[tone]

A bunch of people bought the audiovalve rkv from jan meier when he had the introductory special price but i haven't seen many posts from people about their thoughts on it. I guess they're all busy listening to their amps!

I really dig my rkv so far. The bass on the rkv is just enormous and very well defined. my dt831 headphones now has massive amounts of bass unlike with the mg head where the bass was missing and subdued. I hope that i am not giving the impression that the bass is overwhelming and unbalanced because it is not. it just reproduces the bass so nicely that it was the very first thing that i noticed.

The amp has a nice rich tube sound and is quick and detailed which is what i was hoping for when i bought it. With the hd-600 headphones the amp sounded really rolled off in the treble but when i replaced the stock hd-600 cable with a cardas cable the highs were revealed and i noticed even more detail. i did not notice any treble roll off with the dt831s headphones though. soundwise i have no complaints so far with the amp (that is until i hear something better

). hopefully somebody who has access to an rkv and an ear hp-4 will do a comparison. I remember really drooling over the hp-4 at the headroom show but that was awhile ago.

My only complaints are that the heavy toroidal transformer and tube sockets are mounted directly on the pcb board and not on the metal chassis like on most good quality tube amps. Even if the amp is packed really well the inertia of the heavy transformer may rip it off from the pcb board if it is dropped from a high enough distance (this is what happened to my amp). i've never heard of this happening to anybody else's rkv so my package must have been really abused during shipping.

 

[dvr]

I really wanted to like my RKV, but it lost the battle with my Melos.

Perhaps the RKV just isn't a good match for Etys, which I use for all my listening. Their impedance of 120ohms (if I remember correctly) is close to the RKV's 100-ohm lower limit. Maybe I'd get better results with the low-impedance adapter.

The RKV doesn't sound bad, but it lacks some of the realism that I hear in the Melos. The Melos has more impact and a wider soundstage. In the area of midrange, the two are tied. I expected the RKV to be better, but that's not the case. By the way, midrange was the Melos' weakness until I rolled in some Sylvania tubes that I found for $6.49/tube on ebay.

I'm holding onto the RKV only long enough to bring it to the Boston head-fi meet on the 19th. Then it's going up for sale.

 

[kerelybonto]

kelly has a nice review of the RKV (MKII) in the full reviews section. After Jan Meier got ahold of them they became very popular, especially for the HD600.

I suspect there are quite a few other reviews/impressions posted if you look about a month back into the archives.

kerely

 

[kelly]

No one has been more eager than I have to see some more reviews of this amp.

dvr
I had very different impressions from yours. The RKV has a very broad soundstage, especially compared to the Melos--but I have not heard the Melos with the Sylvanias so maybe that was the problem. My RKV has the largest soundstage of any headamp I've yet heard with the possible exception of the Cary SEI (honorable mention: I really liked the TwinHead too). I wonder if something else might be up with your RKV. Did yours ship with Polamp tubes? You may want to try leaving it on (plugged into a good surge protector of course) to see if it improves once the tubes have been burned in more. My tubes were already well burned in since I got my RKV used from Vertigo. I do also really like the amp with the Etymotic ER-4S so that surprised me too. Of course, I don't expect us to all have the same taste, but small soundstage is just very much not a quality I could imagine with the RKV--in fact, dparrish it was unrealistically large.

tone
The DT831 is a bright headphone and that's why you don't notice a rolled off top on it. In fact, I suspect it'd still be a little too bright and a little too bass shy for me even on the RKV. I agree that the Cardas cables help with the HD600 but not enough--I still wish there was a bit more extension.

kerely
Thanks. There actually haven't been many other impressions yet. As far as I know, only 3 people on Head-Fi besides me had one prior to Meier carrying them. Since then, 88Sound and grinch have posted impressions and then there's this thread and I think that's been it so far.

 

[Nick Dangerous]

dvr: If those Sylvanias grant the Melos a better midrange than the RKV, I'd buy up every last one I could find! My Melos didn't fare as well as yours even with Amperex PQ's, orange globes, Bugle Boys, or JJ's.

I owned a Melos before, and didn't find its midrange perfomance to be a strong point. The MG Head OTL had a much prettier midrange by direct comparison. That's why I'm surprised that you preferred it to the RKV... seeing as how it is so similar yet superior to The Head.

 

[Nick Dangerous]

Heh... wait a second... my Melos IS your Melos, correct?

 

[Hirsch]

My favorite tube in the Melos so far is the Sylvania 7308. Cleans up just about everything that bothered me about the Melos, and that I previously couldn't get past, even with Amperex or Siemens tubes.

 

[dvr]

Right Nick, my Melos is your old Melos (which belonged to Fortune before us)

I've tried JJs and a few sets of Amperex tubes, and they all suck in this amp. The Amperex tubes sound very refined, but lean, almost sterile. I was thinking about selling the Melos as soon as a week after I got it from you. The Sylvanias fixed the midrange problem and I've been happy with it ever since.

And to answer Kelly's questions, my RKV has Polamp tubes and burned in for a week (running 24 hours a day) before I did comparisons. Maybe I'll burn it in some more.

I'll be bringing both amps to a Boston head-fi meet on the 19th, so we'll be able to get some other opinions on the two amps.

 

[tone]

i bought 4 used phillips pcl805 tubes for the rkv from a tube radio/tv enthusiast online. they're used but super cheap so i went for it. i can't believe how hard it is to find old stock pcl805 tubes. i should be getting the tubes in a week or two i'd imagine.

kelly
what amp do you think gives the best treble extension? what headphones where you listening with?

 

[88Sound]

I've already posted that the RKV is an excellent match with the AKG K1000 and I was waiting for the impedancer to use my below 100 Ohm phones with the RKV.

Since I have been convinced that the drastically shortened tube life warning has been overstated and I have two sets of Polamp tubes coming, and two sets of Mullard tubes coming and a fire extinguisher I tried the HP-2's with the RKV.

The RKV/HP2 combo is outstanding, for some reason the High Frequency extention with this combo seems better with the HP2 than the Grace 901/HP2 combo. That was an unexpected shock. When you plug the HP2 into the RKV you get a small amount of hiss with the volume off, this hiss is inaudible to me while the music is playing but can be heard slightly during very quiet passages and the spaces between songs. If the impedancer takes this hiss away and does not adversly effect the sound then the RKV will be the tubed version of the 901, another amp that can play every phone, regardless of impedance or efficiency perfectly.

As a disclaimer the above observations were made utilizing the ultimate audio tweek, a magic twelve year old amber liquid from Scotland. I must take the tweek away to discover if that High Frequency extention part above holds true.

 

[Hirsch]

Treble extension? Berning MicroZOTL. (Wait, I'm not kelly. Oh well). Sugden Headmaster was pretty good, but the ZOTL's strength is the highs, and it's still the king (pending completion of tube rolling experiments with HP4, at which point the competition will be reopened

) Headphones used include Sony R10, Grado HP-1, Sony CD3000, and Senn HD-600.

 

[kelly]

Odd. I don't recall either promoting or disparaging the microZOTL, having still never heard the amp. Often times it seems the clever insults on Head-Fi are lacking in clever.

dvr
That is a lot of burn-in. It really does not surprise me at all that some people would like the Melos more than the RKV--that's just taste. It was really only your comments about soundstage that threw me.

tone
I primarily use the HD600 and HP-1 with the RKV, depending on my mood and the recording. I still think the HD600 is the more comfortable of the two. *shrug* The Etymotic and HP-1000 both give better hf extension and a more continuous frequency response. The HP-1000 is overall my favorite headphone and my favorite sounding headphone on the RKV to be sure.

88Sound
I don't hear a hiss on mine unless I pause the music and turn the volume to near full. I wonder if this may be interference related. I'm using a DIY Ven Hause power cable on mine that may be helping there--I dunno. The HP-1000 does seem to have better hf extension on the RKV than the HD600, but ABing the amp with the Max, Sugen, Corda, etc. it was still apparent the RKV was missing a little on the top. I'm extremely interested in whether you prefer the Grace or RKV with the HP-1000 ultimately.

The tubes I have tried are the stock Polamps, Sylvanias and 1970s Matsu****as which I just acquired. The Sylvanias and Polamps sounded very similar. The Matu****as sound a litle grainier but may not be burned in enoguh--I really don't have a good idea of how much burn in is neccessary to judge the tubes on this amp. I'm not hopeful. If anyone finds a tube that keeps the basic personality of the Polamp with better highs, that's what I'm looking for.

 

[Hirsch]

Quote:

Originally posted by kelly Odd. I don't recall either promoting or disparaging the microZOTL, having still never heard the amp. Often times it seems the clever insults on Head-Fi are lacking in clever.

Since the ZOTL is mentioned, I suspect you are referring to me. I was responding to this question, since I thought it was interesting.

Quote:

kelly what amp do you think gives the best treble extension? what headphones where you listening with?

I do have a rather strong opinion on which amp I've heard has the best high end. The "wait, I'm not kelly" comment was put in because the question had been specifically addressed to you. No insult was intended in any manner, and I must admit to some surprise that you took my post that way.

 

[kelly]

Hirsch
My mistake; carry on. And remember, you don't need a TwinHead. There's simply no reason for you to audition a TwinHead.

 

[Hirsch]

Quote:

Originally posted by kelly Hirsch My mistake; carry on. And remember, you don't need a TwinHead. There's simply no reason for you to audition a TwinHead.

I don't need to hear a Zeus either, dammit.