Why A Linear Power Supply Behind The Modem First

Noise is the loss of resolution in streaming digital audio. Once it’s lost, no amount of downstream upgrades will get it back. Start upgrades with the first link in your chain and work down from your modem to your DAC.

I’ve done this from experience and it has taken me decades to actually realize this. Recently, I used the expensuve Farad Super 6 to power my modem/router and then worked my way down to my Bricasti M12 DAC. I used a Matrix SS-1 Pro to power my switch in the middle and a pair of Finesar converters inside the network and a glass RJ45 cable to my Uptone Regen converter. This placed three high end linear power supplies in my RJ45 network plus a clock in the Matrix SS-1 Pro. Does this matter? An absolute yes! Everything counts and this is a money no object approach.  A lesser costly approach might work but I haven’t done it. You can however and will probably beneift alot.

Why did I wait so long and only focus on the DAC and RJ45 converter first? In reality, the DAC converter (from glass fibre RJ45 to the back of your DAC for input) should be your last concern but most of us always consider it first. That’s what we’ve been condioned to do and its incorrect.

Here’s Why This Works

If you randomly place a linear power supply in your network chain, you are not guaranteed the improvements you’ve paid for and were hoping to get.

In general, the only purpose of networking is to move data from one point to another. Nothing more, nothing less. 

However, a network can perform another far more exciting function in high-sound-quality audio.

The goal is to exclude as much noise as possible from the signal because noise and signal cannot be differentiated later; there’s very little to be done about it once it’s there. A digital system is very sensitive to this and it works.

When the noise is audible, it disturbs the sound quality and your enjoyment of the music.

In Digital streaming audio, the signal comes in 2 parts….the digital, time-based pattern of polarity changes and the analog voltage-based representation of that digital pattern that allows the data stream to be transmitted along wires.  And because of the digital’s 2 part structure, you can do something with it that you can’t do in just the analog domain, namely clean and refine the signal. 

A well-designed and implemented network can clean up and improve sound quality, and not just by a little bit. The more you spend the better your resultting input into your DAC. However, the cost of the components needed always follows audiophile rules and the last 5% of signal quality really costs alot.

Each time your data file is ‘transmitted’ down a wire or via antennae by an active, powered network device, you are essentially ‘re-synthesizing’ the data stream. Of course, as with anything in the analog domain, you include whatever analog noise the network module and its power supply inherently adds to the signal.  So, the better your LPS and cable screening, the less noise you’ll transmit.

The problem in the digital domain isn’t the noise you can hear directly. Instead, noise disturbs the high-frequency digital timing and any processes around it.  Incorrect timing can be measured in the time domain, called jitter, and/or in the frequency domain, called phase noise. And phase noise is nothing more than a distortion of frequencies. When the timing isn’t right the frequencies that result are not, and that’s not good.

Modules along the network chain have an essential characteristic. The quality (finally heard as sound quality) of the outgoing signal is directly related to the quality of the incoming signal.

Improve the quality of the incoming stream, and you improve the quality of the outgoing stream. But there’s a very large ‘BUT’ here.  

Network modules can improve the stream quality, but they can just as quickly bring about its deterioration. If you take a data stream produced using three parts per billion (ppb) oscillator and feed it into another module with a three parts per million (ppm) accurate clock, you have essentially wasted all the improvements the three ppb clock brought about. 

To maximize the final sound quality of your data stream, ideally, that data stream should be improved at every stage of the transmission process – starting with as close to the source as you can get. In streaming, that’s your modem. By doing this, you get ‘compounding’ of all your improvements because the better the incoming signal, the better the output. 

Let’s translate this to some simple numbers. Let’s say we have five network modules feeding into your DAC…a modem, a router, a bridge, a switch, and a server….. for illustration purposes, let’s assign a percentage value to the level of improvement….+20% for better specs and -20% for worse specs. 

If your network is organized in the way I recommend, you’ll get the following improvement:

100+20%+20%+20%+20%  = 207%…a gain of 107%

Now, let’s place a poorer component right at the beginning of the chain:

80+20%+20%+20%+20% = 162%….a gain of 62% 

So immediately, you see that if you upgrade the first element by 20% from 80 to 100, you gain 45%…thanks to the compounding I was talking about.

Now, let’s place the poorer component at the other end of the chain:

100+20%+20%+20%-20% = 138%….a gain of 38% 

Now, these numbers aren’t meant to do anything other than illustrate that placing an excellent low-noise power supply or oscillator in the wrong place in your network can significantly affect what you finally hear.

As your network progresses along its length, ideally, you want increasingly more accurate clocks, lower noise, ripple power supplies, and more thorough vibration and EMI/RFI control.

A well-organized network of moderately good components can thus sound better than a network with some excellent but misplaced components. 

It explains why some people hear an improvement from adding a better LPS while others may listen to very little change.

It also illustrates that the better the downstream components, the higher the rewards of improvements made further upstream.  For example, adding a good LPS to a modem may pay huge dividends in one system and make only a small or even negligible difference in another.

I also use the Puritan 156 power conditioner with a Ground Master and an 8-foot-deep ground rod in my backyard. This also removes the distortion. When done well (through 3 linear power supplies and a Puritan conditioner and ground rod), I end up with just the power amplifier making the distortion, and now things make sense.

In the past, I tried to tune the distortion of the cheap wall wart switching supplies and the power coming into my system. I’ve now found a way to eliminate that (through tube and cable changes, and the tuning I’m doing now focuses on the power amplifier’s 2nd harmonic distortion and distortion coming mainly from the power amplifier. Yes, this is how to do things, particularly with a digital system. This is also why I can exceed the sound quality of an expensive turntable system and gain the convenience I have been trying to use for a long time.

This tuning process begins at the back of the modem power supply and should be done first!

My cost to create the ultimate sounding digital streaming system