Technically, with true balanced signal topology, any common mode interference in the signal transmission is vastly reduced.
Also, current flow due to voltage potential differences between chassis grounds can’t influence the actual audio signal because it’s return path is through the inverted channel and not signal ground (as it’s the case with single ended design).
And it’s always a voltage potential between at least two components causing a ground loop.
Of course, bad circuit design might also cause parasitic interference to be audible.
And to top it off, hum is usually magnetically induced, so using balanced or single ended topology makes no difference - ground loops are rather typified by a buzz, though…
No ground loops, no “hum”, no bad diodes or other components. Both NuPrime amps were effected, not just one of them, both getting power and ground from the same source. Even had the entire system connected to the same power source just as a test. Absolutely nothing to do with ground loops or faulty equipment.
This isn’t my first system. I’ve been messing with this stuff for over 30 years. And I was not attempting to solve a problem by going to balanced. It has always been balanced no matter what.
It’s been a while since I’ve posted to this thread, and nearly everything in the Loft has changed, so I thought I’d snap new photos and share. The Loft is the only room on the 4th floor of our house. It’s 15.5 x 10.1 ft with an 8 ft ceiling, and back half of the left-hand side is open to the floor below. As such, it’s mostly symmetrical above the transition frequency but asymmetrical as far as bass is concerned. Fortunately, I’ve been able to use Acourate to resolve the phase issues in the low bass, and as a result, the soundstage is beautifully balanced.
I’ve downsized both the loudspeakers and components over the years, going from Legacy Audio FOCUS SE towers, which were way too large for the room, to Fritz Carrera 7 BE monitors. My only source is a Gustard X16 DAC, fed by VitOS for RPi4 network audio transport. The RPi4 is powered by an Allo Shanti LPS. A Topping Pre90 preamp routes the signal to dual SVS 3000 Micro subs and Orchard Audio monoblock amps. Cables are mostly from Straight Wire, and I’m using a number of iFi Audio power products, including their PowerStation. Isolation products are from Herbie’s Audio Lab. Room treatments are from ATS Acoustics and GIK Acoustics.
You may notice a laptop on the floor in that last photo. It’s not normally there. I just use it for taking measurements with REW and building filters with Acourate. Since Acourate v2 was just released this weekend, that’s my project for this afternoon. My normal playback control is the delightful rooDial, which helps me to not get distracted by my smartphone when I’m trying to unwind by listening to music. Highly recommended.
Thanks for having a look, and happy listening. Cheers.
Thanks. The Pre90 has both XLR and RCA outputs. One mode routes the input signal to both at the same time. So, I’m running the Fritz Carrera 7 BE’s full-range from the XLR outputs and RCAs feed the subs. The blend is seamless. No high-pass needed…at least in this case.
One more thing, in the SVS, where do you connect the RCA from the Pre90? Left channel from Pre90 to the left input and right channel to the right input of the SVS? I’m sorry if this is a dumb question. Thanks!
Very cool David. I’m curious where the filters from Acourate are being applied in your system? Also what is REW and does it include microphones? I’m curious about how that’s done. Thanks.
This website will explain it all to you. Oner of the best features is adding Convolutions to Roon to fix your Room Correction issues. You will find Mr Thierry is very helpful in finding the proper room correction for your system(s).
My system has never sounded better since taking advantage of what Home Audio Fidelity can do.
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