5AR4 rectifier tube question

The adage that "you are listening to your equipment's power supply" applies. Rectifiers make differences that are easily heard. Which means you have no objective idea which is real. Like lots of other things in hifi, especially tube gear, tube rolling is an exercise in finding the right "fixed-parametric equalizer" for you. It goes beyond EQ because dynamics and dynamic elasticity are also clearly affected.

For all the reverence for NOS Mullard GZ34, 4 or 7 notch according to one's theology on the matter, in many of today's circuits they can make an amp sound "tight-sphincter-ed and unengaging." They are great (and durable) rectifiers but in many circuits can lack musical elasticity. Among new production GZ34, the JJ is the most elastic, but you just have to change them out on a schedule. For daily use stuff, I change them on schedule every 9 months. Some of my amps that were supplied with GZ34 don't use the full capacity of the tube, and I can instead use NOS 5v4 or 5u4 rectifiers. When that works, the vintage 5v4 usually sounds sublime.

One inexpensive modern production rectifier that I love in some of my preamps, power amps and guitar amps is the STR (Special Tube Request) version of the Shuguang 274B that thetubestore.com sells as part of their Preferred Series. In this case, the STR is ultra-hard vacuum, thicker glass and a higher grade plate plating. It's not a true 274B, having the lower filament current draw of a GZ34/5ar4, but a voltage drop about halfway between a true 274B and a true GZ34. It sounds disciplined yet elastic at the same time, with excellent, hard-hitting base and quick, crisp transients and highs. It's proven long-lasting for me. Really nice $35 rectifier. Beats all the Russian rectifiers I've tried in the past, and betters a surprising number of NOS variants.

The real point here is that rectifiers can have a more profound effect on amp sound than rolling the output or input/driver tubes. So it's a good idea to start there, and it tends to be less expensive that beginning with tube-rolling quads of triode, tetrode and pentode power quads.

Phil

"stick with mullard amperex or matsushita old stock 5ar4’s"....bingo

Holland amperex is a great tube...just looked through my globe series 5ar4’s...one bugle boy left.They are all mullard made,All bought on ebay.Never have had problems.Bought from europe as well.

The rectifier tube shouldn’t make any difference in sound. 

@dinov

Agreed. Especially silly is the delusional assumption that they effect sound more than driver tubes that actually have audio signal running through them. They rectify...period, converting AC to DC. The differences may be how consistently at design spec and how long they perform that task.

                                          For the blissfully unaware:

     In SS, linear power supplies: upgrading rectifiers and regulators often makes some of the most audible and dramatic improvement in presentation.     The same applies to tube components (AND: tube rectifiers), BECAUSE (in every gain stage): what the signal does is modulate the power supply's DC, via whatever active gain device the designer has chosen, into a stronger signal, until it ultimately reaches your speakers and ears.

                               iow: You're listening to your power supply!

                                                        again:

     From those that I've spoken to, component designers/manufacturers are well aware, whatever active gain devices* they choose to incorporate in their components: the quality of presentation will be directly proportionate to the quality of the DC *they modulate, as controlled by the signal they're presented.

     Note the number of times, "power supply upgrades" and, "HEXFREDs" are mentioned, in the following upgrades/paths/offers.    Bybee Rails are another power supply upgrade/tweak, btw.

                 http://www.rogueaudio.com/The_Magnum_Series.htm

              https://www.jolida.com/upgrades/upgrading-your-equipment

     Odyssey used to offer HEXFREDs (ultra fast/ soft recovery) as an upgrade, but: now, just as a standard parts.

              https://odysseyaudio.com/candela-vacuum-tube-line-preamplifier/.

                                                and from Cary:

If you have not had it done to your favorite Cary Audio piece, the Hexfred option makes an awesome difference! Hexfreds are high speed low noise rectifiers and replace your existing standard rectifiers in the power supply. You will notice more speed, air, detail, imaging and tighter bass, yet a cleaner clearer sound quality. The Hexfreds help to provide a cleaner, faster DC voltage which shows up very noticeably in the sound quality. There is one more layer of hash and hardness (noise) that is removed so that you can just enjoy the music! Bass is faster with more details and the midrange and highs are cleaner and clearer. You will hear more detail with less bite.