MINIDSP Adept ADC & Phono Preamp Review

[markstein]

Can this thing be used as a loopback (reference) device in REW? Simultaneously can this be used as an input to REW for an XLR-based microphone (in place of a USB microphone) and would there be benefits as such of using an XLR-type microphone over using a USB-type microphone? Perhaps for synchronizing speakers to each other and to a subwoofer in REW more accurately or without relying on the use of an acoustic reference tone (since those are typically too high for subs to reproduce)?

The Adept is no mic preamp but a digital phono preamp and A/D converter. There is no mic phantom power. Wrong device for your use case.

 

[SoySalsaPicante]

The Adept is no mic preamp but a digital phono preamp and A/D converter. There is no mic phantom power. Wrong device for your use case.

Thanks for confirming, Mark.

 

[Sokel]

Can this thing be used as a loopback (reference) device in REW? Simultaneously can this be used as an input to REW for an XLR-based microphone (in place of a USB microphone) and would there be benefits as such of using an XLR-type microphone over using a USB-type microphone? Perhaps for synchronizing speakers to each other and to a subwoofer in REW more accurately or without relying on the use of an acoustic reference tone (since those are typically too high for subs to reproduce)?

???
You mean time-align them?

You don't synchronize speakers to each other, neither the sub. All you can do in such case is to time-align them for a single tiny spot at the MLP.
It would be different to anechoically time align 2 subs with mains, each channel with its own sub, like in a stereo configuration (and with x-over low enough and subs close to mains) and then check at MLP.

 

[SoySalsaPicante]

???
You mean time-align them?

You don't synchronize speakers to each other, neither the sub. All you can do in such case is to time-align them for a single tiny spot at the MLP.
It would be different to anechoically time align 2 subs with mains, each channel with its own sub, like in a stereo configuration (and with x-over low enough and subs close to mains) and then check at MLP.

Correct, I am talking about time alignment at the MLP. I currently use an acoustic reference signal from one of my speakers to do this, but I was under the understanding that it can be more precise to utilize a loop back reference instead. Either way this is apparently not the right device for that, so moot point.

 

[markstein]

Off topic - regarding "time alignment":

If using a USB microphone and a separate DAC for acoustic measurements the clocks of both devices are not synchronized - this can lead to measurement errors.
You should always use an acoustic loopback (an impulse at the beginning and the end of the sweep measurement) when using a USB mic and a separate DAC to correct for this issue. REW offers this option, Acourate impulse recorder, e.g. does as well.

If you are using one sound interface for playback and recording, there is only one clock, so no issue. This is the technical "better" solution, however, the other solution works as well.

 

[ManuCV]

I bought a Rega a2d as a cheap temporary measure (previous phono preamplifier failed). It can easily be bettered by most phono preamplifiers measured here. I suspect that the Adept would be a noticeable upgrade.

I happen to have a miniDSP SHD as preamp and a Rega A2D Mk II as photo stage. When you say it can be bettered by most phono stages measured here, will there be an audible improvement?

 

[MaxwellsEq]

I happen to have a miniDSP SHD as preamp and a Rega A2D Mk II as photo stage. When you say it can be bettered by most phono stages measured here, will there be an audible improvement?

In my personal experience, yes. Phono stages are an area where there are audible differences between products.

A few years ago, my early 1980s excellent preamplifier became too unreliable and difficult to repair. I went to a line-level only system. I don't listen to LPs very often and couldn't justify spending money on a phono stage, so bought the Rega A2D. It was quite a downgrade.

After a couple of years I had saved enough to buy the Cambridge Audio Alva Duo. Compared to the A2D it is quite an upgrade. I don't feel it's quite as good as my original preamplifier, but it's still good.

 

[SoySalsaPicante]

Off topic - regarding "time alignment":
...If you are using one sound interface for playback and recording, there is only one clock, so no issue. This is the technical "better" solution, however, the other solution works as well.

Is there a reasonably affordable device you can recommend for this?

 

[markstein]

Is there a reasonably affordable device you can recommend for this?

I'd say any basic USB sound interface will do the job, e.g., the Focusrite Scarlett 2i2 or comparable devices. Plus a measuring microphone incl. calibration file. For bass EQ this might not even be required.

 

[morillon]

Have any Adept owners had the opportunity to test it via USB ( not can) with Rew, Multitone, Virtins, etc.?
;-)

 

[Sokel]

Have any Adept owners had the opportunity to test it via USB ( not can) with Rew, Multitone, Virtins, etc.?
;-)

Wait for a few days.

 

[AustinJoeC]

Have any Adept owners had the opportunity to test it via USB ( not can) with Rew, Multitone, Virtins, etc.?
;-)

I’ve not tested my Adept with measurement software, but I’ve ripped perhap a dozen albums to Audacity via the USB connection. I’ve really been happy with its performance via USB and have not noticed any glitches in the waveform (which I review critically for clicks and pops when I digitally “clean” the recording.) It acts like a conventional USB device.

My previous solution for this was Philips GA 212 turntable -> Schitt Mani pre -> Swissonic 24/192 ADC (S/PDIF) -> Hifime S2 digi (S/PDIF to USB). The Swissonic was fixed at 24/192k which would occasionally cause my computer to drop samples and which was unnecessary for my 24/96k Flex 8. The Hifime would tend to randomly throw off 1 bit wide clipped, noise spikes which was disconcerting. I assumed it to be a timing or power supply issue, and they were easily removed as just another click but that took time.

There are no such issues with the Adept. Also, I’ve found the High Pass Filter to be a better solution than attempting to filter out low frequency noise post-recording. Getting the gain set properly for the cartridge took a little experimenting but generally it is set and forget. I compared Turntable -> Mani -> Adept -> USB vs. Turntable -> Adept -> USB and I saw no reason to keep the Mani in the sequence. The Adept phono preamp seems at least as good as the Mani. I have been incredibly pleased with the Adept’s ability render exactly what’s on the vinyl to digital without audibly leaving its own mark and to transfer it via USB for recording.

 

[morillon]

Attends quelques instants

I’ve not tested my Adept with measurement software, but I’ve ripped perhap a dozen albums to Audacity via the USB connection. I’ve really been happy with its performance via USB and have not noticed any glitches in the waveform (which I review critically for clicks and pops when I digitally “clean” the recording.) It acts like a conventional USB device.

My previous solution for this was Philips GA 212 turntable -> Schitt Mani pre -> Swissonic 24/192 ADC (S/PDIF) -> Hifime S2 digi (S/PDIF to USB). The Swissonic was fixed at 24/192k which would occasionally cause my computer to drop samples and which was unnecessary for my 24/96k Flex 8. The Hifime would tend to randomly throw off 1 bit wide clipped, noise spikes which was disconcerting. I assumed it to be a timing or power supply issue, and they were easily removed as just another click but that took time.

There are no such issues with the Adept. Also, I’ve found the High Pass Filter to be a better solution than attempting to filter out low frequency noise post-recording. Getting the gain set properly for the cartridge took a little experimenting but generally it is set and forget. I compared Turntable -> Mani -> Adept -> USB vs. Turntable -> Adept -> USB and I saw no reason to keep the Mani in the sequence. The Adept phono preamp seems at least as good as the Mani. I have been incredibly pleased with the Adept’s ability render exactly what’s on the vinyl to digital without audibly leaving its own mark and to transfer it via USB for recording.

Thank you for this feedback...

 

[morillon]

What's funny is that these two products allow you to easily add standard balanced line inputs, but especially asymmetrical 2V inputs, to pro/semi pro CANs with digital inputs, for professional or semi-pro uses... sometimes useful... in a qualitative way... the pocket is really a "snub"...



and even for measurements... getting close to a cosmos without the worries of input impedances... which is enough in a lot of situations... except to measure Chinese DACs in the race for sinad at 1k ;-)

 

[AndyMorris]

For RIAA equalization and LP ripping, you Couihave perfect equalization but headroom is not great. So be sure to clean your LPs before capturing.

Could you expand on this? What would I lose out by using this instead of a separate phono preamp and an audio interface (FOSI X5 and Topping E2x2 say ) ?

 

[xanalog]

As I’m totally unfamiliar with ADC devices like this one:
Would it also be able to handle (convert) signals coming from a cassette deck, via line input?

Flexible Phono preamp powered by Digital Signal Processing (DSP)

Input Source: Maximum analog input (before digital gain & RIAA EQ if applicable)
At Low/Medium/High gain settings
Moving Coil (MC)/RCA: 81mV/29mV/12mV
Moving Magnet(MM)/RCA: 220mV/110mV/68mV
Line-in/RCA: No/2.2V/1.1V
Line-in/XLR: No/4.4V/2.2V

ADept

The miniDSP ADept is a compact high-resolution A/D (analog-to-digital) convertor that accepts single-ended (RCA) or balanced (on XLR) audio signals. The digital output is available on SPDIF coaxial and TOSLINK optical connectors, and can also be recorded to a computer or mobile device via the...

www.minidsp.com

 

[rocksteady]

Interesting idea, thanks for the review, Amir. I don't need it now (phono preamplifier to ADI 2 Pro), but I would have definitely been the target market a few years ago.

All the native ADC-based RIAA devices seem to suffer from insufficient headroom. Scratches and hot cuts with a high output MM should probably be a avoided.

What do you understand by High MM? 4mV or higher?

 

[MaxwellsEq]

What do you understand by High MM? 4mV or higher?

It really depends. But I would say 5mV and above constitutes the upper end.

 

[rocksteady]

That is my understanding as well. Mine outputs an average 4mV, therefore "safe", based on your assessment...

 

[MaxwellsEq]

That is my understanding as well. Mine outputs an average 4mV, therefore "safe", based on your assessment...

That's a bit too much of a simplification. Your cartridge doesn't output an average of 4mV. It probably outputs 4mV at 1kHz at 5 cm/s.

But there are many hot cuts out there. And many 12" 45s are cut hotter. So you are probably safe with gentle cuts on 33 1/3 LPs.

But the real issue with low overhead phono preamplifiers is they are badly perturbed by loud clicks and even small amounts of dirt can overload them. There's anecdotal evidence that a phono preamplifier with good headroom makes LP surface noise seem quieter.