VT-99 is the military version of 6F8G tubes. I have a pair of RCA 6F8G and a pair of Sylvanias VT-99 and the look identical in and out and both sound the same to me. RCA are not the smoked glass version, but the black and chrome glass ones. Both are a replacement for 6SN7 tubes with the adapter. Many people claim to prefer these tubes over 6SN7 ones in general. There are still some options at a very reasonable price, like Raytheon clear glass (wich I haven't tried), but some are crazy expensive like Tungsols black glass wich I find very very similar to the Sylvanias VT-99 on the outside by pictures.
Stock tubes are branded "Line Magnetic". I am not sure who makes them. I also have Shuguang branded tubes. I didn't find much of a difference between them.
I'm not sure if this has been discussed but has anyone tried the Linlai Elite Moly Metal Plate 805 tubes? Linlai™ Global Elite E-805 Vacuum Tubes (pair) – LINLAI™ Global Vacuum Tubes
LM Enthusiasts, Did a back to back with 2 bridged Decware se84c’s. So 4-6 watts/channel? My initial impressions. With Cayin ha1a as a preamp (which helps). The Decwares are broken in. Vs 508ia...not broken in well enough. Decware is cleaner, more transparent. 508ia is more energetic, dynamic. My speakers are Tekton Lore BE w/upgraded caps. 25x15x9 room. Tekton lists lores at 98db. I think it’s actually lower than that. Anyway Either 508is have a more energetic presentation , in my room, or the lores didn’t get very loud with the Decwares. I don’t know if that’s a function of gain on the preamp or something longer.
@Jay805 you need to do a volume match in order to do apples to apples comparison. If volume is not matched than one amp can sound more dynamic than the other. However, it looks like the 508 might be too much power for a 98db speaker.
Devg, I did a ghetto volume match with a phone app (average volume was about 60 dba). I will do a more scientific comparison once I upgrade my 300B’s and get everything burned in. Why do you say it could be too much power? I think the 508ia has about 40 real watts/channel. My speakers can handle 200 watts. Thanks
Pedro, The amp was immediately clearer/cleaner. I am going to get more serious about a listening comparison with different tubes after some more break in. Thanks
LM Enthusiasts, Can someone recommend a super tubey sounding preamp, that has enough gain for the LM preamp input, that doesn’t cost a lot of money? Thanks
You don't need a ton of gain for the LM using the pre-in. I'm using a VAC preamp with 10dB gain and never go above 10 or 11 o'clock on the volume (90+dB). What's your budget? If you're looking for really lush tubey sound you could try a used Cary SLP-98 . To me they sound too lush and you start losing detail 3D space. Perhaps look for a used EAR preamp?
508ia can handle speakers with low 90th sensitivity. For your Tektons you will be better served by 518ia model from LM.
Thanks for the suggestions. I will read up on them. I need to chill out and wait until I get quality tubes and break in everything before I get serious about a preamp budget.
The other thing to consider is whether you will even recognize benefits from running a separate preamp via Pre-In compared to running as integrated. I already had a VAC preamp and it does improve the sound a bit on detail, soundstage, depth, and overall weight....however, it's a $10K preamp retail. After A/B-ing between the two (pre-in vs integrated) I would not go out and purchase a preamp if you're seeking best bang for your buck. The LM more than competent on it's own.
I have realized that there is not much to be gained with a separate pre-amp in front of the LM. You are only bypassing the volume pot at the end of the day and adding another gain stage which then gets attenuated back down. Add 10db gain and then remove 10db. What’s the point?? Do you really need more than 7 tubes to tune the sound you are looking for?
The point is to have tone controls, balance adjustment etc. all of which can be delivered by standalone pre-amplifier.
[QUOTE = "tIANcI, post: 26881513, członek: 112666"] Miałem SLP-05, jest taki dobry. Środek byłby świetny. Kup odpowiednie rurki i ciesz się. [/ QUOTE] I have a modified Cary Audio SLP-03, but when I connect it to the 508, I have too much noise in the speakers. I think it's getting a ground loop.
You're likely correct. Try lifting the ground on the preamp with a HumX. I had the same issue in my system and that eliminated the noise.
It kind of is an odd design choice. I am a new 218ia owner (the 845 version) and while I am in love with absolutely everything about it, the ONE thing I wish it had was a "pre in" and that the pre-in was a straight line to the power amps. I am curious if my tech could install a true pre-in into my 218ia. I would do that mod if it could be done. -Chris
As some have alluded to before (maybe the very knowledgeable @jmpsmash and @AP1 ?), at least with the 508/805 I don't think you can go directly to the "power amp" section = 300B's because they need the prior gain stage of the 6SN7's to get them to where they need to be to run as drivers for the 805's and generate the huge 48W for a SET design. i.e. the 508/805 is not really a class pre-amp + power-amp design in one chassis - it has to be seen as a singular (integrated) amplifier design ...