Supratek Tubes and Tube Swappin' for Everybody

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.

Sorlowski,

I am currently using the Sovtek KT-66(about $50.00 per match pair at tubestore.com in which I have no affiliation whatsoever)that Mick recommended to one owner here which he shared on this thread a while ago. It needs to play at least 50 hours before it shows its real character. With the RC VT-231, Mullard 5AR4, and TFK 6922 plus Mullard M8080 on the phono, my preamp never sounded so good. At least to me of course but I am very impress how the tonal balance becomes so natural in my system with this tubes as regulator. I have compared it to Sylvania 6F6G's which I thought the "it" tube for me, Tungsol 5881, RCA 6L6GC Black Plates, GE 7581, and GEC KT-66 Brown Amphenol base(the only two I have left) and I like the Sovtek better.
Do not make any conclusion about this tube's ability until about 50 hours as I mentioned, after that it gets even better.

Of course, you can take my post with a grain of salt. I am just sharing my findings that's all.

regards,

Abe

Sorlowski. The tung sol 5881 is too pricey only because it is a good sounding tube when used as an output tube in push/pull configured audio amp as well as being very popular with the guitar amp guys where it's in big demand. It's really not that great a tube in the supratek anyway and certainly not worth paying the current market price for. The lowly 6F6g as well as many others inexpensive nos types like the 6v6,6k6,6u6 sound as good if not better for the same cost of the currently manufactured 5881's or 6L6's. The chineese kt-66 reissue is a very good tube if you want new.

Thanks for your answers, but what reissue of KT-66 or other tube would give me most warm, details and drive (if such combination of features is possible) ?
Which new replacement will get me closest to famous WE 350B performance ?
Are tubes from Chinese Valve Art (KT-66) or maybe Harmonics any good ?