Solid state and tube rectifiers. Educate me please!

Re: Solid state and tube rectifiers. Educate me please!

I can kind of tell the difference between solid state and tube rectifiers, but I actually can't tell the difference between different rectifier tubes.
 
Re: Solid state and tube rectifiers. Educate me please!

Sag doesn't come into effect until you're pushing the amp hard enough to pull on the rectifier harder than it can provide. If you're playing at relatively low volumes a tube rectifier will have no problems keeping up and thus will have very little effect on tone.

ahhh. thanks! yeah, it was very low volume.
 
Re: Solid state and tube rectifiers. Educate me please!

I'm gonna throw a wrench in the works here. have any of you ever heard of a Mullard 6n8 rectifier tube, and do you know what kind of rectifier tube i could use to replace it with, besides another 6n8. i got this old UNIVOX Half stack (1970's B type amp, 50watt)that i got with all the original tubes in it i changed all of them except the rectifier tube, since the guys at the store had no idea what to replace it with, and they could not find me any from any tube manufacturer. let me know if any of you have any clue.
 
Re: Solid state and tube rectifiers. Educate me please!

If it's based on the American classification system: 8 would indicate that it has more componants in the tube, than the typical rectifier. Why, I have no idea? 6 would indicate that the heaters run on about 6 volts. Most rectifiers use 5 volt heaters, but a heater on 6 volts means than the mains transformer doesn't need to have an additional 5 volt supply. The other tubes would normally use a 6 volt heater supply.
 
Re: Solid state and tube rectifiers. Educate me please!

I tryed to explain sag to my nephew a few weeks ago, and a simple way of looking at it occured to me. I remembered something Marshall engineer Steve Grindrod once said about power supplies in tube amps.

Basically the power supply sets the headroom, or amplitude (size) that the signal wave can be, before it starts to be compressed or clipped. When the voltage is lower, the headroom is lowered too. With tube rectification, the power supply changes with demand, so you essentially get sag on demand, at gig volume. That will result in a very different and more dynamic "feel". I know it's great for feel type playing, rather than changing tones with one's feet.
 
Re: Solid state and tube rectifiers. Educate me please!

That is a very good way to look at it LPB... thanks a lot
 
Re: Solid state and tube rectifiers. Educate me please!

basically a tube rectifier takes longer to get your amp power so you get sag and usually runs a lower maximum voltage . when you first strike a note it takes longer for the amp to react so there isnt as sharp an attack. the tone may also be browner due to the lower voltages. different tube rectifiers have different properties so some may sag more than others.

+1, and a solid state rectifier is basicly the opposite. It runs a higher maximum voltage, and doesn't sag as much(if at all) and makes the amp react quicker and give a sharper attack. IMO a solid-state rectifier is a MUST have for any type of harder rock/metal.
 
Re: Solid state and tube rectifiers. Educate me please!

Subs for the 6N8 might be the 6AD8 or the 6DC8...right, it's a 6.3 v heater. I remember these from the older Univox/Lafayette etc. 60's Japanese amps, used with the 6973 output tubes...all those tubes used in the off-brand amps (including the 6EU7 stuff Gibson used) are getting a little scarce. Check AES for the 6N8/6AD8/6DC8...
 
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