[adrianjones]

I've recently gone from Clarity Cap ESA 250v in my tweeter (Fountek CD3) to Mundorf EVO OIL and the treble has really opened up.  Far cleaner, clearer and much more detail.  I'd love to try the Silver/Gold version which is supposed to be another step up in airy detail.

 

[TurbOSquiD67]

If you were to choose the best possible single, stacked, and bypassed cap options for a 100uF position (two 100uF output caps in the circuit) in a Crack/Crackatwoa, what would you choose?

Currently I've experienced Dayton 100uF, Evo OIl 100uF, and bypassing the Evo Oils with a Duelund .1uF Silver/Copper Hybrid. My next experiment will be with 100uF Evo Oil in parallel with a Jupiter 10uF Flat Stack, and/or bypassed with the .1uF Duelund.

I read mixed opinions, facts, and other about stacking and bypassing, most of which seems to be dependent upon the cap's purpose in the circuit.

Any experience, knowledge, lessons learned, and anything else you've got is much appreciated.

Thank you,

-T 

https://imgur.com/a/DlxvR

I do love the way she sounds

Edit: just thinking that maybe a 100uF mid forward cap would go well with the Duelund, or Jupiter bypass. Higher frequencies seem to be filtered and smoothed, but also highlighted more than the rest of the range.

Another option is to use a lower value Mundorf 47uF with a mid forward cap to get close to 100uF total, and then bypass.

I'm trying to recreate some of that pure coppy/silver tone with using bypass caps along with stacking values of other types. Because, you know, a 100uF pure copper/silver capacitor is totally affordable

 

[JamieMcC]

https://imgur.com/a/DlxvR

I do love the way she sounds

 

 
Congrats on the Crackatwoa build, it looks great

 
After rolling lots of different capacitors in my own Crack you start to form a preference for a certain sound signature, I slowly gravitated to PIO with teflon bypasses but it is a personally thing and probably one persons best might not be liked by another. So probably its more about choosing a type of capacitor with known traits that will enable you to tweak the signature to suit the type of headphones you use to your own personal preference.
 
With the Crack tube rolling also came into play there is a quiet a difference between a bog standard RCA 6080 and the more sought after tubes like the GEC 6as7g, Tungsol 5998/Western Electric 421a and Bendix 6080 but this might not be such a factor with the Crackatwoa.

 

[TurbOSquiD67]

   
Congrats on the Crackatwoa build, it looks great

 
 

Thanks much Jamie!
 
I slowly getting to the point where you're at - a preferred sound sig. 
Does the Crack have (2) 100uF output positions? I can't remember. 
That's a lot of capacitance to afford, haha. 
I do notice the differences in cap types, but now I'm stuck in a corner not sure where to go next. 
If I take a wrong turn, it could hurt financially, so I'm trying to mitigate that by asking a lot of questions. 
 
What octal tube did you enjoy the most? I've stumbled upon the TS 5998 - so good! 6080/6AS7G/5998 differences are definitely heard in the C2A. 
 
-----------------------------
 
I'm running this with Beyerdynamic T1's and DT-990's, Senn HD6XX and HD-600's (600's are so awesome I can't believe I waited so long to get them!). Dayton 100uF, Mundorf Evo Oil 100uF, as well as bypassing the Evo Oils with a Duelund .1uF Copper/Silver Hybrid - I do love what this has done to the highs. Although it sounds great, the Evo Oil and .1uF hybrid combo highlights treble a bit much, and also smoothed out the sonics. So a bit of good, and decent consequences. It has also recessed the mids and added a bit of wonky bass. This could also have to do with the 12BH7A in the mix which does have a bit of a U shaped sound sig IMO.
 
Seems like there's a lot of really smooth treble being focused on, and recessed mids. I assume this is because the Evo Oils are a bit bright, and the .1uF Copper/Silver highlighted that a bit much. My goal is to balance the sound with a mid forward cap, in parallel with a Mundorf. I was thinking 25% Jantzen Superior Z-Cap, Solen Fast Cap, or  Audyn Cap Plus (or Q4), and then 50% Mundorf Supreme Evo Oil, then top it off with 10uF Jupiter Flat Stacks and the .1uF Silver/Copper hybrid. 
 
100uF position bypassed with a .1uF Duelund vs. 100uF bypassed with a 1uF Duelund. What would be the difference in the effect of the bypass from .1uF to 1uF? More of a full bodied filter into the midrange, instead of only high frequencies?
 
Best!
 
-T

 

[JamieMcC]

  Thanks much Jamie!
 
Best!
 
-T

 
The Crack uses one 100uf per channel for its output capacitors I believe the Crackatwoa circuit is similar to the Cracks except on the Crackatwoa  the power supply is shunt regulated which is where its performance gain is but I am guessing here.
 
You are on the right track the Beyer T1's can be a bit trebly and sibilant at times so you do not want to use anything that highlights the treble region for bypassing a inexpensive Russian Teflon imho is going to sound better than most bypasses you’re going to need to be look at the top end caps like Jupiters, Vcaps, Duelund to achieve similar or better results. My experience with the Crack was that using a Teflon bypass with the T1 was the way to go it worked really well the top end was crystal clear and superb to listen to  the Teflon had a effect throughout the range from top to bottom. The only drawback with th e high end caps is they can take an age to break in especially the Teflon which needs at least 200hrs before they start to come on song. My favourite tube is the GEC 6as7g its the holy grail of the 6as7gand getting harder to find now.
 
These russian MGBO (paper in oil) with a Teflon bypass were a favourite with the Crack and T1
 

 
 
For me the 100uf  K75 40B bathtub pulse capacitor combined with a teflon bypass was my own top favourite for the Crack  the only trouble is its way to big to fit and I had to use fly leads to connect them up but it was worth the trouble and I really enjoyed listening to the Crack using them, ps it sound nothing like the normal K75-10 capacitors if I ever build a Crackatwoa these are tucked away ready and waiting to fit.
 
You can find a few more of my Crack cap rolling adventures here   http://www.bottlehead.com/smf/index.php?topic=5284.0  
 

 

 

[TurbOSquiD67]

Nice! 
 
I think the MGBO-2 400V would be good for me, as I'm pulling a bit more current through the circuit with a slightly lower R1A value on the high current boards - keeps kreg on the low current board in check when running the 12BH7A. Or I could be wrong and 160V would be just fine
 
I could run 3 or 4x 20uF, and top it off with a Mundorf or Jantzen, bypass with teflon or other.  
Which teflon did you go with, the K72P-6? I could possibly run .022uF FT-3's that I have.
 
 K75-40B's are hard to come by! Only a few for sale and their prices are quite high. Those things are huge dude! (that's what she said). I'm not sure that those would even fit in the C2A! Liking the creative mounting you have going on, awesome!
 
Tried adding the Jupiter 10uF HT Flat Stacks in with the 100uF Evo Oils and .1uF Duelund - I like!
Seems a bit more tame, and lush than without. A bit congested, but this is most likely due to the Duelund and Jupiter needing time to loosen up. While this cap setup may be almost perfect with the HD600's, the T1's are still experiencing quite the gap in the mid-range. Regardless, it does sound sublime, and even further detail has been reached! All while keeping a calm delicate representation. I can hear what people are saying in the crowd of some tracks, and voices (Anberlin live in New York via Spotify 320kbps) literally sound like I'm standing right there. 

 
Next I'm going to add a Jupiter .1uF Copper Foil in the same manner as the Duelund, this should even things out a bit more. Although, I really think that the Evo Oils are on the bright side, and mixing a lower value Mundorf with a Jantzen or other neutral cap will yield more balanced results. 
 
Best!
 
-T
 
https://imgur.com/a/MnGhL

 

[JamieMcC]

I used three 30uf 160uf per channel but you might fit four in the c2a with all that space. What was the voltage of the ones that came with the kit the ones in the Crack are 100uf 160v ? You could always measure the voltage on yours to check. Your FT3 Teflons woukd be a great choice  I use some 0.22uf FT3 for output caps in a Eros and they really do sound superb  imo I would probably give them the edge over Jupiter HT and Mundorf SIO as a personal choice.

 

[TurbOSquiD67]

Cool. The C2A comes stock with 100uF 250V output caps. So I guess that question of a lower voltage would be for someone like PB or PJ. edit: oh I see what you're saying.... measure at the terminals of the output caps.

Super interested in Mundorf Silver OIls, as I do like the lush but detailed tone. Hopefully I can hear them someday. Cap buffet testing stores should be a thing.

 

[Elocai]

You do know that it only takes a few seconds for capacitors to set, right?

For capacity the rated number is reached officially (in industry caps) after 1000hrs of use. Most changes happen in the first 10hrs.
You can check standart industry caps that come with documentation (e.g. Wima) there you'll find logarhitmic graphs that show this behavior.

whether it takes a few seconds or a few hundred hours for the caps to settle, i wonder why more amp designers don't take the time to burn them in before soldering them onto the boards.
seems like the simplest thing to do.

Soldering "resets" the capacity (and probably other things) of caps. So after burn in, you would revert all or part of changes made by soldering. This happens because when increasing the temperture of the materials the caps use, it resets it's structure and capacity can be far higher then ratet.

---------

I'm looking to do a coupling mod onto my Soundcard, need 3x12uF and 2x24uF, know the last one could be difficult so i would take 2x12uF for them, making a sum of 7x12uF.

My Budget is about 100€. First i thought I would buy Obbligatto Gold Caps. Now after reading this thread i'm thinking about K73-17 10uF, Wima MKP10 630V 10uF or Erse Pulse X 12uF.
Any recommendations?
And for a further upgrade (incase I find only 10uF not 12uF) any 2uF Caps that go well with the K73-4 or Wima MKP10?

 

[davveswe]

If the amp uses 4.7uf for output, can i use caps with lower values then? or will affect the performance of the amp?

 

[lehmanhill]

Generally speaking, changing the value of a capacitor in an amp will change the performance. Depending on the circuit, it can also cause oscillations which range from making the sound terrible to damaging the amp.

What you can do is combine smaller caps in parallel so that they add up to 4.7 uF.

 

[afshin]

hi all

10nf ERO 1837 PP cap in Olive oil ... by pass K72p6 military teflon capacitor

The main cover of the capacitor is shaved.

It can help a lot to combat environmental vibrations and audio feedback.

If the level of sound brightness was too high for your system, you can cover the glass surface with a copper plate.Lubricate copper foil sheet with grease. Like the picture below ...

Used silver wire and tin containing silver. Used Teflon Coated wire...
Do not forget this 20-hour Burn-in Time...have good time.

thanks .afshin

 

[rafabro]

Did you do it yourself?

 

[afshin]

Yes i have done

 

[Reddart67]

Since a lot of film/oil caps for OTL outputs are huge to get high capacitence at the needed voltage ratings, is there any reason you would not want to mount them outside of the amp chassis (like power supply caps often are mounted) if you have limited interior space? Especially motor run caps, with the connections on one side?