[wilsynet]

I have heard enough tube versus solid state amplifiers to understand intuitively how they're different.  But I don't have a very good intuition for tube versus solid state rectification.

Would someone be able to describe the differences in their essential character and possibly explain why?

This link suggests tube rectification is a terrible idea:

http://www.soldano.com/amp-help/tube-vs-solid-state-rectifiers/

Then there is this quote:

http://www.thegearpage.net/board/showthread.php?t=644127

"What makes tube rectifiers magic to some people's ears is that tube recitifiers do not react as quickly to large spikes in power demand as solid state rectifiers. This causes the voltage drop across your amplifier tubes to 'sag' ..."

Why would sag be a good thing?

Any counter arguments?  How about tube versus solid state rectification in amps versus preamps?

[JakeJ]

I have heard enough tube versus solid state amplifiers to understand intuitively how they're different.  But I don't have a very good intuition for tube versus solid state rectification.

Would someone be able to describe the differences in their essential character and possibly explain why?

This link suggests tube rectification is a terrible idea:

http://www.soldano.com/amp-help/tube-vs-solid-state-rectifiers/

Then there is this quote:

http://www.thegearpage.net/board/showthread.php?t=644127

"What makes tube rectifiers magic to some people's ears is that tube recitifiers do not react as quickly to large spikes in power demand as solid state rectifiers. This causes the voltage drop across your amplifier tubes to 'sag' ..."

Both links have good info and I agree with most of it.

My experience follows:
My ears seem to prefer beefy high power tube amps over the flea powered types.  This may be due to the speakers I have heard the flea amps through.  Oh, by "flea" I mean 2.5 Watts like 2A3 based amps.  I also definitely prefer the high power tube amps to be solid-state rectified as the bass of a high powered tube amp that is tube rectified (even double rectified) just doesn't have the balls that the SS rectified version has (oops, confession; I am a basshead).  Another point of clarification - by "high-powered tube amps" I am primarily referencing the pentode tube type such as the 6L6 family run in ultralinear or pentode modes regardless of Class A or Class AB operation.  With this circuit topology tube rectification is just too loose and sloppy which to me is not realistic or true to bass instruments of any kind.

Now I have heard a couple of 300B based amps in both SS and tube rectified form and I liked the tube rectifed one better.  This experience has me wanting to hear a truly high powered triode design that boasts anything from, say, 20 to 50 Watts and is designed to push conventional, single-driver, or horn design speakers (yeah, I know, pretty big shoes to fill) and I really don't have a particular tube type in mind.  Could be the mighty 211, or the dimunitive and (to me) mysterious 6C33C.  Triode amplification and the requisite tranducer to pull it off correctly are one of the last audio frontiers for me.

Why would sag be a good thing?

Because our ears like it, as stated in several posts in the forum link.  This, IMO, has a great deal to do with how a tube distorts and the effect that tube rectification has on that distortion.  Remember tubes distort in even-order harmonics and SS distorts in odd-order harmonics.  Our ears prefer distorion in the even-order harmonic region.  It's one of those things our brain smooths over more easily.

Now, just to pick nits a bit.  Regarding your first link, while I do agree with what is technically represented I must ask why a link to a guitar amp maker's site?  I ask because guitar amps and home audio reproduction amplifiers have different goals and, thus, design approaches and different results in mind when producing a product.  Just curious.

Any counter arguments?  How about tube versus solid state rectification in amps versus preamps?

Before I reply to that I just want to be clear that all of what I've written here is my opinion, nothing more.  It should be taken with a healthy dose of salt.  OK, that said, it comes down to design and circuit topology...again.  Sometimes changing the tube rectifier will have a dramatic sonic effect and in other application very little.  If the circuit in question, whether pre or power stage, requires a very specific tube type for which there are no substitutions then I think you are going to hear much more subtle difference as you will be limited to the differences of manufacturer and time/date of production.  Some triode amps are designed to take a wide variety of rectifier types intentionally to give the end user more control of the ultimate final tone and color.

Hope that helps a little bit.

[wilsynet]

No reason for the guitar link.  It's just what showed up on Google.

[FullRangeMan]

I think SS rectification offer a more ''modern'' sound, maybe with less harmonics to Hi-Fi tube amps, and tube rectification offer a more old-fashioned or vintage tube sound.
On Niteshade circle there is a sticky topic about it:
http://www.audiocircle.com/index.php?topic=79922.0

[Mark Korda]

Hi Wilsynet,I posed a simular question in the (Lab) section of Audio Circle,(Full wave rectification).I did not know what tube sag was.Mboxler sent me a site that explained it,maybe it may be of help...Mark Korda(http://www.aikenamps.com/Sag.html)

[medium jim]

My experience is mostly with guitar amps and solid state rectification has less dimension, or for better words is drier and more 2 dimensional or less spatial that its counterpart tube rectifier.

Jim

[RPM123]

This topic is discussed in the Niteshade Audio circle which you should find helpful. 

[JohnR]

This topic is discussed in the Niteshade Audio circle which you should find helpful.

Helpful link: http://www.audiocircle.com/index.php?topic=79922.0

I'm somewhat reminded of my car. I thought I would never buy a small diesel car. But I did, and love it to death. Taken as a complete package, together with my needs, what it does is "just right."

[wilsynet]

If there's no discernable difference in a preamplifier, why would (say) the Modwright LS-100 be tube rectified?

[JohnR]

If there's no discernable difference in a preamplifier,

Um.. who said that?

Anyway, googling for "reverse recovery spike" might be helpful for one aspect of PSU design. Or ask Dan Wright.

[FullRangeMan]

This topic is discussed in the Niteshade Audio circle which you should find helpful.

Looks suited to future search, join/attach this topic with the Niteshade topic.
Just a idea.

[cheap-Jack]

Hi.

(1)

I have heard enough tube versus solid state amplifiers to understand intuitively how they're different.  But I don't have a very good intuition for tube versus solid state rectification.

This link suggests tube rectification is a terrible idea:http://www.soldano.com/amp-help/tube-vs-solid-state-rectifiers/

Then there is this quote:

http://www.thegearpage.net/board/showthread.php?t=644127

"What makes tube rectifiers magic to some people's ears is that tube recitifiers do not react as quickly to large spikes in power demand as solid state rectifiers. This causes the voltage drop across your amplifier tubes to 'sag' ..."

Why would sag be a good thing?

Any counter arguments?  How about tube versus solid state rectification in amps versus preamps?

Tube or SS rectifiers so often depends on the current loading of the amp. Small current loading for tube preamps or relatively small O/P tube power amps, full-wave tube rectification are very commonly employed.

But for very HV & large current loading of large O/P power amps, SS rectification are also common employed. For more efficient PS design, SS are usually used as tube rectification will be too bulky & expensive to build & so much less efficient. Not a good idea at all.

Again, all depends on the PS requirement by the loading amps.

Sonic difference?? If the PS are design/built properly, there should not be noticiable different as long as the PS are not overloaded due to the loading.

Take the example of my one-tube one-stage RIAA stereo phonostage, it needs 440V B+ to power the tube.
I have no choice but to design/build a SS PS, as tube rectifier PS would l be way way too costly & to bulky. Not a good idea of a phonostage.

Probably no other DIYers, except yours truly, would have done so. I used one sand diode to do a half wave rectification from 115VAC mains via a very small 115V:115V isolation transformer. Followed by a half-wave serie voltage quadrupler to get the HV up to 460V & chip regulated to 440VDC as required.

Only 4 'lytic caps & 4 sand diodes are used to provide 440V regulated DC. Simple, cheapie & easy to install, small space needed & COOL running.

Yes, half wave rectification needs proper design/built filter tanks & an effective spike snubber as result of DC quadrupler. In fact, what I find out is the spike snubber heat up more than the 660VDC filter caps used.

With this CLCRC filter bank + chip regulator, using 4x660VDC fast speed 'lytic caps, bypass film caps & spike snubber across the final filter cap, the phonostage sounds superb - fast, see-tru transparent & detailed.

I don't think such 440VHV PS using tubes can do a better job, sonically & money/space saving.

Um.. who said that?

Anyway, googling for "reverse recovery spike" might be helpful for one aspect of PSU design. Or ask Dan Wright.

Don't worry. "Zero Recovery rectifiers" using silicon carbide (SiC) has been in the market for many many years & have installed in major HV & huge current loading industrial applications. Home use SiC rectifiers are also available for audio, cheapie to buy & so easy to use!

c-J