[WIJGALT]

Yeah, I suppose we've all heard this tale of woe before. My new RKV - the latest version - sounds as if I've got a flourescent bulb wrapped around my head. Loud hum with the volume pot all the way down, and gets progressively louder as the knob turns. The problem lies with neither channel specifically, just a loud mono drone in the center of my head. Before purchasing this unit I had demoed another RKV in my system & it was dead quiet. I have to assume, therefore, that the problem I am having is related to this specific unit. I've got another set of tubes which I will install later. Hopefully this will be the solution. There's also quite a bit of turn-on & turn-off noise - a whole cachophony really. I was under the impression that this latest version was supposed to have eliminated this. If anyone out there has any other suggestions please let me know. I'm pretty upset right now. I got the unit from Divergent & don't relish the thought of having to ship the darned thing back to Canada (I'm in the U.S.).

 

[bearwise]

I dont have the RKV (yet, one is on the way) but i do have a CAL Alpha DAC wiht had a tubed output stage, and found that i do get some hum, the extent of which is sensitive to both what the unit is next too and where it it plugged in. Rearranging my gear and getting a good quality power stip reduced the hum to inaudible at listening volumes. YOu might try that.
I also vaguely remember another Headfier/wizer having a similar problem (Vertigo?) which he fixed with new tubes (do a search my memory is real fuzzy on this.)

 

[bearwise]

CHeck Templeboys posts on the RKV at Headwize, he found his RKV was pretty poor at excudung RF interference....

 

[WIJGALT]

Well, I switched out the tubes. No change. Still humming along. Then I disconnected the ICs, still humming. Then I shut power off to every component in my system. The RKV was the only thing receiving power (all my components, BTW, are plugged into a Monster HTS5000 conditioner). So here was the RKV, connected to nothing but an outlet, and.....still humming. Something must be awry. And Divergent is closed for the next 2 weeks. Damn.

 

[chadbang]

I had a question here. Those big power-surge, uninterrupted power supplies that you can buy at computer stores so your computer doesn't wink off on you during a thunderstorm, would they serve as any kind of a power conditioner? What would they do sonically to helo a system, if anything?

 

[Dusty Chalk]

Quote:

Originally posted by WIJGALT Well, I switched out the tubes. No change. Still humming along. Then I disconnected the ICs, still humming. Then I shut power off to every component in my system. The RKV was the only thing receiving power (all my components, BTW, are plugged into a Monster HTS5000 conditioner). So here was the RKV, connected to nothing but an outlet, and.....still humming. Something must be awry. And Divergent is closed for the next 2 weeks. Damn.

I found, in my case, for the power supply to my MSB Tech to be the problem. The Monster Cable power conditioner (???2000?) was also a problem, had to put it at a weird angle (weird == not intuitive -- em/rf/etc. aren't radiated in spokes like you think, they are radiated in weird elliptical patterns like magnetic fields around a magnet). Try plugging it directly into the wall and unplugging everything else to see if it isn't, indeed, something like that.

 

[WIJGALT]

Well, after listening to the unit sporadically for the past few days, it's become clear that this RKV's problems go beyond just the humming (and hissing). It sounds just plain goshdarned awful. Heavy & muddy bass response with barely discernable midrange & treble. The unit I had demo'd was dead quiet & sounded luscious. To make matters worse it would appear that there isn't another RKV to be found anywhere. Neither the Canadien nor the US distributor has any. Tash at Divergent, from whence this unit came, suggested I ship it back to him & he'll attempt a repair. My feeling is that I paid for a new RKV & that's what I should have (would you buy a new car at the new price with a rebuilt engine?)Considering the cost of the RKV - which after all is just a one-trick-pony - Tash or Audiovalve should arrange to get a replacement to me. This has been a rather disappointing experience. I'm still awaiting to hear from Audiovalve. Perhaps this saga might still have a happy ending. The ZOTL, initially my second choice, doesn't look quite so homely to me anymore. Ah, who am I kidding......yes it does.

 

[acidtripwow]

My RKV II which I purchased used also has some hiss/static but doesn't really hum. It also suffers from RF interference. It's really noticeable on quiet passages like in Classical music. The Zotl is a much quiter tube amp.

 

[Dave]

I've used My Zotl with quite a bit of varied equipment and it's always been dead quiet. I've even tested it with the volume on max and it's been pure black. Seems to make little or no noise of it's own.

 

[Dusty Chalk]

Quote:

Originally posted by Dave I've used My Zotl with quite a bit of varied equipment and it's always been dead quiet. I've even tested it with the volume on max and it's been pure black. Seems to make little or no noise of it's own.

Here's the real test -- did you try it with Sony MDR-V6/7506's?

 

[Dave]

No, I haven't but.....Should I ? What am I missing ?

 

[tangent]

Quote:

So here was the RKV, connected to nothing but an outlet, and.....still humming.

One more test you should try before sending it back is to take it to a different power system: to work, to a friend's house that's at least a few miles away, etc. It could be that your house just has ugly power.

Quote:

Those big power-surge, uninterrupted power supplies that you can buy at computer stores so your computer doesn't wink off on you during a thunderstorm, would they serve as any kind of a power conditioner?

Only if you get an expensive "on-line" type. An on-line UPS charges the batteries continually and feeds the power outlets from the batteries. Kind of a poor-man's PS Audio Power Plant. Line-interactive and stand-by type UPSes let the power go through untouched until it sees a power dip or surge, at which point it crudely knocks the output back into line. Totally unsuitable for audio equipment.

Quote:

No, I haven't[listened to MDR-7506es] but.....Should I ? What am I missing ?

If there is noise coming out of your equipment, the highly-detailed Sonys will find it and present it to you. That's why they're sold as professional monitoring cans -- so you can hear the smallest flaws in the recording before you send it to the pressing house.

 

[WIJGALT]

Nah, the power in my house isn't a problem. I've had plenty of equipment in & out of here (including a previous RKV) without there being any noise-related artifacts. Acid: You seem to be pretty nonchalant about the hiss you're experiencing from your RKV. The objective of high-end audio is to attempt to reproduce the music as accurately as possible. The creation of a dark, silent background is a crucial aspect of that pursuit. Any noise will compromise the reproduction of the music at those frequencies, not to mention, of course, compromisimg the pleasure of musical listening by acting as an irritant. And this is all the more critical when it comes to headphone listening where potentially you hear everything. Noise, any noise really, from a $1300 headphone amp is inexcusable.

 

[pigmode]

That sucks, how long have you had it? If you haven't had it long, you shouldn't have to settle for a repair, as opposed to a refund or a replacement. If they won't move to give you satisfaction in an expedicious manner, you should call your CC Co. right away.

 

[morphsci]

I used to think that I had pretty good power in my house. However, after buying my BPT unit I can trully say that there is a lot of grunge in AC power lines. I have also noticed that there is a lot of difference between circuits depending on the exact circuit and which side of the 120 volt circuit you are on (at least in my case). Also, It varies with the time of day with night time generally being less noisy compared to daytime.

Anyway back to your problem. Humming can be particularly indicative of a ground problem. This could be internal ( a loose or bad connection or solder joint) or external ( a ground loop). I have generally noticed that people pay much less attention to ground loops in home audio compared to auto sound. However with cable, satellite and antenna systems being integarted into sound systems, the chance for ground loops increases.

EMI and RF intereference generally cause hissing. But then that depends on the definition of hissing versus humming