S.M.S.L - PO100 2024

I have had my Marantz PM6007 since 2022, and was using a Wiim Mini initially to stream music, and sometimes 2.5mm to RCA with my BTR5 connected to my phone to play bit-perfect music.

The PM6007 features an internal DAC accessible only via optical SPDIF and coaxial connections.

For the longest time I was considering getting one of the Fiio Desktop Streaming Player, just to play lossless. But this thing saved me that money.

I now use this with my iPad Pro and connect it to my Marantz PM6007 via coaxial cable. It works perfectly. There are only rare disconnections, if nothing is playing for a minute or so, and I don’t mind reconnecting. However, if I start a playlist or an album it plays it all the way through.

As mentioned by "Anonymous", this is a digital to digital convertor with an XMOS XU316 Chip to reclock the stream.

There is no DAC built in although it shows up as a DAC on Windows and Android.

This cleans up the sound of any jitter and provides a digital input to a good DAC and Amplifier.

Both cables connect securely which is a testament to SMSL build

I have a legacy Onkyo 6.1 receiver that has amplifier circuits built around Texas Instruments' Burr-Brown DAC chips known for their warm, non-analytical sound which I like.

I use the AKG K702 full open back, dynamic driver, with Varimotion dual layered diaphragms via the 6mm jack to connect to the Onkyo Amplifier.

This little device (an economical stripped down version of the more expensive digital interfaces like the Gustard) allows me to get a taste of clean sound without breaking the bank.

A digital signal fed in to the amp sounds better than using the analogue output from my nice iBasso DC05 Dongle DAC Amp to the analogue inputs of the Onkyo Receivers.

Both Optical and Coaxial sound similarly clean. Digital signals do not get colored in any way.

All in all a great purchase.

Very Highly recommended especially for those wishing to wet their toes into this expensive hobby.

As mentioned by "Anonymous", this is a digital to digital convertor with an XMOS XU316 Chip to reclock the stream.

There is no DAC built in although it shows up as a DAC on Windows and Android.

This cleans up the sound of any jitter and provides a digital input to a good DAC and Amplifier

I have a legacy Onkyo 6.1 receiver that has amplifier circuits built around Texas Instruments' Burr-Brown DAC chips known for their warm, non-analytical sound which I like.

This little device (an economical stripped down version of the more expensive digital interfaces like the Gustard) allows me to get a taste of clean sound without breaking the bank.

A digital signal fed in to the amp sounds better than using the analogue output from my nice iBasso DC05 Dongle DAC Amp to the analogue inputs of the Onkyo Receivers.

All in all a great purchase

Initially I was looking for a USB interface that converts USB audio to SPDIF for my Marantz, that accepts optical and coax as digital input and I wanted to feed the lossless music to it through my laptop.
As it's DAC lacked a USB input, I bought SMSL PO100 2024 USB interface. It has high quality XMOS chip and its own clock for asynchronous transmission which is highly required in Hi-Fi setup to reduce jitter.
I used optical for connection but it lacked in the higher frequencies and added jitter causing audio blur. This wasn't adding much to my setup.
So I bought a SMSL SU1 DAC which had USB C input which made my USB interface useless. But to my surprise, when I connected it through USB with my laptop, it was not sounding very good. Turned out, the laptop's noisy power supply was the culprit. So I power the DAC via a 5v DC power bank for linear supply and used my SMSL PO100 USB interface to feed it via Coaxial cable and now it sounds perfect.
The overall sound is powerful and the micro details carry heft in the output. No jitter, no noise, problem solved.

I’m using the SMSL PO100 (2024) to connect my MacBook Pro to an external audio chain via optical, and it’s been flawless. Plug-and-play, no driver hassles, and delivers bit-perfect digital output with zero dropouts. It’s a simple but essential piece of gear that just works—and makes a noticeable difference in sound clarity. Highly recommended for anyone looking to cleanly bridge USB and SPDIF in a hi-res setup.

Awesome product, quality of output is excellent. Only Optical out. Type C in. Works with PC and Mobile

This does exactly what is says....no drivers needed on Windows 11. Just plug and play. It appears as a DAC in Windows Sound Devices. Supports upto 32 bit 192 KHz. I only tested optical connection.

The optical port is strong and latches on to the cable with a satisfying click. Both USB C to C and USB A to C cables are provided. USB C cable is ~6 inches long and white. A cable is 1m (3ft) long and black. It works the same on all USB ports 2.0 or 3.0.

I bought this as the latching mechanism on my motherboards optical port broke. This seems to have better build quality and is small enough to hide behind PC case. It is the size of a matchbox with metal and glass construction.

It is identical to my motherboards optical out in audio quality. Before purchase I read and watched a few reviews of this. The one by "cheapaudioman" is incorrect.

No difference in audio quality compared to my B450 motherboad. And I tested it on 3 DACs - Topping BTA 30 Pro, ifi Zen One and Wiim Pro Plus.

I tried hard in an attempt to justify the purchase.....but there is none. In an A/B test, I couldn't tell the difference between motherboard and PO100 optical out. I guess Coaxial would be the same but didn't test it.

So, buy if you need USB to Optical & Coaxial converter for some reason but don't expect any change in audio quality as there is none.

PS : There is some online conversation about optical volume being too low on earlier 2024 versions fixed with firmware update. But my unit bought in Feb 2025 has no such issues so i guess it already comes with the newer firmware.

Works well, supports connectivity and formats as mentioned in specs
Does not heat up on longer use
Very small does not need adapter, keeps space tidy