Glad you will be getting this sorted out sharpish. It's painful to have a device simply not be what you want it to be. Hopefully it turns out to be an environmental issue and doesn't require a trip to Lukasz.
Hello sir. Just the man I’ve been waiting to hear from. Thanks for coming through with the awesome customer support. I’ll keep you posted as Larry has graciously agreed to have me over to do some testing this Saturday. I’m a happy camper.
I read your post with interest as I had a similar experience with my Lampi GG2. I’d like to provide some background and context. My system prior to the addition of the GG2 (which you can view here https://www.whatsbestforum.com/members/marty.11/#about) was perfectly quiet and had no 60 Hz hum whatsoever for any input source. Much to my chagrin, when I substituted the GG2 for the Meitner DA-2, I had 60 cycle hum that was very disturbing. As many audiophiles know, hum and noise can be the bane of our existence. I thus tried all the usual solutions including 2 prong cheater plugs, the well-regarded Iso-Tek Synchro Uni, praying to unnamed spirits, reciting incantations, lighting frankencense and myrrh and other nonsensical solutions since nothing worked.
Before going any further, let me state that hum can be caused by several things which include the obvious ones such as ground loops, but also some less considered etiologies such as proximity effect. This occurs when the transformers in individual components are placed close enough for them to have an interaction that results in induced hum. This plagued me for quite a while in my phono system when I was using a different phono stage other than my present Zanden 1200, and it took me over a year to find that the solution was simply moving the phono stage to a different shelf! Drove me nuts for far too long when all it took was a simple gear placement change to solve the proximity effect.
So all was humming along beautifully (no pun intended) until the GG2 was installed. And with it, 60 cycle hum returned in all its glory. When I played a CD or if I streamed and suddenly hit the pause button at listening volume, the hum was obvious. My handy spectrum analyzer app “Analyze” on my iPhone confirmed that I had a huge amount of not only 60 Hz, but 120Hz and 180Hz hum as well.
There have been many discussions on this topic elsewhere in this forum that need not be repeated here, but isolation transformers can be highly useful for eliminating 60 Hz ground loop hum which is caused by common mode noise in many AC installations. This is often caused by stray capacitance leakage to ground in the gear that is the source of the ground loop.
I’m certainly no expert in this area, but the following is from Furman literature:
“In much the same way that balanced audio lines can reduce the pickup of hum and other types of electromagnetic interference (EMI), the use of balanced AC power lines in sensitive audio, video, or computer installations can make an enormous difference in system noise and signal integrity. But power distribution in North America, unfortunately, is not balanced. The distribution standards currently in use were derived from practices established over a century ago, when electric power use was limited to lighting and motors, long before any AC noise sensitive applications existed. The emphasis then was on convenience and safety, but not noise cancellation. The result was a three-wire distribution scheme in which 120V branch circuits have a hot wire and a neutral wire, with the neutral tied to a third wire connected for safety to an earth ground. The third wire does not carry any current unless there is a fault. This unbalanced scheme can create hum in audio circuits for two main reasons. First, the current flowing in the hot wire induces hum in any other nearby wires, which may carry vulnerable low-level audio or video signals. Second, because the impedance of chassis and cable shielding to ground is always greater than zero ohms, ground current flowing from power supply capacitors and from EMI pickup causes a voltage drop at 60 Hz and its harmonics. This low level noise becomes part of the audio signals.
Furman’s Discrete Symmetrically Balanced Power is achieved by running the incoming AC into a 1:1 isolation transformer with a precisely placed center tap on the transformer’s secondary. The incoming voltage (120V on the line terminal and 0V on the neutral and ground) is split into perfect halves on the transformer’s output. The AC line now has 60V on the line and 60V on the neutral when referenced to the new center-tapped ground, which remains at 0V AC. What is significant about this is that the two 60V AC terminals are now in opposite polarity. This completely cancels all common mode noise from the incoming AC line. This noise reduction is extraordinarily efficient and linear across a huge frequency range, and the result is perfectly clean power devoid of ground loops and AC hum noise.”
Since employing the Furman, my ground loop and hum disappeared as by magic. (It’s not magic of course, it’s science!). A few additional noteworthy comments. First, I use the Furman only for the Lampi GG2. I do not need it for any other component. One may read the Furman literature and come away thinking, why not use it for all of one’s gear? Well, that is a hot debate topic that will trigger a range of responses among WBF members. There are some users who use isolation transformers for their entire AC supply before AC distribution in their rooms, and others who eschew these devices because they feel they may have a “downside” since common wisdom suggests there is no free lunch including what may happen when power goes through any type of transformer. Me? It’s simple. If there is a downside of using the Furman, all I would say in response is that it’s not even close to the obvious downside of not using it and accepting 60Hz hum in return. Even if your 60Hz hm is nominal (mine was not), I think you would be shocked at how much better the sound is when it is banished in its entirety. The bass in particular is the greatest beneficiary, but the SQ improves throughout the frequency spectrum. 60Hz hum is pernicious and bad. I’ll gladly use the Furman because the alternative is just untenable in my system. Academic arguments to the contrary don’t interest me. Results do and in my rig, they speak for themselves. I should add I bought my unit on ebay and it included a 30 day return policy. That sort of made it a no brainer for me to try.
In retrospect, I bought the 20 amp version because I had no idea what I would hook up to the Furman. However, now that I know it's just the Lampi, I probably could have saved some money by buying the 15 amp version IT-Ref 15i instead.
One final comment. The Furman was designed by Garth Powell, who also designed the well-regarded Niagra 7000 Power conditioner (which uses an isolation transformer as well for the same purpose of supplying balanced power). The difference is that the Niagra was conceived as an “audiophile component” where as the Furman was designed as a work horse for recording studios. The Niagra retails for 7K; the Furman retails for 4.5K (actual cost was about $2200 new on ebay). We had the opportunity to compare the Furman IT-20i to the Niagra 7000 in a friend's system recently. (In this case, the 60 cycle hum was in the phono stage, not the DAC pathway.) Much to our amazement, the Furman sounded better. Go figure…..
Although my Lampi Pacific is dead quiet when plugged into the wall, my purchase was based on a persistent 60 cycle hum emanating from my phono Stage. I used all of the same things Marty did all go no avail. I bought the Furman prior to receiving my Pacific. I must admit I was worried about a hum with the Pacific as I have been reading threads wherein 60 cycle hum on the Lampi was found by several users. Suffice it to say plugging my phono stage into the Furman resulted in complete disappearance of the 60 cycle hum. When I received the Pacific my first thought was to
plug it into the Furman but I wanted to hear it direct into the wall. My power cord used on the Lampi is a Masterbuilt Ultra. Plugged into the walll it was dead silent
as for transformer proximity I totally agree as my entire front and back end is all tube and dual mono and dual power supply. Hence twice the number of transformers. I had similar issues where the power supply if my Doshi pre was too close to the power supplies of my phonostage. Moving it further to the side reduced the hum without need to plug the Doshi into the Furman
as Marty says you have nothing to lose as there is a 30 day money back guaranty
Thanks for your detailed accounts o the various potential offending sources of noise and Ill be sure to keep this in mind moving forward.
Moreover I’ve been toying with the idea of a power conditioner even before current predicament and was looking at the Silver Circle Audio unit as a potential candidate , based on the many glowing reviews as one of the few PC hat doesn’t limit the sound quality. I’m glad there’s another available in the Furman. I’ll look into it.
Also I wanted to note that a friend of mine, who’s an electrician just reminded me that he noticed that the sub panel that’s supplying my entire property has the neutral and ground tied together. This will be remedied on Saturday after I come back from Larry’s.
Al, this is one of several pics I found that depict a ground loop as somehow involving capacitance leakage to ground. As far the accuracy of this image as a proper depiction, that is above my pay grade so I can't answer meaningfully.
Ok sorry I read further and thought I fixed my post. It’s seems it’s a balanced iso transformer. This is a good unit
And can made better by an isolation of the grounding of the unit. A bal iso means it’s 230 volt in and 120 volt out it’s done with two 60 volt windings on the secondary. this helps dc offset and common mode noise. Add a simple high freq tank circuit and iso the ground and it’s top shelf power. Only a well made re hen could better it in specs.
like Marty I tried all of the same things to no avail
the Furman was an instant fix. For me it was my phono pre and for Marty it was the Lampi GG2
I have my Pacific direct into the wall.
only my phono pre and Doshi tape ore are plugged into my Furman. My concern is that my Doshi lies very close to the transformers on my phono pre. Presently I am limited by one pair of Masterbuilt Ultra cables which, due to rearranging my rack has left the cables I use about a half meter short, such that the Doshi Is lying imo too close to the transformers. I have a new set of longer Ultra cables on order that I am hoping will obviate the problem.
Hello Steve I’m very happy to red of your new pacific dac.
I think my post is not making my point correctly. I’m sure it’s me not saying it correctly. I frequently confuse some.
Any way the goal is a quite setup period how it’s achieved is really as per setup.
The Device shown is very good in my view and cheap in price for what it is.
Regarding any pre or even more head premap or phono preamp. None should be 2 or less to sides. Also consider above or below. Most Cell phones have an app to measure magnetic flux. It’s very useful for this. many products use toroidal transformers. The emi radiating pattern makes them a favorite to use. See attached below https://www.google.com/search?q=tor...tern&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari
Any time stack it’s an issue some it’s just more heard. tubes seem to be more hurt then SS I had a iso transformer 4 feet above a tube device
It hummed. I tried tube shields that helped but did not stop it.
Since the OP hasn't post - (as Paul Harvey would say) here is the rest of the story...
The OP asked whether he could bring along his new CJ preamp (I don't remember what model, but it was pretty fancy). He set up the Lampi Pacific and we plugged it directly into the wall socket - not my isolation transformer - using a cheap AC cord. I had earlier done the same with my Lampi and it was dead quiet coming from the wall. We connected my computer and fancy FTA USB cable and 512 engineering RCA interconnects - and there was no noise, just great music. We switched to a cheap USB cable - still no noise. So it was pretty clear - the Lampi was not a problem. We took out the CJ preamp, and the OP said he had heard something moving around in the CJ when he was packing it up. So I suggested we take the top off before plugging anything in. We opened up the CJ and there was a big capacitor (one of many in the CJ) sitting loose, able to roll around in the case! We didn't want to plug it in with the loose capacitor, so we took it out and tried to determine where it belonged. Not sure, but it certainly was not supposed to be loose. The conclusion was that if he had not also packed up the CJ preamp, he probably would not have heard the loose capacitor moving around in the case and determined the problem. Tomorrow there will be call to CJ.