EL 34 is the European designation for the USA 6CA7.
The 6L6 is the USA version of the European KT 66. The best KT 66 is probably the MO Valve or Genelex, and should sell for about $100.00 NOS.
The best EL34's are Mullard and Amperex. Bought used you should be able to get 80% (of new test) for as little as $40.00. New in the original box with test papers could run $200.00 each. It is really all over the place on price.
The Russians currently build a 6L6 that is reasonably priced and sold under the Svetlana name. I personally doubt it would offer performance gain over the Tesla, but I have not made the test in that circuit.
There is a Chinese version of the KT 66, and even offered with brown base, no doubt to honor (or copy) the MO Valve. It has not been spoken of too highly among those I discuss this with, but that would be another affordable test you could make.
I run MO valve KT 66 in place of the (stock) Russian EL34 supplied in my Aesthetix gear. When I first switched these out I was astonished at the improvement. Later when I substituted Mullard EL34, I had a difficult time deciding which I preferred.
If my experience transfers to your gear, the lesson here is that Mullard, MO Valve and other new old stock tubes offer substantial improvement over the original Russian tubes, regardless of which you choose.
If cost is an issue, the Telsa is terrific and priced very reasonably. If you must try other enexpensive EL34 tubes there is Sovtek, Svetlana and Electro Harmonex.
My tests with all these tubes in Wolcott amps, proved the Tesla E34L over the Russian tubes, and ranking below both the Mullard and Amperex NOS.
Let us know how you do, especially if you experiment. It would be nice for others visiting this site to read results of your trials for this particular amp.
The 6L6 is the USA version of the European KT 66. The best KT 66 is probably the MO Valve or Genelex, and should sell for about $100.00 NOS.
The best EL34's are Mullard and Amperex. Bought used you should be able to get 80% (of new test) for as little as $40.00. New in the original box with test papers could run $200.00 each. It is really all over the place on price.
The Russians currently build a 6L6 that is reasonably priced and sold under the Svetlana name. I personally doubt it would offer performance gain over the Tesla, but I have not made the test in that circuit.
There is a Chinese version of the KT 66, and even offered with brown base, no doubt to honor (or copy) the MO Valve. It has not been spoken of too highly among those I discuss this with, but that would be another affordable test you could make.
I run MO valve KT 66 in place of the (stock) Russian EL34 supplied in my Aesthetix gear. When I first switched these out I was astonished at the improvement. Later when I substituted Mullard EL34, I had a difficult time deciding which I preferred.
If my experience transfers to your gear, the lesson here is that Mullard, MO Valve and other new old stock tubes offer substantial improvement over the original Russian tubes, regardless of which you choose.
If cost is an issue, the Telsa is terrific and priced very reasonably. If you must try other enexpensive EL34 tubes there is Sovtek, Svetlana and Electro Harmonex.
My tests with all these tubes in Wolcott amps, proved the Tesla E34L over the Russian tubes, and ranking below both the Mullard and Amperex NOS.
Let us know how you do, especially if you experiment. It would be nice for others visiting this site to read results of your trials for this particular amp.