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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
shkong78's avatar
shkong78
1,485 posts
 
@ geek101

My speaker Lansche 4.1 is specified to be 99db but I suspect it to be around 93db, still pretty high.

I played 1812 overture at full volume in my spacious listening space(1,500 sqf) with vault without any problem.

I also have Rogue Cronus Magnum II with KT 120 tube which company specified at 100W.

But it seems that LM 508 can play louder and deeper than Rogue Cronus Magnum II .

Rogue Cronus Magnum II is a pretty good amplifier but LM 508 is in another league above competing with those priced at 10-20k.



geek101
284 posts
 
@shkong78 wow never hard of Lansche 4.1. They look really exciting. Glad to know you are enjoying LM 508ia at good levels. Wish I could :).

Your speaker must have an active subwoofer section?.  No?.
shkong78's avatar
shkong78
1,485 posts
 
Yes it has  active amplifiers to drive two 10 inch woofers to go down 20hz.

http://stereotimes.com/speak112410.shtml

It is a heavenly match with LM 508.

The most nice thing is pristine treble out of plasma tweeter.

Eva Cassidy’s voice is heavenly with Lansche,

I miss that she had gone to heaven too early.

It’s little brother is on the sale at Audiogon.

https://www.audiogon.com/listings/lis953i3-lansche-audio-no-3-floorstanding-speaker-like-new-full-ra...


Thomas
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
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