I recently had an issue with my REGA ISIS VALVE cdp/DAC . A power surge fried two of the four tubes and a couple of output transistors The pro tech recommended that I also upgrade all four tubes in unison , and go withc options below as a step-up contender and no pretender, up from current OEM units in order:
- NOS matched MULLARDs
- NOS matched RUSSIAN tubes … a particular and limited specific years vintage (his details currently escape me for the moment )
- Note: his take was to also stay away from all the pretenders made in China regardless ..a must-to-avoid unless your budget is severely compromised.
MY TAKE
(1) He first loaned me his personal set of the Russian tubes to first test-drive at home. These Commie options were good but I was still curious.
(2) I took a big leap of faith to contemporaneous buy the MULLARDS from a 3rd party dealer.…there was an immediate further audio performance step-up that was clear and unambiguous . It was not subtle.( maybe a Brit unit meshes better with Brit tubes?)
(3) Quality NOS tubes are Expensive …and yes , but well worth the investment for me in a $CAD 17K MSRP high-end unit . Probably because it has high-design and build quality, with both high-end Wolfson DACs and mutha-size power supplies ,,, a 45 lb heavy beast of a unit.
I can’t speak whether the degree of improvement in mine would be comparable in a budget system…. Maybe yes, or maybe no. If not, then maybe it’s not worth the added drain on your wallet in that case.
FWIW …
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Might I suggest installing a while house surge protector to safeguard your new investment in nos tubes...
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@thecarpathian
yep … already installed since that one-off crazy event ,
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There are certain things associated with tube production that aren't available now mostly due to environmental regulations. And NOS EL34s may sound better but NOS power tubes tend to be quite expensive. And interesting I found the Gold Lion KT77 to be the best of the current EL34 variants, horses for courses as they say.
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Some tubes sound better than others in each individual application. Why? No clue.
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As jond is alluding to, there were materials and processes for tube making in their hay day that are now known to be hazardous. So it follows that whatever those specific processes/materials were, made for a superior tube, among other factors such as superior quality materials used back then because of competition and volume.
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@jond @thecarpathian have your answers.
Metals and materials played the big part.
On the other hand some modern tubes can sound better in certain applications but they will not last longer.
Please note also that component manufacturers voice their gear with modern tubes in mind.
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@jond
There are certain things associated with tube production that aren’t available now mostly due to environmental regulations
This is true. However there are some current production tubes that are very high quality with commensurate cost. I can personally attest to the construction and sound quality of the EML tubes manufactured in the Czech Republic.
I purchased a new pair of the EML XLS 300b in the spring of 2013. I have used them very regularly (9.5 years) and they tested strong on an ampltrex tube tester 6 months ago. They continue to sound superb.
So, depending on commitment and resources, very high quality tube production is fortunately still possible.
Charles
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I am enjoying some old Soviet Era 6922 in my pre amp that are wonderful.
Also pair of Telefunken Black Diamond ECC-83.
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Thanks for your posts (grapes collected long time ago may have better flavour). I have some idea now on old collected grapes and old wine fabrics that do not exist anymore. 😏
Goot point, @petg60 - it might well be the case that new amps are oriented to newly made tubes. Anyway, if the tube amp production will continue, one cannot always count on NOS tubes. Looks like that Russia and China are out of the competition in the current tube production (I personally exclude new JJ tubes which, for my taste sound dull - I even prefer Chinees ones. I also had Yugoslavian EL84 tubes which bowed up too fast, nothing to compare with Soviet EL84s. Does Phillips produce new tubes?).
It is crucial how a tube gets unfunctional. If it just becomes weaker is not a problem for me. If it blows up damaging the amp, it is a big problem. I would not buy such a tube even if it sounds great. One of the supplied EL34 tubes in my SET amp blowed up after about 500 hours or lee of use (I can see white sand inside the glass of the burned EL34, i don't have an idea where it came from). There was a sharp smell of burned plastic; perhaps, it was a resistor (it could not be the tube I guess). I ordered new tubes, replaced them. The amp woks but the channel with the burned tube sounds weaker. So far, I use balance control to somehow balance the sound. The amp has auto bias, I also thought that the bias went automatically low and did not rise "enough" (but there also was this smell).
@akg_ca , i think one may well distinguish sound of different tubes in amps or preamps, I guess in DACs this may not be so evident. I am using Soviet NOS military EL84 tubes (6P14P-EV) for already 20 years in my other amp. They sound fine and remain strong. I rarely need to adjust the bias.
Is there some particular reason for not using new Chinees made tubes? I tried Shuguang tubes, but just for a couple of hours - nothing exceptional but they did not sound terrible. New PSvane tubes are also Chinees by the way.
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It's possible the cathode resistor suffered damage and changed value causing incorrect bias.
The amp works but the channel with the burned tube sounds weaker.
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Yes.
Tubes, cheese, wine and cognac
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@noromance , if cannot be detected visually, can one detect a damaged cathode resistor by measuring the outcoming voltage (sorry, if this is a silly question)?
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Nothing new is as good as the old. 🙂
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This is the kind of discussions that reminds me it was smart to ditch my tube preamp and go back to SS. There are already so many ways to tinker with sound through equipment, accessories and room treatments that I felt the added tube complexity was an unnecessary burden. Not trying to demean the tube sound or trying to talk anyone out of it, just sharing my own experience.
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I had factory tubes in my PS Audio pre & it was ok.I bought a set of 1958 Telefunkens & it was night & day difference.
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A few years ago I bought an ARC, SP9 mkll preamp. When I received it and hooked it up, I was very underwhelmed. Inside I found EH 6jd8 tubes. Long story short, I now have NOS Amperex PQ 6922’s from the 60’s and boy what a fabulous difference!
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@niodari Unless the connection has gone open circuit, you will be able to compare the voltage on both channels. If there’s a difference, something is up. Measure across the resistor and from the tube pin to ground.
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For years I found pretty much all Gold Lion tubes (120w, 150s, 88s, 66s)to be amazingly good in a couple of different power amps, and the KT66s are my preferred tubes in my current fave tube amp, a SEP Dennis Had Firebottle HO (high output, such as it is). Both the Had amp and my Schiit Freya have 6SN7GTB tubes (one in the Had) and my faves are NOS GEs (relatively inexpensive as far as it goes) having tried lots of other brands. Vintage Amperex tubes are great also but harder to find. I have a drawer full of tubes to show for tuberism...tubism...tubophelia? The Had amp is currently resting as a Pass XA-25 is doing the amp work, and it requires far fewer tubes it seems but it still gets pretty hot so at least there's that.
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I just put a early 50's NOS RCA 12au7 in my preamp and new production tubes just don't have the tone they originals do, they just don't
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Everyone agrees that the old sound better. There are some newer small companies that are making some great sounding tubes. The question is how? Is it the glass, the solder, the wiring or metal used in the plates? Or just the craftsman's touch.
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I think that in that era tube production was crucial as there where no semiconductors and tubes were used not only for home for entertainment but also in military equipment. Nowadays tube production is no more if a primary importance, it is done for some audio fans and perhaps enough attention is not given to this matter. This is my personal interpretation. I already tried a number of different new production El34 tubes including Russian Mullards, Tang Sol, Gold Lion and Chinese Shuguang which are twice cheaper. All of them give more or less similar results, no drastic differences. I expected Golden lions would be better, but i think twice less expensive Tang Sol is a bit better in my 5 watts SET amp.
I just replaced JJ E88CC input tubes with Soviet 6n23p. These tubes are basically used for phono amplification in this amp. The Soviet tubes give a considerably more power and more airy reproduction. None of the JJ that i tubes i had i liked, i knew I needed to replace them.
Does anybody know if el34 can be replaced with Russian 6n3c tubes? A correct replacement would be Russian 6p37c but it is difficult to find them. I just ordered a pair of NOS Millard El 34s. Will post on my impressions once I try them.
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