It had to happen eventually... capacitor upgrade question for the Mainline

[JamieMcC]

At least as of this morning, it looks like there's one pair of RTI's left in stock at tctubes if you want to go the teflon route.  (http://tctubes.com/teflon-capacitor.aspx)

Mine are only at 100 hours or so, and I believe Jamie said he was still hearing changes at around 500 hours (which is what AR apparently recommends in terms of teflon burn in) - so I'm probably in no position to give a final verdict.  But they do seem to be excellent caps!

Hi Mike.  My RTI's took a shade over 500hrs to settle down they have been stable for the last week or so now. I'm looking forward to hearing some feedback from you guys on how they are working out in the Main line. I can not imagine doing without them now.

Jamie

[Loquah]

Thanks for the various links.

In Australia, buying high quality caps is a little tricky. So far the only local retailer I've found stocks Mundorf and Auricap (hence my suggested options for the Mainline). Shipping from companies like Parts Connexion, etc. is prohibitively expensive

[George Napalm]

Just pulled the trigger on those last 2 RTI teflons for my Mainline. My first cap upgrade! Pretty excited :-)

[dubiousmike]

Just pulled the trigger on those last 2 RTI teflons for my Mainline. My first cap upgrade! Pretty excited :-)

Glad you were able to snag that last pair!  They're a little too large in diameter to fit down against the top plate where the stock caps sat, so I ended up sticking zip tie mounts on the sides of my output transformers to hold them in place.  In truth, the leads on the RTI's are so stiff that this really isn't necessary, but I understand vibrations can impact the sonics of caps so I figured it couldn't hurt.

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fcdn.head-fi.org%2F1%2F12%2F12b2ab2a_20140322_232102.jpeg&hash=29c8c963de6e62949e2f57b681cf9b474f94073f)

[George Napalm]

Hi Mike,

Thanks for the hint. Did you order your RTIs matched? Also, did you notice any improvements in sound?

[Paul Birkeland]

  In truth, the leads on the RTI's are so stiff that this really isn't necessary, but I understand vibrations can impact the sonics of caps so I figured it couldn't hurt.

It's good that you anchored them down, the 5 lug terminal strips will thank you.

[JamieMcC]

A curious question about fitting those rti caps in the Mainline.  Would there be enough room to fit them in the space they are currently position but closer to the top plate if the boards were offset a little to make the gap wider or is there something hidden that I cant see that will not allow them to drop down or perhaps increasing the height of the boards stand off so they would slide in underneath? Main line build pics are a bit thin on the ground to see.

[Hornet900]

Mainline Jamie... it's your destiny 

[Loquah]

A curious question about fitting those rti caps in the Mainline.  Would there be enough room to fit them in the space they are currently position but closer to the top plate if the boards were offset a little to make the gap wider or is there something hidden that I cant see that will not allow them to drop down or perhaps increasing the height of the boards stand off so they would slide in underneath? Main line build pics are a bit thin on the ground to see.

Jamie, I need to do a little work on my Mainline so I'll take a look when it's upside down and see if I can take a pic or 2 for you.

[Loquah]

Jamie, here are some pics and even a video that will hopefully help...



The link above may not be live straight away as it's still processing at the time of posting.

[JamieMcC]

Lachlan that's great actually thanks.

Edit actually its fantastic because I can clearly see the easiest option as there is plenty of space would be to move the OT transforms slightly further to the back of the Mainline. If not covering the top like I have done with carbon on the Crack I would fill the holes with weld sand flush and re-drill the top plate for the new position. 

Thanks

Jamie

 

[Paul Birkeland]

Most 10uF caps that carry a 200V rating will fit without this much effort.

You may also consider using longer standoffs under the C4S boards, if you are just on the edge of being able to squeeze them in.

[Paul Joppa]

... the easiest option as there is plenty of space would be to move the OT transforms slightly further to the back of the Mainline....

If you move the transformers that direction they will pick up hum from the power transformer. They are centered fore and aft on the power transformer because there's a null in the pickup pattern at that point.

[Loquah]

What do the caps attached directly to the 6C45 tubes do? Any point replacing them?

I've just ordered some Russian Teflons for the caps on the 12AU7 board and will probably get some Mundorfs or Auricaps to replace the 10uF Dayton. I've read as much as I can and still can't decide between M-Cap Supremes and Auricap high resolution. Any suggestions?

[Paul Birkeland]

What do the caps attached directly to the 6C45 tubes do? Any point replacing them?

These are RF suppression caps that are out of the signal path. Substituting them with something else would potentially make the amplifier sound a lot worse.