Purchase Guide

Which 845 tubes to get: The popular upgrade path for Line Magnetic LM-518IA tube amp

Line Magnetic LM-518IA integrated 845 tube amp is the first Chi-Fi amp that was very favorably reviewed by Stereophile back in 2015 and got onto Stereophile’s annual award list later on. It can be considered an achievement milestone for the entire Chi-Fi industry, IMHO.

Before this amp become popular, most 845 amps on the market are monoblocks, which inevitably cost more to produce, more to ship and deliver, which result in less people can afford them. A well made integrated 845 tube amp has brought the retail price mark to below $5000 range. I personally think this is a major contributing factor that has brought Single Ended Triode (SET) 845 amps to the horizon of average consumers.

Of course for every budding audiophile or seasoned music lover, tube rolling is like an addiction – why not try other tubes when there are multiple offerings of 845 tubes from China too?!

We have combed through our past year’s tube order history and come to the statistics of the popular tube upgrade path for this Line Magnetic LM-518IA (now it is called LM-608IA in China, and the western version is LM-845IA):

Most popular (67%): Linlai™ Global Elite Metal Plate E-845

I am not sure if this is to do with FOMO (fear of missing out). 2/3 of our tube upgrade customers went straight to the best of best, also the most expensive 845 tube models we carry, and never looked back! From a vendor’s perspective, the ‘Linlai™ Global E-845 metal plate’ also has zero warranty rate in the entire past 12 months! We will rate its reliability as full 5 star.

Second popular (22%): Linlai™ Global Graphite Plate 845-DG

This tube is a nice upgrade from the commonly used stock 845B tubes from China in almost all new production 845 tube amps. The stock entry level Chinese 845/845B tubes tend to sound dry and harsh without much magic. The 845-DG upgrade tubes offer excellent ‘performance to price’ ratio, aka ‘bang for the buck’, with a unique overhang filament design, coupled with solid graphite plate.

Why is 845-DG not as popular as the more expensive metal plate E-845?

Besides the previously mentioned FOMO mindset, its reliability record is good but not as stellar as the E-845’s zero warranty record, we think the ‘dollar cost per listening day’ for 845-DG really isn’t much lower than E-845 – probably much less than a cup of java. Why not just ‘straight to the point’ could be some customers reason to opt for the E-845 instead.

We have been closely watching the warranty rate trend of 845-DG, and highly suspect some cases are related to users’ amps were not providing the right level of ‘load’ to these graphite plate high power tubes. Please note that ‘underload’ a graphite plate tube over a extended period of time can create excessive gas in the tube, eventually trigger an internal short tube failure. Users are strongly recommended to regularly check the amp bias and keep it in optimal range, besides keeping the amp’s power supply voltage stable with a proper power conditioning device.

Third popular (11%): Linlai™ Global WE845 Replica tubes

Why the ‘Western Electric’ replica version of 845 tubes are not as popular? We think the reason might be western customers do not have the same fetish to ‘Western Electric’ as the eastern customers in Asia do. Western Electric never made a 845 tube – the closest is a 284A, so ‘Western Electric Replica’ doesn’t hold 100% truth as per Chinese tube manufacturers claim. All three tube manufacturers make WE replica 845: namely Shuguang, Psvane and Linlai. The WE Replica tubes are always priced with premium towards the glory of ‘Western Electric’ – so your money goes not just to the tubes, but also to the marketing.

Having said that, WE845 replica is still an excellent tube. Its slim bottom allows it goes into some high end 845 amps such as Nagra brand, while all the other ‘fat bottle’ 845 such as E-845 and 845-DG cannot fit in.

We hope this objective statistical information can help you to narrow down your 845 tube choice for the Line Magnetic 845 tube amp!

We unfortunately cannot give sonic description of each tube with this amp (or any amp) – a system’s final sound will be very much influenced by the speakers used, and the system synergy, and the subjective opinion of the listeners. We suggest you search on audio forums or facebook user groups to find a system similar to yours and read such users’ sonic description, and see if it is to your liking.

Happy Listening.

Rachel@ Grant Fidelity