EC Aficionado (was: The Studio Jr.)

Discussion in 'Eddie Current' started by AppleheadMay, Nov 10, 2015.

  1. Garns

    Garns Friend

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    Now I have corrected my self-gimping of my Aficionado here are some actual impressions. I have pretty much been using it exclusively as a preamp to speakers because... I really like it as a pre.

    It's feeding my monitors: Klein + Hummel O300D, sealed box 3-way with 8" woofers, 280wpc Class AB. Previously I drove these from Yggdrasil 1 via Freya passive. Their input impedance is 10k plus the inline resistance from Freya so... it's a stretch. Mainly, the treble is a bit scratchy and it's ever so slightly limp, but I put up with this because Freya tube mode is a wash - it drops low level detail, is a bit slow, smears the imaging and actually makes the treble less smooth (and I tried a whole bunch of tubes).

    Okay, so compared to Freya passive, what does AF (stock) sound like? Well:
    • Treble is just as present but clearly smoother.
    • More cohesive macrodynamically, at the cost of a very slight congestion in more complex passages. It's more a feeling than an actual congestion. The way I think of it, there's a spectrum which runs from limp with every part clearly delineated, to highly dynamic/aggressive but smeared. The AF is maybe 40% of the way along that spectrum, Freya passive is 20%. My ideal would be like 30-35%.
    • No audible loss of fine detail (though my room may be the limiting factor here). This was my biggest problem with Freya tube and the performance here is very impressive.
    • I feel like low-level detail is being brought up a bit. I think of this as the part of tubey character that isn't to do with warm or gooey tuning. It's done in a very natural way, in particular without compressing dynamics. Depending on taste you could like this or dislike it. In this setup (as a pre into SS Class AB) I'm neutral towards it.
    • Leading edges of attacks are softened slightly. However it is still fast. Delicate impulses and high-frequency transients are reproduced very well.
    • I don't hear the bass as rounded or slow in any way. It seems as fast as the rest of the spectrum.
    • Frequency response only seems to vary from flat insofar as the tubes I put into it do so. I would not call it warm.
    • Imaging is still laser sharp. Probably it is having some effect on the soundstage but the way my room is set up, good luck figuring out what it is.
    Some of these points are just down to the fact that the AF fixes the slight impedance issues I have. But the thing is that it does a really good job of getting out of the way; such slight flavour as it does impose is unobtrusive and agreeable. I have no qualms about continuing to use it as a pre. I am pretty purist about this chain so that counts as a big thumbs up.

    Wall of text about tubes: for power tubes I am sticking with RCA black wavy plate for the time being. For drivers I have been trying WE396a, LM Ericsson gold pin, and CBS JHY. Either all my 396a's are duff (which I suspect might be the case) or I just don't like them in this configuration: too much midbass and top end roll. The CBS JHY and the LM Ericsson are both faster and more detailed and neutral FR wise, in particular having more energy up top. The LM Ericsson is quite lean in the bass and loses some bottom octave, and seems to have something about it (maybe hardness in the upper mids) which is a bit fatiguing after a while. The CBS is maybe 7% less technically accomplished but I think is better balanced, with good extension at both ends, slightly lean in the midbass (my preference) and non-rolled, non-fatiguing treble. I feel like there may be better driver tubes out there but I'm pretty happy with this for now.
     
    Last edited: May 31, 2018
  2. purr1n

    purr1n Finding his inner redneck

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    @BillOhio: The chart reflects the Dueland Cu. Don't you have the AgCu? Not that it really matters. Homemade HiFi guy rated them 14 and 14.5 or something like that.
     
  3. BillOhio

    BillOhio Friend

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    Yep, you're right and I did miss that. Again, my only data point on any of this was the Very casual listening session at JK's where we ran each of the Afs on different tubes while drinking beers and in between BS'ing about women and The Last Jedi while in a room with carpeting (the inhumanity).

    That said, if the Jupiters and copper/silver Duelunds sounded SO similar it's still hard to imagine the differences between the rest of the caps in that chart being more than Very subtle. Maybe I'm wrong, or maybe 'Very subtle' would make the difference to a more critical listener.

    The nice thing about having these expensive caps that Chris very kindly installed is that there isn't any curiosity about what would have have been missed out on for want of the Duelunds. That curiosity is settled by now though. I heard a bigger difference on my rig by switching tubes than in comparing to JK's Af and knowing what I know now, if I were going to put ~$700 into an Af I'd go with the Jupiters and the chance to try a pair of EML 2A3's vs The Duelunds and the JJ 2A3's that I have in now. If I were going to put ~$3,300 into an Af I'd add a the Jupiters, EMLs and a Yggdrasil A2. The JJ's and Duelands do sound pretty awesome though...
     
    Last edited: Jun 1, 2018
  4. JoshMorr

    JoshMorr Friend

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    Subtle difference to one might be a bigger jump to another. I didnt think swap from stock caps to jupiters was subtle, but can see how many others would. Probably same thing goes for Jupiters and other caps. The person who critically listens in a quiet listening spot on high efficiency speakers for 12 hours a day might have a different opinion of what subtle is to the guy who throws on some headphones for a couple of hours at the end of each night to unwind. It all relative, not a great value to some, but if it fixes or improves a specific problem someone is having, might be worth it to another.
     
  5. BillOhio

    BillOhio Friend

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    Yeah, for sure. I heard Jupiter and Duelund as pretty much identical on JK's speakers. Replacing the stock caps though was a noticeable step up to me also and so for sure the Jupiters vs. Stock would probably be worth it to most. YMMV, of course.
     
    Last edited: Jun 1, 2018
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  6. Mark W

    Mark W Rando

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    Hi

    Thanks to all for suggestions on 2A3 tube selection. Noob question: Will bias be user adjustable on the AF ? Is this something I should learn how to do, so as tubes age or change I can make adjustments ? Or is this not an issue ? Thanks !
     
  7. Mark W

    Mark W Rando

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    Hi, has anyone tried the Sophia Princess Carbon 300B 2.5V for 2A3 amps ?
     
  8. Mark W

    Mark W Rando

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    Has anyone ever heard the Ayon HA-3 SET headphone amp ?
     
  9. purr1n

    purr1n Finding his inner redneck

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    Autobias. Not an issue.
     
  10. Priidik

    Priidik Friend

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    I use my EC2A3 often as pre. It's closest to transparent vol control I have tried with difficult amp inputs.
    Now, I should try to 'roll in' some small optimized OPTs.

    Driving pro monitors with their 10k input is not as trivial as many seem to think.
    Passive sux for this application, unless the source is rather beefy and the passive is low resistance type.
     
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  11. jexby

    jexby Posole Prince

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    has any crazy, inside member of the he-man-nut-rubbing-club tried the older 2A3s with (flat) monoplate or dual monoplates inside the Af?
    impressions or general statements appreciated.
     
  12. m17xr2b

    m17xr2b Friend

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    I have a pair of used dual monoplates I don't use. I can ship them to you and you can usps them back once you're done.
    On the Stratus they are great, a bit less refinement than the single plate but the same sort of sound.
     
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  13. jexby

    jexby Posole Prince

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    Are the Af transformers bypassed if:
    a) RCA single ended inputs are connected
    +
    b) the SE line outs are connected to external amp (Vidar?)
     
  14. MrButchi

    MrButchi Gear Master Europe

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    I personally have Kron’s disease
     
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  15. purr1n

    purr1n Finding his inner redneck

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    SE line outs are always on. They are taken from a 3rd winding.
     
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  16. Mark W

    Mark W Rando

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    I've just received my AF. I opted for the 'Jupiter Cap Mod', and I sent the caps in to Craig, and he graciously installed them. The amp has no SE line outs, which upon inquiry, it turns out are removed, as the tertiary windings are hooked up internally with amps that get the cap mod. So, does this mean feedback is now used ? I thought the cap mod would be a straight up swap out. Am I mistaken ? I don't need the SE line outs now, and Craig said I can always convert to SE off the balanced outputs with an adapter cable...so I guess it's all good if I ever need the line out......but I'm curious about whether it's a no longer a no feedback design.
     
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  17. purr1n

    purr1n Finding his inner redneck

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    You probably got the feedback mod. Don't know if you asked for it or Craig got confused of if he just felt the combination worked the best.
     
  18. Mark W

    Mark W Rando

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    Craig did say he thought this was the best set up in this particular case (Jupiter .22 cap mod). But I'm assuming then that he felt the stock cap needed no feedback, because that was the original design. So the Jupiter cap mod influenced a circuit topology change ? There had not been any discussion of this change, either in this thread, or between us in the amp order. I am not unhappy...just caught unaware that a cap roll would necessitate the addition of feedback, in the designer's opinion, in an amp design that had zero feedback as one of its design parameters.
     
  19. raif

    raif Man made lobster/plankton

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    One doesn't necessarily necessitate the other.

    Craig is a fan of the feedback mod. The basic thought is that it tightens things up a bit, pushing the sound more in the "transparent" direction.

    The jupiter caps supposedly push the sound in the "organic" direction.

    Craig likely feels that the two mods are synergistic.
     
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  20. purr1n

    purr1n Finding his inner redneck

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    There is a 300B amp (higher cost) that's coming out, so I wonder if the intent is to tighten up the 2A3 to contrast with the bloomier 300B sound.
     
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