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Line Magnetic 508ia and the Elusive 805 Tube


Greetings, my fellow 'Goners.

I'm the very happy owner of a Line Magnetic 508ia integrated amp, a real powerhouse with a wonderful sound. I have replaced all of the stock tubes except the 805 tubes, as the stock tubes have suited me just fine. However, after a year or so of stellar play, one of them is showing signs of not being able to hold bias, so it may be time to experiment with some other tubes. Fine, but when I began looking around, I discovered that 805 tubes are not exactly plentiful across the land, nor is there much conversation about them. I found some on eBay--the Fullmusic look interesting, but pricey. My usual sources for tubes have none at all in stock.

So my questions are whether anyone out there with an LM 508 has tried rolling the 805 tube, what were your results, and--most importantly--where did you track them down?

I was very pleased with the results of rolling the 300B, 6SN7, and 6SL7 tubes, but the 805 options are relatively limited. Any insights, links, etc., would be most appreciated.


128x128waltersalas
geek101
284 posts
 
@shkong78, wow gorgeous speakers up for sale. 

I am waiting for my delivery of Legacy Aeris, they are active amplified for the bass section.

I am still not sure how LM 508ia will perform with them. I am also considering testing out a beefy class D amp like ATI AT542NC to power the fronts and the center at the same time. Will keep the amp that will do well at the end.
georgehifi's avatar
georgehifi
10,312 posts
 
has tried rolling the 805 tube, what were your results, and--most importantly--where did you track them down?

At the time ebay and retro tube stores/wreckers that specialize in old tube radio transmitters.
The best sounding 805 I had was by far the RCA Black Plate ones over United Electronic, Amprex,Shuguang, GE.

And if you find some NOS with loose top cap or has come away, all is fixable by drilling out the top cap solder to the size of the tube wire, re gluing the top cap back with a very HT two part glue called 24hr Devcon-B then 24hr later re-soldering the wire on the top cap hole.

Cheers George
shkong78's avatar
shkong78
1,485 posts
 
@geek101 
What a beautiful speaker you ordered?

I am pretty sure that LM 508 will work fine with Legacy Aerius which has a active speaker and 95db/w.

LM508 appears to be more powerful than Rogue Cronus Magnum ii which is specified to have 100W.

Enjoy your new speaker.
radiohead99
79 posts
 
I've a pair of NOS United Electronic 805 tubes (made by GE I hear) sitting unused since I sold my Line Magnetic amp. They've less than 100 hours on them.

My impression was bass got fuller and rounder, highs got more extended and there was less noise/hash. The amplifier got quieter and more grounded. This is comparing to the stock tube.
georgehifi's avatar
georgehifi
10,312 posts
 
I found the NOS 805's better than today’s expensive re-makes.
A tube guru told me the reason why is because the materials used in the old tubes were very toxic EG: Nickle ect, which aren’t allowed in today’s made ones

Cheers George
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