What Does Dual Rectifier Mean? Mesa Amp Explained 

Personally, I’m all about solid state rectified amps. It’s why I love the old big Fender piggy back amps, i.e. Bassman, Showman, Bandmaster, etc. They all have solid state rectifier. I understand people play a lot of lead guitar, bluesier stuff, prefer tube rectified because it’s softer and squishier. But i strictly play rhythm guitar, often with the amp turned up a lot. For that kind of rock rhythm guitar, I find solid state rectified to feel and sound better. It’s got slightly tighter low end, and it’s a more direct sound/feel.

Great video. One correction though, the spongy and bold switch does the opposite of what you were thinking. The bold side ups the voltage and the spongy side is lower. Here's a forum page talking about that. Also, the difference between tube rectification and diode rectification is actually surprisingly noticeable when you're standing in front of the amp and listening to it. I have the amp, and have switched back and forth many times, using brand new 5U4G tubes to rectify the signal. Try it sometime! It is a very different sound, at any volume level. Diodes make it sound more like a distortion pedal, very consistent and uncompromising, whereas the tubes have more give and complexity in tone, simply because they inconsistent (inefficient) power supply to the tubes let's them "breathe" more, giving the response of the amp an overall more spongy feel, especially on the spongy setting! It is also louder to use diode rectification, as there's more power getting to the tubes, and of course, louder even more when using the bold setting. I like to use spongy and tube rectification and if I want a more distortion pedal like sound, bold and silicon diodes really kill. But my favorite sound is with tubes and spongy setting. It's easier to listen to for longer www.rig-talk.com/forum/threads/dual-rec-vaccum-silicon-and-spongy-bold.130976/#:~:text=New%20member,-Jan%2029%2C%202013&text=spongy%2Fbold%20affect%20the%20voltage,browner'%20tone%2C%20go%20spongy.

Nice vid. I liked that you went into wiring diagrams to explain it a little deeper, made it more interesting.

Amazing video!

Very helpful/ Thank you/

Rectifiers do and will always...affect the sound character of tube amps. SSR/VTRs each directly changes the plate voltage with VTR lower and SSR higher plate voltage. This will most pronounced when using SiC SSR.

Can you explain how exactly using A1M (used in early revisions) gain pots over A250K (used in following revisions) gain pots fix "the bass issue"?

Ever come to a video for an explanation and leave wishing that you were the one doing the explaining?

Can you do made in USA Ampeg SVT CL?

Wow, more great info Kley. Thanks so much. Question: is the term "dual rectifier" because there are 2 tubes/2 diodes or because the rectification is 2 types i.e. either solid state (diodes) vs tubes? I have a Mesa Lonestar Special (great sounding versatile amp) that uses a 5y3 tube rectifier for the 5 watt and 15 watt settings and uses solid state diode for the 30 watt setting. Is that also a "dual rectifier"? Thanks again.

Awesome video again Kley, always wondered why they'd need a Dual Rec tube in that Amp! Makes sense but like you said, probably not really needed when they have the Diodes as an option

It's actually opposite bro.....bold is higher voltage and spongy is slightly lower

Mesa is giving so much protagonism to a meaningless part of the sound of the amp. Any difference in feel from tube recs comes to play in stadium volumes. For me its more of a marketing scheme to give the customer more tubes and more parts to fail on already overdone amps. Could've called it Mesa Quad Diode Rectifier and some people would fall for it.

I went through half the video and you still did not explain why they use TWO rec tubes instead of one...!!

All I can say is Mesa Boogie amps try to do too much. I don't like them. Give me a simple straightforward amp. I don't need or want all of those little bells and whistles. Plug it in, get a great tone. That is all I want. Oh, I want it to stay that way for decades too. K.I.S.S.

The dual rectifier was supposed to be a series of amps. It’s only dual rectifier because you can switch between solid state or tube rectification. Some lower wattage amps like the blue angel had only one rectifier tube. The tremoverb had a better high gain sound than the solo head which is now only known as the dual rectifier. Personally I think this amp is the most overrated piece of shit mesa ever made. Their most underrated was the mark III