The case for channel switching amps (especially Mesa amps)

[FleshOnGear]

I love my NMV, 4-hole amps. I love the range of tones I can get from them with a couple of pedals and my guitar’s volume knob. But I’m left wondering about one feature of channel switching amps, particularly Mesa amps. That is the ability to switch to higher power amp output on clean channels, and to lower power output on overdrive channels.

It seems to me that with NMV, “single channel” amps, you’re inevitably going to have lower volume when you back off to a clean sound. This maybe isn’t a big deal since the band can back off with you, so it gives everything more dynamics. With the power amp switching described above, though, you can keep your clean tones as loud as your saturated tones. That way the band can keep chugging while you have a pristine clean.

My questions are, how well does this power switching work in practice, and how much does it even matter? I’m not selling my 1987 to fund a Mk VII, but maybe when I start gigging again a Mesa would be nice to have for playing live. What is the case for using one of these amps?

 

[Frodebro]

Mesas almost all get their dirt from the preamp, so all you really need to do is balance your levels with the channel masters.

 

[Matthews Guitars]

I'd use my Mesa Mark V:90 as an example. It has 10, 45, and 90 watt switchable modes for EACH channel.
It has a master volume for EACH channel.
And it has an overall master volume that controls total output level.

Within the scenario you describe, it works flawlessly. I can run any channel at any level and match them as well as I wish.

It works better than any previous Mark amp in this scenario. The Mark IV is close...but not quite as easy an amp to tweak out to your best possible tone on all three channels at once, because there are some settings that are shared between channels.

Marks before the IV have even less flexibility and ability to level match between channels. But they do pretty good.

The Mark III and Mark II models share MOST controls between all channels. The tone controls are shared, presence is shared,
reverb is shared if it's an option that's present in the amp. Lead drive and the lead master are used only by the lead channel,
and some of the tone shift functions that are on the knobs (pull shifts) apply only to the lead channel.

If you're looking for a Mark series amp, my recommendatin is for a Mark V 90 watt head and cabinet of your choice. It's an amazing
amp, and it works so well, you'll really feel like you've got a piece of luxury level gear. Which I'd have to say, it is.

 

[FleshOnGear]

Mesas almost all get their dirt from the preamp, so all you really need to do is balance your levels with the channel masters.

In that case, I’d probably do as well to get a JVM. Is there no benefit from having a Mark V, being able to drive the power section hard in 10W mode on the lead channel, then switching to the clean channel on 90W mode?

I'd use my Mesa Mark V:90 as an example. It has 10, 45, and 90 watt switchable modes for EACH channel.
It has a master volume for EACH channel.
And it has an overall master volume that controls total output level.

Within the scenario you describe, it works flawlessly. I can run any channel at any level and match them as well as I wish.

It works better than any previous Mark amp in this scenario. The Mark IV is close...but not quite as easy an amp to tweak out to your best possible tone on all three channels at once, because there are some settings that are shared between channels.

Marks before the IV have even less flexibility and ability to level match between channels. But they do pretty good.

The Mark III and Mark II models share MOST controls between all channels. The tone controls are shared, presence is shared,
reverb is shared if it's an option that's present in the amp. Lead drive and the lead master are used only by the lead channel,
and some of the tone shift functions that are on the knobs (pull shifts) apply only to the lead channel.

If you're looking for a Mark series amp, my recommendatin is for a Mark V 90 watt head and cabinet of your choice. It's an amazing
amp, and it works so well, you'll really feel like you've got a piece of luxury level gear. Which I'd have to say, it is.

Would you say there’s much benefit in having the ability to totally match the average volume level of your clean tone to your lead tone? Versus simply rolling down your guitar volume for clean through a Plexi style amp, and the inevitably lower volume that gives you? It didn’t seem to matter to the classic rock greats back in the day. I’m always amazed at the range of colors Pete Townshend would get through a Hiwatt like on Live At Leeds, and the band would just chug along. But maybe their sound engineer was riding the faders on Pete’s volume?

 

[Frodebro]

In that case, I’d probably do as well to get a JVM. Is there no benefit from having a Mark V, being able to drive the power section hard in 10W mode on the lead channel, then switching to the clean channel on 90W mode?

Would you say there’s much benefit in having the ability to totally match the average volume level of your clean tone to your lead tone? Versus simply rolling down your guitar volume for clean through a Plexi style amp, and the inevitably lower volume that gives you? It didn’t seem to matter to the classic rock greats back in the day. I’m always amazed at the range of colors Pete Townshend would get through a Hiwatt like on Live At Leeds, and the band would just chug along. But maybe their sound engineer was riding the faders on Pete’s volume?

The biggest advantage to a Mark V (I also have the 90W version) is the tonal variety available, which is pretty broad if you know how to dial it in. The JVM is a very good amp (and one I plan on owning at some point), but it's basically varying degrees of gain of the Marshall sound.

Master volume amps generally all get their tonal shaping from the preamp, with the power section staying mostly clean. With the Mark V in 10W mode you can definitely drive the power section harder, but it's not going to react in quite the same manner as a NMV amp cranked way the heck up.

 

[FleshOnGear]

The biggest advantage to a Mark V (I also have the 90W version) is the tonal variety available, which is pretty broad if you know how to dial it in. The JVM is a very good amp (and one I plan on owning at some point), but it's basically varying degrees of gain of the Marshall sound.

Master volume amps generally all get their tonal shaping from the preamp, with the power section staying mostly clean. With the Mark V in 10W mode you can definitely drive the power section harder, but it's not going to react in quite the same manner as a NMV amp cranked way the heck up.

Is it close enough for live? I mean, I get that there’s nothing like a 4-holer cooking power tubes. But does the power scaling on the Mark V (or VII) at least enhance the feel and saturation enough to satisfy? It’s hard to imagine that the lower power settings on the Mark amps gives you anything quite like the response of a saturated transformer, or a stressed power supply, but does it get you anything more than simple preamp distortion?

 

[Frodebro]

Is it close enough for live? I mean, I get that there’s nothing like a 4-holer cooking power tubes. But does the power scaling on the Mark V (or VII) at least enhance the feel and saturation enough to satisfy? It’s hard to imagine that the lower power settings on the Mark amps gives you anything quite like the response of a saturated transformer, or a stressed power supply, but does it get you anything more than simple preamp distortion?

A Mark V isn't a Plexi, and is very much its own thing. Trust me-wind up a Boogie and you won't be thinking about power section saturation. It sounds painfully glorious cranked up without putting any stress on the back end.

 

[FleshOnGear]

A Mark V isn't a Plexi, and is very much its own thing. Trust me-wind up a Boogie and you won't be thinking about power section saturation. It sounds painfully glorious cranked up without putting any stress on the back end.

It’s funny, I had a Mark IV many years ago, when I was a much less experienced amp user. I read about how great power amp distortion was supposed to sound in guitar magazines, so I’d experiment with insane volume when nobody else was around. I could never get the amp to sound good at that volume. I didn’t know about gain staging, and limiting bass to keep distortion from farting out. But it did sound quite good when there was only preamp distortion. Ultimately, I found that Marshall style amps easily gave me a certain ‘sting’ that I wasn’t getting from that Mark IV, so I sold it.

 

[Ufoscorpion]

It’s funny, I had a Mark IV many years ago, when I was a much less experienced amp user. I read about how great power amp distortion was supposed to sound in guitar magazines, so I’d experiment with insane volume when nobody else was around. I could never get the amp to sound good at that volume. I didn’t know about gain staging, and limiting bass to keep distortion from farting out. But it did sound quite good when there was only preamp distortion. Ultimately, I found that Marshall style amps easily gave me a certain ‘sting’ that I wasn’t getting from that Mark IV, so I sold it.

sounds to me a JVM will be more you’re thing ,

 

[MonstersOfTheMidway]

@FleshOnGear : I have the Mesa-Boogie Road King 2 head (discontinued years ago) that has several features describing what you are discussing. In the Road King 2, there are two ways to change the output rating: change the power amp section via PROGRESSIVE LINKAGE, and/or changing the amp's internal A.C. power voltages via the amp's built-in "variac" labeld BOLD/SPONGY.

For me, the most useful way to manipulate the output of each channel (the RK has 4 channels) is by using PROGRESSIVE LINKAGE. For example, I can set the Channel 1 "clean" mode with four 6L6 tubes that produced roughly 100 watts output. Then, I can select channel 4 "modern" mode with only two 6L6 tubes that produced rougly 50 watts. The PROGRESSIVE LINKAGE feature is at the rear of the amp and each channel has can have it's own setting:


The other way to manipulate the output is with BOLD/SPONGY switch, which Mesa-Boogie states operates similar to a built-in variac. SPONGY switch setting reduces the internal power, and BOLD switch setting operates the amp at normal/full power. I'm not sure how much the internal power is reduced in these switches, but it is quite effective.

Of the two methods, I use PROGRESSIVE LINKAGE most not only to maniupulate power output but also to manipulate tone via different power amp tubes (EL and/or 6L6). You asked " how well does this power switching work in practice, and how much does it even matter?" and in terms of PROGRESSIVE LINKAGE, I'd have to say a whole helluva lot. The tonal qualities of 6L6 and EL34 make a huge difference in this amp in terms of tone. And again, using different power tube options cuts the power output: selecting only two EL34 tubes or only two 6L6 will give you roughly half power/50 watts. Then, you can bump it up to roughly 100 watts with four 6L6 tubes, or with two EL34 tubes+two 6L6 tubes. If you want to keep things the same, you can use two 6L6 tubes for half power, then four 6L6 tubes for full power. So each time you switch to a different channel, you can have a different output.

Finally, you can further alter the loudness of the amp via each channel's MASTER volume in addition to global OUTPUT and SOLO volume controls.

I also have the JVM410H, also have several controls to alter the amp's loudness (two master volume, four channel volumes). Using these four controls, I can effectively and quickly alter the amp's loudness to fit any situation.

 

[paul-e-mann]

Amps I never see are amps with two identical channels with independent controls. Something I've always wanted.

 

[MantraSky]

.

 

[PelliX]

The other way to manipulate the output is with BOLD/SPONGY switch, which Mesa-Boogie states operates similar to a built-in variac. SPONGY switch setting reduces the internal power, and BOLD switch setting operates the amp at normal/full power. I'm not sure how much the internal power is reduced in these switches, but it is quite effective.

Spongy indeed works by dropping the power supplied to the output section. Bold is literally what the switch says. Use that setting at the risk of melting the internals. That switch might just as well read "I like this amp" and "Firestarter"...

 

[V-man]

Amps I never see are amps with two identical channels with independent controls. Something I've always wanted.

Amps like the Mk V cited above make for modern solutions to the problem, but a lo tech solution (especially when moderns don’t capture your preferred tone) is running two rigs with an A/B box. Factor in Small wattage amps, IRs and FOH D.I.s and it’s even more manageable.

 

[paul-e-mann]

Maybe Friedman Twin Sister?

TWIN SISTER HEAD - Friedman Amplification

The Twin Sister is a 40-watt, 5881 powered, dual channel head based on a modified JTM 45 but still delivers the signature British tone for which Friedman has become known for.

friedmanamplification.com

The amp features two identical channels that can give you everything from gorgeous sparkling cleans to a glorious vintage crunch and beyond! Extremely versatile,
the Twin Sister can produce many styles of music from blues to rock and country by just adjusting the structure, gain and master controls.

Wow a pair of jtm45's in one box!

 

[MonstersOfTheMidway]

Spongy indeed works by dropping the power supplied to the output section. Bold is literally what the switch says. Use that setting at the risk of melting the internals. That switch might just as well read "I like this amp" and "Firestarter"...

That incendiary feature was the pure marketing genius that hooked me in!

 

[MantraSky]

.

 

[Ufoscorpion]

A great amp for sure, I've never had "two identical channels" in one amp, so I had to go two different amps, then blend them.....[SLO & BE-100]

Similar deal with my BE synergy module which has a shared eq but independent gain and volume . Really good concept , as you can run one channel hotter or louder or both but maintain the same great tone .

 

[Jethro Rocker]

My Triple Crown has variable power for each channel but first off to really use it you are likely playing at really high levels. And as above, most of the tone is in the preamp. Get the volume up to shaking and power sat means nothing really.
A JVM does just as well IMO and has a different EQ gain structure from Mesa.
I think any decent multichannel amp with volumes with each channel would be just as effective IMO unless you are playing clean above headroom level. Master volumes and gains make em a different critter from NMV.