Review and Measurements of miniDSP SHD DAC, DSP And Streamer

[amirm]

Awesome work, thanks Amir!

I had thought of getting the SHD Studio version, and using a couple of good external DACs if the DAC performance wasn't that great. Given your results, and the input by MiniDSP tech support, looks like it might be simpler and easier to get the full SHD instead!! Following this thread with interest.

I think I know one reason you've had problems getting the software / plugins etc, is that when you create an account to purchase any of the MiniDSP products, it automatically links you to all of the software and plugins you're entitled to.

Given that someone else purchased your test model, then they would have had automatic access to the software, but you wouldn't have. Just my 2c worth.

My pleasure. And you are right about how they provide the information on plug-in. The problem is, neither the owner, nor I, knew about that. I think a piece of paper inside the box saying where the software is would be helpful.

 

[derp1n]

Actually I think I found a mistake in the frequency response measurement. I will post a correction soon.

What was the problem?

Posting incorrect measurements and then silently revising the original post without highlighting that a correction was made isn't ideal. Including a change history would be a big improvement.

 

[amirm]

What was the problem?

Posting incorrect measurements and then silently revising the original post without highlighting that a correction was made isn't ideal. Including a change history would be a big improvement.

There is an Edit remark in the original review and I made a post to that effect just the same.

The error was a simple one: I extended the spectrum to 22 kHz, not realizing that the steps were too coarse, making the next measurement step 17 kHz. The software then drew a line between 17 and 22 kHz, making it look like it had measured the in-between points when it had not.

This is a new template I have been using so it doesn't have much mileage on it.

 

[restorer-john]

So, how many steps does the AP take in the THD+N vs Frequency in the upper octaves?

The low frequency part of the plots appear smooth, suggesting more discrete measurement points and the upper octaves look like finite points with lines drawn between them, suggesting large jumps in frequency.

 

[amirm]

Step count is programmable. The AP templates usually default to 31 steps. Here are the steps and data for that specific measurement:

It is a log sweep and hence the larger steps at high frequencies as you state.

I can add to them at the expense of measurement time.

 

[restorer-john]

Consider there are only three data points in the last 10KHz and if you've got a significant rolloff (like a lot of the D/As appear to have), the last two values are going to be compromised in any case.

I'd be stacking quite a number of additional measurement points 16-22KHz to really see what is really going on up there with the various filters you come across in modern DACs. How long does each step take in the THD+N vs Freq run?

Are the FR plots using a similar number of discrete amplitude measurement points? (31)

 

[amirm]

Are the FR plots using a similar number of discrete amplitude measurement points? (31)

That was the default and part of the problem. The updated one I put up there was a linear sweep with some 260 steps I think. It was pretty time consuming to run because of it.

Question is if anything interesting occurs in the middle of those larger steps. I could also switch to linear progress so spacing remains the same.

 

[restorer-john]

To give you an idea, my ancient AudioLab does 492 discrete frequency and amplitude measurements in a 0Hz-20KHz log sweep. The linear sweep has the same number (492) of steps with definable start freq and step increments.

You could run a top end custom linear sweep with a heap of steps that would easily show the passband ripple.

 

[jdubs]

Awesome review -thank you!!!

Very curious to hear what miniDSP reports back re: the jitter issue.

-Jim

 

[Olli]

And I wonder if it i still there when using its network functionality with Volumio?

 

[Krunok]

I like to go past 22 Khz so that the harmonics of 20 kHz tone are captured correctly.

To what purpose is to measure something that cannot be heard?

 

[Krunok]

https://www.minidsp.com/products/streaming-hd-series

View attachment 15077

If that is the case what are "2 in, 4 out" audio channels in Studio version?

 

[Krunok]

And I wonder if it i still there when using its network functionality with Volumio?

Probably so, as board running Volumio is probably connected to DAC via USB.

Edit: User manual states the internal connection between processor board and DAC is I2S.

 

[Krunok]

Very curious to hear what miniDSP reports back re: the jitter issue.

-Jim

Why we can, and to a certain point should, be interested in those jitter spikes let us not forget they are burried far below hearing threshold (lower than 120dB!) so speaking of any "jitter issue" hear seems inappropriate to me. Even if the manufacturer issues a version where this spikes would be eliminated we would need a very expensive measuring equipment to verify that. I think we should be pushing manufacturers to make more affordable products of satisfying specs instead of pushing them to chase improvements in specs we won't possibly be able to hear.

 

[Krunok]

On the software side, I hope miniDSP reconsiders its software licensing process. Having to screw around with redemption codes and such is just wrong. The unit should come with all the software or proper online link to make it work out of the box.

Can you please clarify this - what software is licensed separately? Are there any additional costs involved?

 

[andreasmaaan]

Can you please clarify this - what software is licensed separately? Are there any additional costs involved?

It's been a long time since I had a miniDSP, but I believe the "plugins" must be purchased separately from their online store and then downloaded. I think they cost about $10 each last time I looked.

There are different plugins for different applications, e.g. 2 x 2-way Xover, 4-way Xover, 2.1 system, etc.

 

[derp1n]

If that is the case what are "2 in, 4 out" audio channels in Studio version?

Digital Audio Outputs
Four channels of digital output. Both sets are active simultaneously.
2 x AES/EBU on Neutrik 3 pin male XLR / Isolated with digital audio transformer
2 x SPDIF on RCA connector / Isolated with digital audio transformer.

 

[Krunok]

It's been a long time since I had a miniDSP, but I believe the "plugins" must be purchased separately from their online store and then downloaded. I think they cost about $10 each last time I looked.

There are different plugins for different applications, e.g. 2 x 2-way Xover, 4-way Xover, 2.1 system, etc.

These are what, DSP plugins, or?

Here's what they say on their support page:

Which plugin do I need to buy for the Dirac Series?
The Dirac Series of processors works a little differently to the other miniDSP products. You do not need to buy a plugin, all the software you need is included in the purchase price.


http://support.minidsp.com/customer/portal/articles/search?q=Dirac+series

 

[Krunok]

Digital Audio Outputs
Four channels of digital output. Both sets are active simultaneously.
2 x AES/EBU on Neutrik 3 pin male XLR / Isolated with digital audio transformer
2 x SPDIF on RCA connector / Isolated with digital audio transformer.

And here's what they say for the "standard" version:

Analog Audio outputs

4-channel audio output, balanced XLR Neutrik connector, unbalanced on RCA

32bit AKM AK4490EQ DAC / 120dB SNR measured / 0.0003% THD+N (Digital to balanced analog)
Max output level: 2V RMS unbalanced, 4V RMS balanced

Output impedance: 100 Ohms (RCA) / 200 Ohms (XLR)

Digital Audio Outputs
Four channels of digital output.

• 2 x SPDIF on RCA connector / Isolated with digital audio transformer.

Funny way of counting outputs.

 

[andreasmaaan]

These are what, DSP plugins, or?

Here's what they say on their support page:

Which plugin do I need to buy for the Dirac Series?
The Dirac Series of processors works a little differently to the other miniDSP products. You do not need to buy a plugin, all the software you need is included in the purchase price.


http://support.minidsp.com/customer/portal/articles/search?q=Dirac+series

Ok, I wasn't aware it was different for the Dirac series.

Yeh, the plugins are DSP plugins.