Anyone experiencing a pop when switching to or from 10W?

I just recently bought a fantastic new Lonestar Classic 1x12 combo and I'm absolutely in love with it! It's really a sweet sounding amp, and I'm finally feeling that I'm close to finding -my- signature lead tone. It's also a great addition/"sort-of-contrast" to the Mark voicing I'm accustomed to.

Anyhow, I've seen a few threads about this issue before, but I couldn't manage to relocate them. There seems to be a loud, pretty noticable pop when switching either to or from the 10 watt Class A setting. It happens when I switch the wattage manually on a channel, as well as when one channel is set at, say 50W and another to 10W and I switch between them. It also happens each time I put the amp off standby to a channel in the 10 watt setting. The pop doesn't increase in volume as the output/master is increased, but it's pretty loud in the first place and could very well be heard in a quieter live setting.

I talked to the guys at Mesa about this and they say it's completely normal and that it's because the amp is switching between two classes/tube configurations. However, I do recall that there were some that didn't experience any of these problems.

It doesn't really bother me that much (yet), but I'm just checking to see if anyone else here is experiencing the same things in their Lonestars and perhaps have had any issues with the popping when playing live, and so forth.

Anyone?

Same thing here with an Express 5/50. When switching between 5 and 50W, there's a loud pop. Turning off the amp to switch it might be a workaround but not very convenient in a live situation... Actually, why switch power levels when playing live?

Marc

The reason this happens is that when you switch to the 10-watt mode, one power tube is being disconnected, two are being rebiased from class AB to class A, and the fourth is being reconnected to hold down the unused end of the OT primary. You are probably hearing the result of the two tubes being rebiased -- as the grid voltage on those tubes changes, the plate current will change, which changes the current going to your speakers, which causes them to move to a new resting position, which you then hear as a pop. As long as it isn't loud enough to cause either hearing or speaker damage, it's nothing to worry about.

Thanks for the explanation, nemesys! It certainly cleared up a lot of things for me.

Animeka said:

Same thing here with an Express 5/50. When switching between 5 and 50W, there's a loud pop. Turning off the amp to switch it might be a workaround but not very convenient in a live situation... Actually, why switch power levels when playing live?

Marc

Click to expand...

Well, it's not so much about the actual volume levels, but about power amp response. A channel set to the 10 watt setting sounds very different than the same channel set to 50 watts with the masters adjusted to compensate for the volume increase (read: very slight volume increase, actually; 10 watt is about half as loud as 100 watt). You can crank the master much further up in the 10 watt setting and thus achieve more power amp saturation/overdrive at lower volume levels. Perfect for smaller gigs. And the fact that you get the option of setting each channel differently, gives you the possibility to say, crank the lead channel with some great Class A power tube saturation in 10 watts, while still have cleans on the other channel with very high headroom in the 100 watt mode.

Octavarius said:

Thanks for the explanation, nemesys! It certainly cleared up a lot of things for me.

Animeka said:

Same thing here with an Express 5/50. When switching between 5 and 50W, there's a loud pop. Turning off the amp to switch it might be a workaround but not very convenient in a live situation... Actually, why switch power levels when playing live?

Marc

Click to expand...

Well, it's not so much about the actual volume levels, but about power amp response. A channel set to the 10 watt setting sounds very different than the same channel set to 50 watts with the masters adjusted to compensate for the volume increase (read: very slight volume increase, actually; 10 watt is about half as loud as 100 watt). You can crank the master much further up in the 10 watt setting and thus achieve more power amp saturation/overdrive at lower volume levels. Perfect for smaller gigs. And the fact that you get the option of setting each channel differently, gives you the possibility to say, crank the lead channel with some great Class A power tube saturation in 10 watts, while still have cleans on the other channel with very high headroom in the 100 watt mode.

Click to expand...

Ok, I admit, I'm a noob So there's a lot more to changing watts than getting louder I get it