slyym
Member
My owners manual says you can take out tubes to lower wattage for the dual rec, but doesnt say that you can for the triple. Is it possible to lower the triples wattage in this way? Thanx..
Triple rec ???
- Thread starter slyym
- Start date
Help Support The Boogie Board:
tele_jas
Well-known member
I talked to Mesa Boogie about this.... and the answer was "No, you can't do this". They said with the Triple, it would throw the ohms off "un-evenly" since you are basically reducing the power by a 1/3 or 2/3 and there is no mathmatical formula that would work to get the ohms correct and would eventually cause some serous damage. He did say, if a tube blew and you had to pull the other tube (the matching one in the set) you could probably make it through a show...... but he wouldn't recommend it.
That's what I was told, I know that's probably not what you wanted to hear....... but I hope it helps.
That's what I was told, I know that's probably not what you wanted to hear....... but I hope it helps.
tele_jas said:
Yeah, it's not an even match, but you still would be able to do it and run the amp safely to a certain point.
If you pulled a pair of tubes, this is what your outs would look like:
16 ohm speaker out would be an 11.2 ohm speaker out..... 16 ohm cab is fine and it's a safe mismatch, yet it might not sound all that great.
8 ohm speaker out would be a 5.6 ohm speaker out..... 8 ohm cab would be fine here
4 ohm speaker out would be 2.8 ohm speaker out.... A 4 ohm cab would still be fine
If you pulled two pair of power tubes:
16 ohm out would be a 5.3 ohm out = 8 ohm safe
8 ohm out would be 2.6 ohm out = 4 ohm safe
Another way you can look at it is this:
The Triple Rectifier's bias is pretty cold in it's stock setup. Your output transformer isn't seeing any additional current when you pull power tubes and fail to compensate for the impendence differences. The only thing that happens is that your power tubes will have a strong load placed upon them. Again, the Triple Rectifiers are biased pretty cold, so it "might" not hurt the amplifier, but I haven't ever tried this and do not plan to do so either. I can bias an amp and have seen and understand what's going on with the Rectos as far as the Plate Voltages and Bias is concerned. I've studied that thoroughly. Anyway, this isn't something that you want to do, unless you're wanting to experiment and see what happens. You will also want to be in a position to where you're comfortable with repairing your amplifier if something bad happens. Personally, if I were to look at this, I would take a look at this while the amp was in it's Spongy/Tube setting because that's where the lowest plate voltages are and that effects the cathode current, which is also extremely low.
So, there are different ways to look at this. I'm not telling anyone to run out and go do this. It's just for educational purposes.
Dale
slyym
Member
I did call mesa today and the dude told me that it was safe to take out the power tubes that are at the ends ( 2 of them) and one recto tube. He did say not to take out any more though.If I try this and it is bad, what is the worst thing that will happen to my amp. **** tripple rec just has way to much power for me and it really only sounds good when I crank it up.Right now I'm only able to turn it up to about 3 which doest really sound all that great. He did say that I can turn on the fx loop and just turn down the send level which would lower the gain a little. One more question, if I take out the tubes do I still run my 8ohm cab into the 8 ohm jack, or should I go to the 4 ohm jack. Thanx for the replys guys.
slyym
Member
anybody want to trade my triple for there dual?
slyym said:
Personally, I wouldn't do it and I don't see where this is going to benefit you volume wise. The amp is still going to be extremely loud and you're not going to notice a whole heck of a lot of difference in volume due to the fact that you would have to knock the power down to 1/10 of the total power in order to cut the volume in half from an audible standpoint. 1 tube watt of power is just a bit louder than a fully cranked television set in your house.
Also, the Output Transformer in your amp was designed to run with all of the power tubes in your amplifier. When you pull tubes, the tone will darken somewhat and you're going to reduce the "flavor" your Output Transformer is adding into the mix.
Like I said earlier in my previous post, you can pull a pair of output tubes and it should run safely, but it's probably not going to sound all that great due to the impendence mismatches being as far off as they are. I've had some amplifiers sound like weak radios when I forgot to match the impendence.
All I can say is run it like it's designed and use your master volume. If you don't like that, sell the amp. If you get a Dual Rectifier, you're still going to have volume issues as well. The Triple is a very loud amplifier and so is the Dual as well.
Pulling power tubes isn't the magical cure and it definitely will not produce any wonderful benefits in my book.
And as far as the Impendence Matching is concerned, read my earlier post again. I specified what will happen when you pull power tubes in a Triple Rectifier.
Dale
slyym
Member
Cool. Thanks for your very informative posts Dale. I guess my best bet would be to sell it and get a single rec cause that is all the power anybody really needs. The 100 watt amps I've had before were never turned up past 40-50% no matter where I played at . One more question , Tube amps sound there best at about 70% volume, correct? You kinda want to over drive the tubes a little from what I've heard.
slyym
Member
Oh yea, Dale, I'm prolly gonna try this and see what happens but was I correct about taking out the tubes from the far left and far right possitions, or take out tubes that are next to each other? In my manual it says for the dual to take out the 2 center ones. Again thanks for your replys.
tele_jas
Well-known member
The tubes are paired from the inside going out.......
* So, the two middle ones are a pair
* the tubes one out from the middle are a pair
* and the tubes on the outside are a pair
(Kind of like playing chop sticks on the piano :wink: )
* So, the two middle ones are a pair
* the tubes one out from the middle are a pair
* and the tubes on the outside are a pair
(Kind of like playing chop sticks on the piano :wink: )
It sounds to me like the solution to your problem is a THD Hot Plate. 
Seriously, I know you can pull the outer two in an *emergency* (like to get through a show), but I wouldn't run it that way for longer than you have to, since the impedence mismatch is kind of goofy.
Seriously, I know you can pull the outer two in an *emergency* (like to get through a show), but I wouldn't run it that way for longer than you have to, since the impedence mismatch is kind of goofy.
slyym
Member
What is the thd hotplate?
It's an attenuator - that is, it allows you to turn up your amp, so the power section gets "cooking" - and still play at reasonable volume.
