10uf ?

JamieMcC · 3176

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Offline JamieMcC

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on: July 25, 2015, 09:48:23 AM
Hello I am hoping for a little guidance on output Capacitor values. I notice several Mainline builders have used larger than the 10uf value specified for the Mainlines output capacitors but have yet to see anybody fit lower values and wondered if using a lower uf value was at all a option?

Specifically as I have a few nice but smaller value caps to hand in the shape of some 3.3uf Jupiter HT bees wax and 2.7uf Mundorf supreme Silver oils (Sex) I would be interested to experiment with them in the Mainline but conscious there must be a point which shouldn't be crossed as performance will suffer so really wondering if the sonic penalties from using a smaller value boutique cap might be offset by any difference in performance it may or may not offer.

I might add that I am absolutely over the moon with the performance of the Mainline and its just my curiosity and perhaps a opportunity to get the soldering iron out with some interesting possible options to hand.

A little guidance on any possible pit falls/side effects of using the lower uf value in the Mainline would be very much appreciated.

Regards
Jamie
« Last Edit: July 25, 2015, 09:50:51 AM by JamieMcC »

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Offline Paul Joppa

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Reply #1 on: July 25, 2015, 02:07:27 PM
For clarity, the Mainline is a parafeed headphone amp, and the capacitor under discussion is the parafeed cap.

Extensive experimentation was done to choose the cap value; hopefully Doc B or PB or Josh will remember something; they are the ones who did the testing.

It won't hurt anything to try different values - if you don't hear a problem then it's not an important problem to you.

Paul Joppa


Offline Doc B.

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Reply #2 on: July 26, 2015, 07:46:26 AM
I don't remember the details. We tried different values, measured the response, and found 10uF to be optimal. That is what I recommend for anyone who wants to optimize the circuit to their taste.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Paul Birkeland

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Reply #3 on: July 30, 2015, 01:04:43 PM
Buy a 2.2uF and a 20uF that are the same brand as those we supply, then listen to all 3. 

Some fairly lazy number crunching suggests that you may well hear a difference between the 10uF and the 2.2uF, but maybe not between the 10uF and 20uF.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline NightFlight

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Reply #4 on: March 25, 2016, 12:15:59 PM
I believe that jives with this experiment: http://www.raleighaudio.com/chapter_2.htm



Offline mcandmar

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Reply #5 on: March 25, 2016, 01:38:49 PM
When i built my 6C45 amp with OT-2's (S.E.X. Iron) i experimented with 1uf to 12uf and measured the frequency response.  The main difference i found was sub 100hz, and tiny bit of roll off from 10khz.  Listening by ears it went from flabby sounding bass, to thin sounding rolled off bass.

I believe the optimal capacitor value will change with headphone impedance, and the output impedance tap of the transformer you are using so the end result will be a compromise if you use different headphones.  I optimized mine into a 32ohm load for my Grados, but the value i settled on probably isn't ideal for my 300ohm HD800's.  I have since picked up a pair OT-3's so i have to redo all the testing and find the optimal value again, keep us posted on your findings :)


M.McCandless


Offline JamieMcC

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Reply #6 on: April 03, 2016, 06:26:19 AM
So out of curiosity earlier today I removed the 10uf RTI Teflon parafeed capacitors I had been using for nearly 12 months now in my Mainline and installed the 2.7uf Silver In Oil Mundorf Supreme's that used to be installed in my Sex amp in their place. I was instantly reacquainted with the Mundorfs SIO's distinctive V shape sonic profile and spacious soundstage I remembered from the Sex. 

So far I think they sound pretty good with the music I listen to and haven't at this point really perceive any immediate weakness that might be attributed to running a lower uf value.

Going to run them for the week and then swap them out for the 3.3uf Jupiter HT bees wax that are in the Sex at the moment. 

Cheers
Jamie

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Offline JamieMcC

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Reply #7 on: April 06, 2016, 12:54:58 PM
Ok so I need to confess I swapped out the Mundorf SIO, I had listened to them long enough to know their signature in the Mainline is not for me they are super sounding caps and I am sure there signature would appeal to many. The 2.7uf worked well enough with the HD800 for me to consider the experiment  worthwhile. But here's the thing after listening to them for a couple of days enough was enough and they just had to come out there was no way I could last a week!

So it was in with the Jupiter 3.3uf HT Bees wax, I left them running for a hour or so and then put the cans on for a listen and just grinned ;D there is absolutely no doubt to my mind they are just insanely good and in a different league to the Mundorf SIO which just don't sound anywhere near as natural to me. There are differences between the 3.3uf Jupiters and the 10uf Teflons but they are for the most part subtle each has its strong points the Teflon sounding super clean and are incredibly resolving. The Jupiters are more intimate with a softer and richer midrange that's just so inviting with the HD800's! Both caps apart from these subtle differences sound quiet similar and both have a beautifully natural sound thats beguiling in the Mainline. Probably I would stick to the 10uf if running a variety of cans to be on the safe side but if using higher impedance cans like the HD800 or Beyer T1 then running with a lower uf value boutique cap is definitely a option worth considering.

 

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Offline Strikkflypilot

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Reply #8 on: April 07, 2016, 07:46:24 AM
Interesting report, Jamie. I am very happy with my Auricap XOs.
BTW Did You mod Your HD800s?

Home system:
Sources: Ibasso DX90, Google Chromecast Audio optical out
DAC: Schiit Gumby
Amp: Bottlehead Mainline
http://bottlehead.com/smf/index.php?topic=7463.0
Phones: HD800S

Office:
Sources: Iphone/ Ipod
DAC: Dragonfly Red+Jtrbug
Amp: Crack/Speedball heavily modded
Phones: HD580,HD600 grilles


Offline JamieMcC

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Reply #9 on: April 07, 2016, 08:49:36 AM
Hi yes my hd800 currently are sporting both the Anaxilus and French mod.

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Offline Strikkflypilot

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Reply #10 on: April 07, 2016, 07:07:50 PM
Wow, both!

I have only the Anax mod featured in the Innerfidelity video.
I am very happy already.
How do You find the addition of the French changes the experience?

Home system:
Sources: Ibasso DX90, Google Chromecast Audio optical out
DAC: Schiit Gumby
Amp: Bottlehead Mainline
http://bottlehead.com/smf/index.php?topic=7463.0
Phones: HD800S

Office:
Sources: Iphone/ Ipod
DAC: Dragonfly Red+Jtrbug
Amp: Crack/Speedball heavily modded
Phones: HD580,HD600 grilles


Offline JamieMcC

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Reply #11 on: April 07, 2016, 10:31:15 PM

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Offline Strikkflypilot

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Reply #12 on: April 08, 2016, 01:00:13 AM
Thanks.

Home system:
Sources: Ibasso DX90, Google Chromecast Audio optical out
DAC: Schiit Gumby
Amp: Bottlehead Mainline
http://bottlehead.com/smf/index.php?topic=7463.0
Phones: HD800S

Office:
Sources: Iphone/ Ipod
DAC: Dragonfly Red+Jtrbug
Amp: Crack/Speedball heavily modded
Phones: HD580,HD600 grilles