Tripath Input Coupling Caps

[serengetiplains]

Originally posted by soongsc

Better than V-caps? Isn't Fluorinert some sort of coolling liquid?

Fluorinert is essentially liquid teflon with a very low dielectric constant (1.75) and probably correspondingly low DA, which is a function of dielectric constant. My paper/Fluorinert caps (despite the paper!) handily bettered VCaps---no contest. My Russian teflon/Fluorinert caps seem to me, after several days' listening, even that much better.

[Pano]

Remember those experiments a few years ago where they had rats breathing an oxygen bearing liquid?
That was Fluorinert, IIRC.

So what are you dong with the stuff? Just injecting it into caps? So that it mixes with the dielectric? Doesn't that change the capacitance?

[serengetiplains]

It was indeed Fluorinert.

Yes, I drill a small hole in the hermetic seal and inject Fluorinert until the cap is full. Fluorinert, because a form of teflon, is evidently chemically compatible with teflon, as after being injected, slowly seeps into the tight teflon windings. After four days, capacitance increases 4-5%. The increase is evidently from displaced air, which can be heard, several days post injection, if the cap is shaken.

The end result is a PIO cap ... without the paper, which is a terrible dielectric, and without the oil, which is but a moderately good dielectric, while theoretically retaining all the advantages of a liquid dielectric (reduced microphonics? self-cancelling DA?) with the superiority of teflon. Match made in heaven.

[Davet]

I have received a number of capacitors inclusion in this test from contributors to this thread. Have built a HZ41 AMP6 Tripath based amplifier for the testing. In addition I have built a test bed just for the ability to switch between the capacitors.

Currently, I am burning in a series of capacitors based on a circuit provided by Michael Mardis. I plant to let the caps burn in for a minimum of 72 hours.

The first test I will conduct is to compare caps that have been burned in to the same cap that hasn't been burned in. I then plan to move onto comparing various capacitors against each other.

At some later point I will test various bypass caps on the coupling caps.

At this point I would like your input. The proposed test will be subjective for those not consumed by the hobby. Music of their choosing will be played through my system and I need criteria for them to rate in.

PRAT is not going to get it for them. I thought descriptors like lifelikeness; bass sounding like a acoustic bass; a piano sounding like it is in the room and proportioned to a piano; breadth of soundstage; air around performers, depth of soundstage; etc. Anything else you can think of that should be included please post or email me.

I will use terms measuring categories such as: really like: somewhat; like; dislike like somewhat; dislike; and hated it.

Once I get your imput and the test are underway I will start a new thread with the testing and results

TIA

[Davet]

Scenerio: Compare Panasonic to Backgate electrolytics

I burned in a group of caps for at 336+ hours using a circuit provided by Panomaniac. I wanted to hear for myself if there was a audible difference between burned in (BI) and non-burned (NBI) in caps.

The first thing tested were Blackgate (BG) to Panasonic 3.3 MFD electrolytic caps. I compared (BI) BGs to (NBI) first and there is a definite difference in the sound of the BI BGs to the NBI BGs.

The BI BGs have a lot of body depth and width of soundstage compared to the NBI BGs. The NBI BGs sounded thin and the soundstage sounded compressed from front-to-to rear and from side-to-side.

I hear very little difference between the BI Panasonics and the BI BGs. The difference seems to be in the air around the performers. The BGs get the edge here.

The NBI Panasonics are tubby in the bass and the highs sound recessed.

Overall, the BI Panasonics and BGs are a wash to my ear. There is a subtle difference in the BGs, but for this application there is not a pronounced enough difference that would warrant the effort and expense, in my opinion, for the boutique cap.

Jan's inclusion of the Panasonics in the 41HZ kit is a winner once burned in.


The caps are the MKT films, BGs, AMP3, and AMP6 Panasonics.

[Davet]

The test bed for these test are as follows:

Input is from either a tweaked Samsung HD-841, or a Bobwire Tweaked Samsung 709 with a SuperPro Dac.

A 41HZ AMP6 T-AMP with a RS ALPS VR.

CAT5 wire is run from the input capacitor pads on the PCB to a 5 gang 11 position Russian Switch (Currently 4 gangs and 8 positions are being used.) Each switch position has caps for left and right channels.

CAT5 wire runs to European terminal strips. This allows for quick substitution of caps in the test bed. Current capacity is for 8 different caps that may be compared at the same time.

Only the capacitors under test are in the circuit at any time. The caps do not share any wiring aside from the CAT5 wire that connects the switch to the PCB.

Note: I have to use the mute switch(sleep) on the AMP6 to switch between caps. There is a horrendous click that comes from the speakers if I try to switch directly.

I will post a photo of the test bed and AMP6 in a subsequent post.

[Pano]

Good work, Dave!

Nice to know that you did find a difference in the burned in caps. Over 300 hours is a long time. I don't know of any other AB test of BI vs NBI caps. Well done.

There also seems to be a change in sound with butn in of power supply caps, too.

Looking forward to reading your opinions of the other caps.

[toolkit]

Originally posted by Davet
I have a number of Russian Teflon 0.1 MFD caps which I may use at some point to bypass PIO caps.

I am also experimenting with various input caps and I've just come across this mention of bypassing the input caps if PIO - could someone explain why this might be necessary?

[Davet]

At this point I don't have a definitive answer for you, but this is one of the test that is planned. I have a number of PIOs which I will A/B with .01 flourinert .01 caps, regular Russian .01 caps, .01 Russian PIO caps, and generic Radio Shack film caps. However, there will be some time before I get to it. I have a lot of caps to test prior to getting to bypassing.

Outside of formal testing I have used the Russian .01 mfd caps for bypassing on any number of caps and I have always heard a positive difference.

I would suggest you give it a shot and let us know what you hear.

[serengetiplains]

Dave, I think the Fluorinerted Russians are 0.056uF which, with the Fluorinert, come in at 0.06uF thereabouts.