Bottlehead Forum
Bottlehead Kits => Legacy Kit Products => Quickie => Topic started by: aragorn723 on December 24, 2014, 05:02:12 PM
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Hi,
Tonight I installed K75-10 russian caps as coupling caps in the Quickie. They are pretty big, and surprisingly good quality. I've never seen caps encased in metal before. Attached are a couple of pics from the install. Notice the difference between the stock caps and the K75's! Got a matched pair of these with 5% tolerance on ebay. Can't wait for them to burn in!
Dave
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You'll be pleased, my friend!
Let us know!
Ciao
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Dave,
You will like these caps. They are USSR Military Surplus. My take on it was if you supplied crappy parts to the military you went missing, never to be seen again.
After about 50 hours you will be almost there on burn in. Let us know what your impressions are.
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Grainger,
That's probably true. I wonder what the original application was? Seems like they were built to last thru some serious environmental stress. There wasn't much juice left in the Quickie batteries, so the CDP has been burning them in for the last 13 hours. They sound pretty relaxed, and have more bass / better midrange clarity than the stock caps. Does it take the full 50 hours to hear the full potential of these? Merry Christmas!
Dave
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Dave,
A very Merry Christmas to you too.
I burn in PIO for 50 hours, film for 100 hours and Teflon for 400 hours. It is a practice with no scientific proof behind it.
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It's frustrating but educational to listen through the breakin period. Some caps get worse before they get better, for example.
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I suggest testing the casing for magnetism- if it's steel, it can be removed with a twist-action pipe cutter (about $10 at a hardware store), the type that has a cutting wheel and a thumb screw to apply pressure. Tighten screw, rotate cap in cutter, repeat 'til the ends pop off (do cut right at the end, btw).
You'll also notice an extraneous solder joint in there- the external leads are different than the internal leads, so you can get rid of that issue as well. A little heatshrink and hot melt glue and you'll have a cap that works great for hifi, without the performance robbing bullet-proofing aspects.
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Has anybody else tried this? I haven't heard of this before.
Dave
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Paul,
One interesting aspect of listening to the Quickie during the burn-in period is the voltage drop on the batteries. While the caps are breaking in and theoretically sounding better, the batteries are wearing down, and the sound is degrading because of that. My batteries are on the lower side right now-plate voltage was 8v last night, and filament voltage was around 1.2v. Popping in some fresh batteries would probably give the system a different sound at this point.. Though I figure it couldn't hurt to leave these batteries now to get some juice going thru them and burn in the caps.
Dave
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8V on the plate is absolutely dead and nearly not passing sound, I wouldn't call that "low".
-PB
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Aragorn- do you really mean plate voltage, or are you referring to the voltage across a single 9v battery? 1.2v on the d cells would not be out of line with the 9 volt batteries being at 8v. As c.b. says, 8v on plate is really low and you should replace asap if indeed plate is at 8v
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Has anybody else tried this? I haven't heard of this before.
Dave
Dave,
I just tested Polyester, Teflon and PIO KKs. The POI were ferrous enclosures. The effect of magnetic fields induced into ferrous leads, end caps (resistors) and bodies of capacitors is subtle in the most revealing of systems. It is not dramatic.
I've happily used KK PIO caps in crossovers and as coupling caps for a number of years. These are directly in the signal path. I haven't heard any problems but others might hear it. Of course, it is impossible to know if the ferrous wrap on the cap is the cause till you try the experiment above and listen to nekkid KK PIO caps and shielded caps.
If you have spares try it and let us know your impressions.
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Hi Grainger,
I don't have any spares of the caps at this point. The quickie is basically stock, except for the pjccs, russian coupling caps, copper couplings for microphonics, and westinghouse tubes. It probably wouldn't be revealing enough at this point to hear a difference, gotta see what happens with these russians once they settle down :) To me it seems like the biggest change in sound would come from changing the amp at this point, but that is probably down the road a bit.
Dave
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I think my brain is beginning to work. The PIO use the can to hold in oil. I wouldn't open them.
I have PIO motor start/run caps in the power supply of my FP 2 that slosh when I shake them. The KK PIO caps do not slosh. So I don't know just how much oil is in there.
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yeah, they probably do.. I wonder if you put enough voltage in them if they spray oil? 8)
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Are the K75 PIO?
My experience was related to the teflon russian caps in cans. Definitely don't open up the oilers-
But the extra leads, connections, and resonant case are definitely drawbacks on the teflons, they sound better without.
Best,
bad
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Yes, they are PIO. I have this bookmarked:
http://www.diytube.com/phpBB2/viewtopic.php?t=898
I also have a page in Russian but can't read much of it.
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Hi,
Just wanted to post a few impressions on the K75s now that they have 50 hours on them. The sound is definitely unique-I like the presence of the midrange, and after reading some views, a few things surprised me about the sound. One thing that was different was that the bass was noticeably tighter than the stock caps. It is that musical kind of sound that draws you into the recording-these make you want to re-listen to your music and hear what it sounds like. The treble sounded a little bit laid back on some recordings (and makes you want more) but other times I felt like there was more treble than before. Overall they sound really nice, and opened up the soundstage from the stock caps.
Dave
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Just the sound I have in my system!
I made this experiment once: I listen to "Pictures at an Exhibition" from my DAC and then from my vinyl.
Tha DAC is above any suspect: no output caps, only decoupling transformers as per diyAudio mods; the phono preamp's coupling caps are K75 bypassed by ft3 and the Quickie has k75.
I could clearly hear the difference between bass and high, and the vinyl was clearly the most extended.
An eye-opener experience!
Ciao, and let us know if you hear any further improvement
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Dave, try bypassing your K75s with a KK Teflon (as Bonzo did and I have done). A small value will work. The Teflons need 200-400 hours of burn in.
I bet your first impression will be good.
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Grainger,
Is that the same as the K72's? They are fairly cheap on ebay, what would that do to the sound? Maybe .02uF would be good?
Dave
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Sorry, yes. There are a number of KK Teflon configurations. There are K72P-6, K72P-3, K72-11, FCH, FT, FT-1, FT-2 & FT-3 (some say the best sounding). There are a couple of others you want to ignore; the "Doorknob" caps and the K72-8 with antenna connectors on them.
Some have studs, some have leads and some have the tabs on the end. I think the differences happen with value (uF) and voltage ratings.
There are a lot of variations out there.
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Wow. I had no idea there were so many. So the preferred cap is the ft-3? The only question is which cap to pick. The cap selection is subjective (ideally if someone had the same piece of equipment as you and had similar taste in sound they could recommend a value (at least that's what I hear from the Bottlehead folks!) Anybody out there tried a bypass on the quickie? Experimenting with these buggers could be a very time-consuming hobby, since teflon has a 200 hour burn-in :P I'm pretty impressed with the sound of the k75 by itself, but you never know when the upgrade bug will strike, so this would be handy information to have!
Dave