V-Cap "ODAM" capacitors

[juihung]

Well those don't put too much stress on the available space there!

Yes, 0.003V is plenty close to 0V.

Thanks for the assurance!  Yeah, they fit so nicely in that space.  The weight is manageable with it hanging in the air by its soldered legs.

[Deke609]

Cool. If you're willing, please share your impressions after about 100 hrs or so -- both of how they sound after 100 hrs and how they sounded during the burn-in process.

cheers, Derek

[isldkid]

Hello,
Have built Bottlehead designed kits for over 15+ years and haven’t posted for awhile, but now I felt I should chime in on the V-cap “ODAM” caps. I installed the ODAM 18uF about about a month and a half ago in my Mainline I have a little over 200 hours on them.
It’s reassuring that as Derek and the rest of you describe your experience with the ODAM caps, it was not my imagination.
The caps are showing it’s real colors now, everything is detailed, fast, open and above all smooth. For along time in the cap burn in my “reference” speed ball Crack was sounding pretty nice. After about 150 hours on the ODAMs in the Mainline started pulling away in every aspect and never looked back.
Paired with my fully modified HD800 I can’t ask for anything more, for the first time the highs are very refined fast very open and clean. Credits should go to the Mainline design here. Well recorded bells,shakers even tambourines are for the first time very realistic.
The low end now are all there it goes deep with weight and detail. The low end was the last thing to show itself in the ODAM run in.
Best, island kid

[Audioraider]

Hey everyone, just found this thread after Derek was kind enough to post on my thread about the ODAM in the mainline. I had originally ordered the 10uf but Chris V asked me to find out the impedance of the OT. Paul told me it was 4K. Chris said at 4K a 10uf cap will start rolling off at 40HZ and if it was his amp he wouldn’t put in anything smaller then 18uf as that would begin rolling off at 22hz. 18uf is a lot of material in the signal path and I’m concerned about the affect on the high frequencies but with my Vérité I certainly don’t want them rolling off at 40hz. As a good paranoid audiophile I now have both coming and must decide which one to keep without trying them because once they’re Soldered in I can’t return them. I am currently using the 15uf Audyn reference caps and they are a huge upgrade over the Dayton’s but the soundstage is not great and they are not as transparent as I would like.
Any input would be greatly appreciated.

[Paul Birkeland]

I went out into the workshop today and hooked my Mainline up to the audio analyzer, got it set with a 300 ohm load on the high impedance taps.  Going from the 10uF coupling cap to a 40uF coupling capincreased the LF rolloff ever so slightly compared to the 10uF.  I would not at all be surprised if these results changed with a different loading impedance. 

[Audioraider]

Thank you Paul, looks like those calculations of a 40 Hz rolloff may have been incorrect. I think I’m gonna go with the 10 UF ODAM because I see no reason to add more material in the single path if there’s no upgrade in sound quality.

[Audioraider]

I have read comments on this and other forums about the great results using the .1 CUTF as a Bypass. I have been reading a lot about bypassing coupling capacitors and the science seems to be that it causes smearing and ringing. The people actually listening seem to be very impressed when the right combination of caps are used. I am currently using the Duelund silver foil .01 bypass caps in combination with the 15uf Audyn reference caps in my Mainline. When I initially installed them I thought I heard some smearing on certain recordings. After 30 or 40 hours of burn in I can’t seem to hear that anymore. Maybe my mind has become accustomed to it but the signal now seems very clean. Part of my confusion is, based on these Values the bypass cap should only have about 1/1500 affect on the sound. Since the change seems to be fairly substantial there must be something else going on or my math is wildly incorrect 😜
I guess I’m trying to establish if there’s any benefit in going to a .1 CUTF over a .01 Duelund as a bypass or use no bypass at all. Both PB and Doc have told me directly that they have found no benefit in bypassing coupling caps.
When the ODAM is burned in I will swap in and out the Duelund and report back what I hear. I Just hope my crazy audiophile mind can keep from ordering the CUTF until I find out if there’s any benefit whatsoever.

[Doc B.]

Chris is giving you an educated guess based upon standard formulae. Arbitrarily saying the transformer impedance is 4K is not going to be that useful. As PB notes the impedance will vary with the load. 32 ohm cans present a different load than 300 ohms cans, etc. And so you really need to take response measurements with the different caps installed and a specific headphone to determine whether a change in value is of any benefit. If the cap value is just right you can end up with a flat response curve with a relatively sharp knee at the bottom created by a resonance influenced by the cap value. If the cap value gets too big that resonance can shift down in frequency and becomes a hump that is way below the rolloff frequency. So the rolloff becomes higher and less sharp, with a valley below it and a hump below that. There are many factors involved and a practical approach is the only way to really see what is going on.

Regarding the benefit of any of these cap changes - it's all in the mind of the beholder. If it sounds better to you, it is better. If it doesn't, well, best you can say is you probably paid too much for what you got.

[Audioraider]

Thank you for the info, I’m learning a lot. I understand the concept of how it sounds to me is what’s important but the problem I have is that I don’t own any analyzers and I can’t afford  to try every different cap value to find the one that works best into a 300ohm load. I’m at the mercy of people with more knowledge and experience than I have to give me advice on the best direction to go.
I have lost my career to the Covid lockdowns and I am under Covid house arrest here in the bay area so all I really have to do is to sit around and think about cap values for my mainline amplifier... sad I know Lol

[Paul Birkeland]

You could buy another couple of pairs of the Dayton 10uF caps to try experimenting with different values without spending a ton of money. 

[Audioraider]

That’s a good idea, I’m also considering soldering in wires with alligator clips to test both the 10uf ODAM and the 18uf ODAM  to see if I can identify a difference

[johnsonad]

Regarding the benefit of any of these cap changes - it's all in the mind of the beholder. If it sounds better to you, it is better. If it doesn't, well, best you can say is you probably paid too much for what you got.

DocB, I'm glad you sell amazing sounding amps and not fancy magic caps

[Deke609]

fancy magic caps

Well, that's the other side of the coin.  I like to consider myself an empiricist: if it can be experienced via the senses then it should in principle be measurable by something other than the ear-brain.  And to the best of my knowledge no one's been able to show measurable differences between, for example, one type of metalized polypro cap versus another. And yet some (like me) believe they hear differences. Is that the work of self-persuasion or want: I want it to sound better so it does? My honest answer: maybe. And it truly bugs me that I can't rule that out or in. At the same time I'm not convinced that "We've not measured a difference" means "There is no measurable difference".  It's conceivable, and to my mind plausible, that the ear-brain can pick out subtleties and make more of them than their minuscule amplitude/duration/etc. might lead one to predict.  Harmonic distortion strikes me as a potential example of this -- some claim to hear certain magnitudes of 2nd harmonic distortion as euphonic and third or higher order harmonics as harsh -- despite the fact that the harmonic distortion in each case is, say, -30dB, which if my math is correct (doubtful) means that the fundamental is 1000 times larger than the harmonic distortion in question. 

I'm reminded of a couple of quotes, one from John Camille and another from PJ, where they report hearing differences between components and setups in circumstances that make no objectivist sense: http://forum.bottlehead.com/index.php?topic=11704.msg106298#msg106298

And yet at the same time, and arguably hypocritically, I find laughable that some people spend $100s or even $1000s on blocks of wood, quartz pebbles, plastic disks and even more fantastic things that are claimed to affect sound at the "quantum level", or make electron flows "more linear", etc. and report hearing sonic improvements.  But in moments of self-honesty, I have to admit to my chagrin that I can't find a principled distinction between my belief that different caps sound different and their beliefs.

It's a pickle.   

cheers, Derek

[johnsonad]

I’ve done my fair share of cap rolling as you can read in my past threads and I'm a fan of Chris's V-Caps. There are eight of them in my primary system gear.    Like Doc wrote, if it sounds better to the owner, that’s all that matters. 

You have to admit that when you read the webpage for that cap, it a masterpiece of advertising to an audience. 

[Audioraider]

I don’t think there is any real debate that caps have substantial differences in sound. Although, what sounds best certainly differs from person to person.

An update on the coupling caps in my Mainline. All testing is done with ZMF Vérité closed and Focal Utopia. These headphones are not only detailed and revealing but they have a completely different tone giving me good insight in to what is going on with these caps.

In one of my previous posts I said I didn’t think I had heard much difference in bass when moving from the Dayton 10uf to the Audyn Tri-Reference 15uf. Last night I swapped the Daytons and the Audyns in and out multiple times. Not so easy since the Audyn is huge and weighs 1lb each. The results just goes to show the fallibility of my audio memory. The difference was dramatic, especially below 30hz. The Audyn caps are probably 2-4db louder and far more detailed in the sub bass. After going back and forth in this and other threads regarding cap size, I am not attributing this to the move from 10UF to 15UF but more to the quality of the cap. These Audyn caps are just as described in the Humble HiFi review. They are very balanced with great bass extension and an incredibly realistic mid range. So much so there are times that male vocals can be shockingly realistic. That said, overall I find them to be a little too dull for my tastes.
The next thing I did was swap in and out the Duelund .01 silver foil with the Audyns installed. Although I initially liked these in the circuit as bypass caps, after swapping them in and out it was very clear that they were softening or blurring the top end. For me that answers the question as to whether to bypass my new ODAM capacitors with the CUTF .1.
I installed the V-cap ODAM 10uf this morning. I feel it’s rather pointless to give initial impressions as they will substantially change over the next 200 hours but I will say that I have burned in hundreds of caps over the last 35 years and these are very different than most. They are  reminding me of the first time my jaw dropped hearing the V-cap tftf in 2004. That day in 2004 fundamentally changed what I thought a capacitor could do in an audio circuit.
I have also installed the V-cap .1uf tftf on the center board replacing the small Dayton’s. I don’t know if this will have much influence on the sound but I do know they will have more influence than sitting in my junk drawer 😁