Orange Amps Forum

Anyone have experience with putting a SS rectifier in your AD30?

If so - what are the results?
Did it catch on fire, or rock your world?

It's safe to do. However be aware, it will increase overall B+ (plate voltage) by 10-20%.

Because there is no warm up of a rectifier tube when using a solid state device, it is critical that a standby switch is used that will allow the power tube filaments to warm up and generate an electron 'cloud' around the cathode before high voltage is applied. This will prevent 'cathode stripping' in the power tubes. It is a good idea to use a standby switch when using vacuum tube rectification, but it is critical when using solid state rectification.

Sound results... less bass, tighter low end. However, I never felt this was really a problem that needed changing with the AD30. You'd get better results by upgrading to a nicer quality tube like a Gold Lion GZ34 for the 5AR4 that's in there now.

Putting solid state ANYTHING into a tube amp just seems sacrilegious.

Fewer valve amps have valve rectifier, and the non valve rectifed are still plenty good.

Nothing sacrilegious about it, it's more valve snobbery really.


It's meant to make them tighter sounding, losing the sag typical of valve rectified amps,as demonstrated with the Ad30. Tone.

No idea but I dont really know why want to........

I'll be the judge of what's "sacrilege" for my amp.

LOL at "valve snobbery." I think there's truth in it, though.
He is right about the plate voltage change; the "rush", particularly.


Tighter response, not necessarily a change in "tone" is what I seek.
I've got new(er) JJs in the amp -

I may put the stock tubes back in the non - phase inverter slots to see what happens.

Because there is no warm up of a rectifier tube when using a solid state device, it is critical that a standby switch is used that will allow the power tube filaments to warm up and generate an electron 'cloud' around the cathode before high voltage is applied. This will prevent 'cathode stripping' in the power tubes. It is a good idea to use a standby switch when using vacuum tube rectification, but it is critical when using solid state rectification.

No it isn't.
Please read:
http://www.valvewizard.co.uk/standby.html" onclick="window.open(this.href);return false;
http://www.antiqueradios.com/forums/vie ... =1&t=45331" onclick="window.open(this.href);return false;

I've got a valve amp from 1972 with no standby switch, the original Mullard EL84s are still working fine, it has a solid state rectifier.
Lots of old valve audio equipment have solid state rectifiers with no standby switches and work just fine, for many many years.

Cheers
Jon

BrianFantana wrote:Anyone have experience with putting a SS rectifier in your AD30?

If so - what are the results?
Did it catch on fire, or rock your world?

http://forum.orangeamps.com/viewtopic.p ... te#p617494" onclick="window.open(this.href);return false;

0000 wrote:It's safe to do. However be aware, it will increase overall B+ (plate voltage) by 10-20%.

Need to be sure that the filter caps are rated for a high enough voltage to cope with that. Otherwise expect things to happen. (Not good!) Electrolytic caps don't take well to over-voltages!


Andy.

BOOM!

Thanks for the link; I didn't have time to search for the thread (on my phone at work) and my cell service is terrible there.

jontheid wrote:

Because there is no warm up of a rectifier tube when using a solid state device, it is critical that a standby switch is used that will allow the power tube filaments to warm up and generate an electron 'cloud' around the cathode before high voltage is applied. This will prevent 'cathode stripping' in the power tubes. It is a good idea to use a standby switch when using vacuum tube rectification, but it is critical when using solid state rectification.

No it isn't.
Please read:
http://www.valvewizard.co.uk/standby.html" onclick="window.open(this.href);return false;
http://www.antiqueradios.com/forums/vie ... =1&t=45331" onclick="window.open(this.href);return false;

I've got a valve amp from 1972 with no standby switch, the original Mullard EL84s are still working fine, it has a solid state rectifier.

Lots of old valve audio equipment have solid state rectifiers with no standby switches and work just fine, for many many years.

Cheers
Jon

This is a bit off topic but that valve wizard link was an interesting read. While most of it goes well over my head, this paragraph certainly got my attention:

On the other hand, leaving a cathode hot without any anode current flowing does lead to the very real effect of cathode poisoning, which reduces the gain (transconductance) of valves. Fortunately this phenomenon really only becomes significant if the valves are left on standby for hours on end.

I often leave my AD50 on standby, sometimes for hours if I'm in and out of my music room doing other things. I thought I was doing the right thing "keeping the valves warm" in between playing. Should I just be switching it off?

Ade

I'd say a solid-state rectifier is worth a try if it's less sensitive to wall voltage irregularities than a rectifier tube. It sounds like the Sovtek SSR is supposed to sound tighter than the Weber, but that might just be internet nonsense.

The more gain, the more a SS recto would be best. I like tube recto for my amps..Fenders and Marshalls. If you want JCM800 type gain or more Solid State recto is the way to go. Anything less than say Judas Priest to Guns and Roses i would go Tube recto. just my opinion.

Mike

a.hun wrote:

BrianFantana wrote:Anyone have experience with putting a SS rectifier in your AD30?

If so - what are the results?
Did it catch on fire, or rock your world?

http://forum.orangeamps.com/viewtopic.p ... te#p617494" onclick="window.open(this.href);return false;

0000 wrote:It's safe to do. However be aware, it will increase overall B+ (plate voltage) by 10-20%.

Need to be sure that the filter caps are rated for a high enough voltage to cope with that. Otherwise expect things to happen. (Not good!) Electrolytic caps don't take well to over-voltages!


Andy.

Filter caps in the AD30 are rated at 450V. IIRC, B+ in mine is around 360V, and mine runs a little hot. He should be fine.

I say do the math, and if your B+ will be within 450V, and the tubes aren't running too hot, go for it. Measure the static draw across the cathode resistor. IIRC, stock should be about 11V per pair. I see 12.5 or so. You'll probably see 15 or 16W or so per tube. That's reasonably hot. If it's much higher than that, it may behoove you to change the cathode resistors out for higher values.

If it's running within reasonable parameters and you like the sound, that's all that matters. However, the amp will still be cathode biased and still have no negative feedback loop. A lot of the loose feel comes from those attributes.

Ade wrote: I often leave my AD50 on standby, sometimes for hours if I'm in and out of my music room doing other things. I thought I was doing the right thing "keeping the valves warm" in between playing. Should I just be switching it off?

Ade

For hours? I'd turn the amp off.

That being said, I wouldn't sweat this stuff too much unless you're running expensive NOS tubes. Tubes can usually take a lot more than we give them credit for. These days I rely more and more on the "if it sounds right, it is right" mentality. Are your tubes worn from cathode poisoning? If the amp sounds good to you, who cares?

I recently re-tubed a friend's JCM800. He's owned the amp for 10 years and never replaced a single tube in it. He plays the amp cranked up literally on 10 multiple times a week. I pulled out a set of Sovtek EL34's of unknown age. The tubes were running at...get this...22W static plate dissipation. I don't know exactly what the Sovteks are rated for, but that's like 80 or 90% of the max...for at least 10 years!

I threw them on my tube tester, and they still had a little life left in them.

Anyways, we replaced the tubes because the amp wasn't sounding good anymore. He had me put it right back at 22W. If it sounds good, it is good.

-Nick