Solid State vs. Tube Rectifiers

[archie2]

What are the advantages/disadvantages of SS rectifiers vs. tube rectifiers in an integrated tube amp?

 

[timgr]

The main advantages of tube rectifiers are a slow turn-on, and no (less?) switching noise. Solid state diodes are simpler and have a lower impedance. And don't require a filament supply, and shed less heat.

 

[battradio]

Use both ,some low noise diode like UF4007's in series with your 5AR4 or 5U4GB and you tube will last a lot longer , the diodes do the work and the tube provides the voltage drop and the time delay .

 

[Shadowdog]

As mentioned UF4007 or better is the way to go. Not all tube rect. give the slow warmup. 5AR4/GZ34 does for sure.


Randy

 

[BillyB]

What about tone??

Does SS sound differnt than tube rectifier?

 

[BinaryMike]

SS rectifiers can affect tonal quality in a few ways:

They improve power supply regulation, which reduces bias shift at high signal levels, thereby rendering the amp's transient response more accurate and its listening qualities more consistent at varying levels. Better regulation also implies increased maximum power output.

They increase power supply voltage unless that effect is compensated somehow. If it's compensated with resistance, then regulation may be no better than a tube rectifier. Increased supply voltage shifts bias points and increases available power output, assuming the amp design is robust enough to survive the experience. Shifted bias points can result in better or worse performance (much like tube rolling) depending on how well the original design hit the sweet spots.

They reduce amplifier operating temperature, which can slightly improve transformer performance and might have subtle effects on other components.

 

[jaymanaa]

As mentioned UF4007 or better is the way to go. Not all tube rect. give the slow warmup. 5AR4/GZ34 does for sure.


Randy

I would think that all tube rectifiers give at least some measure of delay, as they all have a ~10 second warm up period.

That said, the first time I built and heard a SS choke input supply, I was sold.

 

[jaymanaa]

SS rectifiers can affect tonal quality in a few ways:

They improve power supply regulation, which reduces bias shift at high signal levels, thereby rendering the amp's transient response more accurate and its listening qualities more consistent at varying levels. Better regulation also implies increased maximum power output.

They increase power supply voltage unless that effect is compensated somehow. If it's compensated with resistance, then regulation may be no better than a tube rectifier. Increased supply voltage shifts bias points and increases available power output, assuming the amp design is robust enough to survive the experience. Shifted bias points can result in better or worse performance (much like tube rolling) depending on how well the original design hit the sweet spots.

They reduce amplifier operating temperature, which can slightly improve transformer performance and might have subtle effects on other components.

And, if it's a tube to SS conversion, you also get the benefit of a lighter load on the power TX primary, as you no longer need to use the rectifier filament power (as much as 3amps @ 5v for a typical 5U4). So the operating temp of the PT comes down a notch too.:thmbsp:

 

[Kegger]

Just use tubes, they work and sound better..

 

[PakProtector]

I would think that all tube rectifiers give at least some measure of delay, as they all have a ~10 second warm up period.

That said, the first time I built and heard a SS choke input supply, I was sold.

First pair of ground-up amps I did with SS choke input; SiC 1200V/5A from Cree. Re-using those same chokes with 866 rectifiers( bringing those amps to the Fest ). All the IDH rectifiers, damper diodes inclused fall into a 10-15 second delay. DH like 5R4 and 5U4 are more like a second with of delay( with 5R4 being faster ).

Now there some eceptions, Bendix Hy-G-300 rectifiers take more like 35 seconds to conduct...and Hg you warm those first so the issue doesn't really matter.
cheers,
Douglas

 

[jaymanaa]

First pair of ground-up amps I did with SS choke input; SiC 1200V/5A from Cree. Re-using those same chokes with 866 rectifiers( bringing those amps to the Fest ). All the IDH rectifiers, damper diodes inclused fall into a 10-15 second delay. DH like 5R4 and 5U4 are more like a second with of delay( with 5R4 being faster ).

Now there some eceptions, Bendix Hy-G-300 rectifiers take more like 35 seconds to conduct...and Hg you warm those first so the issue doesn't really matter.
cheers,
Douglas

What do you think is a reasonable time to warm up an hg before applying current?

 

[PakProtector]

What do you think is a reasonable time to warm up an hg before applying current?

I'd be comfortable with as little as 15 seconds. That for a regular use scenario that did not involve cooling the tube in something other than straight up. I have read the box inserts that direct long first-time heating( on the order of half an hour ). Once past that, with the Hg properly condensed in the bottom of the tube I bet you can get away with 10 seconds before you start to notice any degredation( using a large sample to sift out the experimental noise ). In the new amps I am running 6NO30 'cause I have more of them than 6NO45...and no 15 second ones...all are 9-pins scored with scopes so what ever Tektronix wanted, eh?
cheers,
Douglas

 

[archie2]

Just thought I'd try the SS plug-in in place of my present 5U4.

 

[archie2]

Put in a SS plug in place of the 5U4 rectifier in my Eico ST-40. All tubes are significantly dimmer and cooler. I don't notice any change in sound quality. There may be some, I just don't hear it.

 

[electroking]

Put in a SS plug in place of the 5U4 rectifier in my Eico ST-40. All tubes are significantly dimmer and cooler. I don't notice any change in sound quality. There may be some, I just don't hear it.

Dimmer? I don't get it. Were they red-plating before?

 

[Bill Ferris]

I would think that all tube rectifiers give at least some measure of delay, as they all have a ~10 second warm up period.

That said, the first time I built and heard a SS choke input supply, I was sold.

 

[larryderouin]

Dimmer? I don't get it. Were they red-plating before?

I believe he's talking about the filament glow. Dimmer extends life (up to a point), lower voltage, and cooler temps from them.

 

[primosounds]

Hi Bill, i am not sure you will be getting a response from Archie as his question was posted awhile ago. But, his take on the use of the SSR in the EICO amp is puzzling since changing out the 5u4 should not have anything to do with the 6.3v filament voltage. And the use of a ssr would also mean about a 5% increase in B+ which should produce more power and drive the tubes harder which if they were borderline before would probably or more likely cause the power tubes to redplate with the ssr.

 

[Bill Ferris]

Hi Bill, i am not sure you will be getting a response from Archie as his question was posted awhile ago. But, his take on the use of the SSR in the EICO amp is puzzling since changing out the 5u4 should not have anything to do with the 6.3v filament voltage. And the use of a ssr would also mean about a 5% increase in B+ which should produce more power and drive the tubes harder which if they were borderline before would probably or more likely cause the power tubes to redplate with the ssr.

Thanks primo, but all I think I did was provide a thumbs up agreement and was not expecting a reply & and or discussion/debate..
as I stumbled across the post while lurking..
Take care Sir. Kind regards, OKB