OLDER DECWARE GEAR SUPPORT >> CSP, CSP2, CSP2+ >> Jupiter Caps for CSP2+ or CSP3 - Value?

Message started by MarkR7 on 01/07/17 at 20:22:35

Title: Jupiter Caps for CSP2+ or CSP3 - Value?
Post by MarkR7 on 01/07/17 at 20:22:35

Hey folks, what is the value of the 4 Jupiter coupling caps in the CSP2+? My current caps are GE film caps, and they are .68uF, but the Jupiters come in .47uF or 1uF, from what I see.

Title: Re: Jupiter Caps for CSP2+ or CSP3 - Value?
Post by will on 01/08/17 at 20:43:44

In my CSP3 there are four .47 Jupiter HT coupling caps. After I sent it to Decware to replace the stock caps, I ended up preferring running the output tube pots higher, liking the more revealing and natural qualities of the Jupiters, but missing some punch from the originals. I wondered if it was a cap value change, and am guessing so since your CSP2+ has .68s.

Recently, when I was putting a new volume pot in the CSP3, I saw the Jupiters were glued down to the plate. Some years ago, when I replaced the stock caps in my Torii MKIII, I had been experimenting a fair bit with vibration reduction in my system to good effect. The Torii's original coupling  caps were also glued down, so I ended up playing around with bluetak to isolate the new coupling caps from the plate vibration some. I liked it best with bluetak, roughly 3/8" plugs, centered, the cap pressed in and seating about 1/4" above the plate (when looked at upside down from the inside of the amp).

This in mind, I very gently released the CSP3 Jupiters (risky! as they appear to be made of paper composite and the glue was strong, finally removing a very thin bit of the outer coat of the cap!!). Then I lightly pressed the caps on bluetak plugs, this time under each end of each cap, finally seating about 1/4" above the plate.

Though first impression was a little lean, it was also a little less thick and more resolving, things I prefer. Settling into the "new" sound, the originally perceived slight leanness "evaporated." I was hearing more a nicer definition, sweetened by more complex micro information...fine detail and space emerging from more emptiness, typical qualities from reducing vibration. A nice little change for me.

Title: Re: Jupiter Caps for CSP2+ or CSP3 - Value?
Post by MarkR7 on 01/09/17 at 15:22:16


Thanks for the very detailed and helpful response Will! Much appreciated.

I also wonder if the drop from .68uF to .47uF affected the bass slightly (as it will when you look at the high pass filter formula Fc=1/(2*pi*R*C)).

That being said, I wonder if I'd be better going with the 1uF, for a little higher cost, and slightly bigger cap. Decision, decisions!

Great feedback on the bluetak too!


Title: Re: Jupiter Caps for CSP2+ or CSP3 - Value?
Post by Matchstikman on 01/09/17 at 18:59:37

Oh wow, is that math?

You guys are next level, for sure.

Title: Re: Jupiter Caps for CSP2+ or CSP3 - Value?
Post by will on 01/09/17 at 19:08:49

Hey Mark,

I can't say on the 1.0 from experience. My feeling is it may be excessive... 0.47 being quite a bit closer to 0.68 than 0.68 is to 1.00, and .68 being quite punchy in my recollection. Also Steve chose the .47 for a reason, so if you feel like heading that way, it could a plan to call him and get his opinion of how a 1.0 would act.

Personally I don't feel a lack of bass from the CSP3 with .47 Jupiter HTs. My output tube settings being higher after changing caps I suspect are a result of: part, cap signature (HTs more spacious and atmospheric...the famous "organic" Jupiter and finely detailed, but friendly/not cool)...also part, a little less capacitor compression...and partially, the value effect on tonal balance.

Also, I easily hit the limit of the CSP3 sounding exaggerated to me before maxing out the pots and/or the master volume. With the tubes I use lately (Mullard E88CC outputs, a Dario/Phillips E88CC input, and Mullard GZ32), I tend to stop at 8 on each tube pot and maybe 2:30 max on the master. I do not use the CSP3 for a volume, instead for its sound and for tuning to different recording qualities. For a long time, with different tubes, I ended up at 7 max on the outputs and 9 on the input. I would say roughly that each of these settings is more about balancing the input and output tube sound more than using the CSP qualities less or more. Before the Jupiters, I think I recall 5-7 output, and 9 input (a lot of the time).

For context, there are a number of folks who rarely, if ever, get up to 7 on the outputs with their systems and tubes. I guess you have looked through the CSP tube threads.... As you have probably found, the rectifier is a big deal in all of this.

The Philips/Mullard GZ32 has a very refined warmth allowing the open/fast/detailed qualities of the tube type without being too intense (at least here). For me a Mullard/Phillips GZ34 also has a very nice and similar balance of traits, but with greater power, tends to being a little too intense and dense for me (so far).

But the GZ34 is loved by at least a few other forum members. Then there are those who prefer a 5Y3GT, which for me is too laid back....then there are the American and European "equivalents" to these, and 5U4s, 5R4s and more!!! point being...any of these choices are system/room dependent with taste preferences, and often with .47 Jupiters in play. At least for me, with the 5U4 and GZ34, I usually run lower on the output pots.

Either way, I love that the tubes are another option on top of settings and cables for punching things up or settling things down if wanted.


Title: Re: Jupiter Caps for CSP2+ or CSP3 - Value?
Post by MarkR7 on 01/10/17 at 00:10:41

I do have a shout out to Steve about the cap values, just waiting to hear back.  I will report back when I hear from him.

I am in the process of trying out all sorts of tube combinations from my stash, as well as getting other tubes that I don't have yet.  From what I have tried, this is one versatile and very customizable piece of electronic machine.  Just in the few combinations I tried, you can make it practically sound like anything you want, and that is great for me since I have a very neutral class D amp (the Red Dragon S500) connected to the CSP2+.

Title: Re: Jupiter Caps for CSP2+ or CSP3 - Value?
Post by MarkR7 on 01/10/17 at 19:22:07

Steve indeed confirmed that .47uF are the preferred value for the Jupiter caps. He mentioned that 1uF would prob work, but feels that the .47uF will most likely sound better.

Title: Re: Jupiter Caps for CSP2+ or CSP3 - Value?
Post by JD on 01/16/17 at 12:57:32

I am running a stock csp2+. I absolutely love using a USN-CEP 7308 Amperex in the driver position. This is my favorite tube of all the 7308,6922 family. I think they are better than my Telefunken CCa.  They allow everything through, and are not completely microphonic but they have a shimmer and shine that comes without the speed and glare that I often associate with shimmer. They hold notes and you can really hear the instruments cleanly and separately, the depth just resonates with me. Very evident when listening to jazz, chamber orchestas, hugh masekela etc. music with such variance. I was lucky enough to just score 5 more of them so I should have a lifetime supply but they are pricey.  Telefunken CCa are so clean but also surgical, almost live driving an automatic sports car. I've got Siemens 7308 behind them. My rectifier is a Mullard GZ34. My input pot is at 8 and output at 6. I concur that I have never run my output higher than 7.

In this time of divisiveness music is the ultimate leveler.  
Happy Martin Luther King Jr. day to all.


Title: Re: Jupiter Caps for CSP2+ or CSP3 - Value?
Post by Lon on 01/16/17 at 13:06:46

I have Amperex 7308s in my Torii Mk III and nothing else has sounded as good there.

My CSP2+ (with beeswax caps and a stepped attenuator) gets secondary use as I run my primary source, the PS Audio DirectStream DAC) directly into the Torii via my ZBIT; I use the CSP2+ for my ZP3 and sometimes my blu-ray player listening. I found a trio of NOS Valvo CCa tubes on ebay that sound excellent there, not sterile as you describe the Telefunkens, but lively and resonant. Odds are they are made by Siemens. One day if I find them at a great price I may get Amperex 7308s for this preamp. . . I bet they do sound wonderful.

Title: Re: Jupiter Caps for CSP2+ or CSP3 - Value?
Post by will on 01/29/17 at 00:33:10

Some years ago I used American Amperex 7308s a lot in the CSP3. As an input, it stayed in a really long time. As outputs, I also liked them depending on what else was in the amp. I think to balance the tube's particular signature, especially its warm/rich and complex mids, and slight upper end roll-off, I used some nice, spacious and fast PCC88s with the Amperex.

But as I progressively got other areas of my system smoothed and refined, balancing edge with very fine detail became a revelation, and these 7308s started having too much signature for me...

Having done a number of modifications over the last few months to the CSP3, musically refining the signal, and many on the forum loving them, I thought I should try the 7308 again. I cleaned up the pins put it in the input.

I left in my latest standard outputs, parasol getter 60's Mullard ECC88s that are warm in the way I like, without sacrificing really good detail, while being extra good at very fine detail. With a fast/revealing/open/spacious yet sweet Mullard GZ32 (this tube has been in my system a really long time for me!), the sound is great. Fine detail and spacious ambient information were quite good, the abundant micro detail of the other tubes supporting the American Amperex's textured, open and revealing midrange emphasis.

These are clearly really good tubes, doing what they do in a beautiful, open, and mellow way. Very quiet, revealing, warm, rich and spacious mids especially, with a refined and musical bass...they seem mellow and revealing at the same time.

Probably because of the mods I have done to the amp, making it more quiet and revealing without edge, the balance has shifted enough for me to really like the American Amperex again. Generally though, I have preferred tubes that are more transparent and neutral....also without edginess, but with less signature.

Now, oddly for me, I am using all Mullard tubes in the CSP3. An A-frame getter 60s ECC88 in front, the parasol getter 60s E88CC in the middle, and a early 60s GZ32 rectifier. This is unusual, being used to getting my favorite sound mixing types and makers.

Like usual, for me, if it is good stuff to begin with, it is more about balancing parts than one tube or another being a good one ;)

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