Supratek Owners Thread

Looking for others’ thoughts. I’m now in a position to upgrade from the Chardonnay, so a couple of days ago I asked Mick what would an "all stops out" single 6SN7 Cabernet look like. He responded that "all out" would be the Grange Signature circuit, but would need the 6J5 instead. It seems he could do it all in the Chardonnay’s main case, since the two extra power supply tubes showing in the the Cabernet photo are 6L6’s moved over for the DHT Cabernet, not the 6SN7 one.

I have some reading to do about the 6J5 (there's a long head-fi thread). My inclination: After going through lots of NOS 6SN7’s and 6F8G’s and equivalents, and lots of time and $$$, I find the Treasure Globe from Rachel of Premium Vacuum Tubes in Canada (from China) easily the best of the bunch for my tastes and hate to give them up, afraid I wouldn’t find anything as good among the 6J5’s. Another possibility that I tossed out to Mick is a Grange Signature w/o the phono section, but don’t know what tubes are involved in that beyond the 6J5, assuming he’d even do that.

Thoughts? Thanks,

If you already have 6sn7 and equivalents you like I would just go with that. If you get curious about 6j5 tubes you can always use an adapter to go from 1 6sn7 to 2 6j5. 

If you are someone that likes experimenting with tubes you might want to get your preamp switchable between 6v and 12v. It costs extra but it has allowed me to try out some tubes that I couldn’t before. The 12sx7 are a stand out and I was actually able to buy several pairs of TS round plate 12sn7 tubes for a reasonable price. 

So either I am really stupid or the Cabernet has one of the most epic transformations with burn in ever. I have complained multiple times about how my Cabernet preamp couldn’t handle the 4v output of my DAC via its balanced inputs. Well, I tried it again all these months later on a whim and its fine.

All I can figure is that I was on the wrong input when I did my initial test. I have noticed that there is quite a bit of bleed between inputs. If you put as signal in on one input you can hear it if you select an other input. That obviously isn’t a big deal because you won’t be playing multiple inputs at the same time. But when I first hooked the Cabernet into my system I thought it was really quiet and very distorted. Then I tried a different input and it got MUCH louder. That’s how I knew I had been on the wrong input. The signal was still really compressed and distorted though. 

Did I really not try another input originally? I find that hard to believe but it is the most likely explanation. So yeah, the Cabernet is fine with higher input levels on the balanced connection.

My 6 month evaluation of the Cabernet is that I love it. Took me a while to sort things out but now my old preamp sounds downright harsh. I have found that tube selection makes a huge difference. I’ve also found that when I change tubes in the Cabernet I have to change tubes downstream too.

For example, the TS round plate 12sn7 sounds amazing as long as I use a tall 7n7 input tube in my amp (Inspire KT88 Firebottle) and use 6v6 outputs. If I just pop some 807 tubes into the amp it doesn’t sound very good until I change the input tube. If I use Raytheon 6f8g tubes in the Cabernet I can’t get sound I really like unless I put in e3375 tubes in the output. 12sx7 tubes in the Cabernet I really like an RCA 6sn7 in the input tube of the amp and 6ar6 tubes in the output. And on and on. Once I dial in the system it sounds amazing but every change requires changes elsewhere to get sound I like.

The switch that allows me to use both 6v and 12v tubes cost an extra $500. That gave me pause but I think it was worth it in the end. I have been able to get several pairs of TS round plate 12sn7 at reasonable prices. That probably evened out the price right there. On top of that I was able to get the so-called “bad boy”  Sylvania tubes with little trouble. I can also use tubes that aren’t available as 6sn7 like the 12sx7 and the 14n7. The latter have extra support rods as compared tp the 7n7 and 6sn7. If you already have a good collection of 6sn7 tubes maybe the 12v switch won’t make sense for you but if you are starting out I recommend it. 

Thanks. Not sure I'll go for the mod when I go up to the Cabernet, but I'll have to discuss that with Mick. Because I use powered speakers, the Chardonnay is downstream from a Lampi dac for me, and with the Treasure Globes (Grant Fidelity), I had to change from a USAF 596 to the Sophia Aqua 274B to get the  bit of warmth I wanted. I don't see changing tubes for the Cabernet to start with. Hope it stays that way because after all those older tubes I really like this combo.