Rectifier tubes compared

[Arkay]

I don't think this has been linked to here before (apologies if it has), but I thought it might be of interest to some here:
http://www.head-fi.org/t/694525/dub...eview-comparison-rectifer-tube-rolling-thread

 

[sony6060]

I rolled a lot of rectifiers in various amps, but nothing as exotic as that. What is interesting is why rectifier tubes sound different.

I suspect various tubes manage average to peak current with better regulation and some operate with less noise overall. I can only assume less noise reduces IMD products in the amplifier tubes plus better regulation can allow a more linear operating curve in the power tube if that is desired. Of course, it becomes more complicated with cathode bias tubes that have a form of negative feedback itself due to varying bias.

Single-ended amplifiers vs push-pull amplifiers are more critical with regard to HV regulation. PP amplifier power tubes reduce current in one tube and increase current to the other tube then back again continuously while playing music. This balances out the current demand much more than a single-ended amplifier.

I design SE power supplies for fast recovery from a higher current demand at 1.5 times the idle current producing about 10 volts sag, then back to no signal (idle) voltage in 16ms or less. I design for less than 1 volt AC ripple.

Push-pull amplifiers only require DC with reasonable regulation and I design for not more than 3 volts AC ripple at idle current. PP cancels most high voltage AC ripple by the design itself.

With regard to DIY SE amps, I use a LCLC filter power supply. I also experimented with shunt regulated power supplies and compared to the LCLC type power supply and heard no difference with a 45 tube SET amplifier. The 45 tube is considered a standard of being a high performance amplifier tube.

I also tried tube type series regulated vs shunt regulated and found the series regulator tube colored the sound too. Shunt regulated generates a lot of heat and is not practical in higher power single ended amplifiers.

I have not attempted to measure with instruments why the various rectifier tubes and power supply design itself affects the audio.

I prefer solid-state rectifiers producing low switching noise (UF4007 diode) with good regulation and high frequency noise filters that are simply a low value bypass capacitor or at times an RC circuit placed at one or more locations in the power supply circuit.

Finally, these comparisons require a good source, a quality amplifier, great speakers and attention via one ears in good condition and well trained for minor details.

Do not loose any sleep due to you do not have a $500 Western Electric rectifier tube in your amplifier.

BTW- I perform these experiments with at least another person present to introduce subjectivity. For example, my son has incredible hearing from 20Hz to 22kHz.

 

[njcanuck]

Sony, thanks for the explanation. I have wondered how a rectifier that's not in the signal path would affect the sound. Now I understand. :thmbsp:

Never lost any sleep over it tho.

 

[sony6060]

Sony, thanks for the explanation. I have wondered how a rectifier that's not in the signal path would affect the sound. Now I understand. :thmbsp:

I think I understand by process of elimination only. I have not any empirical data to support my statements. I have a lot of appreciation for those that take the time to develop empirical data. One person that comes to mind is Dave. He is a great audio 'bloodhound'.

 

[sony6060]

No one else going to comment regarding why tube rectifiers sound different???

 

[jaymanaa]

I'm too old to hear rectifiers, so I just use the best ones I can afford. Given the choice, I'll take Cree Diodes into a choke input supply anyway. Cool link, lots of good info.

 

[chicagozer]

... I design for not more than 3 volts AC ripple at idle current...

I'm not following. The rectified DC in your supply has a 3V AC component? That seems like a lot.

I took a quick glance at the article. I have a tough time with the descriptive text that is not complemented by any #s.

Air, layering, texture? I have no idea how that applies to something designed to provide constant DC voltage.

Jim

 

[sony6060]

I'm not following. The rectified DC in your supply has a 3V AC component? That seems like a lot.

I took a quick glance at the article. I have a tough time with the descriptive text that is not complemented by any #s.

Air, layering, texture? I have no idea how that applies to something designed to provide constant DC voltage.

Jim

6 volts and more AC ripple on 400 VDC is common.

 

[nashvillebill]

6 volts ripple on a 400 volt B+ seems like a lot to me, I'd expect around 2, that's what Duncan's Power Supply utility shows with some typical values and a 5U4.

 

[cduarte]

anyone who uses the term "prat" and thinks it actually means something is a moron.

 

[Pio1980]

No one else going to comment regarding why tube rectifiers sound different???

Aside from how a given example may affect the 'stiffness' of a PS from the front end, I dunno.

Sent from my SCH-I605 using Tapatalk

 

[sony6060]

6 volts ripple on a 400 volt B+ seems like a lot to me, I'd expect around 2, that's what Duncan's Power Supply utility shows with some typical values and a 5U4.

A lot of SS voltage doublers are more than 3 volts AC ripple.

 

[captainclock]

One thing I noticed about that girl's article is that she supposedly reviewed 2 rectifier tubes that she said were supposedly identical to the 5U4GB tube, one of them being a 1641, and the other being a 596 both of which according to the tube substition manuals I have are NOT direct substitutes for a 5U4GB Rectifier tube.
First of all both of those tubes have two electrode connections at the top and if your equipment doesn't have the proper electrode connectors for those electrode connections at the top of those tubes then they aren't being used properly and are at risk of blowing those tubes, plus they're older 4-pin tubes which aren't compatible with octal connections.
Apparently this chick hasn't done her homework as well as she claims she has... :thumbsdn::nono:

 

[sebrof]

This chick busts her ass and does all this work comparing these tubes, posts reviews and pictures so people can read and maybe get ideas on ones they'd want to use, and because some of us don't understand some terms she used and because she may not be technically accurate (but only practically accurate) she's a moron and gets thumbs down.

Nice, fellas. Real nice.

It amazes me how some people can't help but dump on just about anything.

 

[captainclock]

This chick busts her ass and does all this work comparing these tubes, posts reviews and pictures so people can read and maybe get ideas on ones they'd want to use, and because some of us don't understand some terms she used and because she may not be technically accurate (but only practically accurate) she's a moron and gets thumbs down.

Nice, fellas. Real nice.

It amazes me how some people can't help but dump on just about anything.

I wasn't trying to dis her whole article I was just merely pointing out the fact that she tried to use tubes in a 5U4GB amp Circuit that wasn't even meant to be used in a 5U4GB amp ciruit in the first place because it wasn't even wired for them in the first place.
As for the emoticons I used I was using them to show disapproval of that particular mistake not the whole article.
Other than those two tube issues I thought the article was well written coming from someone who was probably no older than I am (I'm 25 years old and guessing from her avatar and her username she couldn't be any older than that).

I would of given her overall article a 4/5 Stars had it not been for the fact that you had to be a member of that website in order to do any ratings or commenting.

 

[JP]

One thing I noticed about that girl's article is that she supposedly reviewed 2 rectifier tubes that she said were supposedly identical to the 5U4GB tube...

She said similar, not identical.

 

[captainclock]

She said similar, not identical.

Well either way, you can't just go using tubes that don't even have the same kind of pinout/pin arrangement as the original tube (1641 and 5U4GB) in a tube amp circuit that calls for a 5U4GB or equivalent tube.
In this case the 539 and the 1641 that the girl used in her comparison article aren't even listed as direct substitutes for a 5U4/5U4G/5U4GB/5U4GBA tube, in fact in the tube substitution manual I have it lists the 1641 as not having a direct substitute except for itself (the Euro version of itself as its an industrial tube).

 

[sebrof]

I would of given her overall article a 4/5 Stars had it not been for the fact that you had to be a member of that website in order to do any ratings or commenting.

I thought it was at least well thought out, too. She had some pretty rare tubes in the mix, tubes I've never knew existed.
I use the Philips 5R4GYS in my amp (from Upscale Audio as she mentions) and like it, but I really didn't do an A/B vs. the potato masher 5R4WGB. Truth be told, I got the Philips because I liked the looks of it

 

[sebrof]

I would of given her overall article a 4/5 Stars had it not been for the fact that you had to be a member of that website in order to do any ratings or commenting.

I thought it was at least well thought out, too. She had some pretty rare tubes in the mix, tubes I never knew existed.
I use the Philips 5R4GYS in my amp (from Upscale Audio as she mentions) and like it, but I really didn't do an A/B vs. the potato masher 5R4WGB. Truth be told, I got the Philips because I liked the looks of it

A lot of reviews of rectifiers I see are comparing different tube types (example 5R4 vs. 5AR4) and so really it's not so much the brand but the fact that you're changing the operating points of the circuit. I know when I sub any 5AR4 into my amp that change overrides any brand differences.

 

[JP]

Well either way, you can't just go using tubes that don't even have the same kind of pinout/pin arrangement as the original tube (1641 and 5U4GB) in a tube amp circuit that calls for a 5U4GB or equivalent tube.
In this case the 539 and the 1641 that the girl used in her comparison article aren't even listed as direct substitutes for a 5U4/5U4G/5U4GB/5U4GBA tube, in fact in the tube substitution manual I have it lists the 1641 as not having a direct substitute except for itself (the Euro version of itself as its an industrial tube).

I've no idea what substitution manual you have, but I'd imagine if the basing, etc. are different it wouldn't be listed as a substitute - I believe 'plug and play' is a requisite for such guides.

That doesn't mean the types are electrically dissimilar to not work acceptably if someone decided to modify the socket and add cap connections, as it seems she did. I haven't look at either tubes characteristics, so I've no opinion on their electrical similarity with a 5U4G(B).

It would seem she not only did her homework, but also did extra credit work.