Aesthetix Rhea and Calypso Tube rolling-what did you do?


Hey all!  been having a blast with the Calypso and Rhea here, both in signature versions.  Have a Stradivari v2 cart fronting that and looking to start rolling some new NOS tubes in both units.  Price really isn't 'too' much of a consideration.  I am happy to experiment and play around some here.  That being said, the list out there goes far and wide, and deep.  Looking to add a bit of warmth but keep the top end as airy as i can here.  The units are a bit dark and seem to roll off the top octaves just so slightly.  Bass isn't bad, not last word of slam and could be improved on probably as well, but far more concerned with midrange and top end dynamics

Would love to hear what the community has done with their units and how you got to your 'sweet spot'.  Thanks!
73cuttysupreme
I don’t have experience with the Rhea but with the Calypso the 12AX7 probably has the most effect on sound. Adding warmth in the midrange while keeping the highs airy and the bass tight is not easy to do. I’m not familiar with a killer tube that works magic in the Calypso so I’m going to suggest a couple of tubes that are considered among the best.

Amperex Holland. They come with various brands; Amperex, Phillips, etc. They are identified by a left facing right triangle etched into the glass at the beginning of the tube code. If you want to learn about tube codes, check out Brent Jessee’s website. In the yellow boxes on his home page in the middle of the second row there is a "Euro Tube Codes" box and a "Telefunken Tube Codes" box.

I think the Amperex 12AX7 might be what you’re looking for. Get them from the early to mid 60s. They would have white printing on them. I65 would be the tube type, also etched into the glass. Some people feel the later tubes with orange or green printing are not as good.

Many people believe that Telefunkens are the best tube ever. They would not add any midrange warmth, but are considered among the best overall, the result of the fabled German engineering and manufacturing. Many have date codes painted on them but often they don’t. I don’t think there’s any time period that is considered better or worse for these tubes. They come in two varieties, smooth plates and ribbed or laddered plates. There is no significant sound difference between them, but the smooth plates are usually more expensive.

If you want to try a tube that is known for being warm, check out Mullard. You may lose a little in the highs and bass though. If you’re using the stock tubes any of these and more would probably be an improvement.

If you want to get into really expensive tubes, we could talk about the Mullard 10M or the Telefunken ECC803S.

If you want advice on where to buy or get a professional opinion on these, especially about a mix of tubes to get your Rhea and Calypso working together really well, let me know.
Thanks for the response.  I have spent a good deal of this weekend crawling the web and it seems the Amperex Bugle Boys may be right up the alley for the 12ax 7 positions.  Now to figure out the 6922, maybe Amperex 7308s?  Maybe telefunken?  Not too expensive, especially when you take into account these can last from 6-10k hours, price 'per hour' is negligible. Been looking at vintage tube services and upscale audio.  There's some other people out there on the 'fringe' or in other countries, and would have little recourse if it's total BS.  These two seem pretty trusty from reviews.  
I bought my Calypso Signature 2nd hand  with Telefunken 12AX7’s and Mullard 6922’s from Vintage Tube Services. It sounds great and is very quiet.
I think talking to Andy Bouwman at VTS or Kevin Deal at Upscale Audio would be the best way to go. Kevin has his fans and detractors. I think his detractors don’t like his style, although some say they have gotten bad tubes and a hassle returning them. I’ve never had a problem with him. Brent Jessee is a good dealer too. I think you’ll be happy working with any of them.

pdreher's suggestion sounds like it would work too.  Many people swear that Andy is the best.
Andy at Vintage Tube Services is recommended by Aesthetix. When purchasing tubes for your Rhea you need to have matched very low noise tubes in the V1 and V2 spots.

I had a very good experience with Andy.
Gave Andy a call.  I already have Amperex 7308 green globes in the 6922 position in the Calypso, but pulling the stock Sovteks and going with a pair of 60's Amperex bugle boys.  Looking forward to the see what the change will be.  I'm certain for the better.  Once that's put to bed, might go same way with the Rhea signature as well, Amperex all the way through.  
There's a ton of great info and feedback on those Amperex 12ax7s.  Seemed like a 'safe bet' to start there.  I can see how this becomes an addiction real quick.  I thought I had a problem with Pinot Noirs, betchya that takes a back seat to tube rolling.
Old thread but current thoughts... I have had the Calypso and Rhea Signatures for a long, long time, tried most every band/type and find a 5751 RCA triple mica black plate to be the weapon of choice in my pre, with Amperex 6DJ8s. I utilize an NOS quad of Telefunken smooth plate 12AX7s (Amperex Bugle Boys were also very nice, perhaps offering just a bit of music sparkle (NOT overly tipped up at all)) in the first gain stage of the Rhea for their clean, top to bottom linearity and lack of added colour, and RCA 7058s (per Glenn at Aesthetix) in the 2nd stage (RIAA). The 3rd has far less influence on tone. I found a date matched pair of Telefunken 6DJ8 medical grade that are dead quiet (between the music of course) for the final sockets. Sounds lovely and very revealing.
73cuttyspreme, I certainly agree with your choice of gear and your take on what you want sonically out of these fine components. It very much mirrors my own. Your approach is sound. After investing what you have in the hardware it would be a huge misstep to be cheap about valve selection, ridiculous actually, especially given the lifespan of a well vetted set of signal tubes. These offer more to the mix than does a good set of performance rubber on a sports car or dash of spice on a otherwise excellent meal. I have had my two units since before sending them both back to Glenn and Jim for Signature Editions. Now thinking toward Eclipse upgrades... 

Bye the way, there are several very reliable NOS tube sources still in business but a note from experience, Andy at VintageTubeServices is a rare gem and a gentleman! I have signal tubes that he hand/ear picked over a decade ago that are still sounding as sweet as the day I plunked done my hard earned dollars for the privilege. If you where interested and couldn’t readily find a pair of RCA 7058s (for the second gain stage), they are commonly pretty cheap when one can find them, but PM me and I’d be happy to send you a pair. 

Please follow back up in this thread and tell us what you find and how it worked out. Do this for future readers (as so many don’t bother to do).
I went with Andy B over at VTS.  Super stellar guy.  Takes the time, wants to ensure you know what you are getting.  In this current age of commerce Andy is a breath of fresh air.  I cannot recommend him highly enough!  He's got my business for life, and should probably stock up on every tube I can right now and get a lifetime supply in the 'audio drawer'. I ended up with Amperex 60s vintage 12ax7 and 6dj6 tubes and wow, just wow.  Super quiet, wonderful transparency.  I was able to drop the gain on the Rhea one click, after many years, finally aware of what this unit can do.  I am most likely going to send it out for an Eclipse upgrade here at some point.  I think this is finally the sweet spot in regards to the hifi here.  You can't necessarily do better, you can only do different, and that's a great place to be in....