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  3. 136420-3158

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
waltersalas's avatar
waltersalas OP
952 posts
 
@miesdavis 

Thanks for your feedback.

I considered the Fullmusic CNE tubes, but the lowest price I could find was $700-800 per pair on eBay. What do you think of them? I will research the Cossor tubes, as I have never heard of them. Would love your feedback on those as well.

As it turns out, the stock 805 tubes are only $90 each straight from the vendor for Line Magnetic stock tubes. That is half the price quoted by the dealer. For anyone out there who owns a 508ia, there is an excellent thread on the Steve Hoffman website with lots of information on tube rolling in this amp. Very informative and helpful. One guy tried several different 805 tubes and eventually went back to the stock. He has Elrog 300Bs, which I believe go for a cool $1500 per pair. I am sure they're excellent, but my EMLs will have to do for now.



facten
2,891 posts
 
@waltersalas

Can you provide the link or contact info for the vendor of Line Magnetic stock tubes?

waltersalas's avatar
waltersalas OP
952 posts
 

@facten 

Sure thing. Contact Glen at Arizona Hi-Fi at this link.

http://tubeaudio.com

slaw3
139 posts
 
Hi waltersalas - can you specify which tubes you rolled and results?
Have had my 508 for about a month and ready to start rolling.
Which tube set should I start with that had the most impact to the sound?Thx!
waltersalas's avatar
waltersalas OP
952 posts
 

@slaw3 

After doing a lot of reading on the excellent and very informative discussion on the Steve Hoffman website regarding tube rolling in the LM 508, I tried the EML XLS 300B tubes, which are excellent and definitely a step up from the stock tube. I replaced the 6SN7 tubes with some 1940s vintage Sylvanias from Brent Jesse, which were also terrific. 

I have tried a two or three 6SL7 tubes, settling for now on a Mullard ECC35--it is a bit on the pricey side, but sounds great. I think the finesse of this tube is a nice complement to the robust dynamics of the EML 300Bs.

So far, I have stuck with the stock 805 tubes. I may roll in some others at some point, though what I would really like to try would be some Elrog 300Bs. These are REALLY pricey, so it may be a while before I can experiment with these.

I am not sure I can say which change would result in the biggest difference, but I would certainly suggest trying some different 300Bs. Before you do anything, spend some time reading the Steve Hoffman thread. There are several 508 owners there who have done a lot more tube rolling than I have in their amps. You might benefit from their experiences, as I did.

The 508 is a good amp even with the stock tubes, but you can definitely take it higher by finding a combination of tubes that suits your particular tastes.

Happy listening!

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