Differences in model year of 50/50 power amp?

[Rob227]

I am looking at replacing my Peavey classic 50/50 power amp (el84) with a Mesa Boogie 50/50 power amp (6l6) and I have heard that there are some minor differences in the same model over the years. I have a quad preamp that I am going to use with it and I want to know if there is much difference in a newer or older model.

Is it true that some of the old units didn't have any 12ax7 tubes? And they just had four 6l6 tubes?

The price difference between an older model and a newer one isn't going to be much, I just want to get the best possible model I can. Does anyone know the differences or what year I should be looking at getting?

Thanks.

 

[crane]

No, every model has some preamp tubes (12ax7), two for the PI (one per channel) and one as input tube (one triode per channel).
The difference between the olds (there are severals I think) and the new is the voicing.
The new one has more "modern" sound, and the old one was voiced for the Studio preamp, then for the Triaxis (Maybe there are some other voicing).

 

[Darth Bacelar]

I think the change in the voicing, it´s about the deep mod.

When mesa changed the 50/50 to match it with triaxis, they added a deep function, similar to the deep mode in the 2:90, only that it always working. And, they changed that about 93-94' I believe...

 

[Rob227]

I'm still not really clear on if I should get the newer model or older one. It would seem that the older unit is voiced to the studio/quad preamp but how much of a difference is this really going to make? Is the newer voicing just better overall?

 

[Rob227]

I've been doing a bit of review reading and I'm starting to think that I should get an older one voiced for the studio/quad preamp. Mostly what I want is an 80's metal tone for lots of soloing and sizzling riffs. I don't want an overly bassy tone except for the mark 3 lead channel of the quad so making it overly deep overall might not be a good thing. I hope I don't miss the resonance/bass control knob the peavey has in the power amp that the mesa doesn't have.

 

[Darth Bacelar]

Well, I use a modern 50/50 (from 2002) with the Quad, and it´s ok for me... It has a lot of bass if you want it!

But well, if you don´t want too much bass, you always turn dows the 80/240 sliders and still fine

 

[Rob227]

Hehe, good point. I'm probably getting overly worked up over nothing and any model of 50/50 is going to be a nice upgrade from the Peavey 50/50.

 

[shatteredsquare]

how do you tell which one you have? I have one with the blue light, is that the older model or the newer one?

 

[giorikas81]

The only difference is a cap before the power amp that if clipped, stops filtering bass. As a result the deep mod is nothing more than letting the power amp handle more bass. A simple push pull switch can be made to have this mod to both channels, on the volume pot (push normal, pull deep).


That means buy whatever you want and you can reverse it to the other state easily. By the way you may like the idea of "more bass" but I've found out that is not always the case in a band scenario and mr midrange, cuts through better and is easier to amplify louder.

 

[rjriley1]

I own 2 older Mesa 50/50's. I have one on a Studio Pre. Sound is awsome. I have another 50/50 on a Triaxis. Sounds awsome. I have newer Mesa 2:90 that sits. It sounds good but thinner than 50/50's. It seems like it is missing something and I can't quite put a fingert on it. I prefer the older Mesa 50/50's..you can buy them cheap used on Ebay ($400-500)...the inside components /electronics/boards are more iron clad solid than the new amps. A Mesa Cert amp tech told me the older Mesa amps are build better. Just look inside and make your own educated opinion. The older amps are bulkier and rough. They look like they were build in someones garage and not on an assembly line. I'm driving 2 full stacks of Mesa traditional cabinets (16 12" speakers) with one 50/50 amp. Buy an older Mesa 50/50 and never look back.

 

[Triaxstasy]

Hi,

there are quite some more differences. I modded mine according to a Mesa modification instruction document.....
I posted a detailed instruction including pics following all steps from the modification document on the adadepot forum....
Here´s the link

Greets

Magnus

 

[crane]

Thanx for that link Magnus !