8417 tubes

kuys · #1 10-13-2010, 05:06 PM

I have an old Harman Kardon "Commander" PA head with a pair of 8417's in it that are I believe are starting to crap out. I've been trolling around here and consulting the oracle but I can't find a vendor that sells these tubes. Any help?

doctec · #2 10-13-2010, 05:21 PM

Yikes. 8417s have become really scarce and expensive -- if you can find any. I'd suggest getting someone to mod your amp to use 6550/KT88s. IIRC, it just requires changing the bias voltage...

KramerBassFan · #3 10-13-2010, 06:31 PM

8417's haven't been made since the 80's.

IIRC they are bigger than 6550's or KT88's.

You can still buy them on ebay, for about $40 or so for a single one.

8417's could do 100w per pair. So I'm not sure if 6550's are really good drop ins...

okcrum · #4 10-13-2010, 06:38 PM

I've seen NOS 8417s here, but they cost more than new KT88s - better to mod the amp or move it to a collector and get something you can support.

kuys · #5 10-13-2010, 07:41 PM

Quote:

Originally Posted by okcrum

I've seen NOS 8417s here, but they cost more than new KT88s - better to mod the amp or move it to a collector and get something you can support.

That was a thought I had but something about this amps tone with a humbucker guitar and a good marshall cab in my ears is so unique I don't want to get rid of it. I'd rather get it serviced and the tubes replaced.

johnk_10 · #6 10-13-2010, 08:19 PM

then i would buy the best pair of NOS ones that i could right now and pay the price ($200 a pair) for them. they should last at least 1-2000 hours (and probably closer to 4000) rather than mod it for 6550's.

KramerBassFan · #7 10-13-2010, 08:39 PM

Quote:

Originally Posted by johnk_10

then i would buy the best pair of NOS ones that i could right now and pay the price ($200 a pair) for them. they should last at least 1-2000 hours (and probably closer to 4000) rather than mod it for 6550's.

Would you recommend converting an amp that uses 8417's to 6550's? What WOULD be a good conversion? As far as i know, 8417's are quite a bit bigger than 6550's... but you are the one with the real experience, not me.

kuys · #8 10-13-2010, 08:58 PM

Quote:

Originally Posted by johnk_10

then i would buy the best pair of NOS ones that i could right now and pay the price ($200 a pair) for them. they should last at least 1-2000 hours (and probably closer to 4000) rather than mod it for 6550's.

Ok, Sylvania or GE then? Thoughts?

poorbassist15 · #9 10-13-2010, 09:30 PM

KT120s are the answer.

edbass · #10 10-13-2010, 09:50 PM

Quote:

Originally Posted by KramerBassFan

Would you recommend converting an amp that uses 8417's to 6550's? What WOULD be a good conversion? As far as i know, 8417's are quite a bit bigger than 6550's... but you are the one with the real experience, not me.

According to the Sylvania spec sheet they are almost identical size wise, and are rated to output about the same 70 watts in push pull.

KramerBassFan · #11 10-13-2010, 09:53 PM

Quote:

Originally Posted by edbass

According to the Sylvania spec sheet they are almost identical size wise, and are rated to output about the same 70 watts in push pull.

Really? I never knew that. Thanks!

okcrum · #12 10-14-2010, 08:38 AM

Quote:

Originally Posted by kuys

Ok, Sylvania or GE then? Thoughts?

I used to use a Bogen MO-100A as a bass power amp with a homebrew preamp. It had 4 8417s and sounded great. I understand your reluctance to convert or change amps.

Both the GE and Sylvania tubes had no problems in it. Whatever the modern lore says, I remember that Sylvania made ~~almost~~ all the Phillips and GE tubes as well as their own, so I'd personally call it a wash.

Edit: checked, not almost, all

johnk_10 · #13 10-14-2010, 08:55 AM

generally, i prefer sylvania's over GE's, but as stated, sometimes the tubes are the same and just re-branded.

GlennW · #14 10-14-2010, 09:29 AM

Bogen made a few PA amps that used 8417s. You might find something decent in one of those.

kuys · #15 10-14-2010, 01:57 PM

Quote:

Originally Posted by okcrum

I used to use a Bogen MO-100A as a bass power amp with a homebrew preamp. It had 4 8417s and sounded great. I understand your reluctance to convert or change amps.

Both the GE and Sylvania tubes had no problems in it. Whatever the modern lore says, I remember that Sylvania made ~~almost~~ all the Phillips and GE tubes as well as their own, so I'd personally call it a wash.

Edit: checked, not almost, all

Thanks, Sylvania it is then.