Got the new Mesa TC-50 Triple Crown, but why no 16 ohm selector?

[icipher]

got the amp, love it through my mesa 2x12 at 8 ohms.

I am concerned that there is no 16 ohm selection switch. I have Marshall 4x12's which are 16 ohm cabs. I've read many times that going from 8 ohm amp to 16 ohm cab, while safe, will result in less volume and punch which is unacceptable to me especially being in a metal band.

Every amp I've owned, which has been over a dozen, has had an option for 4,8, or 16. Why did mesa cheap out on this? Should I consider returning the amp because I am not willing to part with my 16 ohm Marshall cabs?

PS. As a disclaimer, I realize it was my lack of research that led to me buying the amp before realizing this. As I mentioned, every amp I've ever owned has had a 16 ohm selection on back, so I didn't even think to wonder about this on an $1,800 amp.

 

[TedEH]

You can do all the reading in the world, but does it *sound* like you're lacking punch when you play the amp this way? It's not worth throwing out any gear cause someone on the internet said this isn't the optimal setup. Use your ears. Does it sound fine? Then it's fine.

None of the Mesa amps I've used recently (I own a Mark IV and a V:25) have a 16ohm option, but they sound just fine through a 16ohm cab using the 8ohm plug. The manual for the V:25 suggests that these amps are designed to work just fine with mismatches as long as it's not extreme. In my experience, the difference in sound between each impedance setting is so minute that it's barely worth mentioning. It's not like using a 16ohm cab is going to suddenly put you in a spot where the amp can't keep up with the volume of a drummer or something. I've borrowed cabs at shows that were 16ohm and still gotten compliments on my amp sound despite the mismatch.

 

[JD27]

got the amp, love it through my mesa 2x12 at 8 ohms.

I am concerned that there is no 16 ohm selection switch. I have Marshall 4x12's which are 16 ohm cabs. I've read many times that going from 8 ohm amp to 16 ohm cab, while safe, will result in less volume and punch which is unacceptable to me especially being in a metal band.

Every amp I've owned, which has been over a dozen, has had an option for 4,8, or 16. Why did mesa cheap out on this? Should I consider returning the amp because I am not willing to part with my 16 ohm Marshall cabs?

PS. As a disclaimer, I realize it was my lack of research that led to me buying the amp before realizing this. As I mentioned, every amp I've ever owned has had a 16 ohm selection on back, so I didn't even think to wonder about this on an $1,800 amp.

The majority of Mesa Heads only have 8 and 4ohm outs (Some of the Rectifiers have 16ohm) and the Cabs are almost always 8ohm as well. None of my 4 Mesa heads have 16ohm outs and I run some of them through my 16ohm Orange 2x12 on occasion. Sounds just fine to me. No reason to part with your Marshall Cab (or new amp) if you are happy with the way it sounds through the TC-50. If you aren't happy, then that is a different story.

And this is from the TC-50 manual with regards to connecting 16 ohm cabs...

"A 16 Ohm 4x12 or 2x12 Cabinet should be used in the 8 Ohm setting and will see a slight reduction in maximum power, thought it will likely be unnoticeable with the additional coverage four or even two speakers provides."

 

[icipher]

"A 16 Ohm 4x12 or 2x12 Cabinet should be used in the 8 Ohm setting and will see a slight reduction in maximum power, thought it will likely be unnoticeable with the additional coverage four or even two speakers provides."

Guess I should have read the manual. This is helpful, thank you.

 

[Yodel]

You know what two 4x12s with 16ohms wired in parallel give you resistance-wise, right?

 

[TheWarAgainstTime]

You have a number of options to avoid a mismatch, assuming your Marshall cabs have the normal two inputs and stereo/mono selector switch.

1. Use both speaker outputs at 8 ohms into two of the Marshall cabs

2. Use one 4 ohm output into the 4 ohm input of one of the cabs

3. Set one cab to stereo and use both speaker outputs at 4 ohms into each side of said cab

 

[icipher]

You have a number of options to avoid a mismatch, assuming your Marshall cabs have the normal two inputs and stereo/mono selector switch.

1. Use both speaker outputs at 8 ohms into two of the Marshall cabs

2. Use one 4 ohm output into the 4 ohm input of one of the cabs

3. Set one cab to stereo and use both speaker outputs at 4 ohms into each side of said cab

Their the infamous mode 4 cabs with vintage 30's. Only one 16 ohm jack.

 

[TedEH]

^ I don't know specific details about those cabs, but I'd assume any 4x12 that can be wired as 16ohm could be re-wired as 4ohm. Correct me if I'm wrong though.

 

[macgruber]

^^ correct.

 

[cGoEcYk]

Question is why does Marshall make 16-ohm 4x12s

 

[Daeniel]

Actually in my experience every time I have hooked up a 8Ohm out from any amp to my Orange 2x12" I got increased higher mids and treble. Therefore I got more punch. And volume wise - even live with a Mesa I have never used the Master volume higher than 5.
I a few words - no worries

 

[Wizard of Ozz]

Question is why does Marshall make 16-ohm 4x12s

Because at 16 ohms you using are all the windings (both primary and secondary) of the output transformer. In lay terms, you are getting full output from your amp, which gives a brighter, more cutting tone. At 8 ohms your amp is seeing a reduced load and your are not running at full output power, which gives a darker, warmer, more bass heavy tone. Which personally I do not like. Mesa needs to start adding 16 ohm outs to their amps.

 

[TedEH]

Because at 16 ohms you using are all the windings (both primary and secondary) of the output transformer.

Would this not depend very heavily on the rest of the design of the amp, and the specific transformer being used? I assume that not all transformers are exactly the same.

 

[Wizard of Ozz]

Would this not depend very heavily on the rest of the design of the amp, and the specific transformer being used? I assume that not all transformers are exactly the same.

No. Class AB push-pull power amps all share a similar OT design. Mesa likes its amps to have that dark, bassy, low-mid flavored tone. Part of which comes from running at 8 ohms.

 

[cGoEcYk]

At 8 ohms your amp is seeing a reduced load and your are not running at full output power, which gives a darker, warmer, more bass heavy tone.

If a watt is the unit of measure for power, is it not true that tube amps put out the same power (measured in watts) regardless of impedence?

I think that what you are saying is that running 16-ohms is light wearing tighty whiteys. It doesnt actually change the size of your package (output power) but makes it look more defined.

Seriously, I've never heard of that though! So if you run two of these Marshall 16-ohm cabs simultaneously, resulting in an 8-ohm load- then the TONE (frequencies, etc) will change? I dont mean to be argumentive or anything, just curious because this is different from my current understanding.

 

[CapnForsaggio]

Because at 16 ohms you using are all the windings (both primary and secondary) of the output transformer. In lay terms, you are getting full output from your amp, which gives a brighter, more cutting tone. At 8 ohms your amp is seeing a reduced load and your are not running at full output power, which gives a darker, warmer, more bass heavy tone. Which personally I do not like. Mesa needs to start adding 16 ohm outs to their amps.

I'm sorry, but there is so much wrong with this statement, that it hurts my face.

Tranformers primary and secondary windings don't work that way. Both sides of a tranformer are needed to "transform" anything....

The tranformers are designed to operate with a certain resistance applied (4,8,16 ohms). If too small of a load is applied to the tranformer, it will run too hot and melt windings.

This is why using a cab with higher ohms and amp setting with low is ok, but the opposite might melt your amp down.

 

[JumpingInFire]

If a watt is the unit of measure for power, is it not true that tube amps put out the same power (measured in watts) regardless of impedence?

If this were true, then amplifiers would not be rated differently at specific impedance loads.
This can impact your headroom and tone but I doubt you would notice in this application.

http://www.transcendentsound.com/Amplifier_Output_Impedance.html

 

[cGoEcYk]

If this were true, then amplifiers would not be rated differently at specific impedance loads.

That applies to solid state designs (where lower impedance increases the output) but not tube.

 

[4Eyes]

mesa is relying on safe mismatches when it comes to cab/half power etc switching. there is no 16ohm output because it's completely safe to plug 16ohm cab to 8ohm output on the amp

 

[op1e]

Question is why does Marshall make 16-ohm 4x12s[/QUOTE

Because I don't think they make their amps with 4ohm outputs. My SLX only has 16 and 8 on the selector switch. Two 16 ohm 1960 cabs = 8 ohm into the head. I've had this argument many times with my guitarist and its confusing and varying from manufacturer to manufacturer. Mesa calls for the 4 ohm outputs for 2 of their 8 ohm cabs. But dam if he wasn't right when I read the manual for his rd45. It says to use the 2 8ohm outs for 2 8ohm cabs. Other than that the Diavlo has one 16 and one 4ohm out.

In the beginning I always thought "Parallel Out" meant just that. Set the jack to the rating of the cabs and thats what you had x2. But not so much. As for safe mismatches, 6L6 amps handle them way better than el34 amps. My tech told me they'll pop in a heartbeat in comparison to anything running a beam tetrode type tube.