a 2-wire harness
  • I might bypass the PSU as well as onboard step-down, and replace the IEC inlet with two DC barrels for 24v and 5v

 

Part 4 - Usage

• Streamer
  • Instructions to follow (and as documented) are quite simple. Plug it into Ethernet, and point your browser to minidsp-shd.local. This is the same as using Volumio on any Rpi based solution.
  • Volumio has been customized with a branded look and feel (background, colors) and locked menus (removing those that are not applicable)
  • http://minidsp-shd.local/dev also works, allowing SSH access. However, I do not know the username or password. If someone knows this, I would love to know in the comments.
  • I had trouble getting the unit on the network at my home as well as my friend's. Going through hubs or FMCs may not always work, but connected straight to a router seems to do the trick.
• Software
  • There are two distinct pieces of software involved:
    1. The MiniDSP controller. Used to communicate with the SHD over USB
    2. The Dirac Live Calibration tool. Used to take measurements and generate the filter to be uploaded. 
  • All software is nicely zipped up and hosted, and a link is sent via email to purchasers
  • The Dirac app does not work with the SHD. There are indications that v2 is in the works, which might enable the app experience.
• Measurement notes
  • Note: two unused USB ports are needed - one to connect to the SHD and the other for the Mic. Out of the box, there is about 8ft of USB cable, but you can always sit closer to the listening area and plug in the SHD to a nearby outlet during measurement.
  • Documentation on measurements is great and easy to follow.
  • Dirac will let you proceed with only one reading, without warning you. The only indication that there are more measurements remaining is subtle - dots that have not yet turned green. Make sure you take all 9 measurements before proceeding
  • It is not immediately apparent that you can limit the window of frequencies to which correction applies. There is an "anchor point" close to each edge of suggested curve, and the correction window slider will not go past anchors. You need to double-click the anchor points in the region you wish to leave untouched, then slide the window over.
• Listening notes
  • Without Dirac
    • The DAC warms up nicely in 10-15 mins
    • It sounds quite nice, and comparable to the Allo Katana stack I have in my setup.
    • When heard on my friend's Gryphon Diablo 300, too, it sounded convincing
    • However, compared to the Gryphon DAC module (ESS9018) the higher frequencies were lacking detail and was fatiguing to listen to. Granted, the Gryphon's DAC is a $5k+ module, but this did prove, that the streamer is quite good. We used Airplay.
    • This might be due to the power supply. I shall upgrade and report back.
  • With Dirac
    • Applied to the full spectrum, the system sounded really bad. High frequencies sounded sharp and robbed of air, dynamics, imaging and magic.
    • Limited to 1 Khz, things were much better. Better control over bass. My 44 Hz peak is happily tamed.
    • Note: Room Correction addresses the speaker/room combination, and it addresses all issues at once. You may have liked some of these characteristics, but there is no way to isolate them without either advanced analysis, or trial and error. In my system, the bass sounded drier. I'm trying to re-insert some of the peaks to see if I can get that "moisture" back and will also try limiting the correction to 500 Hz.
• Delay/sync
  • Some have asked the question about delay when using in a video setup.
  • I am happy to report that there is no noticeable delay of the audio stream when compared to the video using Volumio's Airplay receiver functionality. You can configure the Apple TV to use Airplay speakers, and Volumio powering the SHD has this functionality built in. 
  • The delay is likely compensated for in the Shairport Sync library.

 

[smolteni]

Just beautiful report i'm going to buy a SHD (i own a SHD Studio with RME ADI 2 PRO) to simplify my setup.

I'm curious to know if you notice some improvement changin with a Linear PSU...

Did you try also as pre-ampli section?

Regards.

[AbsolutK]

59 minutes ago, smolteni said:

Just beautiful report i'm going to buy a SHD (i own a SHD Studio with RME ADI 2 PRO) to simplify my setup.

I'm curious to know if you notice some improvement changin with a Linear PSU...

Did you try also as pre-ampli section?

Regards.

Thanks! I have not managed to do the linear power supply mod just yet. Life has been far too busy! 

 

Yes, the unit is used as a preamp powering my DIY Neurochrome power amplifier. The volume control is great and the remote for this works perfect, giving the ability to switch between Dirac on/off and 4 profiles on the fly. Though, I suspect this is the same as the Studio. 

[smolteni]

Yes is the same SHD Studio.

Thank you for your reply, and if you replace the PSU please share your results.

If i understood well the unit need 2 separate power:

 - 1 24V 5A

- 1 5V

How about connector? Are simple to find? Is it better to sold directly to the board?

Regards.

[AbsolutK]

The PSU is 85W without the heatsink, so it should mean 24V 3.5A, which should easily be possible with supplies like these:

https://www.ebay.com/itm/100W-Ultra-low-Noise-100VA-LPS-R-core-Linear-power-supply-DC-5-24V-Optional/133061111162

 

And then, yes, a 5V supply, which are also easily available. I've been following the threads on Allo's new 5V supply, Shanti, and reports are terrific. 

 

As for connector, both the 24V as well as 5V is provided through a harness. I would recomment keeping those intact and making your own harness end-point for the supplies. Note that the 24V supply is dual, so either you jumper the positives and negatives to supply them from a single 24V source, or you find a dual 24V source (it may be designed in dual mono, who knows). I suspect the former is simplest and best though.

 

I recently acquired a Micromega M150, so sold the MiniDSP, so sadly no more experiments from me.

[asdf1000]

On 7/15/2019 at 7:43 AM, AbsolutK said:

• Limited to 1 Khz, things were much better. Better control over bass. My 44 Hz peak is happily tamed.
• Note: Room Correction addresses the speaker/room combination, and it addresses all issues at once. You may have liked some of these characteristics, but there is no way to isolate them without either advanced analysis, or trial and error. In my system, the bass sounded drier. I'm trying to re-insert some of the peaks to see if I can get that "moisture" back and will also try limiting the correction to 500 Hz.

 

Brilliant  write up.

 

Is limiting the DSP to a certain range easy?

 

Could you show a screenshot/photo of how/where these limits (whether 1kHz or 500Hz) are applied?

 

Thanks again

 

 

[smolteni]

You can limit Dirac moving the apposite cursor in the filter customizatoin section, it is very easy...

[AbsolutK]

6 hours ago, asdf1000 said:

 

Brilliant  write up.

 

Is limiting the DSP to a certain range easy?

 

Could you show a screenshot/photo of how/where these limits (whether 1kHz or 500Hz) are applied?

 

Thanks again

 

 

Thank you! As smolteni points out, this is easy to do in Dirac in the step after taking measurements. You drag the “active” window from the right. Here’s a screenshot I stole off the Internet showing what it will look like after. If you can’t move it left, it is because there’s a marker for where you’d like the target curve to be. It’ll be a yellow diamond on a yellow curve. Double click the diamond and that will unblock the window resizer. 

[audiobomber]

On 7/14/2019 at 5:43 PM, AbsolutK said:

I have been wanting to tame a few room anomalies for quite some years now. My source/amplification is a super-integrated DIY (Allo Katana DAC stack, 2 stereo amplifiers and all related power supply). I don't have very many options for DSP, let alone DIRAC. So when I saw the MiniDSP SHD, and amirm's measurements over at ASR, I was sold. It was icing on the cake to learn that Tom from Neurochrome had designed its output stages, whose amplifiers I'm using for my current build.

 

There's not much on the internet regarding this device, what's inside, what's good and bad. So I'll try to cover my observations in case they help someone else. Ask away, if you have any questions and I'll try my best to answer!

 

I just ordered an SHD. I've bookmarked this awesome post! 

 

Any update on the PSU upgrade? I have a power supply I had built for my previous DAC, which looks to be very suitable for the SHD; two Welborne Labs PS-1 power supplies ( +/- 5V to +/- 24V) and a PS-Reg (+5V to + 24V). I will tackle this eventually but voids the warranty so I don't want to rush it. 

[AbsolutK]

1 minute ago, audiobomber said:

I just ordered an SHD and I've bookmarked this awesome post! 

 

Any update on the PSU upgrade? I have a power supply I had built for my previous DAC, which looks to be very suitable for the SHD; two Welborne Labs PS-1 power supplies ( +/- 5) to +/- 24V) and a PS-Reg (+5V to + 24V). I will tackle this eventually but voids the warranty so I don't want to rush it. 

Thank you!

 

Sadly I never got around to the PSU upgrade because I sold the SHD a few months later. I found another product that fit the bill - the Micromega M-One (M150) - that included a *very good* 150 wpc Class AB amplifier. At ~$7k new ($4k used), it was a no brainer to replace 2 boxes (one of which was big) with one. 

 

I would later go on to selling even the Micromega, to have a simple system where a Chord Hugo TT2 drives my speakers directly with its 7wpc!

 

 

[audiobomber]

OK. Thanks for the detail and photos anyway, very useful.

 

@AbsolutK, just wondering if you actually measured 24V in the power supply, or are you just going by the writing on the Meanwell cap? I thought saw elsewhere that the SHD was +/-15V internally, and the Studio used a 12V wall wart.

[AbsolutK]

1 hour ago, audiobomber said:

OK. Thanks for the detail and photos anyway, very useful.

 

@AbsolutK, just wondering if you actually measured 24V in the power supply, or are you just going by the writing on the Meanwell cap? I thought saw elsewhere that the SHD was +/-15V internally, and the Studio used a 12V wall wart.

@audiobomber I measured the harness with a DMM to confirm that 24v was being output by the PSU. On the main PCB there might be a network of LDOs in the power path that drops it to a +/- 15v rail.

[audiobomber]

11 minutes ago, AbsolutK said:

@audiobomber I measured the harness with a DMM to confirm that 24v was being output by the PSU. On the main PCB there might be a network of LDOs in the power path that drops it to a +/- 15v rail.

I believe I misread or misremembered. Here's the post I was looking for: 

https://www.minidsp.com/forum/shd-series/15661-power-supply-for-shd-vs-shd-studio#41754

[AbsolutK]

35 minutes ago, audiobomber said:

I believe I misread or misremembered. Here's the post I was looking for: 

https://www.minidsp.com/forum/shd-series/15661-power-supply-for-shd-vs-shd-studio#41754

Happens to the best of us! What I believe the author of the quoted post was trying to say is that analog sections are often powered by +/- 15v rails. The SHD very well might also (doing its own regulation from 24v to 15v on board).  

[audiobomber]

Buyer's remorse, I cancelled my order for the SHD. 

[jaaptina]

30 minutes ago, audiobomber said:

Buyer's remorse, I cancelled my order for the SHD. 

Why? It's a great sounding device! 

[audiobomber]

17 minutes ago, jaaptina said:

Why? It's a great sounding device! 

I wasn't confident the SHD would sound as good as my Audiolab DAC/preamp. I may try again later. 

 

[Nickolay_V]

there is Volumio player based on NanoPi NEO2

[AbsolutK]

8 hours ago, Nickolay_V said:

there is Volumio player based on NanoPi NEO2

Oh yeah - that looks suspiciously similar! Nice catch

 

[audiobomber]

11 hours ago, Nickolay_V said:

there is Volumio player based on NanoPi NEO2

Not sure how that is relevant. The SHD has a highly configurable crossover, Dirac capabilities and four onboard DAC's as its claim to fame. As far as I can tell the Volumio you mention has none of the above

[InfinitelyBaffled]

I think Nikolay_V is simply stating that he has identified the streamer board to be the NanoPi NEO2, at least based on appearance. it sure looks to be identical.

 

I question the relative merits of purchasing the device with an integrated streamer and Volumio when I already have invested quite a bit in an analog powered pi/DigiOne Streamer using RopieeeXL (for Roon.) Having used Voluimio before, I see it as a potential step backwards. The DDRC-22D may be the best answer for those who are satisfied with their streamer hardware.

[Pro Jules]

On that same topic 

 

Is anyone here using the MiniDSP streamer function? (Volumio)

 

If so, how do you find it?

 

How is the remote (phone / tablet) control of Qobuz or Tidal working for you?

 

It's all Web right? There is no ios app to control volumio? 

 

@InfinitelyBaffledhow is using Volumio a step backwards? 

 

I had an Auralic Aries G1 (was great) but sold it and now using MConnect ios app to control UPnP streaming of Qobuz  

 

Mconnect is pretty clunky but just about tolerable. Can't imagine volumio to be much worse. Might try the free install on my Mac....

 

Thanks

[InfinitelyBaffled]

I am using Volumio, but only as a Roon end point. For that, it works fine. Regarding my "a step backwards" comment - I meant from Roon to Volumio being a step backward, which it would be. However, the SHD works just fine under Roon. IIRC, the Volumio control app on the browser works fine on an iphone or tablet - it is browser based. 

 

I would not buy an SHD primarily for the streamer function - there are plenty of better options out there for that money.

[Pro Jules]

Right

 

Thanks very much. (I am struggling to locate Volumio / Qobuz experiences online) 

Thing is, the Mini DSP SHD could act as a "one stop shop" hub I could hang off:

 

It's streamer (built in) - Qobuz

Chromecast audio - optical

TV spdif digital out - coax 

AES/EBU digital XLR out - to self powered speakers. 
 

Is there another product or (combo) that could do this better? 

[jaaptina]

I have SHD Studio. To stream from NAS and Tidal I use Bubbleupnp instead of mConnect. It has better looks. Both are much more user friendly than the Volumio app.