Concerning tube tolling: What I bought so far: 300B: Western Electrics 300B current production. I read that the 300B do not make that much of a difference (in comparison to other tubes). I‘ve also made that experience so far. But still I like the WE 300B more that’s the ones that came with it . Rectifier Tube 5U4G: I was absolutely not sure whether they will make a difference. What I can say now (however, I just tried three different ones) they do. Not tonally, I think, but in terms of the devices overall performance. I don‘t know what brand the 5U4G tube that the amp came with is. What I tried: 1. 5u4G-SV TAD Premium 5U4G-SV TAD PREMIUM SELECTED . They say it makes everything softer. And I agree. Too soft for my taste. 2. Today I received a 5U4GSED (=5Z3S) winged C NOS Svetlana tube with black plate. Produkt - BTB - Elektronik . I like it so far. Not that much of a difference (if at all?) to the one before. Maybe more open a bit. Not sure if the bass is slightly softer. But could be just my fantasy. 3. Ordered: RCA 5U4G RÖHRE 5U4 1949 NIB. RCA 5U4G TUBE 5U4 1949 NIB New in Box | eBay => No idea what to expect. 6SN7: 1. Well, the Sovtek mentioned (didn‘t like it, too bright…) 2. Ken-Rad 6SN7GT (VT231) NIB 6SN7GT (VT231) KEN-RAD NOS / NIB (USA) Much (!) better than the Sovtek. Voices were really not that spectacular with the Sovtek. Voices are back with the Ken-Rad. 3. 6SN7GT JAN CHS VT-231 Sylvania 6SN7GT JAN CHS VT-231 Sylvania I like this one most so far. Great voices. I don‘t see that it lacks bass in comparison to the Ken-Rad (that was what I was expecting). 4. Ordered: RCA JAN CRC 6SN7GT VT-231 Grey Glass Valve Tube Used Tested Strong (V14) #2 RCA JAN CRC 6SN7GT VT-231 Grey Glass Valve Tube Used Tested Strong (V14) #1 | eBay Still waiting for this one. What‘s the difference to the RCA mentioned shortly before? 5. Ordered: 1x 1578=6N8S=6SN7=ECC32 MELZ 1x 1578=6N8S=6SN7=ECC32 MELZ Smooth Anodes Audiophile Triode Tube NOS Tested | eBay Still waiting for the Melz. Some suggest that it‘s the best. However, mine is from the 80s. But then again, read someone‘s comment on the 80s version and he still thinks this one is great. 5687: 1. 5687 WA Raytheon (1959): Those came with the amp. Maybe they are just as good as the Tung-sol? Have to put them back one day. 2. Pair Tung-sol JTL 5687 D Getter black Tube E182CC 7119. Those are the ones that are installed right now. Like it. Not sure if 5687 make a big difference at all?
Thank you Robert! I appreciate it! When I bought it I asked the vendor if I could do some tube rolling. He said yes, just asked me to have the original tubes in the device for one week or so. So I took this as a yes. Didn‘t ask back that specifically (which I did then today ).
Brian from ANK says: “yes no problem on 6sn7 GT“. So no problem. Then it comes down to personal taste.
No, so far not. I have to admit I don‘t know much about all the tube types being used in this amp. I‘ve just done some research during the last 2 weeks which ended in the purchases so far. Which tube(s) would they replace?
The early Kenrads that get the most praise for their bass are the ones with so-called "black glass". I have both types and they are more similar than different. I also like these quite well and only lose out to my favorite tubes by a small margin. Actually my favorite 6SN7 tube is a tie between the Sylvania 6SN7W and the Meltz 6N8S (1578). A very nice tube with a darker presence, quite warm. It's the same tube as the one previously mentioned, the previous one is simply a different iteration and therefore "collectable" by those interested in minutia. It's worth mentioning that tubes marked VT-231 were labeled that way for military use. However they were no different at all than the tubes made for civilian use during the same production era. The value of them being labeled VT-231 is not that they are better than the non-VT-231 tubes by the same manufacturer, but that this guarantees what era they are from: the WWII era where many of the most desirable sounding tubes were made. The Meltz 1578 ties for my favorite 6SN7 type. However 100% of the ones on eBay are fake, including this one. Non-1578 Meltz 6N8S are plentiful and you'll hear reports on their sound ranging from quite good to abysmal. Fake 1578 tubes abound, so be wary, do the research and know what you're buying. These things basically don't exist anymore unless you are very persistent, lucky and are prepared to pay the price. They are also prone to becoming noisy and reports of getting one quiet out of two or three purchased is not uncommon. Or at least it was common until the supply dried up. I feel incredibly lucky to have found a pair two years ago and I'm planning on funding my retirement with them when I sell. Not really, but one has to have a dream... Cheers, Robert
7N7's are essentially 6SN7 with a different wiring of the pins. This means using a base with the tube that corrects for the different pinout. This is something else to explore.
I guess if you like paying a premium for tubes and then pounding the living hell out of them until they fail. Although pin compatible with 6SN7 the 5692 has a much lower plate voltage and dissapation rating than the 6SN7. This is how they achieved their "long life" rating. Running them at 6SN7 spec gives them a candle in the wind lifespan. Cheers, Robert
The 6SN7 tube discussion is getting this 300b tube amp thread wildly off topic. Apologies for participating in thread drift... Here are a couple of good places to learn more: Shootout of Nos 6sn7 tubes The Reference 6SN7 Thread Cheers, Robert
IMO, yes. @WildPhydeaux already gave you the scoop on the suffixes. None of them would damage the amp though. Reports we have from our customers indicate it to sound better than the KenRad, saying that it has all the strengths of the NOS tubes but none of the weaknesses, which is a really high complement. Lifespan is another matter and the jury is out on that one.
Thanks again, Robert! I appreciate it! I asked the seller to cancel my order but it has already been shipped. Okay, we all know the situation in Ukraine so it‘s okay for me if they earn some money, even if the product isn‘t what I expected it to be. Maybe I should have done more research as well. „This 1578 tube is not a "fake", it was really produced at MELZ tube factory, Moscow, at 1980's, and marked as "1578". You see, 1578 tubes exist in two variations: with holed anode (1x 1578=6N8S=6SN7=ECC32 MELZ Holed Anodes Audiophile Triode Tube NOS Tested | eBay , $300 one), and with smooth anode ($150 one), the one you ordered. The characteristic of 1578 tubes are the large metal mounting elements on top mica inside the tube unlike small mica elements at regular 6N8S tubes.“ So one more question on the MELZ: is this the real deal then? 1x 1578=6N8S=6SN7=ECC32 MELZ Holed Anodes Audiophile Triode Tube NOS Tested | eBay
Me too! However, maybe the 300B used doesn’t make that much of a difference in general? At least if compared to other tubes.
To answer your question. In the meantime I also bought this tube for my 300B amp. I must say a very, very good tube! Although I have good NOS tubes (see my post above) and there is another very good one to come, I often went back to this tube. Very nice balance. However: I like it when the tone is rather dark. The RCA gray glass NOS does this very well. That's why I like to have it in my amp right now. But if I want to show what the amp is capable of, I would currently always plug in the Linlai. Worth every penny. This is the first time in my tube-rolling history where I would attribute qualities to a tube from current production that may even surpass good NOS tubes. But I still get the following: TUNG-SOL 6SN7GT Black Glass Oval Mica NOS. Let‘s see how it sounds. For the 300B tubes I will go to the ELROG at some point in the (distant?) future. Although my experience has shown that the 300B tubes have less of a difference than the 6SN7 tubes in the preamp. But that may be different with other amplifiers. But then again, if prices continue to raise as they did in the last couple of months/years, it might be even more beyond reasonable so I might stick with my WE300B tubes or buy them again.
Don’t mean to derail, don’t really want to start a thread on the topic. Since owning my 300b, I’ve had 1 new Gold Lion 300b, 1 nos Sylvania 6v6, 1 Hytron 6sn7 and 1 Marconi 6f6 crap out in the course of 3 months. Is this bad luck? Is it typical to have nos tubes blow like this? I have a bunch of new ones coming and am really thinking of cancelling order. Might go back to solid state. Losing enthusiasm for tubes in general.
That's a good reminder. I have the same 6sn7 installed originally on my new amp. I do remember by nature they sound very flat. I'll put an NOS tonight. There's like 3 of them per channel. I dont know which one is the input
In that case, you may need to have the amp checked like pronto. You may have a problem with biasing and can easily be fixed. It will do the same thing too if your output tubes are not matched within 10% or less per side if you are using 2 or more tubes per channel. I'm using 4-300b total (2 per side) and its going 3 years now and still reads like its new. But you have to monitor it every 3 or 6 months if youre comfortable. If youre using a single output tube, then you just need to see if the tubes are not running too hot. PS. Id save those tubes, for it happen to me on a KT88 amp. there are times it was eating tubes like crazy till I get it dialed right. I was able to revive 4 out of 6 dead tubes and even last me over 2 years after that incident.
Your line voltage may be too high try getting a variac and running your amp off a steady 115v. I was losing lots of tubes that fixed it and lowered the noise floor.
Thanks for the response. The amp builder has been incredibly patient and helpful. I’m new to tube amps and have grown to love the sound. Strange that these things were built to survive wars and last years. Anyway, I spoke to a tube dealer and ordered a bunch of highly recommended tubes. If I blow one more tube, I will send the amp back to be checked. The sound is second to none but this inconvenience is too much. If my current 6v6’s go, I have no replacements and no music. Frustrating
