Rectifier Tube Question

Jess 1971

Silver Supporting Member
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4,457
Apologies in advance for the noob question. Can I replace the Sino 5ar4 rectifier tube (pictured below) in my Friedman DS40 with any other brand 5ar4 rectifier tube (e.g., Sovtek, JJ, etc.)? Will I need to rebias the amp if I'm just replacing the rectifier tube?

41cmt60oIuL._AC_SX425_.jpg
 
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ericb

Gold Supporting Member
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10,994
Apologies in advance for the noob question. Can I replace the Sino 5ar4 rectifier tube (pictured below) in my Friedman DS40 with any other brand 5ar4 rectifier tube (e.g., Sivtek, JJ, etc.)? Will I need to rebias the amp if I'm just replacing the rectifier tube?

41cmt60oIuL._AC_SX425_.jpg

Yes you can replace it with any other 5ar4 and no you don't need to rebias..
 

Jess 1971

Silver Supporting Member
Messages
4,457
Yes you can replace it with any other 5ar4 and no you don't need to rebias..
Awesome. Thank you. Very much appreciated.

Now for a 5ar4 rectifier tube, is there any particular brand that is recommended? Is it worth paying a premium for Tung Sol or Mullard, or does it not really matter much? I love the sound of the amp the way it came with the stock Chinese-made Sino tube, so I'm not looking to change the tone or add gain or whatnot. I really just want to get something that will hold up from a lot of use and still sound good.
 

ericb

Gold Supporting Member
Messages
10,994
Awesome. Thank you. Very much appreciated.

Now for a 5ar4 rectifier tube, is there any particular brand that is recommended? Is it worth paying a premium for Tung Sol or Mullard, or does it not really matter much? I love the sound of the amp the way it came with the stock Chinese-made Sino tube, so I'm not looking to change the tone or add gain or whatnot. I really just want to get something that will hold up from a lot of use and still sound good.

Personally I wouldn't worry about it and would buy a current JJ 5ar4, or a Groove Tubes Gold, which GC is selling for 23.00 on sale (that would either be a Russian or Chinese tube) . . They won't make much of a difference and they shouldn't rattle and should last just fine. The only thing I'd say about my older Rectifier tubes is like almost all tubes back then, they're built to last a lonnnng time, but I don't think you have to worry. I was absolutely neurotic about tubes for about 15 years or so and have a huge amount/collection of them, but this wouldn't concern me buying either of those 2 options! Good luck

EDIT, I just read that you wanted to replace it for the sake of replacing it.. I thought it had broken or stopped working. . I'm with RAG7890 in that I wouldn't replace it unless it stopped working or was rattling or blowing fuses, etc. :)

Eric
 

Jess 1971

Silver Supporting Member
Messages
4,457
Personally I wouldn't worry about it and would buy a current JJ 5ar4, or a Groove Tubes Gold, which GC is selling for 23.00 on sale (that would either be a Russian or Chinese tube) . . They won't make much of a difference and they shouldn't rattle and should last just fine. The only thing I'd say about my older Rectifier tubes is like almost all tubes back then, they're built to last a lonnnng time, but I don't think you have to worry. I was absolutely neurotic about tubes for about 15 years or so and have a huge amount/collection of them, but this wouldn't concern me buying either of those 2 options! Good luck

EDIT, I just read that you wanted to replace it for the sake of replacing it.. I thought it had broken or stopped working. . I'm with RAG7890 in that I wouldn't replace it unless it stopped working or was rattling or blowing fuses, etc. :)

Eric
Thanks. I'd blown a fuse, which completely stopped the amp from powering on. I've since replaced the fuse, and now it seems like it's working fine again. However, when I spoke with Dave at Friedman and he said that when the fuses start to blow, it may mean that a rectifier tube is starting to die. So I figured I'd get myself a new one to have on hand in case I blow another fuse. So I'm definitely not looking to replace it just for the sake of replacing it. Just thought it made sense to have one on hand in case it craps out on me during a show or recording session or something.
 

ericb

Gold Supporting Member
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10,994
Thanks. I'd blown a fuse, which completely stopped the amp from powering on. I've since replaced the fuse, and now it seems like it's working fine again. However, when I spoke with Dave at Friedman and he said that when the fuses start to blow, it may mean that a rectifier tube is starting to die. So I figured I'd get myself a new one to have on hand in case I blow another fuse. So I'm definitely not looking to replace it just for the sake of replacing it. Just thought it made sense to have one on hand in case it craps out on me during a show or recording session or something.

Gotcha! That was a vital piece of info. :) I've had 1 rectifier tube die ever, and yep it blew the fuse. I'd stick with those 2 choices mentioned above, but if you did buy a NOS rectifier from a reputable dealer, it wouldn't necessarily make your amp same better or different but should last a lifetime (as should the current ones mentioned, but no guarantees, huh!) Good luck, Eric
 

Jess 1971

Silver Supporting Member
Messages
4,457
Gotcha! That was a vital piece of info. :) I've had 1 rectifier tube die ever, and yep it blew the fuse. I'd stick with those 2 choices mentioned above, but if you did buy a NOS rectifier from a reputable dealer, it wouldn't necessarily make your amp same better or different but should last a lifetime (as should the current ones mentioned, but no guarantees, huh!) Good luck, Eric
Thank you so much! This is so helpful. I really appreciate it.

Thinking about my amp some more though, I suppose it's quite possible that I simply blew a fuse and my rectifier tube is fine and will last few a few more years, yeah?
 

ericb

Gold Supporting Member
Messages
10,994
Thank you so much! This is so helpful. I really appreciate it.

Thinking about my amp some more though, I suppose it's quite possible that I simply blew a fuse and my rectifier tube is fine and will last few a few more years, yeah?

I'm not a tech, but I have a lot of experience with amps, and typically there's a reason for a fuse to blow. If it's the HT fuse, typically it's a rectifier tube that's going bad, or bad, OR something with intermittent Power Tubes, either a bad tube, or a runaway bias, etc. IF you've noticed nothing 'visually' with the power tubes , i.e red plates, excessive glowing in 1 or both, etc , Rectifier tube is a good suspicion. This is my experience with my amps. Other things can cause the fuse to blow, including just a bad fuse, but typically that's not the issue. I think it's a great idea to buy the 2nd rectifier tube

Eric
 

HeavyCream

Silver Supporting Member
Messages
6,090
I’d grab a SS rectifier just for backup. They’re cheap and are a good backup plan. Plus, you might even prefer the amp with a SS rectifier.

There’s a reason OP 5AR4/GZ34’s are expensive and it’s not because they have magic tone. It’s because they last. Unlike modern GZ34’s. 5AR4/GZ34’s are high voltage rectifiers and have to be built very well in order to prevent rattle, arching and catastrophic failure. Unless your amp has diode protection, a rectifier failure could take out other parts of the amp.

If I don’t have a good OP GZ34, I use a SS rectifier. Weber makes some SS rectifiers that are supposed to sag like a tube rec. Haven’t tried one but I hear they work great. If you are going to go with a modern 5AR4/GZ34, I would honestly ask Dave what he’s using ATM. Not because it’s the best fit for your amp or something like that… Dave knows which ones have high failure rate ATM. It’s alway changing. 3 years ago JJ’s might of been blowing left and right… last year Sovteks… IDK. No one knows better than amp builders that make high quantities. He’s probably not using Sino anymore.
 

Jess 1971

Silver Supporting Member
Messages
4,457
Personally I wouldn't worry about it and would buy a current JJ 5ar4, or a Groove Tubes Gold, which GC is selling for 23.00 on sale (that would either be a Russian or Chinese tube) . . They won't make much of a difference and they shouldn't rattle and should last just fine. The only thing I'd say about my older Rectifier tubes is like almost all tubes back then, they're built to last a lonnnng time, but I don't think you have to worry. I was absolutely neurotic about tubes for about 15 years or so and have a huge amount/collection of them, but this wouldn't concern me buying either of those 2 options! Good luck

EDIT, I just read that you wanted to replace it for the sake of replacing it.. I thought it had broken or stopped working. . I'm with RAG7890 in that I wouldn't replace it unless it stopped working or was rattling or blowing fuses, etc. :)

Eric
I took your advice and picked up a Groove Tubes Gold 5AR4 from Guitar Center online. Less than $30 shipped, so I'm all good. Many thanks for all the helpful info.
 

Jess 1971

Silver Supporting Member
Messages
4,457
Well good luck and hopefully you never even need to use it!
Since I posted this thread two months ago, the amp has been working fine with just a new fuse. Fast-forward to tonight, and I blow another fuse. I replace it with another, which then also promptly blows. So I swap out the 5ar4 rectifier tube with the Groove Tubes 5AR4 I got from Guitar Center last month as per your advice. Fired it up again and it's all good.

Amp seems slightly darker with the new tube though, or maybe thats how it's supposed to sound and I'd just gotten used to the sound of a dying rectifier tube? Anyway, all good. Many thanks again for all the help.
 
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Mystix

Gold Supporting Member
Messages
1,642
Since I posted this thread two months ago, the amp has been working fine with just a new fuse. Fast-forward to tonight, and I blow another fuse. I replace it with another, which then also promptly blows. So I swap out the 5ar4 rectifier tube with the Groove Tubes 5AR4 I got from Guitar Center last month as per your advice. Fired it up again and it's all good.

Amp seems slightly darker with the new tube though, or maybe thats how it's supposed to sound and I'd just gotten used to the sound of a dying rectifier tube? Anyway, all good. Many thanks again for all the help.


Wouldn't hurt to have an amp tech look at it - im no expert either but my amp tech told me once that - something is causing the fuses to blow -

hopefully does not lead to something serious...
 

Jess 1971

Silver Supporting Member
Messages
4,457
Wouldn't hurt to have an amp tech look at it - im no expert either but my amp tech told me once that - something is causing the fuses to blow -

hopefully does not lead to something serious...
Perhaps. I kind of figured it was the rectifier tube that was causing the problems, as once I swapped it out that seemed to bring the amp back to normal. I'll certainly keep a close eye on it though, and if the problem persists, I'll bring it to my amp tech.
 

ericb

Gold Supporting Member
Messages
10,994
Since I posted this thread two months ago, the amp has been working fine with just a new fuse. Fast-forward to tonight, and I blow another fuse. I replace it with another, which then also promptly blows. So I swap out the 5ar4 rectifier tube with the Groove Tubes 5AR4 I got from Guitar Center last month as per your advice. Fired it up again and it's all good.

Amp seems slightly darker with the new tube though, or maybe thats how it's supposed to sound and I'd just gotten used to the sound of a dying rectifier tube? Anyway, all good. Many thanks again for all the help.

Man, glad to hear it and I hope this one does the trick!

Eric
 




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