Radu Tarta EL34 SE

Discussion in 'Tube Gear' started by StevenZ, Nov 11, 2017.

  1. MikeyFresh

    MikeyFresh Junior Member

    Ok those should be fully compatible, I think they are a so-called long plate 12AX7, but I don't believe they have very different electrical characteristics, maybe somewhat higher gain.

    They do however carry the ECC803S naming, originally a Telefunken design if I'm not mistaken. I'm sure the Haven's tube amp builders can provide more information, but those should be fine.
    TubeHiFiNut likes this.
  2. Ernie

    Ernie Active Member

    Then again, it is in those front-end tubes that most of the voicing occurs, when tube-rolling.

    Once things settle down, you can post the tube complement, if there is any change in sound you might seek. Some of us might have suggestions for you to explore, and samples to test.
    fiddlefye and TubeHiFiNut like this.
  3. TubeHiFiNut

    TubeHiFiNut Administrator

    Agree 100% with @Ernie. :)
  4. StevenZ

    StevenZ Active Member

    Quick update. The "preamp" came today and I'm finally able to hear this amp for what it offers. And you know what, it's downright excellent! I'm thankful that the PVA works so well with my source and the amp as it reaffirms my previous findings. With using the Beresford's fixed output and the PVA as a volume control I'm hearing the last 20% that I figured was inside the amp. Yes, that's correct, I'd estimate that I was missing roughly 20% of the performance by using the Beresford's preamp section. Not sure if that was by design or if there might be something wrong with that preamp section. However when I spoke with Stanley via email he did agree that the DAC and Preamp section sounded entirely different from another. Either way I so happy with what I'm hearing.

    That aside, I'm still on the hunt to replace the caps with better. And a long shot, to have the entire thing re-wired as point to point, scrapping the PCBs that Radu used (modified for this circuit) to see what else might be missing here. I know some of the parts aren't actually BAD, but I'd like to use better to get just a bit more performance out of the amp, or to at least assure myself that I've put in highly reliable, well known quality parts.

    Thanks for tuning in, folks. What a pleasant surprise this amp has become.
    TubeHiFiNut and opa1 like this.
  5. TubeHiFiNut

    TubeHiFiNut Administrator

    I am very glad that everything continues to improve. :)
  6. BH


    That's great news Steven! It's hard to explain why the passive device is giving you what you seek, but there's certainly no point in questioning the end result.

    As far as what you are contemplating in regard to capacitor changes, and a possible point to point rebuild, please allow me to give you some advice based on my having worked on literally hundreds of amps over the years: leave it alone!

    There's no guarantee that a point to point rebuild to Claus' exact specs will offer you more than what you are now getting. It's a gamble, and if the result is less satisfactory you will be disappointed.

    As far as capacitors go, there's nothing wrong with Illinois capacitors! They are probably manufactured in the same Asian factories as all of the other "American" brands. I've encountered them in a great deal of equipment and they work as well as anything else. Then, there's the issue of so-called "audiophile grade" capacitors. Going down that path is likely to cost you a significant amount of money without rendering any improvements. Much has to do with expectation bias- the more you spend on a cap, the better it will sound (the same goes for tubes). And, adding multiple caps in parallel (as some advocate), will only cost money without providing benefits.

    Rod Elliott did an excellent paper on capacitors which debunks many of the myths. It is very technical, so please read the first 7 paragraphs of the introduction and the full conclusion. If, after reading that, you still decide to chase capacitor upgrades, you will at least be doing so with prior education and knowledge. As far as I know, no one has ever taken Rod up on his challenge to furnish proof that exotic dielectric materials like beeswax can make a bit of difference in the resultant sound. My own experience with blind listening testing certainly mirrors his assertions and conclusions. Obviously, others will disagree with all of this which is fine. A person needs to consider all points of view and then choose their own path.

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  7. TubeHiFiNut

    TubeHiFiNut Administrator

    @BH - Thank you for sharing the link. :)

    An interesting read, although I am not a fan of blind, double blind, ABX, etc. testing.

    Just my opinion and YMMV..... :)
  8. StevenZ

    StevenZ Active Member

    Thanks BH!
  9. BH


    I agree that such testing is probably best at revealing obvious (and perhaps some less obvious) differences and that long term listening is the best way to go. What I find wrong with the latter method is that I believe our ears/brain get accustomed to a particular sound. So what may initially not be totally pleasing becomes so after a while. Wish I had a definitive answer! In any event, this article is also an interesting read:

    StevenZ likes this.
  10. TubeHiFiNut

    TubeHiFiNut Administrator

    Thank you for posting the link. I will review and comment.

    In general, though, I gauge things around how much music I listen to: the best components beckon me to listen to more music. :)

    The bad ones drive me to watch "Judge Judy". ;) ;)
    MikeyFresh likes this.
  11. StevenZ

    StevenZ Active Member

    This was a really good read. Thanks for posting.

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