Aesthetix Calypso vs ARC LS25 MK2

Depends what you consider inexpensive. I'd say you'll need to spend a minimum of $400 to $500 to do it right. Don't try to skimp on tubes or buy from a dealer without a solid reputation or you may regret it.

You'll need two closely matched 12AX7's & two matched 6922's.

I have a variety of tubes that I have used with my Calypso's.

For the 12ax7 tubes, I prefer Mullard CV4004 Platinums (available from Upscale Audio) or Telefunken 12ax7 smooth or ribbed plates. For the 6922's, i like "white" label Amperex or Phillips SQ's.

In addition to Upscale Audio (good prices, but kind of snooty), I like Brent Jessee's tubes and also Vintage Tube Services (be prepared to wait 3 weeks to get your tubes if you buy from Vintage Tube Services). All of these suppliers can be found via Google and they are reputable.

Calypso has been a recent addition in my system and I've embarked on a little tube rolling.

I've tried JJ Tesla 12ax7, cryo treated NOS Jan Phillips 5751 & Sylvania triple mica black plate 5751. The JPs offered greater air and clarity and the Sylvania same again with a touch more natural warmth. The later were bought at a reasonable price s/h from a guy I'd come across. They were noisier than expected given thier rep for low noise and went pop within 20hrs of use, leason learned. Will be on the look out shortly for NOS Sylvania. It was the 6922 that surprised me. From what I'd read rolling these makes less of an impression. My unit came with Sovteks. I changed them out for late 60s UK Mullard ecc88. Big difference, fuller sounding with greater weight and impact. Very pleased with them.

Pdreher, I've read that the signature has less of an issue with the tube noise. Whats your impression?

Defride - I have not had issues with tube noise from either the stock Calypso or the Signature version. I think the original stock version of the Calypso had some issues that were purely tube related, but that was overhyped. I've never had a problem with either of the two Calypso's I've owned. Great preamps and a great company to deal with.