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.

Tubedepot lists that it has NOS 805s though they don't specify which brands  - might give them a call

The dealer that sold me mine says that the stock tubes are so pricey that he usually recommends other options, including Psvanes. I may try a pair of those, or Fullmusic. Hoping for feedback from those with experience or links to sources for this tube other than eBay, though if someone has had a good experience buying from certain vendors on eBay, that is also welcome.
I have the Fullmusic CNE tubes and the newish Cossor 805’s. Lots of folks recommend the Psvane 805AT but I didn’t like that tube. If I have to buy one tube to really compare to the stock 805 it would be the Cossor. 

Also so check out the LM owners group on Facebook. 

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.


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

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!


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!

Hello Waltersalas 
Im from Argentina and I bought my 508 from china directly from an authorized dealer because there's no Line Magnetic dealer here and the price difference was huge. › ... Its a very profesional dealer and you can trust him. I bought a lot of items from him with out problem. 
One of the things I bought were the Psvane 805A-TII tubes and they were a noticeable upgrade from the stock tubes: especially with more detail and stronger and fuller bass. 
Those Psvane are not too expensive (about USD 150 plus shippment). 
The only thing is that on my second pair, one I bought as a back up, I got one broken. I only had to send it back for a replacement and it cost me about USD 30 for the return shippment. 
I hope it helps. 
Kind regards 

PS: I have not tried Mullards, but for 6SN7 and 6SL7 tubes in the 508, I like Tungsol the best, by far. I have tried Sylvania, RCA, GE, Ken Rad, Westinghouse, National and Shuguang Treasure and WE Replica. 

@plga Thanks for responding, Pedro. I appreciate your thoughtful input on my thread.

I hope you enjoy your 508 for a long time to come!
You are welcome Waltersalas. 
I hope one day I can hear your LM-508 with your Tektons DI. I bet they sound GREAT! 
With my Q Acoustics Concept 500 the LM508 sounds BEAUTIFUL!
Specially with upgraded tubes, Power Cord (DH Labs) and Fuse (Hifi Tuning Supreme). 
Kind regards 

Are there any measurements published for this amp when it is driven to peak i.e close to 48 Watts?. 

Anyone here have noticed problems when driven with speakers that are 92 dB efficient?.
@ 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.

@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?.
Yes it has  active amplifiers to drive two 10 inch woofers to go down 20hz.

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.

@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.
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
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.
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.
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
It is nice to hear from you about  NOS United Electronic 805 tubes.

I believe your opinion.

The only catch is how to connect from the top to other connector behind tube.

I read the instruction from the thread in Steve Hoffman Forum.

But I am not comfortable with the connection.

I also ordered new version called  COSSOR VALAVE 805 made by PSVANE.

It is supposed to come on next Tuesday.

Let me see what happen.


I heard similar opinion from my Guru.

They did not spare the cost of material earlier but now they try to save the material cost.

My Guru has a NOS stock tubes worth more than 10 million USD.

Next time I see him, I will ask whether he has some NOS 805 tubes.

By the ways my Guru is not in USA.
@shkong78 Legacy Aeris is what I got myself.

Heard a lot of speakers in RMAF 2018 recently and this is what I thought is best sound and value to me. Got the Wavelet too a must in my opinion.
@shkong78 I'd love to hear your impressions of the Cossor, please do update us when you have it up and running.
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I'm also interested in your impressions of the Cossor. I've been pretty active in teh Steve Hoffman thread - I'm also interested in better options to the Psvane 805ATs.
By the way, are any of you 508 owners using separate preamps? If so, what are you using?
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PSVane is coming out with their ACME 805 tubes. I think it may be too early yet but priced at $900, it may be worth a try? How are reliability on PSVane's? 
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One of Psavne Acme 805 tube went bad  with bias reaching only 50mA instead of 120mA after use of just 7days.
I had tried to reach seller five times asking for replacement tube for  6 days.
But he did not respond to my message at all.
I had ordered tubes three times from him..
Previously, he used to respond to my inquiry within 2 days.

Now I do not have any faith in reliability of Psavne Acme tube which is pretty expensive.

I recommend you not to order any item from this terrible dealer.
For Psvane tubes, I highly recommend North American dealer Grant Fidelity. Stellar service and very strict quality control over every tube they sell.

@lalitk agreed. That is where I purchased my 805 PSvane ACME tube from. Very quick cross-border shipping too. 
I received a replacement Acme 805 tube from the dealer on free shipping on 21st, January.

It sounds fine after playing for 3 hours.

I will go into detail of the sound of tube after one more day of listening.

I can recommend this dealer to the forum member after free replacement of defective tube.

PSVANE Acme Serie 805 Vacuum Tube High-end tube Be

I had listened to replaced Acme 805 with Line Magnetic 508 for 24 hours.

It is one of the best new tube with transparency,excellent soundstage and nice details.

I have Synergistic Blue fuse, Shuguang Treasure 300B and CV181z(6SN7 equi) and Mullard ECC35 in Line Magnetic 508.

Although the price is a little bit on the high side, with two year of warranty on Acme series,   one may consider using it.

Just a quick note to say thanks for all of the valuable input from OP and everyone else.  I’ve had my 508 for about a year and love it.  I now find myself with some time and will investigate replacing some of the tubes, and now know where to go to replace the 805s when necessary.  
Any more impressions from folks regarding their favorite NOS 805 tube. I currently have RCAs but was looking to try a different brand. What are your top two NOS 805s?

I've been thinking about trying the Psvane ACME Supremes 805s.  Have you any experience with them?

are the products China HiFi sales legitimate Line Magnetic?  i was told by the distributor in in Thailand that they are not?  but maybe he just wanted me to buy the 805IA which is 2x the price of the 508IA as listed on the China Hifi site?

China Hifi is Black Market stuff no one knows where the stock really comes from.