Quad of 6F6G vacuum tubes plug in sub for 6V6G RCAs, and WIzard by RCA
$ 15.84
Description
For sale is this lot of four 6F6G vacuum tubes tested on our calibrated Jackson 648A tester- The two RCAs test strong at 88% of NOS new. On this tester, 70 is considered good, 100% considered new, and even tubes in the 40s usually sound ok. the Wizards made by RCA (they have the same "Licensed only to extent on carton" engraved below base=RCA) test 71 and 100%. 6F6G can be plugged in 6V6 6V6G 6V6GT amps, no bias change necessary, they are plug in substitute. Per pair, 6V6G are designed for 14W max output and 350 max plate volts. Per pair 6F6G output 13W at 350 plate volts, but are also made to run up to 375 plate volts with output 18.5watts. You probably will notice very little sound difference with these 6F6G plugged in instead of 6V6G, but you can see a NOS quad of RCA 6V6G often sells for over $200. 88 88 100 and 71%, do they have to be matched in my amp? Power wise no, push pull amps output max power with each output tube on about 55% of the time, if they are on 70% of time they waste output power, most output tubes are on about 65% of time, with the 71 100 pair, they'd probably be on 55 and 65% of time, probably no significant difference in output power, maybe slightly crunchy beyond the last watt of output power (like outputting 14-15 watts on a 15 watt amp). Hum wise, equal plate currents cancel hum IF the power supply is under filtered. In 1930s, a Gibson amp only had 10 and 10uF power supply caps, under filtered by todays standards, these always had so hum in the 1930s, and a 71 / 100 unbalanced pair might add slightly more hum (the hum buck switch on a guitar might totaly cancel that out). In modern amps like a guitar amp, or hi-fi Fisher, Harmon Kardon etc. The power supply has over 100 uF of power supply caps, in a Fisher at zero volume, you can remove 1 power tube (a 100% mismatch) and not hear any hum difference. price is $29.99 for this 6F6G quad, enjoy just plug them in your 6V6 6V6GT or 6V6G's amp, and even many 7408 6V6GTA amps.
