Cap Upgrades for TRAM2

[jacklee]

Hi Thorsten,

I have the TRAM2 for a while, love the sound. I have Duelund caps on my supertweeters and found those caps to be excellent. I'm thinking of upgrading the input caps and possibly bypass the output caps with Duelund caps.

Anyway, my questions are:

1. What is the min vol ratings for the input cap and the output cap?
2. The stock input cap is 0.22uF. Would a larger input cap, say up to 1uF, improve performance or would make no difference?

Thanks.

Jack

[Desmo]

Allow me to answer this one as well...

See the attached pics of my Tram II. In my preamp the stock input cap was 47nF (not 220nF as you mention for yours..!?) Amongst other upgrades I use Duelund CAST 100nF, 200V on the input. For the output I have 6 x 2,2uF Obbligato tinfoil.

Both are really nice upgrades. On the input the CAST gives a more coherent and natural sound than the teflon caps, but the biggest improvement was the upgrade of the output cap. I'm not that fond of having different types of caps in parallel, hence no Duelund in parallel with the new output caps.

Hope this helps,
Morten

[jacklee]

Hi Morten,

Thanks for sharing your mods. They look really nice.

I was under the impression that the Duelund CAST is rated at either 100V or 630V?

Btw, have you got a chance to test the new Duelund Alexander cap? These are much cheaper (relatively speaking of course) than the CAST PIO so could be a candidate for the output cap, perhaps one piece of 13.2uF?

Thanks.
Jack

[Desmo]

Hi Jack,

Please check the dedicated Tram II thread here in the forum for the complete list of mods I have made...

Regarding the caps:

The CAST you can basically order any way you like regarding value and voltage. Since they are getting very big in 630V versions they are now also making lower voltage ones. What I like especially about the CAST is, that they combine the best from typical teflon caps with the best from typical paper in oil caps: They have BOTH the details and transparency of the teflons AND the coherence and richness of the PIO's. No other cap that I know of has this in one cap. The cheaper VSF types come close, but the CAST are the best...

The Alexander are so new, that the hardly hit the market yet. If you look closely to the picture I uploaded you will see a pair of 100nf Alexander caps parallel to the blue PP caps on the triode heaters. In this application the -for some reason- make the noise floor of the Tram II a bit lower, and the hiss that is still there is more ''listenable'' and less annoying. So the calm things down somehow. I also tried them as coupling caps on the input, but of course they are no match for the CAST. The Alexander are really nice, slightly darker than CAST and less detailed, but still with the Duelund coherence and beautifully layered soundstage.

To be honest I think the Obbligato tinfoil are soo good for output caps that I have not even thought about the Alexander for that application. As mentioned earlier the upgrade of the output cap to all tinfoil is a real ear-opener..! I had a feeling that the 10uF ''standard'' Obbligato cap was used to make the Tram meet a certain price point and in that regard it's a very good design to use 10uf of a lower quality and 2,2uF of a better quality. But since these tinfoil caps are just 20 $ each the upgrade is just 200 $ and IMHO really worth every $$$

Cheers,
Morten

[jacklee]

Hi Morten,

Thanks for sharing the impressions of the cap upgrades.

I'm planning to follow suit to upgrade the output caps to Obbligato tinfoil - but then Simon told me today that it's out of stock till Dec ... have to wait till then.

Your finding of bypassing the triode heaters is very interesting. If it lowers the noise then it will be very worthwhile. Perhaps I can try using my unused vcap in that position and see if it brings any benefits.

Jack

[Desmo]

Originally Posted by jacklee

Your finding of bypassing the triode heaters is very interesting. If it lowers the noise then it will be very worthwhile. Perhaps I can try using my unused vcap in that position and see if it brings any benefits.

Jack

I can't say for sure, if the level of niose is actually lower, but it sounds ''smoother'' somehow and therefore the noise does not draw attention in the same way. Maybe (just maybe) the sound is also a tiny bit more coherent with this cap installed...

If you have some good quality caps on somewhere between 100nF - 470nF it's an easy experiment to try out. Give it a go..!

[jacklee]

Originally Posted by Desmo

I can't say for sure, if the level of niose is actually lower, but it sounds ''smoother'' somehow and therefore the noise does not draw attention in the same way. Maybe (just maybe) the sound is also a tiny bit more coherent with this cap installed...

If you have some good quality caps on somewhere between 100nF - 470nF it's an easy experiment to try out. Give it a go..!

I have a pair of VCap but they are 1uF. Will that be too large a value? Thanks.

Jack

[Desmo]

Originally Posted by jacklee

I have a pair of VCap but they are 1uF. Will that be too large a value? Thanks.

Jack

It's fine, just give it a try..!