Post by brucew268 on Apr 5, 2024 11:56:27 GMT
When I changed from CD’s to file-based playback 12 years ago, I fed the DAC with a Fidelized and tweaked laptop running JRiver. It had pretty decent sound but I knew I should be able to do better and so went to microRendu for a low noise option.
These are items that received my attention:
Choice of processor
Power Supply
Local storage vs networked storage
SSD vs HDD
Fan vs fanless
USB2 vs USB3
CPU frequency
Status update frequency
Processing & Volume control
Hyperthreading & Turbo on/off
Choice of Processor
If going with a player that doesn’t upsample or use Roon, processor power doesn’t seem to be an issue. So, I reasoned that for anything 5th generation or newer a Core i3 should be sufficient, certainly no more than a Core i5. The greater the power capacity the item is designed for, the more electrical noise is likely to be an issue, effecting the noise floor. It’s the type of noise you never notice until it’s gone. Yes, a mini-Itx allows for aftermarket USB or SPDIF cards, but they also require a stronger power supply, with its issues of noise and cost both for the computer and power supply. If cost is no object, you can find lots of threads here pursuing best sound down that path.
As mentioned, I wanted a high quality 19V linear power supply that could well handle 1-1.5A and chose one based on the Studer900 PSU phantom power design. That has excellent low noise performance and cost around £150 including the board, case, transformer, and supplemental capacitors. One could buy it complete on Ebay for less but suspected it might not be properly spec’d (espec. transformer) to support this voltage/power combination.
I used a microRendu and UA Ultracap LPS-1 for a few years with a remote fileserver, but always felt like it lacked the sense of timing and very low noise floor that I’d had with a CD transport-based system. So, in 2022 I switched to an Audiolab 6000CDT transport, started spinning discs again and was rewarded by what I’d been missing. After a year or so with that I wondered if I could get to that same sound with a file based player without many boxes and 10x the price of my disc spinner, so started experimenting and used the CD transport as a reference.
These are items that received my attention:
Choice of processor
Power Supply
Local storage vs networked storage
SSD vs HDD
Fan vs fanless
USB2 vs USB3
CPU frequency
Status update frequency
Processing & Volume control
Hyperthreading & Turbo on/off
For software, I tried JRiver Media Center and Euphony Stylus on a NUC, sometimes with the files in a separate NUC as server and sometimes as a separate drive inside the player.
Choice of Processor
If going with a player that doesn’t upsample or use Roon, processor power doesn’t seem to be an issue. So, I reasoned that for anything 5th generation or newer a Core i3 should be sufficient, certainly no more than a Core i5. The greater the power capacity the item is designed for, the more electrical noise is likely to be an issue, effecting the noise floor. It’s the type of noise you never notice until it’s gone. Yes, a mini-Itx allows for aftermarket USB or SPDIF cards, but they also require a stronger power supply, with its issues of noise and cost both for the computer and power supply. If cost is no object, you can find lots of threads here pursuing best sound down that path.
But I wanted a one PC solution that could use a high quality ultra low noise power supply that didn’t need to handle 4A or more. So I looked for an i3 or i5 NUC that had a low power requirement, less than 26W, so I could use a 19V 1-1.5A linear power supply. Since I couldn’t find any fanless cases to fit a 5th generation NUC, I chose a refurbished 7th generation i5 NUC. I also needed a NUC spec’d to support two internal drives rather than one. My cost was £200 between the NUC and an Akasa Plato fanless case.
Running Euphony Stylus, it never even gets close to 1A except during the boot sequence.Power Supply
General consensus seems to be to get the best quality low noise power supply you can afford. It makes a big difference to the sound quality.As mentioned, I wanted a high quality 19V linear power supply that could well handle 1-1.5A and chose one based on the Studer900 PSU phantom power design. That has excellent low noise performance and cost around £150 including the board, case, transformer, and supplemental capacitors. One could buy it complete on Ebay for less but suspected it might not be properly spec’d (espec. transformer) to support this voltage/power combination.
SSD & Local storage
Tony recommended I store the files on an interior drive instead of a network server and that I use an SSD rather than an HDD.This ran counter to most of what I’d read, since SSD’s are thought to be electrically noisier and best to get file storage away from the player. But he said that an SSD requires less current than an HDD and so allows the computer to generate less noise, more than compensating for any electrical noise from the SSD itself. I found that to bear out in SQ when I changed from HDD to SSD on the storage drive. Of course, I used separate drives for OS and file storage.
He also said that wired networked devices will tend to add noise to the system unless a lot of care and expense is put into galvanically isolating them from the player. So, I used a dedicated WiFi 4G router just to enable use of a remote and to have access to the internet, required by some player software. I again found his recommendations to bear out in the resulting SQ.
Fanless case & USB
I moved the NUC into an Akasa Plato fanless chassis, which had a good result to SQ in addition to now being physically silent running. The Plato also allows connections from the USB2 options on the board and I found those to have more accurate transients than the USB3 ports either front or back. At least for a NUC, turn off all USB3 ports if possible as they spew lots of RFI. USB3 off makes a huge difference in SQ for me -- not optional.
CPU Frequency
I’ve also heard from multiple sources that setting the CPU frequency is important to the SQ performance and I found this critical in order to get close the disc spinning performance. Fortunately, Euphony’s Stylus software allows easy switching of CPU frequency on the fly for immediate comparison. In my comparisons, changing the frequency could affect: transients, sharpness, midrange, handling of complex passages, dimensionality of images, timing, etc., and I found that the best setting often changed when I changed anything else on the computer and required a lot of comparison testing.
For instance when in the original case with a fan, the best CPU Frequency seemed to be 13000 and the timing sounded off when below 10,000. But when in the fanless case, 6000 sounded best in my setup.
Status Update Frequency/Processing
In Euphony, one can change how often the song position is updated when playing. There was a marked improvement in SQ when it was set to least often. Between 20 sec and "never", I eventually settled on “never”. This was nearly as significant as the CPU frequency setting. (Euphony: Settings/ Music Service/ Playback Options/ Song Pos Update). Similarly, if using JRiver, the volume control should be Disabled and DSP bypassed.Hyperthreading & Turbo
For some reason things sound worse when both Turbo and Hyperthreading are off. I currently am liking Turbo off and Hyperthreading on. It’s worth popping into UEFI/BIOS and trying them both ways.
For some reason things sound worse when both Turbo and Hyperthreading are off. I currently am liking Turbo off and Hyperthreading on. It’s worth popping into UEFI/BIOS and trying them both ways.
Input voltage from PSU
On a NUC7i5 running Euphony (Unix-based) the input voltage proves to have as much impact on the sound as anything in the OP. The effect seems fairly linear in parts of the range, from sharp and busy at higher voltages down to calmness, imaging, soft leading edges, and deeper bass at lower voltages. However, there is a lot of hit and miss as well. It's worth trying every 0.05VDC for a half volt on either side of the target voltage. This has a major effect on the musical presentation.
6000CDT reference
OK, so my cd transport’s board hasn’t functioned in nearly three months so most of my comparisons have been from memory (!). Up until I’d made all the above changes, I didn’t feel this file-based player could really compete with the CD transport, but now I wouldn’t be surprised if it did as well or better. Still waiting on the replacement board so it may be another month before I can compare them directly.
