Mesa Rect-O-Verb conversion to tube rectifier

[BrianBB]

Hi everyone, I'm new to the board.

I just bought my first Mesa, a brand new Rect-O-Verb 2 combo. I love the sounds I can get but the amp sounds very tight. I wanted to know if it's possible to convert to a tube rectifier to gain more sag in the output. Also, will breaking in the speaker help soften the sound?
Thanks,
Brian

 

[Monsta-Tone]

You would have to add another transformer for the filament supply of a tube rectifier.


But, Weber VST offers what they call a Copper Cap. It is a simulated tube rectifier. They come as a module, or a tube like device which would plug into a tube socket.



http://www.tedweber.com/

They have many different models to create any sag or voltage drop you could possibly want. The "Module" type simply screws onto your amp's chassis and gets wired up where your old silicon rectifier is now.

 

[BrianBB]

Thanks Monsta-Tone, that may be the answer. I read in the manual that the tone controls have a large effect on sag and sensativity as well. What about the speaker, is that part of the tightness and will it loosen up over time?

 

[chennie]

Breaking in speakers help a lot !
See the topic on this forum for "instructions", you could also try to replace the 6L6 with the EL34 tubes.

 

[Monsta-Tone]

That's funny, I didn't even notice the wor "New," when I read your post.


You wil absolutely need to break in the speaker. Your amp will sound 10 times better afterward.


If it still souns too tight, replace the Preamp tubes with JJ's. Bob at Eurotubes offers a "High-Gain" set for about $50.

I ran mine with EL-34's. It makes the amp breakup very nicely. You will, hoever, loose some of the headroom that the 6L6's offer. This means that at higher volumes, the amp will have much more distortion, especially on the Clean channel.

A good rule of thumb is to turn down the Gain as you turn up the Master Volume.



I think that if you play your amp enough to break it in, you will be pleasantly surprised at how versatile and incredible the Rectoverb can sound.

Can you tell I miss mine?

 

[BrianBB]

Monsta-Tone, I am already amazed at the sounds I can get from this Rect-O-Verb. I am used to Marshall plexis, can I say Marshall here?, and am always looking for more gain. No more, with the Recto there's more than enough. Turning the mids down helps to increase sag. Any suggestions how to break in the speaker? Thanks, Brian

 

[Monsta-Tone]

Brian,

If you are used to Marshall tone, you should definitely try the EL34's. You won't be disappointed.

If you have ever had the pleasure of playing a Lee Jackson amp, the EL34's in a Rectoverb will get you so close that you won't be able to tell the difference. Except for the fact that there is so much more BAASSSS in the Rectoverb.



As for the speaker. There are many theories about this. Ted Weber says that you should hook up a function generator and send a 60 hertz signal through it for several hours.



I do something much more easy. When you would normally turn your amp to Standby, don't. Let it run for a while with just the hiss from the Lead Channel.

Don't leave it on overnight. You will kill your amp. But, when your band is on break, leave it on. Turn the Master Volume down so that the Hiss is barely heard.

I've also tried turning the guitar up just enough to get some hum (I play mostly Strats), or placing a noisy 12AX7 in the amp to induce some hum. The tube thing works very well, but may affect the tone when playing. I don't mind since all of my noisy tubes are GE or Mullards.



Your speaker will start to bloom more in no time. If you do this for a couple of practices, you will definitely notice a difference.


The other thing you can do is play the hell out of it. Try the amp at different Volumes. Don't be afraid to go loud. Mesa has already tested your amp. Break that puppy in.



When I got mine, it was used, and very well broken in. I found the MC-90 speaker to be too tight sounding on the Cleans, but very good on the Lead Channel. I eventually replaced it with a Vintage 30. This is what the amp needed, the Vintage 30 really opened it up nicely. The Cleans were sweeter, and the Leads were still stiff like Angus Young's upper lip.

 

[BrianBB]

I have never played through, or even heard of a Lee Jackson amp. I like EL34s but want the clean headroom of the 6L6s for greater versatility of the amp. I bought the amp for its aggressive modern sound but like it for it many sounds. Among others, I want to try for a gutteral 70's Marshall sound, open and organic.

I'll try the break-in technique you suggested. How does your Vintage 30 handle the power of the Recto 50? I guess a 25w Greenback would not be enough to handle the tight bass of the amp.

 

[BrianBB]

I have some old Philips EL34s but don't know how to switch the bias on the back of the amp. Is it a guarded switch? Do I need tools?

 

[chennie]

I just flip it with my fingers, and it works fine as in I have no damage.

 

[BrianBB]

Do you have to pull a guard off the back or something to get to the switch? I only see a black plastic cover on mine and don't know if that slides or comes off.

 

[jbird]

It simply slides to the left or right. :wink:

 

[BrianBB]

J-bird,
What I see on mine is black plastic, about 3/4" by 1/4" and flush with the back of the amp. It has a small slot in it where you must either slide it or remove it. Is that what yours looks like? Thanks.

 

[Monsta-Tone]

I have never played through, or even heard of a Lee Jackson amp.

Lee used to modify Marshalls for all of the guys in Hollywood/LA in the 80's. He and Mike Soldano are the main reasons why every Metal Head in those days could get the tones they had. Soldano moved to Seattle and makes some serious amps. Lee Jackson started Metaltronix. He even had George Lynch endorsing his amps for a while.

I think that Mike Soldano is a much better business man though. He has really flourished.

Lee also worked for Fender and co-designed a couple of amps with Rivera.

He designed the VL series of amps from Ampeg which are killer.

www.leejackson.com , or do a Google search.








As for the Bias switch, I think it's a sticker or piece of tape over the switch. When I got mine, it already had EL34's in it, so I never saw the way it looked brand new.

It should be a slider type switch that you have to use a pick or screwdriver to move. If you don't see it where it should be, consult your manual or call Mesa. They are eager to talk about their amps and are very helpful.

 

[chennie]

from the mesa site

This is the switch, for all I know there are no covers, tapes, secret slide doors or boobytraps on this switch. You can slide it to the left or right.

 

[BrianBB]

chennie, yes that's what the switch looks like the one on mine. I didn't want to force anything but I'll see if I can move it.

Monsta,
Thanks for the history on Lee Jackson and Soldano, et al.

I find that the tone controls on the Rect-O-Verb are more responsive and interactive than my other amps. My Vox AC30 for example has only one sound and very little variation in tone by moving the controls. The Recto has lots of variation. I'll stay with the 6L6s for now, I'll be glad when the speaker softens up a bit.

 

[exposeenmity]

I'm not familiar with the term 'sag' that was used, could someone explain what that is?

 

[BrianBB]

Sag is what you feel or hear when you hit a hard chord and there is a fraction of a second delay before hearing the sound. You don't really hear the delay but you feel it because it adds a softness to your playing and doesn't feel so brittle. I don't know if I can explain it any better than that but both have their advantages.