Supratek Tubes and Tube Swappin' for Everybody

Iwas wondering if any of the NOS 6SN7s sound close to the KR VT231s,,RCA maybe?

Ecclectique, I'm intrigued by your explanation of your switch to the 7193, but am a little more than confused yet on the actual process-electronics not being one of my strong suites. I'm wondering if you or someone else who has done the switch would consider posting a step-by-step expose of the operation and being very specific? (I have a Sauvignon , but system is not up and running yet.)

Hi Gang. Raytheprinter.... The kenrad black vt-231 really has a flavour all of it's own with perhaps the most dynamic bass energy of all of the 6sn7 types, albeit a little on the tubby side when compared to most of the others.Above the bottom 2 octaves it is very clean with great ambience and air, it throws a big soundstage thats both deep and wide. By comparison, the greyglass rca vt-231 possesses a very similiar character tonally. It's bass range is also somewhat overly ripe however it is a well balanced tube from top to bottom with a beautiful timbre, harmonically rich with a realistic soundstage and liquid mids. Not quite as vivid and organic as the kenrad but a beautiful voice none the less. Kpinneo.... Congrats on your new Sauvignon. Regarding the wiring for the 7193, I am assuming your sauvignon is set up with the 6sn7 for line gain duty. The 6sn7 [a dual triode] is basically 2 6j5's[a single triode] in one bottle. Both the 6sn7 and the 6j5 are octal based tubes and utilize the same tube bass. My cortese is set up for 2 6j5's for each channel or 4 6j5's in total for line gain. The 7193 is the electrically equivalent to the 6j5 except it's connection to the grid [pin 5 on the base] is now rerouted to the top of the tube and connected with a top cap. The anode [pin 3] is also rerouted to the other top cap on the tube.

What are the best new replacements for 5881 which comes with Chenin, because NOS replacements like WE350B or Tung Sol 5881 are awfully expensive...

Kpinneo. Further to the above thread.... I was reviewing what I had written and clicked the submit button by accident. Anyway.... The re-wiring for mine is a little more straight forward considering I only need to unsolder and re-route two wires. I am assuming here that you have some soldering skills,basic electronic fundamentals and a little experience with vacuum tubes in general. If not; I would suggest you work with a local techie or a modder to do the change for you. Furthermore: You will have to run the extra wires with the top caps either/or from the underside of the preamp and up the sides to the connections on the top of the 7193 or drill holes beside the tube socket to route the extra wiring needed. The wiring and pin connections for the 6sn7 is somewhat different being it has two triodes sections. The heaters [pin 2 and 7 ] or the same for both tube types. The cathode [pin 8 ] is also common to both tubes. Remember the 7193 is a single triode so one triode section of the 6sn7 will be unsoldered at the tube bass. The unsoldered wires will be at pin #2,3,and 4. Those wires should be folded and labelled. The connections for the 7193 should be as follows: Pin #8 is wired for the cathode, pin #7 is wired for the heater. Pin #6 will be unsoldered as this wire will need to be re-routed to the top of the tube and a top cap soldered to it. Pin # 5 is the anode, unsolder and re-route the wire to the top cap of the tube. Top Caps must be snug at the tube connection. Always mark the wires for identification for converting it back. Remember, the gain of the preamp will now be 1/2 of the 6sn7 unless you use a pair for each channel. For those that want to use the standard 6j5 and equivalent subs....leave the connections as they are at pin #5[grid] and pin #6[anode] and unsolder pins #2,3, and 4. Please note: I will not be held responsible for any damages to your equipment as a result of this post and I would strongly suggest you consult with mick at supretek before you proceede. Hope this helps and best of luck.