Why tube rectification?

Thanks @jond. One additional benefit of tube rectification might be for some that it adds to the cool look. They are usually pretty big tubes and so add visual impact. I am learning not to discount visual impact as quite important in our sound based hobby :-)  I hope we get some more input on this.

Tube rectifiers develop a larger forward voltage drop than silicon rectifiers (up to 50 volts for the tube vs about 2 to 3 volts for the diodes) so that may have quite an effect on the amp as it will change the operating parameters. I would vote No on that one.

I have used both tubes and diodes. Nowadays there really is no reason to go with tube rectification because it’s biggest advantage of being quiet can be rivaled with the Ultra Fast Reverse Recovery diodes (ie UF4007). I can buy a thousand of them for the cost of one NOS rectifier.

How I chose a rectifier is dependent on the amp. When I built my single ended 2A3 mono’s I was looking for the Old School look and sound. I find the 5Y3GT rectifier has a certain synergy with the 2A3 tube, bringing out its character better than others I’ve tried. And the extra glowing orange light just adds to the feel. However, when I built a pair of KT150 60-Watt A/B push-pull triode/Ultralinear, I opted for the UF4007. First reason was I needed 430 volts, and with tube rectifiers I would have to go with a higher voltage transformer and then use 600V capacitors. Those are harder to source, are much bigger and more expensive. Second, the amplifier was fitted with delay start, fixed bias voltage, LED indicator lights, fault protection circuits and circuit breaker trip switch. All that required a printed circuit board, making it much easier to populate the overkill power supply on the board than screwing tag boards and parts all over the chassis. In this case, solid state met the performance objectives.

That’s basically it. No advantage of one or the other just on their own standing, at least in my opinion.

I don't do the EE' thing. I leave that to the EE's who do design and build my Tube Equipment.

I own Tube Pre Amp - Phonostage - DAC - Power Amp, of which all are Bespoke Design Commission Builds from a selection of EE's who have Valves as their Electronics of Interest. For the record, I also know a selection of EE's that live and breathe SS Circuitry and who would not express and interest in a Valve Design.

In relations to Phon's the Best Phon's heard is from my Assessment is designs produced by the Tube EE's I know. In the same area, the best SS Phon' from my assessment that has been heard, is produced by a known EE who does not get stimulation from Valves. I choose Phon's as a description as I have heard over the Years, phon's at Bake Off's that can have a collective value to well over £100K, with £10K commercial phon's being present for comparisons.

In relation to Tube Rectification on a Power Supply, the design does have the capability to influence the end sound. Again on the Phon' I own, O have heard it used with a few different Power Supply Designs and each did effect the end sound. The other 'Valvuable'  thing about a Tube used for the Rectification, is that the Tube can be Tube Rolled. A very good end sound / options for an end sound, can be discovered as a result of experiencing a range of tubes as part of the process for making a tube selection. 

This type of interaction with a Circuit where EE skill levels can be low in relation to typical EE concerns, is where Tubes and Tube Rolling is a winner. If an inexperienced with EE requirements Individual is OK with the cost to be incurred as a result of choosing to Tube Roll, that individual can make discoveries about end sound that is available with ease. Such an experience is not as easy to reproduce with SS Circuits.

In relation to tweaking with SS Circuits, I have the Option on the Tube DAC to exchange a Filter CHIP, which has a multi pin connection to the Circuits soldered base for the CHIP to plug in to.

The EE Designer has supplied a selection of CHIP's that have obvious evidence of having been modified, I suppose to meet the end sound that the EE is wanting, their own Signature in the CHIP to produce sound and not that of the Manufacturer.

Exchanges of these CHIP's for somebody with my experience is precarious and much much more difficult than swapping out a Tube. Concern for damaging very fragile pins where having a visual observation is very limited, does justify the concerns, Hence, CHIP Filter changes that are readily at hand are not a common experience.   

I don’t think there is anything close to a perfect correlation between electrical performance and preferred sound.  That is why tube gear is preferred by many, myself included, even if measured performance is not better.  The same probably applies to rectifiers vs. diode bridge.  A local dealer who also makes tube gear uses both.  He recently found an electrical engineer who designs, builds, and repairs gear as a sideline.  Although he is new to the shop, he makes bold decisions.  He took home to repair one of the shop’s custom build.  After fixing it, he said he was thrilled with the sound but thought that an amp this good deserves a tube rectifier and converted it without bothering to get permission.

I use tube rectifiers in my builds, partly to conform with the vintage circuits I’m trying to replicate, and partly because I prefer the sound. Even with ultra-fast diodes I can still hear a slight coarseness and reduction of fluidity and "air." OTOH there tends to be an improvement in the bass response, so it’s a bit of a trade-off. Another advantage of, say, a 5AR4, is the slow warm-up. With solid-state diodes you can, of course, add a delay circuit, but this adds more complications to the build.

That said, a lot of very nice vintage tube amps used diode rectification--the HK Citation II, the Eico HF-87, the Fisher 500C, among others--and very few tube-lovers will take issue with the sound of those pieces. And for anything above 30-40 watts per channel, solid-state rectification is probably a better way to go. And like any other audio design, you can voice the amp in many different ways to compliment the power supply design you choose.

For my purposes I stick with tube rectifiers because to my ears, and within the limits of the amplifiers I build, it’s just a nicer sound.