First Impressions: RKV tuberolling

[ServinginEcuador]

This will be brief and to the point: after spending hours every day with the RKV for the last month + time wise, I finally decided to try swapping the Polamp tubes for the Telefunkens I got with the amp. I am on my first disc that I'm very familiar with, and what I notice so far is more detail coming thru the headphones than before. I just listend to this album several times last night to make sure I knew the songs quite well, and what I'm hearing is different in a few ways. For example, when certain songs have 2 or more singers singing harmony at the same time, I can delineate between them better with the Teles. Certain songs that were recorded live now have voices of people from the audience that I can now hear during softer passages.

I'm not sure if part of the soundstage compressed a little, and that's what is bringing the singers and instruments that I didn't notice before to my attention. So far I like the Teles slightly different presentation a lot.

I'll post more on this later, but wanted to post what I'm hearing while it's fresh in my mind.

[Costas]

ServinginEcuador I have just sold my SS amp and am about to embark on the journey into tubes.

This to me sounds like a potentially frustrating journey though. My main gripe with tuberolling is that by changing the tubes the whole character of the amp seems to be modified. Is this a good thing? Are we then deviating from the way that the amp was originally designed to sound? Are we "adding colour" to the sound that wasn't supposed to be there?

If that is the intention, why don't the tube manufacturers add some tone controls on their amps (with a defeat switch for the purists) and we can dispense with tuberolling and get "extra bass" by simply turning a knob?

Look, I am saying the above tongue in cheek as I can see myself spending years and $$$ continually changing tubes on my tube amp (when I decide what to get) and whilst it appeals to me in a "tinkering" way, it also foreshadows some frustration lying in wait for me.

Why don't the "higher end" manufacturers like Audiovalve put the best possible tubes into their amps in the first place and leave it at that? It's not like their products are budget priced...

[Hirsch]

Originally posted by Costas

Why don't the "higher end" manufacturers like Audiovalve put the best possible tubes into their amps in the first place and leave it at that? It's not like their products are budget priced...

They can't. Plain and simple. A manufacturer has to use tubes that are available and that he can continue to supply. He can't scavenge around for the odd dozen tubes of a particular brand, which is only enough for one or two customers.

You're right that tuberolling can be both expensive and frustrating. It's also worth it, when you lock on to the right tube set for the particular headphone you're using. This is a bit different than adjusting a tone control. If the bass is loose, adjusting a tone control will never tighten it, just attenuate it. Switch tubes, and the whole sound can tighten up...or not

Interestingly enough, my RKV came with RCA's...made in Japan.

[ServinginEcuador]

Costas,

The "journey" with the RKV is not frustrating at all. So far there are only like three tube options for it: RCA, Polamp, and Telefunken. None of these tubes changes the overall character of the sound that the RKV produces. The only change I can detect, so far, when I swapped tubes is in the detail department. Everything else seems to still be there from before, but now there is just more to listen to than before the swap.

I think some basic tuberolling info might help you here. For tube amps, the vast majority of the signal amplification is done thru the tubes, other than hybrids, so when you change tubes you can change the sound characteristics and signature totally when you swap out a tube. Each manufacturer has slightly different design changes, different materials, different construction, etc that make the sound slightly different from one tube to the next. Audio Valve designed their amp around the Polamp tube, and that's why it changes so little when you tuberoll it. The audio signal only runs thru the tubes and nothing else in the amp, and it seems that the available tubes are very similar in design, so their sound is very similar. It's not like the 12ax7 series where there are some 40+ different combinations of manufacturers and configurations that can be rolled into the same spot. (5751, 12au7,12ax7,ECC803S, etc, ad nausium)

Other tube amps, like the Melos, MG Head, Reality, et al, changed drastically when the tubes were swapped. It seemed like you had to give up something to gain something else. If you wanted great bass you chose one tube, when you wanted great detail you used another tube, etc. And when you did so you gave up something that you wanted, I got more bass, but lost the warmth; I got more detail, but where's the bass, etc. This is a generalization I know, but you get the general idea.

And yes, the journey to find EXACTLY what you want in a tube amp can be frustrating and expensive. The easiest way to find out what combo works/doesn't work is to ask around here first and see what other people say. Research before buying is the name of the game. Read the various reviews that people have posted about tube combinations. Most here can narrow your choice of tubes down to a couple for each tube spot in the amp you buy. Those who can afford to buy and sample are somewhat rare, but they are helpful in helping those of us who can't do so decide before buying.

I suspect that there are no tone controls on headphone amps as the vast majority of users would throw a fit, claiming that it will affect the sound quality. It would to some degree, and most are purists who want the best signal possible coming thru without adding extra junk to boost some bass. You'd be better off buying a set of cans that had more bass and leave the audio signal as pure as possible.

Hope this helps answer some questions, and not add too much confusion!

[Costas]

Originally posted by ServinginEcuador
Other tube amps, like the Melos, MG Head, Reality, et al, changed drastically when the tubes were swapped. It seemed like you had to give up something to gain something else.

Hi ServingInEcuador. The above is my point exactly. Whilst the RKV seems to have a limited range of tubes, the amp I am considering (the ASL OTL32) seems to have boundless supplies of tubes.

Whilst I appreciate that there are "others who have gone before me" for some of the other amps and whereby I can get some information on the most suitable tubes, there is no-one I am aware of with an OTL32 apart from McGino.

As such, I will be getting into unchartered and potentially expensive and frustrating waters...

Your point about sacrificing one aspect of an amp's sound for another is spot-on. What is more important to each individual will also vary so one's opinion of the perfect set of tubes for a particular amp may be another person's idea of rubbish! This also adds to the complexity of selecting the right tubes.

Personally, I think that we will never be fully satisfied with tuberolling. Just when you think you've got "the sound" there will always be another set of tubes out there that just might be even better... The search for that perfect sound would never end. Maybe that's not such a bad thing - I don't know.

Maybe someone should set up a "tube library" whereby members can loan specific tubes for a period of time and "try before they buy". Something to consider, particularly for us newbies?

[ServinginEcuador]

An endless supply of tubes = an endless supply of money and time trying the various combos using your equipment, ears, cabling, etc. The limited range of tubes for the RKV are in plentiful supply, very cheap, and only make some minor tweaks to an already incredible amp. Lack of options is, in this case, better, cheaper, and makes little difference in the overall sound.

If having lots of options for tuberolling is what you're after, by all means buy the new ASL OTL32. At seven tubes it will be endless options tube wise. Not to mention costly to boot.

I wish I had bought a quad of RCA tubes to see how/if they change the sound of the RKV. So far, everyone who owns the RKV has loved it and spoken very highly of it. There is very little to improve upon with this amp as it does so much so well. It could use some high end extension, but other than that I have not heard anything else nearly as good. (Hirsch's HP4 aside) So far I got more detail with the Teles, but lost nothing in the process. It still sounds like the incredible RKV I have enjoyed these last few months.

Your point about sacrificing one aspect of an amp's sound for another is spot-on. What is more important to each individual will also vary so one's opinion of the perfect set of tubes for a particular amp may be another person's idea of rubbish! This also adds to the complexity of selecting the right tubes.

Personally, I think that we will never be fully satisfied with tuberolling. Just when you think you've got "the sound" there will always be another set of tubes out there that just might be even better... The search for that perfect sound would never end. Maybe that's not such a bad thing - I don't know.

I am totally satisfied with what I have tube wise, and was satisfied when I had my Melos. I found that one tube that did what I wanted, and made sure I was satisfied with it. Anything else and, as you said, you'll never be satisfied and will constantly look for that next tube to satisfy whatever you are missing. There is NO amp in the world that does everything perfectly. Solid state or tube! It is always a trade-off, it's just a matter of what is more important to you, what you prefer, and what you're willing to live with/without. You could get an Orpheus and say you hate it for lack of bass. Who knows. Find what you really can't live without in your sound preferences, then buy the amp that already has that, then swap tubes to add MORE to it, not find what you were looking for in the first place.

Maybe someone should set up a "tube library" whereby members can loan specific tubes for a period of time and "try before they buy". Something to consider, particularly for us newbies?

There was a packet of tubes being sent around for the MG Head, but I'm not sure what happened with that. There were some 7 tubes or so in there for people to try and see what they preferred. Neat idea and well implemented by Nick Dangerous. It would be much harder with different countries involved, but would work well for people like you who are just starting out with tube amps.

[Costas]

Thanks for your advice and erudite comments Serving. Your posts are always a good read.

The RKV sounds fantastic but is beyond my budget. The poor exchange rate and hideous customs duties here put it beyond my reach. The limited tube options is a big advantage though...

The OTL32 is a total unknown at this stage for me. I think the first batch arrive in Australia at the end of the Month. The idea of tuberolling 7 tubes does not appeal at all though!!! There's a potential lifetime of tinkering there...

Perhaps I should stick with SS Then I could replace my tuberolling activities with cable swapping instead!

I think hifiers are perfectionists at heart. We will never attain perfection but we won't give up and will have fun trying...

... and will keep the economy ticking along in the process .

[ServinginEcuador]

Costas,

I hope you truly fall in love with the OTL32, and that you can find your own little audio bliss using some really cheap tubes that sound incredible! So far the couple of people who've actually heard the new OTL32 have absolutely raved about how good it sounds. You may find it to your liking right off the bat, and then tuberolling becomes the mere search for something more to add to the sheer pleasure that the amp already provides.

I'm suprised that the OTL will cost so much less than the RKV in Australia. THe RKV sells for $890 new, while I heard that the OTL32 will cost like $600-650??

Make sure you post your thought on the OTL32 once you buy it. And you will be buying it if I read you correctly, so let us know what you think right off the bat, and then what you're looking for. That way everyone here can throw in their .02 worth and totally overwhelm/confuse you. If you're looking for certain characteristics there are some real experts here with the tubes that amp uses and can give some sagely advice on which tubes can provide it.


(OBTW, I forgot what erudite meant, so I looked it up to make sure you weren't insulting me. Thanks for the compliment. It sounded nice, but then again so does pedant, but a pedant is not a good thing.)

[Costas]

Originally posted by ServinginEcuador
(OBTW, I forgot what erudite meant, so I looked it up to make sure you weren't insulting me. Thanks for the compliment

Me insult the illustrious ServinginEcuador? No way

Yes, the OTL32 looks like it will be moving into my house. I need some explaining to do to my wife though...

Customs duties etc here in Australia push the price of the RKV quite high. At least the ASL products have an agent here in Australia and thereby I don't have to worry about importing an OTL32 and incurring the associated costs.

Yes, I too hope that I like the OTL32. There is a local high-end manufacturer of some top notch SS amps who I have commissioned to build a demo headamp and I am hoping to do a shoot-out between it and the OTL32. Should be interesting I imagine...

Stay tuned for that one when it happens.

Good luck with the tuberolling for the RKV!

[ServinginEcuador]

You're commissioning someone to build you a headamp, and you can't afford an RKV?? There's something wrong with these two statements methinks. Nik had a headamp built, and the cost of that thing could have bought a small island near Hawaii.

At least you can get the ASL stuff without too much added costs. It reminds me of living here in Ecuador. You can't find anything here, and anything you send down will cost you a fortune in customs. We sent our personal effects down here, and the shipping costs thru a UPS affiliate were like $1200. The customs guy here charged us another $1100 just to get our stuff from customs. I can't imagine how much it would cost if I, for example , ordered those Axiom Audio M80ti speakers I'm drooling over. They would assume that they cost several thousand dollars, and would try and charge me the same. Like most countries it is cheaper to pack the stuff into your suitcases and fly round-trip to get it yourself. At least for us we can pack up tons of household items we need, seasoning packets for food, and other such items, along with my electronics spending habit stuff.

If your wife is anything like mine, after she hears how good the thing sounds she might like it. That and if it looks nice doesn't hurt. The RKV with its gold and black design looks nice sitting on our desk here, so at least the "cosmetic" test passed with flying colors. She, wife Diane, hated the Melos as it was a full-sized rack unit that was all black. Too big and bulky for her tastes. Maybe you can start telling your wife about the Cary headamp that costs $3200, and when she has a cow tell you that you thought it was too much also, so your second choice was the ASL OTL32 at a mere $600! Not telling you to lie, just seeing if you can put things into perspective for your wife.

Man, that new OTL32 should be quite the awesome amp, and I really hope that you enjoy it and get many years worth of use out of it. THere's nothing like finding that tube amp sound that works well with the equipment that you own. I am still blown away by how much I enjoy this amp day after day. If I kept my old Reality I would have been happy, but now I'm downright giddy with this "investment" in audio gear.

[Costas]

Originally posted by ServinginEcuador
You're commissioning someone to build you a headamp, and you can't afford an RKV?? There's something wrong with these two statements methinks.

Ha ha. The deal with the amp manufacturer is that I will purchase his amp only if it is better than the OTL32. He is building the amp as a demo unit. He has accepted the challenge and the resultant shoot out will be pretty interesting I'm sure. I can't wait. His pre-amps and power amps are pitched (and priced) in the league of Krell, Levinson etc so I imagine the headamp will be pretty impressive. The price is on par with the OTL32 which is pretty reasonable given the components he will be using...

I love your tips on dealing with the wife issue. You sound like a seasoned veteran. Perhaps if I mention Nik's amp first, she might let me get away with a Cary for a "mere" $3,000 Worth a try...

Incidentally, I (and I bet every other Headfier) am curious as to what on Earth you are doing in Ecuador. Sounds like an interesting place! Wouldn't mind working as a Customs Agent there...

[Hirsch]

I tried the "tube library" approach with the ZOTL. I had been playing around with the idea, and someone asked to borrow a set of tubes. I sent them along, and then asked if anyone else wanted to try them while they were in circulation. I was met with dead silence, so I shelved the idea.

I need to get the Impedancer and a couple of extra tube sets for the RKV. (I wasn't actually planning to get an RKV, but one came up with a price too good to pass up, so I didn't ) BTW, don't forget the Mullards in your list of tubes to try. A friend of mine thinks the Polamps are probably better though.

[ServinginEcuador]

Originally posted by Costas
I love your tips on dealing with the wife issue. You sound like a seasoned veteran. Perhaps if I mention Nik's amp first, she might let me get away with a Cary for a "mere" $3,000 Worth a try...

Wow, I may be the "veteran" but it sounds like you took my efforts and took them a light year ahead of where I went with them. Wow, what a sharp mind you got there Costas. I sure hope you don't decide to turn to a life of crime. You might prove quite elusive.

Incidentally, I (and I bet every other Headfier) am curious as to what on Earth you are doing in Ecuador. Sounds like an interesting place!

Actually, my wife and I are missionaries who live here in Ecuador. Poor missionaries with some really nice stereo equipment that is. (Just check out the profile. You'll never believe how little all that stuff cost. I guaruntee it!) We've lived here for a little over 18 months, and plan on living here for at least another 10-20 years working and serving here. Bet that wasn't what you were thinking, was it? I get more PMs and emails from people wondering that same thing, so I'm quite used to it. I was in aviation electronics in the US Navy for almost 10 years, so I got into high end electronics after learning about how it works. Funny, since I'm now a missionary, and own more nice gear than I ever did before. Actually, it's own right weird when you think of it. Ever since we got married we've never bought anything nice. We had hand-me-down furniture, bought used cars, and only had expensive stuff that we were given for wedding gifts. Now, for the first time we bought new furniture, a nice handmade kitchen table, fridge, beds, and the assortment of stereo stuff. We were actually laughing about buying something new when we were shopping for a sofa set. It's so nice and comfortable we still love sitting on it to watch movies each week.

Wouldn't mind working as a Customs Agent there...

I always wondered why those guys drove up to the airport in a Mercedes Benz? Maybe they tried to charge someone $200,000 to get their imported Merc out of customs, and when they refused to pay that much, the official drove it home with him. ;-P

[vwap]

Originally posted by Hirsch
I need to get the Impedancer and a couple of extra tube sets for the RKV. (I wasn't actually planning to get an RKV, but one came up with a price too good to pass up, so I didn't ) BTW, don't forget the Mullards in your list of tubes to try. A friend of mine thinks the Polamps are probably better though.

you COULD always pass the RKV on

[Hirsch]

Helmut Becker of AudioValve read this thread, and sent me an e-mail. He doesn't feel his English is good enough to post publicly, so I'll try and relate the concepts, and hope I get them across intelligibly.

The reason that changing tubes makes an audible difference is the operating characteristics of the tubes (the curves). These can vary depending on the brand of tube, the age of the tube, etc. Most tube amp designers do not do enough to stabilize the tube. By having circuitry in the amplifier that controls the operation of the tube, the tube's operating characteristics become relatively unimportant, and tube changes will not cause significant differences in the sound. It is very important to use the components needed to create a stabilizing circuit for the tubes, or the sound of the amplifier will change any time a tube changes. Leaving the sound up to the random choice of tube is bad in a high-end audio product. The RKV uses a DC-coupled servo regulator circuit that minimizes the influence of the operating characteristics of the tubes on the sound. This makes the amp sonically stable using the same tubes for very long periods of time without losing any musical quality, as well as making the RKV very resistant to sonic change produced by rolling tubes.

So, Mr. Becker has very deliberately designed the RKV to be resistant to tuberolling. It should have pretty much the same sound regardless of brand of tube used. I'm still going to try one or two other brands, just to see for myself how resistant to tubrerolling the RKV really is...