[Nounours18200]

I have just found mine that was sleeping in its parcel since 3 or 4 years, because I have almost never used it (I moved to another town just after purchase...).
 
I am about to turn it on for the first time since many years ! I will tell you how it sounds with my HD-600.
 
By the way, although it is not required with the HD-600, I am looking for a dealer (or website) to buy the Impedanzer : do you know where i could buy one ? it seems impossible to contact the manufacturer directly from their website...
 
Thanks

 

[AudioDwebe]

I was under the impression that the RKV was discontinued years ago until earlier this year (or late last year) I was informed that it was still being manufactured and, in fact, was still available.  I then went through the tedious task of tryiing to get ahold of the manufacturer to ask questions about its (along with the Impedanzer) availability in CONUS, along with pricing.
 
I don't recall who I communicated with, but the importer, at least at that time (and I no longer have the contact info), quoted me what I felt was an outrageous price for the RKV.  To the best of my recollection, the price was near 3K.  The one thing I don't remember is whether that price included the Impedanzer.   
 
Regardless, I felt the price to be crazy expensive.  As I recall from my readings, the going price when it first gained a bit of popularity 'round here was in the 1K range.  And I think that the Impedanzer cost an additional two to three hundred bucks.  So the amp to have tripled in cost over the last five or so years...well, that's just ridiculous in my book.
 
You'd probably be better off financially to just purchase some cans that better match the RKV without the need for the Impedanzer, unless you luck out and find one for sale somewhere.  Or, you might also want to be on the lookout for the EC/DC from Eddie Current.  I have one, and it allows for the use of lower impedence cans with the RVK.  But then, those don't really come up for sale very often, either.
 
Never mind...back to the "cans to better match the RKV" recommendation.
 
Sorry.
 

 

[pigmode]

Quote:

 For a pure, relaxing musical experience, this amp is really hard to beat.

'Dwebe

 
The RKV was one of about three older amp designs that I looked into, before settling on ordering a Yamamoto HA-01. My first experience with the RKV happened during an 8 hr.+ head-fi meet, where ample time was afforded to appreciate its particular sound signature. The RKV gets it right in so many ways that relate to the enjoyment of music, as opposed to the enjoyment of audio. 

 

[purk]

The tonality of the amp together with its laid back nature really compliment the K1000 really well when I had mine.  The only bad thing about the RKV is that its hum like crazy with lower impedance cans, thanksfully, the impedancer helps solve that problem.

 

[Nounours18200]

 

Spoiler

Regardless, I felt the price to be crazy expensive.  As I recall from my readings, the going price when it first gained a bit of popularity 'round here was in the 1K range.

You are right ! I bought mine around 850€ some years ago...
 
 

Spoiler

So the amp to have tripled in cost over the last five or so years...well, that's just ridiculous in my book.

That's for sure... We should start a back-engineering process to define the skematics of the amplifier, and it would be far less costly to build it as a DIY headphone amp... There is not enough parts to make this back engineering too complex.
 
 

Spoiler

You'd probably be better off financially to just purchase some cans that better match the RKV without the need for the Impedanzer, unless you luck out and find one for sale somewhere.

I use the HD600 so I do not need it actually: I plan this purchase "just in case", if I should use another kind of headphone in the future. The 600 ohms impedance of the HD600 is OK for the RKV-II (I believe).
 
 
Do you have an email to contact Meier ? There is no way to contact Audiovalve on their website, unless I missed the info ?
 
 

Spoiler

Or, you might also want to be on the lookout for the EC/DC from Eddie Current.  I have one, and it allows for the use of lower impedence cans with the RVK.

 
I do not know this device: any photo somewhere ? still in production ?
 
But MOST important: what is your preferred tubes (RCA ? Amperex ? Siemens ?) and where do you buy them : I have to find a set of 4 and do not what is the best and where to buy them !
Thanks for your help
 

 

[pigmode]

Quote:

The tonality of the amp together with its laid back nature really compliment the K1000 really well when I had mine.  

Agree. Being exposed to such a rich and forgiving sound so early in my headphonitus, I might have benefitted from actually buying an RKV instead of trying to recreate it with so many other equipment combinations. Unfortunately I was at the time prejudiced towards the RKV due to its opamp design and its circuit board construction, the latter of which would still be my main criticism. Seems like the current pricing would better justify a wire-to-wire construction on an aluminum plate, within its glass and metal casing.

 

[Nounours18200]

 
Quote:

Unfortunately I was at the time prejudiced towards the RKV due to its opamp design

 
I have been told that the original LF351N op amp can be changed for much better op amp: do you know what kind of op amp can be installed instead of the LF351N ??? I know that the OPA627 are very good but nobody can confirm me that they be installed in the RKV-II instead of the original LF351 is the OPA627 compatible ??
 
 
Quote:

Unfortunately I was at the time prejudiced towards the RKV due to its ...  circuit board construction, the latter of which would still be my main criticism.

 
can you precise what you do not like in the circuit board construction ?
 
By the way, I would like to buy the Impedanzer in case I need it in the future, in some of you wants to sell it, please contact me....

 

[00940]

That's for sure... We should start a back-engineering process to define the skematics of the amplifier, and it would be far less costly to build it as a DIY headphone amp... There is not enough parts to make this back engineering too complex.

 
 

Well, the schematic is online. At least the schematic of the RKV I, which isn't too different (the commercial one seems to seperate more the channels, has a better PS and has something to prevent thumps at turn on). It is not a simple amp at all, compared to most of the tubes amps on the market.

http://www.jogis-roehrenbude.de/Verstaerker/PCL805-KH-Amp/PCL805-KH.htm

Btw, if you want to use opa627 instead of the LF351, it would be good to check for stability with an oscilloscope and to compensate the opamps as necessary in case of oscillations.

 

[00940]

error when editing

 

[00940]

Agree. Being exposed to such a rich and forgiving sound so early in my headphonitus, I might have benefitted from actually buying an RKV instead of trying to recreate it with so many other equipment combinations. Unfortunately I was at the time prejudiced towards the RKV due to its opamp design and its circuit board construction, the latter of which would still be my main criticism. Seems like the current pricing would better justify a wire-to-wire construction on an aluminum plate, within its glass and metal casing.

 

Circuit board construction makes more sense than P2P in the case of the RKV. A PCB makes it easy to guarantee the stability of each amp build. Considering the many small parts in the design, it is also probably more reliable in the long term and easier to assemble that way.

 

[lextek]

I wish I still had mine.  It was true magic with AKG 501's and HD600/Cardas.  Live and learn.  Are these amps still made?

 

[pigmode]

Quote:

 
Circuit board construction makes more sense than P2P in the case of the RKV. A PCB makes it easy to guarantee the stability of each amp build. Considering the many small parts in the design, it is also probably more reliable in the long term and easier to assemble that way.

 
 
Thanks for the correction of my "wire to wire" (dud). My post concussive syndrome does kick in every once in a while.
 

 

[purk]

Quote:

I wish I still had mine.  It was true magic with AKG 501's and HD600/Cardas.  Live and learn.  Are these amps still made?

I think they are, but it is quite a bit more expensive now according to the poster above.  The only thing that I didn't like about the RKV in stock form is its transparency.  Certainly the MKII could be a bit beter in that department.  Given its characteristics, I think it will be very nice amp for the HD800 as well.  I really enjoy the RKV MKII with the K1000 as well as the HD-650 when I had mine.  Seriously though, the RKV + K1000 was pure magic and this even before op-amp rolling.  Upgrading the op-amps to OPA-627BPs (don't quote me on it) really tighten the sound considerably and give more definition to the low ends.

 

[Nounours18200]

 
Quote:

I think they are

 
Yes, I confirm that the RKV-II is still in production, but the price considerably raised: I believe it is around €2.200, but negociation might be possible based on what I have eared around...
 
The impedanzer is also in production and i am waiting for the price: I will keep you informed when I get the info.
 
Quote:

Upgrading the op-amps to OPA-627BPs (don't quote me on it) really tighten the sound considerably and give more definition to the low ends.

 
This is what I would like to do ! but did you just replace the original LF351N by OPA627BP , or did you have to electronically adjust something ?
 
In other words, can I just remove the LF351N and plug the OPA without doing anything else ?
 
Thank you for your reply,

 

[purk]

You need to search around for more info.  User "Blorton" has successfully performed the op-amp upgrade.