I was just composing a post that asked a similar question to George...
I've been going through the thread a bit, but checking all 49 pages is a daunting task. So forgive me if this has been covered: Has anyone tried the EML 274A/B tube? How about the Svet 5U3C? I've tried a few NOS Mullard 5AR4's and found it just softens everything out a bit too much for my taste (with RCA 6CG7 cleartops). TungSol 5u4g big bottle (mid 50's I think) is currently in, but I think I preferred the RCA 5u4G. I'm going to leave it in there for a while and go back. There are so many affordable (read: available) rectifiers out there - it's interesting that everyone is so drawn to the most expensive (read: exclusive, scarce) variants. Has anyone done any blind testing (with the help of a friend) to see if their preference held up? I do know how significant a difference an input tube or a driver tube can make, but my own experiences with rectifiers (mostly in amplifiers) does not seem to reflect the , "....my god, it's like having a brand new component..." epiphany that I'm reminded of when reading folks experiences with the EML tube. I'm open to the possibility of change, certainly, and I know they certainly can and do make a difference. But for the price of a single EML you can get perhaps 8 tungsol variants or other, more readily available NOS...is it really THAT much better than all of them?
Marco, I see a number of variables in the tube selection process - personal taste, other equipment (synergy) and room etc. When we started the early tube rolling activities the preferences on rectifier tubes seemed to shift into two broad camps: 5U4G and GZ34, with the individual preferences being the Tung Sol 5U4G and the metal base GZ34. Prices for both then started to increase and most of the available tubes at a 'reasonable' price were used, for example a used metal base GZ34 was around $200 compared with a NOS at over $600. Along comes the EML 5U4G, which most of us find combines all the strengths of the 5U4G and GZ34, and also adds a dose of something else in addition. Furthermore a significant buying risk is eliminated as the performance is consistent, it's available from a reputable source, the price is fixed and it has a guarantee. In contrast I have a boxful of used vintage tubes, some that have failed and some that are going strong. Given the view that it's considered a strong performer and a 'safe' purchase it's very easy to see its attraction and why the majority of the owners do consider it THAT much better, you get the best rectifier tube with minimal risk. As most of us have started with the 5U4G/GZ34, and then moved on to the EML, it is difficult to take a backwards step. I consider these factors explain why the the EML tube is so popular.
As I currently cannot use the EML I've had to go back to using my other rectifier tubes, for the last few days I've been using an old Emerson 5U4G with the Tung Sol 6SN7 round plates - the combination works very well and makes great music. For those that cannot use the EML, or choose not to go down the EML path, I agree with George in that you can have a great sounding system based on these signal tubes. But again the downside with these tubes is that the buying risk is increased and you have to screw around with adapters, this increases the cost and each adapter currently available isn't perfect. This is one of the reasons I explored the Shuguang 6SN7 last week, if it worked out it would have given us the option of having a readily available, low risk, new tube without the risk and scarcity issues. Some of us are prepared to take greater risk and experiment, others just want to lower the risk and listen to music. I understand all this, unfortunately I fall in the high risk experimenters camp, with the wrong caps
NB
I believe the EML 274A/B is the same tube in terms of spec as the EML 5U4G, but has a different pin layout - not 100% sure on this.