Hello All,
How much of an impact would the 5AR4 and 6SN7 tubes have on the quietness and overall sound of a MC pre amp? For a big sound and one that would present voices and orchestras in the best way which brand of the newer tubes would you use and why? Thanks up front for all comments.
jazzbo
Jazzbo: I haven't really fooled around with the 6SN7, but there a couple threads here where we were discussing the effect of changing the rectifier tube, including a 5AR4, and it makes a difference even though that tube is in the power supply of the gear I've been fooling with- a phono stage - and not directly in the audio path. But since amplification stages rely on their ability to deliver power- sort of like "you are listening to your power supply" it can make a real difference. I can point you to the links where the discussions are, they relate to an Allnic phono stage, but what works in that design may not be generally applicable to other circuits. One of the things that Myles raised in those threads was the amount of voltage drop or 'tube sag' that varied among these different rectifier tubes- the point where the tube can't deliver more current and gets stymied. It's something that the guitar amp guys are very focused on, for a 'crunch' where the amp starts to sound distorted because it can't deliver more power. That's why some guitarists like tube rectification in their amps- for a particular sound. As Tim pointed out in another thread, that's not good for hi-fi though.
Also note that some tubes that can be treated as "equivalents" are not well suited for certain circuits.
And there are some interesting stats on the various rectifiers that you can find on the web regarding voltage and application, including original data sheets for each tube. I think you need to know a little more about the circuit as well, but that's beyond my pay grade.
I can tell you though, that I presently have a number of different rectifier tubes around for my phono stage, and as others can tell you as well, each one sounds different.
PS: I did a little poking around, non-technical stuff, re the 6SN7 and found a page where various older tubes were compared, sonically, based on various listener comments, from what i can tell. I know you want new tubes, not old ones, but I think it's a worthwhile read anyway. Here's the link:
http://www.dehavillandhifi.com/6sn7_vt.htm
