The Line Magnetic 508IA, now replaced by the 805IA, is undoubtedly one of the best integrated amplifiers I have ever had the pleasure of owning. Having previously owned two amplifiers that retail for around $5000 more than the Line Magnetic (Pass INT250 and Audio Research GSI75), I can confidently say that it stands out as a true winner in the value for money rankings. In my year of ownership of the 805IA, I spent an average of 4 to 5 hours per day listening, and I can honestly say that it did not leave me wanting for more control of my passive ATC SCM40 V2’s.
Tube Rolling
When it comes to tube rolling, I spent slightly less than $4000 on a wide array of new and NOS tubes, and I would suggest that you will need to have a budget of at least $2000 to better the stock tube set that comes with the amplifier. The mix of rebranded PSVANE and Shuguang tubes are so well considered that some tube rollers have resorted to simply buying an extra set from Line Magnetic’s US Repair Center. In my experience, changing the large power tubes has the single greatest impact on sound. While the PSVANE 805A or Shuguang 805AT power tubes will get you closer to the stock 805’s than most, the new Cossor black bottle 805 (by PSVANE) is as good, and possibly even slightly better. If you are looking to maintain the visceral grunt of the LM508IA or 805IA, this is a great option. The stock 300b is serviceable and not likely to be bettered by anything in the middle of the exhaustive 300b selection available. However, one exceptional tube that I found to be brilliant in the high end and upper midrange was the TJ Fullmusic 805 CNE. It was completely out of sorts at the low end, which makes it a great tube for this amplifier when paired with the Shuguang 300b-z black bottle tube—these are both now very difficult tubes to find. While there are 300b tubes out there that can tweak the sound of the amplifier, I would argue that unless you’re planning on having $2000 in 805’s around to partner with various 300b’s, you may not find a better match than the stock tube set or similar-sounding tubes.
As for the signal tubes, which have a more subtle impact on the soundstage and openness of the sound, I experimented with NOS tubes that were hit or miss. I found that the Shuguang 6SL7-Z and CV-181-Z (6SN7 equivalent) retained some of the improvements I heard in the better NOS tubes without all of the matching, microphony, and vacuum loss worries presented by NOS tubes. While you can certainly better these Shuguang signal tubes, doing so will likely turn you into a tube collector, and you may not have as much time or money left over for listening to music.
Conclusion
In my opinion, the Line Magnetic 805IA or a used 508IA are excellent integrated amplifiers for anyone looking to spend less than $7000 who can live with less than 200 watts. If possible, I would recommend finding an opportunity to hear this amplifier before buying any other. Ideally, take one home for review, but be sure to have help lifting it into place. There is a magic in the sound of SET amplifiers that has never been an economical option for those who use less efficient or larger speakers. What this amplifier does with 48 watts is truly unbelievable. The amplifier also allows you to add a preamplifier, which I did with a Backert Labs Rhumba 1.2 for some time. The combination sounded almost exactly like the ATC P2 300-watt amplifier I tried with my ATC speakers.
One of the things that impressed me about the Line Magnetic 805IA is the build quality. The amplifier is heavy, weighing in at over 80 pounds, which is a testament to the quality of the materials used. The transformers are massive, and the chassis is very rigid. As will all tube amplifiers, the 508IA and 805IA can benefit from isolation accessories. I settled on the HRS Nimbus couplers and was happy with the resultant soundstage focus. I used both amplifiers on credenzas and not a purpose built equipment rack so you may find less impact or need for specialized isolation if you are using a properly designed rack.
Overall, I highly recommend the Line Magnetic 805IA to anyone looking for a high-quality integrated amplifier. I owned the 508IA for two years as well and that iteration of the amplifier was more visceral and gritty. The 805IA has a more polished sound that compares more favorably to more expensive lines. If you intend to buy the older 508IA, I’d be prepared to have a technician check the capacitors and connections if you don’t have the skills to do so yourself. I once shipped a 508IA out for a capacitor upgrade and power socket fix and it came back sounding a lot like the 805IA.