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New Dedicated 20A Circuit Wiring Questions

Hello All-

Sorry for the length but I spent allot of time trying to make this as clear as possible and straight forward with all info I felt relevant.

I had a low grade buzz/hum in my current system, had to upgrade home power service to 200A and ran a dedicated line to the stereo while at it. The house also has a home surge protector on incoming power now.

Overall Thoughts on Wiring (with time to make changes if necessary)

   I have 12/2 solid Romex with Hubbell PVC 1-gang box and Hubbell extra HD hospital, isolated ground #IG8300R outlet. To this red/orange outlet, the ZeroSurg with a duplex outlet is plugged in (using the ZeroSurg equipped power line).

   Into 1 of the outlets of the ZeroSurg is plugged a new AntiCables level 3 power cord. This power cord then feeds into a Lowell Mfg 12” 15A (w/breaker) 7 outlet power strip. The power strip then supplies the stereo needs. Of Note here are a number of Anticable L3 power cord reviews that documented owners who experienced a decrease in noise (out the speakers) with use. Yes, that influenced me, wouldn’t that be a nice benefit.

   The pathway noted in above paragraph was recommended to me by Paul (owner) from AntiCables. Paul also recommended plugging all my stereo components into the power strip that now serves the 20A dedicated line.

   Curious about any recommendations to better this with additional info supplied below. Due to reading on this forum and others I have questions concerning noise from ground loop and/or RFI, EM which I want to keep in check.

Some facts about my vintage system to keep in mind:

   1) I’m thinking the cleanest AC will be that which has passed through the ZeroSurge, then through the Anticable power line and offered in the power strip to the stereo?

   2) Not to forget, there is one extra outlet left open on the Hubble duplex 20A outlet of the dedicated line after the Zerosurg was plugged into it. There is also 1 outlet available on the duplex outlet of the Zerosurg after the other was taken by the Anticable L3 power cord supplying the power strip. Of course the available extra Zerosurge outlet is Zerosurg protected where-as the extra Hubble outlet is only protected by the Home surge protector.

   3) My Yamaha C-85 Control Amplifier (Pre) has 6 AC outlets available on its rear panel, 5 switched and 1 unswitched. My Yamaha M-65 Class A Power Amplifier has 1 available unswitched AC outlet.

Things I’ve read of concern, and should I alter Paul’s wiring recommendation?

   A) I have the SOTA Total Eclipse Package on my VPI Prime Turntable. The prime power is now delivered through the “Condor PSU” - Wall Wart; 24VDC  500mA and the “Road Runner Tachometer (RR)” - Wall Wart; 9VDC  300mA.

   B) I also have a Cambridge Audio DacMagic Plus, also a Wall Wart; 12VDC 200mA. Digital; my Pioneer Multi-Play CD, PD-M700.

   Concern is 3 Wall Warts and a digital CD player. Simply put, I’ve read that these components by some audiophiles are dealt with independently of the analog direct 20A line. Seems the consensus is “wall warts” and “digital” are additional unwanted noise to the line (question here is a DAC digital?). Conundrum, 2 of those wall warts are my Prime! I have to have my turntable on the dedicated line don’t I? I don’t want to run 2,3,4-6 dedicated 20A lines, my system is far from that deserving.

   So, to be complete; I have a Audiocontrol Octave Equalizer & Spectrum Analyzer which probably could be plugged into the power strip, Pre amp, or Power amp. Any preference that any of my components be plugged into the PreAmp/Amp components vs the power strip? I also have a VCR and Blu-Ray which I have plugged into a separate circuit on the wall, I have 4 more outlets of that non dedicated house circuit open.

   In summary, if using Paul’s recommendation (all stereo components plug into Power strip). I would have 3 wall warts (including the 1- Dac and 2- TT), a digital CD player, Power Amp, Pre Amp (or plug Pre into available Amp outlet?), and EQ all on the dedicated line. Should “wall warts” or certain ones go to the wall outlets? Are there any benefits to plug a component into extra outlets on rear of Pre-amp vs into the power strip?

Dedicated isolated ground

   I have read that a good method to wire ground wires was by using a “star” shaped ground bar but never found any online. So, I have a 4” length brass bar with 10 screws for securing ground wires and all my stereo components metal chassis ground wires run to it. Some components have thumb screws to attach your wires & others came with wire attached, all different sizes, strand or solid. I used what was given and also used sometimes size 14 copper. For no apparent reason I attached chassis grounds to the bar from both ends toward the middle, both ends equally ascending in size from small stranded to larger sizes toward the middle. Therefore, the center wire on the bar was the “main ground wire” & largest size (12) that will run directly to the Hubbell duplex outlet green grounding screw that also secures the 12/2 ground wire of the dedicated 20A line.

   There are no other grounds run to that dedicated line except the “main ground line” from the brass bar. The 12/2 Romex is not encased by conduit, the Hubbell outlet is within a PVC single gang box. At the 200A service box the dedicated ground attaches closest to the incoming main house ground serving the house panel and other end at outlet as described.

   If looking at my ground bar (from LT to RT) the components order (determined only by size & luck of the draw) resulted as follows: EQ  CD  Sota-Motor  VPI-Main-Bearing  MainGND-Line  PreAmp+Amp  Condor+RR  DAC  TruSweep. The MainGND-Line size 12 runs to Hubbell green GND screw.

   Note: the PreAmp+Amp as well as the Condor+RR, both sets of grounds, were daisy chained in line, containing the 2 component chassis grounds as indicated(+) & secured to ground bar on 1 screw each as all others.

   Any problems with this grounding scheme?

Thanks for any comments, suggestions-

Robes

128x128robes
terry9
2,239 posts
 

@pindac

Sure. Oversimplifying a bit, an isolation transformer works by routing the power from the wall through an inductor, and back to the wall (primary). The inductor then energizes a secondary coil which mirrors the phase and frequency and power of the primary. Thus a huge surge in the primary is routed back into the wall, and the inductor smooths that out while transmitting the transient signal (much attenuated) to the secondary.

Everything gets smoothed out: surges, noise from switching power supplies, back EMF from motors, radio interference. When the electrical inspector came to certify my isolation transformers, he said that he had never seen cleaner power, and he used to work at a power generating station.

Primary connection is best if it comes from its own line from the panel. Secondary should output to your room. Ground should be AT LEAST as big as the biggest wire - this is important because if an inductor is taken out of a circuit, it tends to punch the same current through whatever barrier changed things. This 'inductive kick' as it is sometimes called, can run to 1000 volts. It is important that if anything goes wrong, the path to ground can handle the maximum current that the transformer handles.

So much for the technicalities. How does it sound? Smoother. Cleaner. Clearer. More resolving. A layer of nasty edge came off the sound. It was like replacing a good phono stage with a great one.

If you are building a dedicated room, you might want to do as I did, and optimize the dimensions. There's lots of snake oil out there from the usual suspects, and even industry insiders from the old days, but the real work has been done at the University of Salford, School of Acoustics, by the great Cox. It's all neatly tabulated in a published paper. And it works - at least, it worked for me - but the builder wasn't too thrilled to be working to 3mm tolerances.

pindac's avatar
pindac
2,452 posts
 

@terry9 Dr Trevor Cox is Bookmarked.

After recent exchanges in another Thread, it looks like I have a tip to take a step closer to being in front of a Great Phonostage. If has been suggested I am deficient in this experience, which I must agree is possibly correct.

I have experienced a selection of what my forum ego will refer to as really really good ones.

 

zlone
421 posts
 

@erik_squires I was not aware of that option, thanks. Probably not in the budget this time around, but I will give it some thought. 

mijostyn's avatar
mijostyn
8,223 posts
 

@robes What you have there is a real mess. First of all, try it out. If there is no hum then you are good to go. Many components have chassis ground connected to the negative signal jacks. So for instance, if you have an amplifier that passes ground to the negative signal wire (the shields) it will ground everything that does not float it's ground (ground not connected to negative side like balanced units.) In which case you are forming multiple ground loops which you might have to break if you have a hum. If you want to know what you are dealing with you have to have a meter and check continuity between the chassis and the negative side of an RCA jack.

robes's avatar
robes OP
18 posts
 

@mijostyn  @erik_squires       Finding a meter and learn how to use it would be costly in time for me. it takes me days to buy anything because I have to see all available, reviews, comparisons, etc. then read, watch videos  how to use it. It's not fun to be me when I'd rather get this mess together first and see,

Thought more grounds would be better, didn’t realize what the floating ground business was. I plan to try rewiring without using any of the grounding I added to the non-grounded chassis components.   

Will leave all disconnected chassis ground wires that I added to components ( mentioned below in below discussion) nearby to more easily reconnect to test if I hear hum that wasn’t there before.

See EQ below, Recommendation is EQ to receive its power from PreAmp. Would this be due for floating GND? I have open filtered outlets left on Furman PST?

Last paragraph under TT, the motor housing mount to lead puck I grounded before, will not this time. But the motor, 2 wall warts, condor & Roadrunner are not actually attached in any way except by motor/platter belt(non conductive), so thought maybe wouldn’t hurt to keep that ground?

Will run all 3 wall warts (ww) and CD to Furman PST sharing the 2 ultra-sonic filtered outlets using Y splitters. Therefore 2 ww to one outlet, 1 ww & CD to other outlet. Leaving me 4 unused filtered outlets unless EQ is added.

VPI PRIME TT

  The TT has GND nut. Added a 14 awg from TT bottom spindle nut to TT GND nut (per rec’s by a number of owners who say spindle never grounded). Plan to GND TT (as mentioned) to ground bar. TT Power plugs = 2 wall warts connecting to Furman PST-8 Digital Power station “ultra sonic” receptacles.

  NOTE: PreAmp manual suggests grounding TT to PreAmp but if Hum develops to remove it. No plan to do this.

  My TT has been upgraded with the Total Eclipse Package, from Sota Turntables. It includes:  new Motor, Condor PSU, and Roadrunner (RR) tachometer. The Condor and RR each have separate “wall warts” and no grounding screws or wire from their small chassis or the motor housing. All 3 units interconnect with each other. The Condor also has ~1/4” contained power cable which couples and screws tight to the motor housing.

  Previously, I ran a GND wire between the Condor & RR component boxes then onto the GND bar. Will not this time.

  The new belt driven Sota motor within the original VPI housing is external to TT. The motors stainless steel housing has 4 rubber feet to inhibit crawl when running. I previously removed feet and pinned the housing to a 5” diameter x 1” thick puck of pure lead (to increase its weight).

  Previously, I grounded this motor housing/lead junction to the ground bar. Plan not to ground this time.

CONTROL (PRE) AMP (Yamaha)

 The Power Amplifiers manual suggests running its GND to the Preamps GND. Plan to ground Amp to PreAmp terminal and onward to ground bar as before. PreAmps Power cord to Furman PST-8D.

AMP (Yamaha)

 Amp GND to PreAmp (as before, per owner manual). Power cord to Furman PST-8D.

EQ

 No GND screw or wire. Will not run chassis GND this time. Per EQ Manual rec’s, will plug Power Cord into switched connect on PreAmp.

CD

 No GND screw or wire. Will not run chassis GND this time. Power Cord to Furman PST “ultra-sonic” filtered receptacle

DAC

 No GND screw or wire.Will not run chassis ground this time. Power cord “wall wart” to Furman PST “ultra-sonic” filter

 I have Ground/Lift Switch set to GND.

 From Manual:

 Ground/Lift switch:  When Grounded the Dacmagic Plus is connected to the earth connection of the PC directly. When Lifted the ground connection is made via a network designed to break any hum loops that may be caused by the source equipment.

We advise using the Grounded setting unless audible hum is experienced.

 

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