What does the Rectifier do?

[stevel]

I think they change AC to DC???

But why do you need to do this - and does this mean an amp could theoretically run on batteries?

Also, what's up with dual and triple rectifiers - if one is good, is two or more better, or is there some other reason?


TIA,
Steve

[Blue Strat]

Yes, they convert AC to DC. If you could get a 400+ volt battery with enough current you could run an amp on it.

Tube rectifiers can only pass a limited amount of current...enough for an approximately 50 watt amp. For higher powered amps you need multiple rectifiers in parallel to be able to provide enough current.

[timowens316]

Yes, a rectifier converts AC to DC voltage, tubes and transistors need a DC power supply. You could use batteries but a tube amp usually runs at over 300 volts DC so it would take a lot of batteries and it would affect the tone.

[somedude]

Originally Posted by stevel

I think they change AC to DC???

Correct.

But why do you need to do this

Because the power coming from your wall is AC, and your amp requires DC.

- and does this mean an amp could theoretically run on batteries?

Some amps do.

Also, what's up with dual and triple rectifiers - if one is good, is two or more better, or is there some other reason?

Dual Rectifiers were named to highlight that the amp had dual rectifiers... tube and solid state. The different rectifier types change the way the amp responds. Tube provides a darker, slower/saggier response while solid state provides a brighter, clearer, faster response.

[rrhea]

I actually wrote a post on rectifiers for my blog. I swapped out a tube for a solid state plug on my favorite amp. I explain a little about rectifiers in the process...

http://www.ryansguitars.com/2008/05/...ifier-for.html

RR

[diagrammatiks]

it makes things saggy.

[ampkitchen]

The diode was semi recently perfected, 1n4007 is a good choice

[stevel]

Originally Posted by somedude

Dual Rectifiers were named to highlight that the amp had dual rectifiers... tube and solid state. The different rectifier types change the way the amp responds. Tube provides a darker, slower/saggier response while solid state provides a brighter, clearer, faster response.

Oh, so dual rectifiers have one of each - I assumed they would both be solid state (or rarely, tube)???

Does something with dual rectifiers usually allow you to choose one or the other, or are they just there for more power.

And what about a triple rectifier?

Steve

[stevel]

Originally Posted by Blue Strat

Yes, they convert AC to DC. If you could get a 400+ volt battery with enough current you could run an amp on it.

Tube rectifiers can only pass a limited amount of current...enough for an approximately 50 watt amp. For higher powered amps you need multiple rectifiers in parallel to be able to provide enough current.

Fender Twin - 85 watts - dual rectifier? What about all those 100 watt Marshalls - I've never heard them called dual rectifiers - are they and they just don't advertise it?

Steve

[fiveightandten]

Originally Posted by stevel

Fender Twin - 85 watts - dual rectifier? What about all those 100 watt Marshalls - I've never heard them called dual rectifiers - are they and they just don't advertise it?

Steve

*Tube* rectifiers are limited in the amount of current they can supply. Solid state (diode) rectifiers can supply a lot of current if the right diodes are used. You only need one solid state rectifier. 100W Marshalls are solid state rectified. Most high powered guitar amps are.

For instance, if you had a 100W amp with tube rectification, you would need 2 5U4B rectifier tubes, or 2 GZ34/5AR4 rectifier tubes. But a single diode bridge rectifier would supply the amp with its DC power.


Something else to note is that although the high voltage power supply to the tubes is DC, the electricity that powers the tubes' *heaters* is AC in most cases. The heaters also usually draw more current than the high voltage power supply. The amp takes AC power from the wall, uses that to power the tubes' heaters, and sends AC to the rectifier in a separate section, so it can be rectified to DC power and used for the high voltage supply to the tubes.

-Nick

[FourT6and2]

"Dual Rectifier" is the name of the Mesa Boogie model. It refers to the fact that the amp has two types of rectifier circuits (tube and solid state) and the amp is switchable between the two. Marshalls (like a Super lead, for example) have no tube rectification.

[somedude]

Originally Posted by stevel

Oh, so dual rectifiers have one of each - I assumed they would both be solid state (or rarely, tube)???

No, one of each. The Single Rectifier only has a single rectifier (solid state).

Does something with dual rectifiers usually allow you to choose one or the other, or are they just there for more power.

One or the other.

And what about a triple rectifier?

It's a marketing spin on the Dual Rectifier name to highlight that it's 150w instead of 100w as it only has dual rectifiers.

[stevel]

Ahh - OK. Thanks guys.

Steve

[keithb7]

I see a 5Y3 tube rectifier in my 68 Vibro Champ. I don't recall seeing a tube rectifier in my 64 Bandmaster. I'll assume it has solid state diode rectifiers? I seem to recall seeing diodes in my bandmaster.

[riffmeister]

the wrong juice coming out of the wall needs to be rectified.