Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: mingles on November 16, 2010, 09:49:15 AM
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I just ordered a Crack and Speedball. I'd like to upgrade the output caps to film. Parts Connexion has a 20% sale this month, so it's a good time to buy. Does anything stand out as a best bang for the buck? These are what I'm considering:
100 uF Solen 400 vdc PB (56mm D x 72mm) $28.17
two 50 uF Axon 250 vdc (37.5mm x 53mm) $9.28
I don't know if four Axon will fit in the stock chassis. I've seen recommendations for motor run caps, but don't know where to buy them. I also wonder how big they are and whether they'd fit.
I scoured this thread: Output Coupling Capacitors http://www.bottlehead.com/smf/index.php/topic,526.0.html and came across another suggestion by Paul:
Quick note here - the last power supply capacitor is equally important to the sound IMHO.
What is the value of that last power supply cap?
Many thanks!
Mark
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The last power supply cap is one of those 220uF 250V Panasonics. I upgraded all the power supply caps to the Panasonic TS-ED's, available at Mouser. As far as the output cap, I plan on installing these http://www.diyhifisupply.com/node/31 (http://www.diyhifisupply.com/node/31) when I finally sort out my attenuator issues and install the speedball. Where oh where I'm going to stick them, aside from in my crack (wink,wink,nudge,nudge) is another issue entirely. I've also got a pair of GE 100uF caps that are even bigger. Have fun.
Rich
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Those solens are going to be huge. I have 47uf Solens in my SEX and they are the size of soup cans. Don't know if the 100uf will fit.
Partsconx has a couple motor runs that they sell. Can also find them on mouser, dk, and ebay. I am a big fan of motor runs for power supply caps. Have used Diversitech motoruns and like their performance. Will use them again. But they aren't small either. Have some picks of them in this thread. ttp://www.bottlehead.com/smf/index.php/topic,458.0.html
Used similar motor runs in my SEX with the stock chassis but it was a tight fit and required quite a bit of rewiring and larger feet for extra clearance. http://www.bottlehead.com/smf/index.php/topic,861.0.html
Enjoy, can't wait to see how it turns out.
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Hey Rich,
I've got a pair of those Obbligato PS caps in my Crack (and some folks wonder why I'm grumpy!) and while I liked them at first, they may be going through a weird phase right now. I just noticed it a couple of days ago so I haven't really done any investigations to be sure that it's the caps but they're my #1 suspect.
The mids have sucked in and there's a mechanical sound to the highs.
Kinda weird at this stage of the game (I've got well over 1000 hours on them now).
I'll take a little time in the next couple of days to switch them out and report in this thread.
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Steve,
Are the Obbligato caps your output caps? If so try a pair of 0.1uF 600V KK Teflons bypassing them. Well, use them if you got them.
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The 100 uF Solen are definitely big: 56mm x 72mm (2.2" x 2.8").
Here's a picture with reference to a coin: http://www.bottlehead.com/smf/index.php/topic,526.msg5890.html#msg5890
I'll ask dumbo if they fit.
FWIW, the tolerance of the Obbligato are rated at 10%. Solen and Axon are 5%. Does it matter in this application?
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Steve,
Are the Obbligato caps your output caps? If so try a pair of 0.1uF 600V KK Teflons bypassing them. Well, use them if you got them.
Thanks Grainger. I'll give that a try. I do have a number of .01uF K72 caps that I've already burned in so that should be a snap.
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. . . FWIW, the tolerance of the Obbligato are rated at 10%. Solen and Axon are 5%. Does it matter in this application?
The tolerance is on the value. And it is not critical that the parts be the specified value. Practically speaking, if they are made at the same time they are often much closer in value to each other than the tolerance (closer to being matched). Random samples from large lots are within the 5% or 10%. The voltage rating is going to be what it is specified at or better.
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Hey Steve, did you ever resolve the weirdness you were hearing? did the teflon bypass caps help out?
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Hey Maxwell,
You know, I totally spaced that out. I've been working on a bunch of other projects so I don't know when I'll be able to get around to it.
I think I'd stick with the Solens or Daytons since the folks who've tried them seem pretty happy.
BTW, I just noticed that I misplaced a decimal in my last post. That shoulda been .1uF K72's.
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I recommend Clarity Cap ESA series caps for the output caps. They'll need around 100 hours or so to settle down.
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Does the ESA range come in 100uF?
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> Does the ESA range come in 100uF?
I was wondering the same thing. It doesn't look like it. ClarityCap PX does come in 100uF. They cost $52 from Madisound. That's more than I was planning to spend. I have to question whether they sound any better than Solen Fastcaps for half the price.
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I was literally just on Madisound looking at those two caps, wondering the same thing. I feel that the Clarity Caps will inherently have better sound as they are an audio cap while the Solen is made for power supply use.
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I haven't used the CC PX caps but have used solens a lot. Just from the looks they seem about the same quality but who knows.
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Will a 91uF value be close enough for the output cap? They're only $15 at Parts Connexion.
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I was trolling around looking for various stuff and came across these, anybody ever heard of them? Price seems right. http://www.erseaudio.com/MPX25-03-100-00
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91uf should be close enough...John
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Yep, Erse makes decent caps.
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The specs on those Erse caps look pretty good. Might have to give some a try. They also look a bit smaller than some of the other similar rated caps -- motor runs for sure.
-- Jim
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I ordered a set, after I get some hours on them I'll let you know what I think.
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I am new at this, and am curious how much one can deviate from the actual values. For example, with the 100 uv 160 volt capacitors how high or low could I go with either value? Thanks.
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With regard to the Voltage ratings of capacitors, it is almost never a good idea to use one with a lower rating. This is because it is usually safe to assume that the designer chose the Voltage rating specifically to perform at the Voltage in the circuit, less whatever margin of safety the designer feels comfortable with, then chose the capacitor with a Voltage rating nearest to that which was commercially available, without going under his design's lower limit. Practically speaking, you can usually choose a cap with a higher Voltage rating, although you may not find the increase in size convenient.
As far as the capacitance rating is concerned, what you can get away with will depend on how the capacitor is being used in the circuit. If it is an output cap, for instance, the capacitance value may very well determine the lower limit of frequency it will pass. If it is a power supply filter, the capacitance rating can effect other things.
Perhaps the designer will stop by and answer you specific questions.
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I am new at this, and am curious how much one can deviate from the actual values. For example, with the 100 uv 160 volt capacitors how high or low could I go with either value? Thanks.
For the Crack output capacitor you might get away with a smaller value if it is a better sounding capacitor, non-polarized, Black Gate or film. But as you make the value smaller the bass begins to erode. It might be only a couple of notes if you only change by 10% or an octave if you cut the capacitor value in half.
So better at the same value or even a little smaller with a better sounding cap. Larger values if you are sticking with electrolytic caps.
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There's an excellent chart that shows the low frequency cutoff using different output cap values and different headphone impedances. It's definitely worth consulting:
http://www.bottlehead.com/smf/index.php/topic,526.msg6045.html#msg6045
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Ok! The Erse caps showed up today and sweet christmas they're huge! I was worried at first that I might not have room for them, my speedball should be here sooner or later and I almost waited but yeah... no such luck so I made sure I left room for the SB. I put some pictures on my flicker account so anybody interested in these caps will know how big they are.
http://www.flickr.com/photos/28861421@N02/
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i always read good thing about black gate caps, can we mod the Crack using this? any recommendation?
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i always read good thing about black gate caps, can we mod the Crack using this? any recommendation?
I am running my crack with 33uF Black Gates which work fine with my 300 ohm Sennheisers. They sounded a bit bass light initially but improved as they ran in. (Got my son to confirm this impression in case I'd just got used to them.)
There are two problems with Black Gates:- They tend to be quite costly.
- They are no longer made, so if you can't find the type, value and voltage you want then you never will.
I fell victim to the second problem last year when I upgraded my Lowthers to a more efficient model of driver. My ParaSEX amps were fitted with film caps, 10uF before the PSU choke and 15uF after. The higher efficiency speakers showed up too much hum, so I searched for 47uF 500V Black Gates to replace the 15uF film caps (47uF film caps just wouldn't fit in the case). I searched for weeks and eventually had to settle for Mundorfs which I hated until I strapped 2.2uF film caps across them (then everything snapped back into focus).
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I may eventually use some black gates in my Crack. I have a tightly matched pair of 150 uF 350v NHs, and another pair of the same, but not as tightly matched. I may use the matched pair as the output coupling caps, and the other pair in the power-e configuration as the last power supply cap.
Then again, I may not feel that it's necessary, and I'll save the caps for another project, another day.
-- Jim
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Anyone tried Mundorf Mcap 400V? It is available at 100uF and 150uF.