8417 tubes

[Enzo]

I don't know whether to put this here or down in the flea market. In another forum the guy is selling some 8417.

For Sale - Five 8417 - diyAudio

Cool tubes, 100 watts from a pair. The old SG amps were based on them. I have a bunch to sell later on.

[Chuck H]

Very cool tubes. They've always intrigued me because the specs read like an enormous 7591 (which is sort of a big 7189). That is, makes a lot of power for it's size, doesn't require a lot of grid drive and doesn't require high bias voltages. I've wondered how these tubes didn't come into favor during the watt wars from the major manufacturers. Should make tre' bitchin' guitar amp tubes, provided one can find an OT that can take advantage of them?!? Who's up for a Champ with the same output as a Deluxe Reverb?!?

Looks like you can still get a pair on *bay too. Mostly good pulls. So any design that uses them will end up a little spendy to retube after a few more years, but still likely possible.

[g1]

I've wondered how these tubes didn't come into favor during the watt wars from the major manufacturers.

Because Bogen used them?

[52 Bill]

And Gibson.

I think that they came along too late for them to catch on. They were more expensive and harder to source and after a few years the "tubes are dead" designers started to control the market, making new designs with them a tough sell.

[Chuck H]

Yep. I looked up some history about them. The site I looked at said they came along about 1963. So that's pretty late in the game. Too bad too. Great size for a working guitar amp and probably nice, crunchy overdrive. The NOS market is full of tubes (other than what we typically use) that perform between the big bottles (12 to 20 watts) and the little bottles and max plate voltages of about 250V. I suppose this great tube is a little hard to come by because of it's short history and popular use in home audio. A bunch of crap was made that uses the 8417 for the few years that it was in production and then folks that had that crap must have bought up any leftovers when re tubing.

[Leo_Gnardo]

Because Bogen used them?

Bogen used 'em all right. I have a beastly Bogen MO200A that used 8x 8417 & deliver 200W. It appears to be two 100W amps joined at the input, output and feedback loop. I separated the amps to 2x 100W and used to drive horns in my PA way long time ago.

Sano amps for accordion - had a couple in with 8417 pairs self-biased. They rattled like maracas & left with 6L6GC's in their place.

Guild Thunderbass, similar solutions to Sano.

[nickb]

My understanding is that the high gm is due to a close cathode to grid spacing. This made them hard to manufacture and unreliable.

[Enzo]

I mainly ran into them servicing the old SG amps, and I have to say in all the years I have never seen a bad one in there. They seem to last forever.

[tbonuss]

Holy crap. I just got an SG-610 in with RCA 8417s in it. Wow. Just wow. These things do whatever magic pixy dance el34's do all the way up the drive-train-- albeit at like a bazillion times the volume. I have a feeling I'm gonna' be like Brad Garrett running off with Jerry's Saab when I get the effects fixed.