What does it give you when you used the preamp ?
The S500 system when connected to a Select or Cascade is a bit different to optimize than other DAC->Amplifier combinations. The first thing you need to do is make sure that the S500 impedance switch is set to 75 Ohms. There are two switches near the input jack, gain and impedance. The impedance switch is the toggle with the smooth round handle (nearest the input jack), the gain switch has the rectangular sharp handle (farthest from the input jack). My procedure for setting up the amp for the Cascade is to push both switches into the downward position, this setting is 75 Ohm and low gain. Then I put on the quietest recording that I regularly enjoy. I then sit in my listening chair and adjust the volume to the loudest I would ever listen to that recording and if this setting is below 100 I leave the amp in low gain, If it is above 100 I switch the gain switch (the sharp rectangular handled switch) to the next level (middle position) and listen again. If it is still not enough set the gain switch the upper position. Make sure that when connected to a Cascade or Select DAC you only use the 75 Ohm (down) position of the round handled toggle switch. Once that is done the amp is now optimally adjusted to your speakers, room, and volume preferences.
Next to optimizing the direct Cascade DAC to S500 connection is the cable solution. The characteristics of the XLR cable in our system is very important. Cables that may perform well with other setups may not sound good in this setup and cables that do not sound great in other setups may sound great with our system. This is because normal amp to preamp (or DAC) connections have the driving end of the cable at low impedance (say 10 Ohms) and the receiving end at high impedance (say 20,000 Ohms). Many XLR cables are optimized for this condition. In our system both the driving and receiving end are at low impedance (75 Ohms) so you may require a bit of experimentation with different cables until you find one that works well. If the cable manufacturer will tell you the real impedance of their cable I recommend one that is between 50 and 90 Ohms. This will give you the best chance of finding the right cable on the first try. I also recommend fully shielded (braided shielding seems to work best on average) analog cables as this gives the best chance of achieving the right cable impedance and also keeps interference at a minimum for our system. Cables with filters or âmatching networksâ integrated into them rarely have good results with our system even though they may work well with other systems.
The last thing to optimize is the system grounding. The grounding that is commonly the best is to have a 14 AWG or larger wire connecting the Cascade power base to the amplifier ground lug (the smaller brass lugs, NOT the main binding posts). If you really want to do a deep dive into grounding then you need a âLeakage Clamp Meterâ such as the Amprobe ALC-110 or the Fluke 369. It must be a âLeakage Clamp Meterâ because only these are sensitive enough to use for this application. Attach the clamp meter around one of the analog interconnect cables and take a note of the current, then try different power and grounding schemes until the current reading is minimized. Say you begin with 5mA of âleakage currentâ and you then connect the S500 and cascade power base with a ground wire and it goes down to 1mA, keep that ground wire. If the reading goes up to 7mA then donât keep the ground wire. This is really the last possible optimization and not everyone will be up to it but it is the last thing I do to optimize a system.
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Henrik
All musical aspects sound better
Dustin
This is exactly what I needed. Will try all this. Vince G also said the interconnects will okay a role. I have since order a pair of AudioQuest dragon interconnects for between Cascade and s500. Hoping it comes in next week. Do the speaker cables have a similar concern or not? Lastly, regarding your grounding comments, can you recommend to me a quality grounding cable to order that you have experience with?
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Speaker cables act pretty much exactly as they would for any other amp. Nothing unique to the S500.
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Dustin - thx!
All
Can someone recommend a grounding cable?
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I use Entreq too model or use the Nordost.
There are many brands there make it.
Like Solecky, I always found that a preamp addition (I use the ML52 from Mark Levinson) brings a lot of analog texture and makes the listening more human. Both from the times of the good old DAC IV Diamond to the recent years with the Reference DAC and lately with the addition of the Reference DD. Moreover I have a TT directly connected to the preamp for 33 rpm vynils.
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Thx
I did have a Soulnote P3 there topmodel but I like the DAC as a preamp a lot more.
It remove the color the pre amp made and the music come more a live.
I like to listen to music and not the gear and if a drum or guitar sound right Iâm happy.
Msb give me all that and more to.
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@ Dustin: ref. to the grounding connection between Dac and Amp, I think MSB should strongly emphasize that in the manual.
I had a Reference Dac first and got a S500 later on. But did not made that grounding connection until 9 months later. I prepared a diy loudspeaker cable for a friend and by this also made a cable for the grounding connection between Reference Dac and S500. And I was deeply impressed by the advantage in sound quality I got.
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