My_Ref Fremen Edition - Beta build/Fine tuning

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I don't want to spoil the party, but IMHO it is absolutely necessary to install good changeover relays or similar means when you want to A/B different make but otherwise nominally identical components with some minimum seriousness. Of course you must randomize the positions somehow during switching so you effectively are doing blind testing.

C7 would be a perfect candidate for that kind of on-the-fly testing.
 
KSTR, I don't quite understand. Can you elaborate. I would certainly agree that all my tests were subjective, short and fast, but what specific techniques are you suggesting?

I don't think your spoiling the party - just suggesting a different approach. Please explain !
 
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Probably the warmest cap tested, but to me sounds compressed. The clarity is there but it makes me feel life I'm listening to a good amp - not sitting in the concert venue. Not much difference with twirling the orientation. To my ears, the Wima FKC2 10 nF is my preference.

Very strange... I suppose you're comparing KP1834 Vs FKC2, right?

In my setup the KP1834 doesn't sound warm but deadly neutral with more refinement and more soundstage.

FKC2 sound pretty neutral too with a (tiny bit more) snappy bass but less refined.

Can I ask you to burn-in further the KP1834 and re-evalute it after?

Those polystirenes takes a lot to fully break-in.
 
What I suggest is some form of real-time A/B switching between two capacitors or resistors, which in most cases can safely and simply done with a small toggle (single pole, dual throw) relay placed very close to the PCB. Something similar to the output relay, just smaller. Of course some precautions must be taken to not run into intererence / stray pickup problem but for testings things like various models for C7 position this is pretty much a non-issue.

I found this technique very insightful and helpful to guard yourself against perceived audible changes that are not real but come from expectation bias etc, especially when you have a helping friend that does the install and selection of parts so that you have no chance of knowing what parts are in there, which one is active in a given switch positions, even if the parts are identical or the switching is faked (does nothing), etc.

I know this kills some of the fun of DIY but it may help to save money and increases your knowledge and skills (including listening skills).
 
OK, I'm in for a set 🙂

Details will go via PM, right?

Sure.

Welcome KSTR:

  1. ClaveFremen x 2 (IT)
  2. Suburra x2 (IT)
  3. SoIL4x4 (US)
  4. Bmcbob (US)
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So far Italy 6, USA 5, UK 1, Indonesia 1, India 1, Germany 1, land of no one ( 😉 ) 1.

Thanks to KSTR we have reached the needed 40 stereo sets so partecipants are required to PM me their PayPal accound and shipping address in a week so I can send you all the PayPal invoice.

Indicative shipping fees:

Italy ca 6€
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Land of no one (??) 😀

Until I make the PCB order further partecipants are allowed.

If further partecipants join there may be a price reduction (5 more equals 4€ less).
 
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Thanks for your test mix, Bob. The bass player in the first section is killer!

I personally use much longer test sections, typically a complete CD of one artist in one go, and keep A/B switching to a minimum, something like once or twice per song / 5 minutes or so. That might have to do with my rather meditating style of listenings (eyes closed, completely isolalated from the world -- cell phone OFF etc) but I need to get fully immersed in the music and its emotions to be able to judge miniscule changes in soundstage etc.
 
You'r welcome. Nothing special but it worked for what I was trying to do.

The second biggest chunk of my listening is Classical/Orchestral and I intend to do much longer sessions over the following days. I'll probably swap just C7 and C32 and maybe try Darios R2 suggestion along the way.
 
Addendum - I neglected a very good option, Wima FKC2 220 pF Poly-c flm/foil for C12. There is a very clean image with this cap (yellow) that just beats out the FKS2. A very smooth & warm character with good 3d presentation.

The orientation was interesting as I heard more and deeper bass - less kick drum on the Big Band part with the writing side toward C13. Reversing it switched the prominence of those two. That's nit picking for sure, but demonstrative of how a builder can customize to their liking. For me the FKC2 stays in.
 

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Dario, the original sounds good but to me, not quite as transparent and a little less warm. They are all close and I think this spot will take more extended listening to confirm what I hear.

SoIL4x4, Super close - I can't think of anything significant other than the change from thru-hole to SDM of a few parts on the next version. There may be some minor swapping if I find the general personality of my build favors a category of music - Big Band, Classical, Small Group/vocal - over longer sessions.

The big bumps in my set:

Mundorf AG caps C3/C8
Blackgate at C9
True Copper at C13
300 VA toroids

Those, I would consider "Upgrades". Everything else I have done I'd consider updates and beneficial tweaks. Does that make sense?
 
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