Dual Rectifier Guitar Amplifier...wtf?

"D from BC" <

** In a Mesa Boogie, dual rectifiers = two 5U4s wired in parallel, cos one is simply not enough to do the job in a 100 watt amp. However, some Boogie " Dual Rectifier " models use only silicon diodes.

The name is a registered trade mark of Mesa Engineering, so can be used purely as marketing hype.

Far as Boogie amps design and construction is concerned - I am 100 with Sylvester the Cat when he famously pronounced

" I hate those Mesas to pieces !!! "

....... Phil

' Mesa/Boogie (also known as Mesa Engineering) is a company in Petaluma, California that makes amplifiers for guitars and basses.

Mesa was started by Randall Smith as a small repair shop which modified Fender combos to give them more gain.'

sniped from

thats just what we need - more distortion

neil.

Check out the part on

snipped 'The MESA Boogie Rectifier Recording? PreAmp is basically a Rectifier, designed for silent recording. It can also be used as the front end of a rack mounted Rectifier guitar setup."

Basically a rectifier....huh?? When I hear rectifier I think of things like diode, bridge and unidirection current. Is it some sort of tube lingo? D from BC

groan... So...it's just doubled up diodes/tubes for the power supply.

D from BC

I found schematics here:

The rectifiers are in the PSU. Not surprising, I guess.

As for why they provide an option to switch the PSU between between silicon diodes (4007) and valves (5U4), I don't know whether this is just marketing voodoo or if it's actually a useful acoustic reverb mechanism.

"D from BC"

** Mesa also make a " Triple Rectifier " model as well - with guess what ?

Yep - three 5U4s in parallel !!!!

Widely rumoured to be the favourite guitar amp of Saddam Hussein.

How did the former dictator sound ?

Like Shiite - of course.

...... Phil

This valve mania is getting beyond ridiculous. I saw a promo on a music website for a particular 'high end' musical perfomance amp, cost over $4000. It used 6L6s. IIRC the 6L6 is a piddly little tube, just a bit bigger than the 6V6 which was the audio output stage for most mantel radios for many years.

It's a very expensive fuzzbox with a response that will please even the most discriminating heavy metal guitar phool's ear: "The amplifier has a very low-midrange voicing, and very strong in the bass frequencies. It also has excessive preamp gain, amplifying frequencies to the state of thin, harsh buzziness." ;-)

"dual-rectifier" just means that it chops both half-cycles, for that "symmetric" sound. ;-)

The simplest fuzzbox is a diode in series with the speaker.

Cheers! Rich

Diode in series with a speaker....ewwwwww.. :P D from BC

I saw that in Poptronics or something about 40 years ago. ;-) Here's one that's close:

Cheers! Rich

A very long time ago I did try to design some fuzz boxes.. I think I was trying to create 2nd order transfer functions for even order harmonics (2,4,6,8..etc..if that's right) and playing with expander/compression/limiter (compander?) type circuits.

I think I also tried some stuff kinda like what's done in RF mixers for frequency conversion. D from BC

I've just discovered about 48X 1N4148 diodes in one of my junque bins; I have a 556 - I wonder if it'd be worth the bother to make a Dalek. ;-)

Cheers! Rich

Dalek's are made with computers running CGI software.. :P D from BC

What does "voicing" mean?

John

It's like "timbre" - like, for example, differently shaped organ pipes have different combinations of harmonics/overtones, and the distinct sounds for a set of pipes is tne "voice" or "voicing". Some high-end organs have a "vox humana" which sounds very much like a person singing "ah....."

You have a certain amount of control over it with your bass and treble controls, or a graphic equalizer.

I guess what distinguishes one "voice" from another would be the overall shape of the spectrum.

Hope This Helps! Rich

Ah. Another subjective, undefinable audio term. I'll add it to my list.

John

Not always, used in studios (as voiceing a room) for fine tweaking the acoustics and getting the speakers to sound good, usually adjusting the sound adsorbers, getting the reverb correct, and the scientologists use 1/3rd octave equalisers in the feed to the speakers amps, evil bastards

more here

Martin

Phil Allison snipped-for-privacy@tpg.com.au posted to sci.electronics.design:

Wasn't that Jinks the cat (Ol' Jinxie)?

I have no doubt that it is definable, but a time varying spectrum and amplitude graph would be beyond the real world comprehension of most of us. Could you relate such a graph to the sound of a violin or a piano or even an electric guitar?

Jim