I used to have a Shunyata Research Hydra 6 and later upgraded to a Hydra 8. My experience is that they sound different rather than better. The smaller model sounded quicker and had more clarity while the Hydra 8 sounded darker, quieter and more organic.
2 Likes
Add ISOL-8 to the list.
1 Like
Does this device generate any hum in itself?
1 Like
It’s a 108lb, laminate core transformer that I bought from a radio station. After tightening/torquing the case halves back to spec, the hum it generates on a bad day (i.e. lots of garbage on the line) is inaudible from more than 2 or 3 feet in a silent room. The moment HVAC turns on, or any music is played, it’s inaudible from anything but inches.
On a good day, which is most days where I live now, it’s silent even from 12" away as you crawl towards it.
Lam core transformers are much more resistant to audible humming/buzzing as a result of DC saturation than toroidals. It’s a bit of a lottery, but this xformer and the 2.5kVa Topaz Ultra (.0005pf) in my tube system are both appropriately quiet.
1 Like
What do you mean by DC offset?
I don’t have hum transformer problem, neither hum or hiss in the speakers. But little pop pops and stridency in one speaker, but heard only at around 3, 4 cm distance from my ear and the speaker. Maybe RFI EMI.
Not prepared to invest into a 3k Puritan device as I got recently a Furutech 608 for similar price.
1 Like
Could it be a problem with the crossover in that speaker? Maybe a faulty capacitor or something like that?
DC offset is me being lazy in describing it; I’m not biasing an amp. Lol.
DC Components on the AC line in trivial amounts are so common, that they are nearly assumed to exist. Half-wave rectifiers in power supplies, SMPS’s themselves, etc all dump DC onto thew home AC lines. Think of every single phone charger and modem power supply, smart speaker PS, Flat TV PS, LED smart bulb or strip, etc. They all do it.
Now, realize that every occupied home is doing it; dumping DC components on the AC line. Every apartment and condo. Many businesses as well. It’s just a thing we live with now. Which, in consideration of those facts, Naim transformer hum (and other brands, too.) seems to make much more sense.
The Little pops and cracks could be a number of things, though. Certainly possible with RFI. I have actually been experimenting with RFI mitigation at a very high level and have seen good results from some strategies. BUT, those sounds tend to indicate a failing capacitor (Maybe a small tantalum cap?) as opposed to RFI. RFI affects an entire device and is, in my experience, unable to select one channel over another.
If it doesn’t bother you, it’s probably fine.
1 Like
It’s not a failling capacitor, as I had the same phenomenon with a Nap NC 250 new, one month ago, and now with a new amp.
All DC ( SMPS) are away from my hifi, on a separate powerblock. It may be some nasty mains in my old building. Depending on the day, the noises are very tiny and sometimes more present.
1 Like
If I inverse the cables, it goes to the second speaker. So don’t think it’s a faulty crossover.
1 Like
So it’s in your pre? Is the pre the only constant?
2 Likes
Like Lucifer says, the same channel across two different amps seems to suggest something upstream (like a preamp), right? Or have you already controlled for that?
1 Like
@frenchrooster Have you considered Static Electricity? Do you have a Hygrometer? It sounds like very low humidity might be causing excessive Static Electricity.
Also, you may have to disconnect everything and start with just the power amp and preamp. adding one component as you go along… If nothing else it’ll give you a chance clean all the connections.
1 Like
Will try another amp, an integrated one, to see.
2 Likes
Please update us. I’m interested what you find. 
1 Like
One other thing: I tried an RCA to RCA cable, instead of the XLR I am using. The noise was inside both speakers.
1 Like
I’m no expert but my basic understanding is that DC offset is caused by an asymmetrical sine wave on your power supply. It saturates the core of our transformers causing them to hum or buzz. It can come from poorly designed power supplies elsewhere in the home or even be on the supply entering the home. I think you can test for it with some multi meters and a little know-how. I’m not sure if an inexpensive purpose built test device is available but it seems like one should be.
1 Like
Have you had an electrician out to inspect your electrics rather than changing amps again?
If I was in UK, a good dealer would probably had sorted that issue already. Here in France, they know very little on those things. They are not really professionals.
I have to ask them to borrow different cables, to try a power conditioner, to try different speakers ( next step), and a different integrated. And it’s not easy to borrow, they have never time. They have time when you want to buy something.
1 Like
The electrician will be the next step……
I will not change again the amp. Maybe even get back the NC 250. I bought the 250 and then swapped for the Ear , for the same money. But same problem.
Now I have to decide which one I will keep.
2 Likes