Mark III, Marshall Cab & an Attenuator

[#2121313]

Hey guys, curious about getting an attenuator. I want to be able to use my Mark III at bedroom/practice levels too. I was thinking of getting an attenuator. Questions:

I have a Mark III with the usual one 8 ohm and two 4 ohm jacks in the back. My cab is a Marshall 1960 with either a 4 ohm or 16 ohm settings. I usually plug into the 8 ohm jack on my amp an 16 ohm jack on my cab, (I always thought the lower the ohm setting the louder the amp will be) not sure if this is really true or noticeable. Should I be getting a 4 ohm hot plate/attenuator and use the 4 ohm jack on my amp and 4 ohm on my cab? Or can I (and is it even worth it if I can) plug in using the mismatch 8 ohm amp and 16 ohm cab connection and incorporate a Hot Plate - what ohm would the Hot Plate need to be?

Sorry if some of my questions are stupid options, I'm just trying to work things out before I go out and buy stuff...

Thanks!

 

[boogiemon]

the master vol knob on these things works just fine: no attenuator required.

 

[#2121313]

the master vol knob on these things works just fine: no attenuator required.

Thanks for your help.

But I'm obviously aware of the master volume knob, I'm interested in experimenting with an attenuator for those who can help I'd appreciate it.

 

[MrMarkIII]

Those four ohm speaker jacks are not designed to use with four ohm cabs.
It's a very common misconception.
If you were to connect two four ohm cabs (one cab to each of the four ohm speaker outs), the total load will still be two ohms (two four ohm loads in parallel).

Reading the manual, one would find that two EIGHT ohm cabs should be connected to the four ohm jacks. The jacks are parallel. Your set-up, with the eight ohm speaker out connected to a 16 ohm cab (low to high), is a safe mis-match. It would also be OK to use a 4 ohm cab from the 8 ohm jack (high to low), but it is safer to go low to high. You may be interested to know that your configuration actually results in LESS overall output. If you could find an 8 ohm 4 x 12 cab, the amp would be a bit louder and cleaner, with more bottom end. Impedance mismatches lower the power, clip earlier, and thin out an amps sound. So you are already attenuating the amp a bit.

Download a recent Mesa manual, such as the Lonestar. There are examples of many different speaker hook-ups in the back.

My experience with attenuators has been the THD Hot Plate and the Weber Mass Lite 100, using my Mark III into a Celestion G12T-100. I couldn't tell the difference between using the attenuator or using just the Master, so that's my two cents. I was planning on using the attenuator live, so schlepping along more gear made no sense to me. If you want to record silently, they're a good solution. My understanding is you match the attenuator to the amp, not the speaker, so you should get an 8 ohm attenuator. The 16 ohm cab should work fine.

Monstatone has a Weber for sale in the Classifieds.
Hope this helps

 

[gonzo]

i hear a very large difference, in the sound and type of distortion, between using the master, and running the amp hot with an attenuator.

in fact, i find it really hard to believe that some folks cannot hear a difference.

how hard your output tubes are stressing, completely changes the sound, and feel.


i use a weber mass lite, with a IIb 60 watter, using a avatar vintage 1x12 for recording..
no problems.


i use combinations of sounds without the attenuator, and master set low, and the amp wide open, with the attenuator doing it's thing.

 

[#2121313]

Those four ohm speaker jacks are not designed to use with four ohm cabs.
It's a very common misconception.
If you were to connect two four ohm cabs (one cab to each of the four ohm speaker outs), the total load will still be two ohms (two four ohm loads in parallel).

Reading the manual, one would find that two EIGHT ohm cabs should be connected to the four ohm jacks. The jacks are parallel. Your set-up, with the eight ohm speaker out connected to a 16 ohm cab (low to high), is a safe mis-match. It would also be OK to use a 4 ohm cab from the 8 ohm jack (high to low), but it is safer to go low to high. You may be interested to know that your configuration actually results in LESS overall output. If you could find an 8 ohm 4 x 12 cab, the amp would be a bit louder and cleaner, with more bottom end. Impedance mismatches lower the power, clip earlier, and thin out an amps sound. So you are already attenuating the amp a bit.

Download a recent Mesa manual, such as the Lonestar. There are examples of many different speaker hook-ups in the back.

My experience with attenuators has been the THD Hot Plate and the Weber Mass Lite 100, using my Mark III into a Celestion G12T-100. I couldn't tell the difference between using the attenuator or using just the Master, so that's my two cents. I was planning on using the attenuator live, so schlepping along more gear made no sense to me. If you want to record silently, they're a good solution. My understanding is you match the attenuator to the amp, not the speaker, so you should get an 8 ohm attenuator. The 16 ohm cab should work fine.

Monstatone has a Weber for sale in the Classifieds.
Hope this helps

Hi MrMarKIII thanks for taking the time to reply a lot of good info here. Make sense about matching the attenuator to the amp (no the cab).

I was a little confused with where you mentioned: "Your set-up, with the eight ohm speaker out connected to a 16 ohm cab (low to high), is a safe mis-match. It would also be OK to use a 4 ohm cab from the 8 ohm jack (high to low), but it is safer to go low to high."

The statement seems to contradict itself if I'm reading it correctly, I thought if having a cab with a lower impedance than the amp, like when you mention: OK to use a 4 ohm cab from the 8 ohm jack (amp) would be a unsafe mismatch?

i hear a very large difference, in the sound and type of distortion, between using the master, and running the amp hot with an attenuator.

in fact, i find it really hard to believe that some folks cannot hear a difference.

how hard your output tubes are stressing, completely changes the sound, and feel.


i use a weber mass lite, with a IIb 60 watter, using a avatar vintage 1x12 for recording..
no problems.


i use combinations of sounds without the attenuator, and master set low, and the amp wide open, with the attenuator doing it's thing.

I was also under the impression that you'd be able to hear a difference with an attenuator, otherwise attenuators would only be for non-master volume amps, right? My Mark III sounds pretty terrible when I have the Lead Master and the Master one below 2. Even at 1.5 it's pretty loud for bedroom/practice. Sounds killer when I get both volumes at 4+.

 

[gonzo]

well, you can run a non-master amp hard, to get that tube saturation, but you have to deal with the volume.

if you put the attenuator on it, you can get there without ALL the volume, and there is a sweet spot where you can stop, and the more you drive the amp, all you get is more fuzz and saturation that compresses- lots of tube sag and all that.


it's the same with a master volume, there is a sweet spot, where the amp gets into that 'AHA' balance between preamp distortion/gain, and power tube saturation.

everyone 'feels' it different, as well as hears it, so that 'sweet spot' may be different for everyone, but in general, it differentiates between touch sensitivity and just pure gain.

some guys like to hide behind gain....
and others like the amp to show every nuance.


the attenuator simply allows you to dial in that 'sweet spot' on the amp with a bit more control.

you can't get there, just bringing the master way down.....
then all you're getting, is preamp distortion, and the power amp is just idling a bit.

 

[MrMarkIII]

",... I was a little confused with where you mentioned: "Your set-up, with the eight ohm speaker out connected to a 16 ohm cab (low to high), is a safe mis-match. It would also be OK to use a 4 ohm cab from the 8 ohm jack (high to low), but it is safer to go low to high."

The statement seems to contradict itself if I'm reading it correctly, I thought if having a cab with a lower impedance than the amp, like when you mention: OK to use a 4 ohm cab from the 8 ohm jack (amp) would be a unsafe mismatch?..."

It's a matter of degree. Not totally unsafe, but less safe than the other way, as explained in the section above highlighted in red.

 

[#2121313]

I see, thanks for clarifying MrMarkIII.

 

[kdorsey]

",... I was a little confused with where you mentioned: "Your set-up, with the eight ohm speaker out connected to a 16 ohm cab (low to high), is a safe mis-match. It would also be OK to use a 4 ohm cab from the 8 ohm jack (high to low), but it is safer to go low to high."

The statement seems to contradict itself if I'm reading it correctly, I thought if having a cab with a lower impedance than the amp, like when you mention: OK to use a 4 ohm cab from the 8 ohm jack (amp) would be a unsafe mismatch?..."

It's a matter of degree. Not totally unsafe, but less safe than the other way, as explained in the section above highlighted in red.

+1

In reality, there isn't an "unsafe" impedance mismatch with a MkIII, within reason. Don't go and match a 2 ohm load to the amp and push master volume to 7, or expect your tubes to last about a month! But otherwise, MrMarkIII is absolutely right: go too high an impedance and you'll only get a thin, wimpy tone.

I like the Marshall PowerBrake. It delivers quality but only with 8 and 16 ohm output. Not a big deal but you really should properly match that impedance with your speakers. Mine worked for years until I changed my setup and play in bigger venues!

 

[#2121313]

Thanks guys I appreciate the info, I definitely have a better understanding of things now. I just figured the 8 ohm amp into the 16 ohm cab made most sense to me. I always read many players who use Boogie's Amps into Marshall Cabs and the impedance would (in most cases) be a mis-match).

I wonder though, with four 16 ohm speakers can they be re-wired to 8 ohms? That would allow me to go 8 ohm amp into 8 ohm cab and be set!

 

[MrMarkIII]

Thanks guys I appreciate the info, I definitely have a better understanding of things now. I just figured the 8 ohm amp into the 16 ohm cab made most sense to me. I always read many players who use Boogie's Amps into Marshall Cabs and the impedance would (in most cases) be a mis-match).
I wonder though, with four 16 ohm speakers can they be re-wired to 8 ohms? That would allow me to go 8 ohm amp into 8 ohm cab and be set!

Nope, you'd need four 8 ohm speakers, in series parallel. Two speakers are hooked up in series (8 + 8 = 16), then the two 16 ohm loads are hooked up in parallel, which results in 8 ohms.
With four 16 ohm speakers, your choices are 64 ohms (series), 16 ohms (series/parallel), or 4 ohms (parallel).

 

[#2121313]

I didn't think so, too bad. Thanks for explaining makes sense.