Mainline version history question

Sorry for the dumb question but if I'm replacing the Dayton 10uf caps with the recommended VCap ODAMs, does it matter which end of the new caps go to which solder terminal? I suspect it doesn't matter because I don't see anything like a "+" indicator on the old or new caps but I don't want to make a mistake!
 
OK, as long as I'm burying you in questions today, Paul: Is there any reasonable way to change the volume control to something more "traditional" without harming audio quality? Like one high-quality pot that moves smoothly instead of the steps? Not at all sure this is a good idea or something I'd do but I wonder what's possible for someone with only a modest level of experience building these things.
 
Sure, you can upgrade the output transformer.  The Magnequest TL-404 will work in the Mainline circuit but you'll lose the balanced output. The Sowter 8983 would also function similarly but also without balanced output.

The V-caps are directional in a certain sense, but not at the signal levels seen in the Mainline.  The short leads on those caps should go to the plate of the 6C45 and the long leads to the output transformers. 

Yes, you can put a single stereo pot into the Mainline.  If you do that, you should take off all the hardware on the front panel and pull the labeled overlay panel off and throw it away since it's no longer correct for the kit.  The stereo pot will definitely not perform to the level that the stepped attenuators do, and you will nuke the resale value of your Mainline by doing this.
 
Thanks for all that...I hadn't even realized that there were short and long leads on the caps but indeed there are!

No way I'd want to nuke the value, nor reduce performance, so I won't change the volume pots.

Also don't want to lose balanced connection so won't change the transformers. Wasn't really looking to do that anyway. Just shows a certain psychological problem that I had a dream about that. ;-)

I'm trying to do research on the 6C15 vs 6C45 tube question and will let you know if I learn anything.
 
Attached are pictures of my new VCap ODAM capacitors installed. I went with 18uf because I found them MUCH cheaper than 22uf and I figured (probably wrongly) that either is a huge improvement when going from the original 10uf Dayton caps (not that those are bad).

Thanks for all your guidance, Paul!
 

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Hey all,

I swapped 6C15P (6S15P) for the two 6C45P (6S45P) -- which can have -E as an identifier as well for a better-built tube -- into the mainline and it works great and sounds great. Not yet to the point of being able to tell if it sounds different. But if it does it's not obvious.

For those asking why I'd do such a thing since the 45 is almost certainly a better quality tube than the 15, the answer is very idiosyncratic: I try to always use tubes made in the year I was born and the 45 only began being made well after I was born. This was one of the most challenging experiences I've had finding a tube from the year I was born. Ended up getting them from sellers in Kyiv, Ukraine.

Best,
Ross in Denver
 
Rossputin said:
Attached are pictures of my new VCap ODAM capacitors installed. I went with 18uf because I found them MUCH cheaper than 22uf and I figured (probably wrongly) that either is a huge improvement when going from the original 10uf Dayton caps (not that those are bad).

Thanks for all your guidance, Paul!

Would you say there isn't much if any difference?
 
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