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If I still owned anything that required the 5AR4/GZ34 rectifier and hadn’t changed them already, I’d be investing in either a Mullard(Blackburn) GZ34 or Philips 5R4GYS(if it fits). For over four decades, every piece of gear that I’ve owned(plus a plethora of my customer’s and friend’s pieces) have had their(generally inexpensive) rectifiers replaced with faster and softer recovery diodes/bridges(when SS), or NOS Mullards(when valved), as the first upgrade performed. Without exception, there’s been less background noise/hash and a greater sense of ease, realism,(what I call), "organics", and(sometimes) more dynamics. You’re listening to your power supply, and the better each of it’s components, the better the overall presentation. I’d probably have the Amperex tested, and if strong, leave it alone. They made some of the very best rectifiers out there. (https://www.upscaleaudio.com/collections/vacuum-tubes/products/philips-5r4gys-made-in-holland) (http://tctubes.com/5AR4-GZ34-tubes.aspx) Given the usual lifespan of Mullard’s rectifiers, one may outlive you and whatever it’s powering.
Rectifier tubes absolutely change the sound of your gear as much as small signal tubes and power tubes, IME. I have rolled 5AR4 types in my Lampizator Golden Gate, and it can have a big influence. Whether you will like the change a given tube is always the question....but it is another lever to pull in dialing in a system.
As rodman99999 replied, the Philips 5R4GYS is a wonderful sounding tube and I do have a pair that I switch out on occasion[in my pre] with the Brimar military CV717/5R4GY. The Brimars sound more open and organic than the Phillips but not as detailed in the highs, with a huge sound-space and crazy good dynamics. They can be hard to find and a bit pricey... but worth the price in my opinion.
The tube rectifier's job is to convert AC into DC. If the load is greater than the DC supply, this will cause a voltage sag which results in a compressed sound. My question is, if the pre or amplifier's rectifier is properly designed to avoid voltage sags, will changing the tube rectifier to a different brand, not type, affect the sound?
Voltage sag and compression aren’t the only cause of changes in the sound of a component's presentation. Mainly, that affects it’s dynamics. That’s why I said, "sometimes", that will improve with a rectifier change. The short answer to your question is, "yes". BUT- there’s much more involved than just a, "different brand" involved. Most of us that have enjoyed various aural improvements through rectifier upgrades, have been using higher quality, NOS pieces, manufactured decades ago. Given that relatively few newer components have been designed with valve rectifiers(and/or regulators), there’s not been much demand and little motivation to produce great ones, these past 30 years or so.
Thanks rodman9999. Yes, very few new tube amplifiers are employing tube rectifiers in their circuit because of voltage demands. I still see quite a few preamps that use tube rectifiers as the voltage demand is within the tube's capabilities. I am just having a hard time understanding that if a rectifier is providing more than adequate DC current demand, how can a different brand of tube sound different if the DC electrical parameters are identical? In any event, I going to try again, some different tube brands in my preamp.
There are a few companies now manufacturing tubes, that have tried to produce valves, copying the internal construction/design parameters of some of the most popular, from decades back. Mainly, what they’ve succeeded in duplicating(capitalizing on) is the marque only(ie: Telefunken/Mullard/Gold Lion/Tung Sol), as none genuinely perform like the originals. The time involved in hand construction, attention to detail and(in many cases) materials used, are no longer either profitable or(perhaps) available.Try some authentic, older, well reviewed valves(as mentioned above). Worst that can happen is you’ll have to turn them, should they not turn you on. It may cost a few bucks to experiment, but- what doesn’t, in the audio affliction/addiction? Our, "rewards" are SO subjective! Happy listening!
brf 5-2-2017The short answer is that they are not identical.
Most tube characteristics are specified as nominal or typical values, without a +/- tolerance or max/min specification. (The main exception to that being what are referred to as "absolute maximum ratings," which define the maximum amounts of voltage, current, and power the tube is rated to handle without the likelihood of damage or a significant reduction in longevity). And even in cases where a +/- tolerance may be specified for a given parameter, it will rarely be a narrow one.
So significant variations in electrical parameters can be expected among tubes of the same type that have been produced by different manufacturers, and/or in different eras.
Regarding rectifiers specifically, my suspicion is that what is likely to be the main contributor to sonic differences in many applications is simply differences in the voltage drop across the tube, resulting in differences in the DC voltage that is applied to the circuits the rectifier is powering, especially the tubes that may be in those circuits, resulting in those tubes operating at different points on the curves which define their operating characteristics.
Okay, I must be the exception. I hear no difference when swapping out rectifiers in my pre-amp. When talking to the manufacture, I was told that my preamp's DC requirements are conservative, therefore, the power will not sag when pushed.
This could be correct. But if you know how to play around with the voltage, that could change this.
There are a few companies now manufacturing tubes, that have tried to produce valves, copying the internal construction/design parameters of some of the most popular, from decades back. Mainly, what they’ve succeeded in duplicating(capitalizing on) is the marque only(ie: Telefunken/Mullard/Gold Lion/Tung Sol), as none genuinely perform like the originals.
General statement maybe true but when trying the copy cats, you may need to adjust the voltage as they may need some adjustment here.
For the GZ34, I have been using JJ's with great results over some of the NOS tubes. Cheap to!
See Almarg's comments above mine.
Bigkidz if your preamp has a regulator after the rectifier then changing the rectifier won’t change much. If it’s a classic design LCRC filtered then I would expect you to easily be able to hear it.
Also I think getting slightly different tubes e.g. 5U4, 5Y3, 274B, etc and roll to experiment with sag as long as voltage requirements don't exceed spec yields more obvious results than just dumping the inheritance into buying Western Electric whatever plate whatever lettering 274B.