[pelopidas]

Hey dimkasta,
 
did the k73-16 ever develop the lower end on your setup?
Curiosity got the better of me as I had some K73-17 sitting around. These are made from the same material but are blue dipped flat caps. I was expecting them to sound horrible, based on their geometry. It stands to reason that a cylinder can be wound to fairly uniform tolerances and these "sandwich" capacitors should have variance that could affect the sonics of the capacitor. Well, maybe its too late at night and my ears are tired but these guys sound very similar to the -16's. The first hour was unpleasant but now, doing A-B over and over listening to the same passages of songs to compare presentation and detail, I would be hard pressed to tell the difference.
 
Take this initial impression with a grain of salt as these caps are way to cheap to sound this good. Even more ridiculously inexpensive than the K73-16. http://www.ebay.com/itm/2-2uF-10-160V-PETP-Capacitors-K73-17-Lot-of-20-NOS-/251469144773?pt=LH_DefaultDomain_0&hash=item3a8cbaa2c5
20 for $7 is ridiculous.
 
A more thorough analysis soon to come.

 

[nhall]

Well, don't tell anyone, but having built another version of my phono with ww resistors, 1000mF panasonic storage caps, and mostly PETP's (with one russian polystyrene in the filter), I've just ordered a load more of the PETP's .. so that's what I think of them.
On first listen I thought the bass had nearly disappeared, but then after a couple of records I realised how much tighter and cleaner the bass was, and how much more detailed and clean the mid's and upper were .. that was over the last mainly Teflon infused version.
Seeing more posts elsewhere rating these cap's I think the supply will soon start to dwindle .. so I say get some in hand now!

 

[dimkasta]

I have recently started working on my turntable and phono stage again and got a K73-16 on its output, so bass is thin once again for me...
 
I need to give it a week or so, and start listening to my CD again because my MM is a bit crappy...

 

[nhall]

Dimkasta .. if you aren't already sorted for your phono stage, I'd urge you to try out either the Boozehound Labs one (but without all the PIO's), or one of the early Salas simple one's (not the more complex folded ones - but the simpler ones like the Le Pacific) with the jFets .. as you're into cap re-housing one of them would be so easy, and well executed with wise component choice will wipe the floor with many others out there .. they are so simple, you wouldn't loose much to try them, and I think you'll be amazed at their performance! - can also easily be run on batteries if you wish.
 
The PETP's work very well in the one's I've built! .. bass wasn't as huge (and I mean it was over the top huge initially with PIO's) with the PETP's, it was however much tighter and overall more controlled (real), and the finer detail better retrieved - as you can gather, I love mine .. just planning another version as a comparison .. so easy and simple with relatively few parts, you can keep trying different variations -
 
Next one will be denuded and wax potted cap's (this time I have tissue to first wrap the innards, and real beewax) 
 
with ww resistors on ground plane built as tight together as I can for min. signal path's, etc.. lottsa fun!

 
 Here was the image I wanted to paste previously, showing the slight difference with the end cap's of the K73-15's .. just for reference.
 

 

[dimkasta]

I have a salas folded premium kit, but I do not intent to build it yet. I need to close some projects first. I m currently using a vsps 300 and a phonoclone with which I very happy

 

[pelopidas]

Since we are playing "ill show your mine if you show me yours" here is a nude K73-17
I thought the winding would be softer on the edges but the entire capacitor is rock solid. The flat sides do appear to be more compressed though as you can see somewhat by the shinyness in the picture.
The sound of these is almost identical to the K73-16 but it seems even clearer up top. The only difference at this point is that there can be a bit more sibilance but these are "fresh" and are also calming down the more I listen to them. They sound zestier and livelier than the K73-16 but this could also be just the need for the cap to settle in.
I was listening to the FT-3 by it self and it is really a beautiful clean sound. A-B with the K73's I am having a hard time finding resolution and air missing with the little cheap K73's. The are more aggressive than the teflons but this is not unpleasant in my system. Compared to Dayton MPT they are so much more dynamic an alive.
 
nhall: you said you used to have teflons throughout your system. Were these russian teflons? How does the sound differ from the teflons?

 

[nhall]

Hi Pelopidas
 
I'm at work at present, so cannot get the goods to do a shot, but yes, the big cylindrical (armour jacketed!) Russian teflons ..
 
To be honest I didn't have all the values in them for the circuit, so some positions were in the EQ and coupling were the teflon's, and one position in the EQ was one of the square block Russian polestyrene (I'll do a pic of one of those as I have a load more ordered (and I also like them .. but they are just like a plastic outer case that easily can be cut off the core, which is like a dense cast plastic block .. but curiosity is now getting to me and I'll have to open one up!) and one position a green PIO Russian bypassed with a smaller value Teflon.
All my recent experiments are around the phono stage (two gain stages with passive filter network) - which is straight into the headphone amp. 
My first task when I restarted my last go at my system .. (I was guitar building / pickup winding and guitar amp building last few years before) was to re-make the deck (pic. below of the sub chassis - constrained layer with lasered ally sheets and end grain balsa
 [This shot was before finishing and polishing..]
then I got Jeff (Audiomods) to sandblast my Audiomods arm so it was a nice matt silver to go with the new deck - and I'm still playing with motors, drive electronics, etc (don't have a pic. to hand of the complete deck unfortunately) - I've sent two cartridges off to get them cleaned and refurb'd - so the phono was next in line! For ref. I still use my moving iron AKG P8ES's .. way back I started with a Garrot microscannered one, then moved on to len's (the cartridge man)
 
A number of years back I spent ages on valve phono's - many variations - thought I'd really cracked it when I went choke input on the psu, but after years of turning my back on tranny gear I gave the Le Pacific types of phono a go, and after a few variations I was smitten - loved the dead quiet background (well no background noise - only what's on the records - with or without battery supply), and I really was stepping up to a higher level of detail retrieval, especially when cap. swapping.
It's odd, but on the valve phono's, I felt that that cap swapping didn't seem anywhere near as big an issue in terms of detail retrieval as with the tranny phono - with the valve circuits, messing with the type of biasing and psu appeared to be more where it was at, whereas on the current phono, the psu (well I never start with crap designs, or cap's anyway) hasn't made that much difference, whereas the cap's used on my current unit really has changed the throughput a lot!
 
Back to your question - I haven't really had the time to do thorough A/B testing, however, when I used the same ckt board to do the last build (all except one cap as PETP's) v's the previous teflon infused build, I'd say initially it sounded much leaner, but in fact when listening over a number of records there is definately more small low level detail getting through (for instance I can more clearly make out the reverb tank on guitar amps vibrating around and after notes/chords are struck, which makes it easier to be certain on say which type of amp is being used on a recording .. just getting more ambient info through too.) ..
 
All I can say is that I've ordered a load more of the Russian PETP's in different values, along with some more of the Russian pale blue/green block polystyrene's, and they'll be in the next version .. I'll also stick with the Welwyn wire wound's were I can get the value's too .. oh, and next time the panasonic smoothing cap's along with the others will be stripped naked and beeswax potted .. just need another order to arrive, and the time (have all the other stuff to hand now)!

 

[dimkasta]

Unfortunately no 10uF for the 17s...
 
Damn I hate having so low input impedance on the amps...

 

[nhall]

Parallel cap's? .. mix your own flavoured cocktail, or is that taboo here?

 

[pelopidas]

Ok, I jumped on the wood and wax bandwagon.
 
I got a nice 1" dowel and drilled it out for the K73-16.


So I went from a small, compact capacitor to a pretty fat one

Then I figured, well, since I'm drilling and making a mess, lets try the K73-17 as well.
So I made a pot for them to sit in.
 

 
The K73-17 looks like a weird electrolytic now.

 
So here are the wood and wax k73. I obviously made 2 of each but in the pic its just one of each.
 

 
How do they sound? Different, really different. I have only been listening to them for the last 15 minutes and while writing this. At this point I don't really know what I am hearing that is different but something is.
(20 mins later)
At first I thought the top end was muffled. Some of the air seems gone. But this is not quite the right explanation. The mid and low end are bigger. For some reason it sounds softer but just as detailed. It sounds more like silver mica softness now rather than K72 teflon crispness. Both seem equally detailed but the silver mica is a woman wearing a clingy soft silk dress and the teflon are more like latex. Both have their appeal.
Voices are smoother, fleshier. Imaging is really good. Overall dynamic seems less but I am still somewhat confused by what I am hearing. I had no Idea wax potting the caps made such an impact.
Ok sitting here listening to these, it is apparent that they need to be burnt in again. The hot wax pushed some reset button, but they are changing while I am listening to them.
Enough rambling, I let you know how they turn out in a little bit.
 
I was thinking about doing this to my teflons FT-3, K72 but I dont know if I should.
 
First impression: I do not like. Second impression: I am intrigued. Third impression to follow...
(20 mins later)
Third impression: These are fantastic!
What I thought was a reduction in air is actually a much blacker background. The dynamics have come back in full richness.
 
dimkasta, you said that wax potting smoothed out the sound. Now I know what you mean   What a captivating sound it is. I wonder if this is the sensation that one has listening to the mundorf silver/oil. Smooth, smooth and clear and extended. Thank you for encouraging me to try it.
 
Ok I should not be writing while listening to music because it leads me to ramble.

 

[mcandmar]

Originally Posted by pelopidas /img/forum/go_quote.gif
 
The K73-17 looks like a weird electrolytic now.

 
Don't know why but the Flintstones popped into my head.
 
Interesting experiment all the same, do try an FT and let us know as i'm interested to know how it sounds out of the alloy casing.

 

[dimkasta]

FT-3 is quite easy to do, with excellent results as well. You just need WAY bigger dowels
Speaking of dowels, where did you get those lovely 1" ones?
 
By the way, get some 400 grit sandpaper and do the leads a bit until they are shinny. That is before you apply any solder on them. You won't believe your ears

 

[pelopidas]

I picked up a long dowel rod at Home Depot. Its about 1 meter long I would guess and cost 4 dollars. I was looking at some beautiful ebony dowels but they are really hard and slightly expensive, instead I wanted to practice on these first. Those small holes are very simple on a drill press. Making the cups is a little more difficult without marring the wood. Now i have to get some fatter dowels and skinnier ones too. But first, I need to finish the case for the amp and make sure I have space for all these little logs.
The ft-3 are so damn big I will need go go buy more tools as I don't have anything that can make a hole that big. The Diameter is about 1.25"

 

[lehmanhill]

Hi Guys,
 
I have really enjoying this current conversation and am just catching up after months away.  By the looks of things, I will be cutting and potting a few inexpensive caps in the future.
 
Someone wondered about Mundorf Silver/Oil in comparison to some of these Russian + bypass caps.  I have a MyRef Fremen Edition amp (100k input impedance) and have tried several caps as input DC blocking caps (1 uF).  For a long time, my favorite was the K75-10 with a 1 nF Amtrans polyprop bypass cap.  Like others have said, it had a nice warm mid-range, solid bass, and with the bypass a pretty good image and high frequency.  I found the coherence was pretty good at 1/1000 and a single bypass.
 
Recently, I have tried the Mundorf Silver/Oil as a single cap.  I would say that it gives up a little warmth in the mid-range, but not much.  The big advantage was improved detail and clarity.  The soundstage also seems better.  Overall, depending on the system, I would say that I prefer the Silver/Oil, but then again, not by so much as to offset the price difference.  I hope that helps.
 
Jac

 

[dimkasta]

In that case you really need to try the K73-16