Yes, the 6BG6 is an interesting tube, although not a greatly attractive sub for a 6L6. You can often buy 6L6 tubes for very little more than $6 each if you are frugal, and then you don't have to modify your equipment.
There are so many other alternatives. 5881, 7581, 8417 etc. etc. There are also plenty of manufacturers still making new 6L6es. Slovakia, Russia and China have all been churning out masses of them. The pricing is largely shaped by the perception of the market that there is something special about a 6L6. As to the 6BG6, well... You can buy them for $2 each here: http://www.k3dn.org/sale.htm Here's a new one on in box, eBay for (Buy It Now) $3.00 = Item #5863073238 6BG6 asking prices seem to be all over the map going as high as $11.95 each. They are $4.50 each from here: http://www.amradios.com/tubes.html >From $2 to $6 here: http://www.testequipmentcanada.com/tube6.html http://www.earlytelevision.org/dobush_tubes_6.html These are $6.85 - http://tubes2u.com/6ab4-6ew6.htm Four USSR ones for $8 here: http://www.choronzon.com/tetrode.html The eBay asking prices seem to average around $6 for a new one (e.g. 2215944857) so that $6.00 asking price seems reasonable after all. I am just used to seeing them begging to be bought at hamfests and they generally get taken home or they wait in line BEHIND the 807s and 1625s which sell for around $1.00 each! On the other hand this guy has NEW 6L6GC tubes for under $4.00 each! No need to modify your equipment after all! http://www.gstube.com/tubes/?submit=alltubes He has new 807s for $7 New 5881 tubes for $6 No price listed for his 6BG6 tubes but I bet they are low too!
