[bagwell359]

I recently had mundorf evo oil (aluminium) 3.3 450v coupling caps put into the line stage of my valve preamplifier. the sound seems a little bright and not as full as i was expecting. is this likely to change after significant burn in hours? Anyone used these caps ? how long to burn in? Hanks.

I think they mellow with 200+ hrs, but other variables were changed so hard to say for sure. Bypass caps used in this amp? Any other changes during same tineframe?

 

[bagwell359]

Quick question for anyone that knows - needing to replace the power filtering caps in my Marantz PM-66 Ki Signature amp.

Stock are uncommon 56v 12,000uf - would it be safer to replace with 50v 15,000uf, 63v 15,000uf or 63v 10,000uf?

Thanks

What's the +/- on the stock caps? In a blind situation I would avoid any with v under 56. If your caps are +/- 10% 15k uf should be fine. Also a trick I use for cheap caps and resistors is buy 3 or 5, then test them and use the best match and toss the others in the back-up pile.

 

[ostewart]

What's the +/- on the stock caps? In a blind situation I would avoid any with v under 56. If your caps are +/- 10% 15k uf should be fine. Also a trick I use for cheap caps and resistors is buy 3 or 5, then test them and use the best match and toss the others in the back-up pile.

I've found some Kemet and Epcos 12,000uf 63v caps - so I've just got to decide which to go with

 

[bagwell359]

I've found some Kemet and Epcos 12,000uf 63v caps - so I've just got to decide which to go with

Buy 3! That's good, better than taking a chance.

 

[ostewart]

Buy 3! That's good, better than taking a chance.

Decided to go with CDE 12,000uf 63v big caps

And a mix of Nichicon FG/ES (ES where there was no FG option) and Elna SILMIC II for the rest of the board

Nice little project when I get a free day at some point.

 

[bagwell359]

SILMIC II and FG's both have a transparency and rich treble harmonics that really set them apart. Nice that they are affordable too.

 

[ostewart]

It was successful, however some of the Silmic II's are quite a bit bigger than the stock caps so I had to use the legs to position them better.

Also the 63v 12000uf caps are a bit wider than stock too, just about fit but again had to offset some of the surrounding caps.

From what I have read, whilst not the neatest solution, it's fine to have them standing up away from the board

 

[Deleeh]

Hello,

Has anyone by chance heard the Vcap CuTf in a tube amp?
I have the TFTF in it and am actually happy with it.
I don't know what I'm hoping for, it's probably a passing fancy of mine that the CuTFs might work better than the TFTFs.

 

[JamieMcC]

Hello,

Has anyone by chance heard the Vcap CuTf in a tube amp?
I have the TFTF in it and am actually happy with it.
I don't know what I'm hoping for, it's probably a passing fancy of mine that the CuTFs might work better than the TFTFs.

Hi yes I have Vcap CuTf output capacitors in my Elekit TU-8900 300B amp if you wanted to visit the Elekit 300B BB you will find a good few Elekit TU 8900 and TU 8600 owners who have installed them and get a few more responses than here, probably one or two who might have done the same swap your thinking of as well.

https://www.head-fi.org/threads/elekit-300b-amp-kit.869957/

All rhe V-caps are super caps and hard to fault the Cutf is amazing for sure.

Fwiw I did run RTI tin foil teflon caps in another amp (Bottlehead Mainline) for 6 or 7 years and it was a killer combo and hard to beat with the Sen HD800 out of curiosity I added a pair of the Duelund JDM Silver foil bypass caps and was very impressed with the results.

I've done plenty of cap rolling in the past many of the big brands but the effect of adding the silver bypass caps on the teflon were like listening to a different DAC and amp.

So while I have V-cap Cutf in my amp currently the Duelund Silver bypass caps are also fitted to them and am very happy.
But a swap out of the V-caps for a full silver capacitor is scratch that will need to be itched when funds allow.

If your capacitor uf value is not to high maybe think about making the jump to a silver foil capacitor or if it is a higher uf value and super expensive then consider adding the Duelund JDM silver foil bypass cap to your V-cap TFTF.

 

[Deleeh]

Hello,
Thanks for the feedback.
I had a look but didn't find much in the Elekit forum.
It's a great amp too, the 8900R itches a bit too.

About the caps,it's a Feliks Euforia amp,under the 6SN7 socket I installed the TFTF and under the 6AS7G the Vcaps Odam also for space reasons that was just right.
The Feliks has silver wiring, I don't know if silver caps would be good like the An Silver.
I actually want to move away from the neutral a bit as the Feliks already is,with the TFTF and Odam's there was a noticeable improvement without question.

I was just wondering if the VuTfF on the 6sn7 base will become less neutral.
A little more heat would certainly be a good thing.
Of course you could also use something else like the An copper or Duelund.
The capacitor strength is 0.33 uf 600v.
The Odam has to be baked because I didn't do it myself and had to have it done.
You have good access to it on the 6sn7 socket and it can be done in a few minutes.

 

[JamieMcC]

Hello,
Thanks for the feedback.
I had a look but didn't find much in the Elekit forum.
It's a great amp too, the 8900R itches a bit too.

About the caps,it's a Feliks Euforia amp,under the 6SN7 socket I installed the TFTF and under the 6AS7G the Vcaps Odam also for space reasons that was just right.
The Feliks has silver wiring, I don't know if silver caps would be good like the An Silver.
I actually want to move away from the neutral a bit as the Feliks already is,with the TFTF and Odam's there was a noticeable improvement without question.

I was just wondering if the VuTfF on the 6sn7 base will become less neutral.
A little more heat would certainly be a good thing.
Of course you could also use something else like the An copper or Duelund.
The capacitor strength is 0.33 uf 600v.
The Odam has to be baked because I didn't do it myself and had to have it done.
You have good access to it on the 6sn7 socket and it can be done in a few minutes.

Maybe something like the Jupiter Silver foil vitamin-Q might give you what your after they are not to spendy either. They have not been out that long and limited values are available and feedback is pretty scarce.

 

[Deleeh]

Hey
I don't know if decoupling is a good idea on the amp.

According to the Vcap calculator it spits out 0.08 so the 0.1 from duelund would fit.

However, I have to say that when I first changed the TfTf I used 0.33 uf instead of 0.22 uf where it was installed.
That was an ordering error on my part.

But I think that the 0.33 uf is better in terms of clarity and depth effect.
According to the Vcap calculator, it even plays deeper than with 0.22 uf.
But I lose a bit of volume, so it takes 1-2 mm more away, which is not wrong.
Because you have more control over the volume.

What is actually with these here?
https://www.hificollective.co.uk/components/copper_foils.html

Are they above or below the Vcap Cutf in terms of sound?

 

[les24preludes]

Hi guys, I need a recommendation for a coupling cap for a DHT valve stage. Value 0.47uF to 1uF. I have plenty of teflon FT-2 0.1uF which is my standard choice but I want something larger for a DHT valve preamp project.

So far I rigged up a quick and dirty setup where I could add caps after my existing FT-2 coupling cap. This yielded:
- no added cap. The cleanest sound, unsurprisingly
- K40Y 0.22uF, 1000V. Didn't like this one, shouty and hard tone on vocals.
- KBG-MN 4uF, 600V. Huge size, and too large a value. But very promising. Absolutely nothing I didn't like - everything smooth with nice tone. Sound was more expansive while the FT-2 is very focussed. Vocals were very natural. Piano a little more rounded, but the overall sound was very pleasant. Impossible to add to existing equipment due to the size, but possible for a new build.

So any opinions on these:

• MBGCH
• KBG-MP
• K71-4 polystyrene.

And any recommendations for good value non-Russian caps? Not boutique prices.

 

[Jon L]

Hi guys, I need a recommendation for a coupling cap for a DHT valve stage. Value 0.47uF to 1uF. I have plenty of teflon FT-2 0.1uF which is my standard choice but I want something larger for a DHT valve preamp project.

So far I rigged up a quick and dirty setup where I could add caps after my existing FT-2 coupling cap. This yielded:
- no added cap. The cleanest sound, unsurprisingly
- K40Y 0.22uF, 1000V. Didn't like this one, shouty and hard tone on vocals.
- KBG-MN 4uF, 600V. Huge size, and too large a value. But very promising. Absolutely nothing I didn't like - everything smooth with nice tone. Sound was more expansive while the FT-2 is very focussed. Vocals were very natural. Piano a little more rounded, but the overall sound was very pleasant. Impossible to add to existing equipment due to the size, but possible for a new build.

So any opinions on these:

• MBGCH
• KBG-MP
• K71-4 polystyrene.

And any recommendations for good value non-Russian caps? Not boutique prices.

Try the Russian military K75-10. It's a hybrid paper/polyethylene film in oil cap, which sounds great and still plentiful on the Bay.

 

[les24preludes]

Try the Russian military K75-10. It's a hybrid paper/polyethylene film in oil cap, which sounds great and still plentiful on the Bay.

Yes - I know some like this cap. I tried it once and the FT-2 was so much better I dropped it from my "interesting" list. I have some KBG-MN in 0.5uF coming in the post. From what I heard of the 4uF ones I have this will be a good coupling cap. Quite rich and full compared to the teflon, but a very pleasant sound. I'll report when I get them. They may suite a leaner tube like the 2P29L - that's a combination I'm going to try.