MiniDSP releases $55 ADC 'Pocket ADC'

[morillon]

Just to know

Post in thread 'Introducing PocketADC, a tiny Audiophile Analog to Digital converter.' https://www.minidsp.com/community/t...-analog-to-digital-converter.23540/post-73679

Post in thread 'Introducing PocketADC, a tiny Audiophile Analog to Digital converter.' https://www.minidsp.com/community/t...-analog-to-digital-converter.23540/post-73834

PocketADC

The miniDSP Pocket ADC is an extremely compact high-resolution A/D (analog-to-digital) convertor that accepts a stereo analog input on single-ended (RCA) connectors and converts it to SPDIF coaxial and TOSLINK optical digital outputs. This pocket size converter supports high sample rate and...

www.minidsp.com

Ps the transformer in the pack seem, at mesureament, good...

;-)
Somes sweeps like thd-n/thd vs level with 50hz or 15k not only 1khz
(one of the strengths of the 555)
or ccif vs level?


;-)

 

[AnalogSteph]

- 2 chips en la etapa de alimentación:
5430
TI 484
ZJX6G4

Presumably a TPS5430? That's a buck converter.

T9L08

You sure it's not a 79L08? That would match the 78L08 below.

My guess is that they would be using the TPS5430 as an inverter to generate a negative supply and then clean that up with the 79L08. The raw positive input DC voltage then goes into the 78L08, giving us +/-8 V rails for the analog stage. A fairly common choice among soundcards and whatnot.

- Los mismos 2 amplificadores operacionales cercanos a la salida SPDIF Toslink:
5532D
B097F
JRC

Trusty NJM5532D. I'm surprised they'd be using a DIP package part.
EDIT: It's probably an NJM5532MD, the low noise "D" rank of the DMP-8 package part.

- 4 condensadores electrolíticos:
Rubycon YXF 220uf 25v

Rated 7000 hours at 105°C. Impedance <0.25 ohms at 100 kHz seems about normal for the size. So "normal" ESR, high endurance caps. No complaints there.

.LLVB (Desconocido)

I swear I've seen that one before. LP5907, apparently. LDO for ADC supply, I guess?

 

[miguelangel32]

First of all, please forgive me if I'm not clear; I'm using a translator.

I've looked at what's inside this pocket ADC. I have practically no idea about electronics. If anyone who understands electronics wants to shed some light on the design of this ADC, that would be great. Here is what I have seen with the complete codes:

- 2 chips in the power stage:
5430
TI 484
ZJX6G4

79L08

- Possible inductors:
220

4A7

- Possible diode:
SL K1

- 2 op-amp chips very close to the RCA L and R inputs
5532D
B097F
JRC

5532D
B097F
JRC

- ADC:
ESS
ES9821Q
D324
TGWDSXV621

- Crystal:
TXC
49.152
7225A

- The same 2 op-amps near the SPDIF Toslink output:
5532D
B097F
JRC

5532D
B097F
JRC

- 4 electrolytic capacitors:
Rubycon YXF 220uf 25v
Rubycon YXF 220uf 25v
Rubycon YXF 220uf 25v
Rubycon YXF 220uf 25v

- 3 unsheathed electrolytic capacitors very close to the 5430 and T9L08 chips:
KNE2
220
25V

KNE2
220
25V

H13Z
47
50

- Chips unknown to me:
.309

V25
V25

- Bottom of the board (3 chips total):
OP1678 (Texas Instruments op-amp)
TI 41K
AVZX


78L08 (UMW linear regulator)
UMW A30

.LLVB (Unknown to me)


As for my experience with this ADC, I'm using it with quite a few consoles; 3DO, MD and MegaCD, PS1, Neo Geo CD NES, etc... and I'm noticing a lot of aliasing (I'm not sure, but it looks like aliasing) with almost all sources; it's less noticeable when I increase the sampling to 96 and 192kHz but it's still present, I also notice the audio is more dispersed than usual, lacking precision and roughness in the audio, I expected much more to be honest, in comparison my OSSC sounds much better. Maybe it will improve with a good quality LPS, when I get the studer900 from China I'll try to see if it improves anything, but seeing that the internal regulation of this ADC is switched I don't have much hope to be honest.

I have also uploaded several photos of the PCB

 

[miguelangel32]

Presumably a TPS5430? That's a buck converter.

You sure it's not a 79L08? That would match the 78L08 below.

My guess is that they would be using the TPS5430 as an inverter to generate a negative supply and then clean that up with the 79L08. The raw positive input DC voltage then goes into the 78L08, giving us +/-8 V rails for the analog stage. A fairly common choice among soundcards and whatnot.

Trusty NJM5532D. I'm surprised they'd be using a DIP package part.
EDIT: It's probably an NJM5532MD, the low noise "D" rank of the DMP-8 package part.

Rated 7000 hours at 105°C. Impedance <0.25 ohms at 100 kHz seems about normal for the size. So "normal" ESR, high endurance caps. No complaints there.

I swear I've seen that one before. LP5907, apparently. LDO for ADC supply, I guess?

This is my first time commenting on this forum. This time I've commented in English and added a couple of photos of the PCB for anyone interested.

 

[Nutul]

This is my first time commenting on this forum. This time I've commented in English and added a couple of photos of the PCB for anyone interested.

where are them?

 

[miguelangel32]

where are them?

I'm in Spain

 

[MCH]

where are them?

They were there a few minutes ago.

@miguelangel32 tus fotos han desaparecido, podrías subirlas otra vez? Gracias

 

[miguelangel32]

They were there a few minutes ago.

@miguelangel32 tus fotos han desaparecido, podrías subirlas otra vez? Gracias

I've added them as attachments because they lose less quality, you should be able to see them.

 

[miguelangel32]

I've tried the linear power supply and it definitely sounds much better. I've recorded some audio captures from old game consoles with this PocketADC in case you want to see how it sounds:

 

[Per]

I've bought one £70 inc. shipping to UK, but it sits on the desk. I'm going to use it to convert phono pre output (spartan 5) into digital coax for the RME ADI-2 DAC, so I can EQ/room correct the turntable as well as the digital side. ADI-2 ordered since 01/05/2025, but nothing available in the UK at this time, unless you want to overpay. Hurry up RME

Anyone see an issue with this use case?

How did it work? I have exactly the same need to convert the analog output from phono stage to an RME ADI 2 DAC.

 

[morillon]

How did it work? I have exactly the same need to convert the analog output from phono stage to an RME ADI 2 DAC.

there are no surprises...and it's basic as a use...

 

[Crook]

How did it work? I have exactly the same need to convert the analog output from phono stage to an RME ADI 2 DAC.

It works well, as described and at a fair price. I think Amir has one, so hopefully it is measured at some point, but measurements from manufacturer are decent. From my side, the ability to EQ the turntable outweighs any losses that there might be with an extra conversion in the signal chain (I can't tell any difference from that), but the EQ makes a big improvement. End of the day it's a turntable to we are hardly SOTA performance to begin with.

 

[wgh52]

Hello friends,

is there any chance that Amir (maybe even someone else who is capable) would make a thorough evaluation of this pocketADC? ...or have I missed a test?

I have the pocketADC running (fed by a Topping P-50 supply) in my phono chain for some time now and am quite pleased with the sound. I'd be grateful for a thorough test to compare my subjective perception with objective technical results. I'm in Europe, though, so cannot send my unit to him for testing...

Regards,
Winfried

 

[morillon]

Hello friends,

is there any chance that Amir (maybe even someone else who is capable) would make a thorough evaluation of this pocketADC? ...or have I missed a test?

I have the pocketADC running (fed by a Topping P-50 supply) in my phono chain for some time now and am quite pleased with the sound. I'd be grateful for a thorough test to compare my subjective perception with objective technical results. I'm in Europe, though, so cannot send my unit to him for testing...

Regards,
Winfried

The ones already provided by minidsp seem rigorous...see the adept...
on the same type of bench AP from here etc.(and it's a very simple machine to test, It's just that, given the performance... for serious measurements, it's necessary to have a source with some performance margin...)
( Just be aware that there's a trigger at -68dB.)
(It seems that a device has been entrusted from a long time now)

 

[Mort]

Mini DSP sends everything in for testing. However Amir has a long backlog and cannot test every item.

 

[morillon]

Mini DSP sends everything in for testing. However Amir has a long backlog and cannot test every item.

Even though the example was observed in 48 and 96/24... the main standard measurements here are extremely quick and easy... but it's the formatting/text etc. that is clearly tedious and time-consuming... Then there's the option of producing raw, "unformatted" results, enriching those already produced by minidsp...

 

[xlinknz]

Hi all I'm looking to get a MiniDSP PocketADC to allow myself to listen to my turn table via my DACs headphone amp (as the vintage preamp the TT is connected to has no headphone output)

I'd be using the following path TT->Preamp Tape 2 out->PocketADC->Toslink->DAC->Headphones (coax on the DAC has the BR/SACD/CD transport)

Can anyone see any issue with that or considerations that need to be made?

I was considering a low cost 'disposable' AliExpress ADC to test that before getting the MiniDSP but may not

 

[wgh52]

@xlinknz

My own set-up is somewhat similar to yours. TT (with Benz hig output MC) ->PhonoPreamp (Lehmann Black Cube SE II) ->pocketADC->digital chain (e.g. Topping D50s DAC or digital active speakers).

So far there I've seen no issue, no clipping, no distortion, no hum, no (additional) noise, just nice, plain Music. I have not evaluated with headphones, though (because I'm not using them at all). I recommend the pocketADC. In my view the most viable alternative would be a complete phonoDSP like the Waxwing, if one looks for its immense functionality.

Regards,
Winfried

 

[morillon]

I don't quite understand why this little ADC, which can do so many things... rather surprising, it seems to me... hasn't been tested here yet... or even in a more basic way in the few quick tests that could complement the seemingly rigorous ones from minidsp..*

. And Happy New Year!

(* if I had a source with enough headroom, like the best high-performance Chinese DACs in the ASR style, I would have already done it....;-) )

 

[wgh52]

I don't quite understand why this little ADC ... hasn't been tested here yet...

Agreed! Quite a pity to my mind. I'm checking ASR almost daily to not miss Amirs pocketADC test

Best wishes for a great 2026 to all!