Tube Rectifiers do sound different

[M Gregg]

Kind of curious here ....some seem to think that rectifiers all sound the same therefore do all caps and all resistors likewise sound the same? Maybe since we have moved our heads 1/8 from the listening position that if we could duplicate the same listening position then there would be no difference in the sound between different caps either.

Yes components do sound different..given the same circuit..However what one person will call clarity and open another will say the circuit is at fault.

The argument would be if we design a circuit so we cannot hear the difference (could that be thought of as filtering out comonent sound) could we then hear good sound?

Its a bit like saying I can hear the rectifier quick put a notch filter in to remove the frequency..and then they all sound the same don't they?

And you can hear it in HIFI conventions a perfect sound rolled of at the top and bottom end selective bits missing or distorted..then step into another room and different system and wow...the singer is in the room..

The question is how do you get the balance right..

Watch the comments..LOL its been done to death..

Regards
M. Gregg

 

[Burnedfingers]

Well I'm pretty sure what I heard differences in rectifiers. Maybe I'm not all wrong. Looking at something like the #26 line stage for example there is a following for the AZ1 rectifier tube because it sounds better. Maybe something has to do with the circuit we are dealing with. The #26 of which I am gathering parts for is very finicky in my opinion. A plate resistor will deliver a different sound than say a choke loaded plate will.

 

[M Gregg]

Well I'm pretty sure what I heard differences in rectifiers. Maybe I'm not all wrong. Looking at something like the #26 line stage for example there is a following for the AZ1 rectifier tube because it sounds better. Maybe something has to do with the circuit we are dealing with. The #26 of which I am gathering parts for is very finicky in my opinion. A plate resistor will deliver a different sound than say a choke loaded plate will.

Its also the same with choke or resistor type PSU..even some people hate regulation or type of regulation...bypassed chokes or cap types or bypass types..

Power supply resonance..and de coupling...types of ground system....

You are going down the rabbit hole...this is the audiophile way...nothing wrong with it..however it will drive you nuts...
So what do you do? You have to find what you like and run with it..if you make the mistake of listening to more systems you will start chasing again...

I did this and then junked my kit and bought an expensive all in one system...the problem was I could not settle with it, after a while I missed the tube sound..so I build a tube headphone amp guess what I stuck a SS amp on it..then a tube amp and here we go again..LOL

Regards
M. Gregg

 

[Evenharmonics]

Evenharmonics;

ears hear differently than microphones. Where microphones hear boosts and cuts on frequency response, ears hear reflections and diffused reverberation of still the same sound. That's why Denon Audissey makes sound much better than other equalizers that try to compensate variations caused by microphone position.

My point was about the difference between a device mounted on a stand and a person (getting up, walk up to the amp, change the rectifier tube, come back to the same seat and try to hold his head at the same position that he thinks where it was) in terms of the stillness of a position before and after.

 

[xneakers]

Up until just recently if anyone had told me that rectifiers sound differently I would have responded with something to the effect that they were crazy. But, I swear they do have different sonic qualities and no I haven't been drinking. I first thought I heard a difference when I experimented with different rectifiers in my 6SN7/6SN7 Aikido P-to-P line stage. I started off with a home made SS plug in rectifier and then progressed to a 5Y3. I thought the
SS sounded a little punchy. I then tried a 5AR4 a JJ that I had handy and then a Japaneese Mullard 5AR4. The Mullard sounded better. Then I tried a Chinese 5Z4P and it sounded really smooth. Then I tried a #80 in a octal to 4 pin adapter and it sounded the best of all.

I ordered (2) #83's to try.

So, the question is am I right? Do rectifiers really sound different. Even the wife admitted she heard some difference after telling me just play the damn thing.

I also tried different rectifiers in my Stereo 70. The Japaneese Mullard first followed by the JJ followed by the SS plug in followed by a 5U4. To my ears the Mullard sounded really good followed by the 5U4. The 5U4 has a really nice smooth midrange and this is after setting the bias to the correct setting because it was lower with the 5U4 than the 5AR4.

Am I totally nuts?

No you are not...

They do sound different... even sound really different on some parts...

The B+ different probably wont cause that much different... Noise, distortion, etc probably? But I would prefer guessing the internal construction itself... Why some Telefunkens sound better than other?

Thanks.

 

[DF96]

But the internal construction manifests itself in variations of effective series resistance, which creates difference in DC voltage, ripple waveform etc. Whether a particular thermionic rectifier design sounds better or worse will depend to a great extent on the rest of the circuit. SS is different, as there we have stored charge effects.

 

[kstagger]

from
The Amity, Raven, and Aurora

Matt Kamna also demonstrated a technique for zooming in on the waveform on the power-transformer secondary (about 10V/div on the scope screen). The rough appearance around the zero-crossing was very obvious with solid-state diodes. HEXFRED's gave a small improvement, but conventional tube rectifiers looked much smoother, and the TV damper diodes were by far the smoothest of all. So even in low-current preamp applications, TV damper diodes give the least noise. I know from experience in the Tektronix Spectrum Analyzer division that it's much easier to eliminate noise at the source than filter it afterward. If there was an even quieter device, I'd use that, but as far as I know, TV damper diodes are the quietest from the viewpoint of switching noise. Considering that the main B+ supply is switching five hundred volts, this is not a small consideration, since switch-noise is radiated in all directions, into the B+ supply, the interior of the chassis, and back into the power cord.

meh, can't find the link - but there was an article about switching noise, grounds, and the unexpected villains of power supply design. SP?

Anyways, with a well-designed power-supply, especially utilizing two stages of chokes - swinging choke / cap / choke / cap, I've heard minimal differences between rectifier brands - eg, a Shuguang 5AR4 pretty much sounded like a Mullard like a Hitachi. On cheaper PS - like something for a guitar amp or whatnot, it seemed to make a bigger difference.

Funny thing - I used to be in the tube rectifier only club, but my current amp has SS diodes and just big 'lytic buckets. It does absolutely fine.

 

[lechuck]

This weekend I have tried to work out if I can hear a difference between SS and VT diodes in the power supply. The amp used for this modification is my current development amp, which is a push-pull dc coupled EL509.

Original situation: The amp has been running with ultra-fast(<20nS) switching diodes followed by a simple CRC filter (220u, 22r, 220u), fed by 275VAC

New situation: 5R4 GY rectifier, followed up by a CRC filter (100u, 22r, 220u), fed by 315-0-315 VAC.

The power supply output voltage is almost the same for both situations, when the power tubes conduct there is about 110mA of current flowing through the power supply, the B+ voltage in this situation is +355V.

At first I didn't notice any difference at all. After a while I did notice a slight change in the audio reproduction of the amplifier; with tube rectification there is a slight "softness" to the sound, however this change seems to be noticed un-consiously so it could just as well be my brains are telling me "something has to be different, so it must be this".

Just as 'kstagger' I used to be vacuum tube only, however this small experiment got me of this path. In my opinion the advantage of SS rectification would be budget wise. The costs for the power transformer are lower (no 5V winding, lower high-voltage and there is no need for a center tap which saves allot of copper) and of course you save out on a tube

 

[Bigun]

In some engineering circles performance differences that are inconsistent and hard to track down are often because there are two or more factors at play instead of just one control variable. I suspect that differences in sound arising from the use of different rectifiers is a sign that the circuit is sensitive to the nature of the B+, whereas when differences are more difficult to discern the circuit is insensitive to the nature of the B+. With so many different amps, and considering that the speaker load is part of the circuit, there will always be circuits that are sensitive to the nature of the B+ supply and it will therefore, be a topic with adherents for different rectifier options. For somebody that likes to brag about a particular amp, especially trying to sell it, then the use of a 'good' tube rectifier minimize any chance of criticism.

Personally I haven't compared different rectifiers or tube vs SS rectifiers but I would not be at all afraid to use SS rectifiers in a tube amp design.

 

[trobbins]

Another aspect of tube rectifiers is that the harmonics in the rectified ripple can be modified by the tube's on-voltage. In a particular circuit, a rectifier with a higher peak working on-voltage will conduct over more of the mains cycle, and will have a more gradual switching transition. With this view, a rectifier with a 50Vpk would be a 'better' rectifier than one with a low voltage drop (which is what many would initially infer to be the better tube).

Not only could this impact the B+, but any heater winding would be less prone to passing on higher frequency noise from the rectification process.

 

[Bigun]

I suspect that what gave some SS rectifier PSU's a bad reputation was, just as you say, the switching noise heading back into the system. But I wonder if most of this was because of cap input filter after the rectifier - using a choke input filer holds the promise of much reduced current surges and a much smoother waveform. Throw in some series resistance (power resistor) with each diode and you can get variable voltage 'sag' - if you need it to achieve your design goals. And no wasted heater power.

Even better, use separate heater trafo's. They aren't that expensive and you can place them close to the relevant tubes where wiring can be kept really short.

And this allows you to pick a common garden variety trafo for the B+, designed for a bridge rectifier. Use a common mode choke input filter after the bridge for a very cost effective solution.

And then there are 'active' rectifier diodes made out of MOSFET's... so many possibilities.

 

[Junm]

This is a non ending debate...like who comes first...an egg or the chick...tsk...tsk..

Afaik, rectifiers=> rectify and amplifiers=> amplify and speakers produce sound....if rectifiers sound good, I might as well build a rectifier as an amplifier or speaker.....just for a break....hahaha

 

[TonyTecson]

@TS, you want to listen to rectifiers?

 

[xneakers]

My question is simple for you who post a lot of things in here...

Have you ever tried yourself?

I end up speechless when somebody saying a lot of things, but at the end saying, 'i havent really compared them'...

I have tried myself different rectifier both ss and tube, different input (choke and capacitor), even I have multi-tap HV secondary to avoid what they call different B+ output voltage (maybe not 100% exact same, but at least I minimize the different). The result? Try yourself

Well, I dont measure ripple or noise induced by different rectifier (which I suppose this 'noise' will affect what we hear). Feel free if anyone wants to post their result.

It doesn't take a genius to hear the different... but please, if you havent tried yourself, dont speak that there is no different... simply you will mislead the other... This is a forum to share, I believe....

Thanks.

 

[trobbins]

Its the lovely lower harmonic structure of twice mains, mixed with a tinge of mains fundamental from tube assymtry, married with the extra treble character from the switching noise that I find most pleasing.

 

[TonyTecson]

i pick tube rectifiers on the basis of current output capability, then design the filtering circuit to give me the lowest ripple and impedance possible......

i don't care witch tube rectifier sounds best, as long as i know i have designed a very capable power supply, then i look elsewhere for the sound voicing that i want....

 

[20to20]

I wipe the dust off the tops of my tubes.. It seems to create a cleaner sound. Has anyone else tried that?

20

 

[tcqanh]

does anyone take comparision : tube rectifier vs diode rectifier with the same CLC filter ?

off course, B+ and current capacity are also the same.

 

[TheGimp]

I don't believe a comparison between tube rectifier vs diode rectifier with the same CLC filter is a proper comparison as the filter has to be designed for one and will not be optimized for the other.

This is one problem in the comparison of vacuum vs SS rectification. Each requires it's own optimized filter to achieve the best (lowest noise?, minimal hum?) operation.

 

[Michael Koster]

The problem is distinguishing between something that changes the sound vs. something that has a sound.

I don't have an answer to that yet.

Then there is the related problem of being able to identify a change in sound. If I see a flashing light, my mind can usually synthesize a sound that follows the light... etc...