Lonestar with 6V6's?

[theroan]

Can anyone give me some insight has to how this sounds? Or may sound?

Thanks!

 

[djw]

It sounds great! I use 6V6s almost exclusively in my LSC. Tone questions aside, they also have the nice effect of bringing the headroom down to a more usable level (for me), so it's easy to get some good power-tube mojo going.

Tone-wise, it's a lot like the manual says: 6V6s have a nice, bubbly, chimey quality. Beautiful high-end roundness that's clear but not too glassy. Lots of sweet harmonics. They also tighten up the lows considerably; bass response is diminished, but that isn't really a problem for the LSC and in fact is probably a benefit. Still a full-bodied tone, but emphasis is in the mids and highs. They're more similar to EL34s that they are to 6L6s.

So, you lose a bit of the beef you get with 6L6s, but you get a lots of chime and harmonics, and earlier breakup, in return.

 

[gregrjones]

I notice that the manual for the LSC says to keep the amp set at the low AC wattage setting when using these tubes. However if that's true, then why would we need to insert 4 6v6's? Aren't you only using 6 (outer pair?) when running 50 watts?

 

[boogiemon]

i think i remember reading that the recommendation is to run in 100 watt mode but use the tweed setting & plug the speaker(s) into one of the 4ohm jacks.

I notice that the manual for the LSC says to keep the amp set at the low AC wattage setting when using these tubes. However if that's true, then why would we need to insert 4 6v6's? Aren't you only using 6 (outer pair?) when running 50 watts?

 

[hugsy41]

I notice that the manual for the LSC says to keep the amp set at the low AC wattage setting when using these tubes. However if that's true, then why would we need to insert 4 6v6's? Aren't you only using 6 (outer pair?) when running 50 watts?

The low AC wattage (Tweed function) lowers the internal voltage, but the amp still runs with all 4 tubes. The wattage setting determines how many power tubes are being used. So I guess if the amp was set on 50W you could most probably get away with using 2 6V6's.

 

[djw]

This is how I understand it: Mesa recommends using the 100w setting AND the 4ohm output with a quartet of 6V6s because the output impedance matches better that way. This is for the same reason that they print on the back of the chassis, near the speaker jacks above the 4ohm output: "Use with 50w setting". When you cut the power output in half, you ideally want to mismatch your output to speaker impedance by 2x (4ohm output to 8ohm load) to compensate. Mesa doesn't make a big deal out of it because the amps are tough enough to deal with most mismatches, and having potentially two different power settings at the same time (e.g., 50w Ch1 and 100w Ch2) just confuses things. Ultimately, it doesn't matter that much under most circumstances. (BUT PLEASE look at the manual for safe and UNsafe impedance mismatches!!!)

I think that would also mean using the 50w setting with 6V6s -- in other words, using just a pair of 6V6s and actually producing more like 25 watts -- would imply an ideal match another level up, like using a 16ohm load on the 4ohm output. (Do NOT quote me on this.) But again, Mesas are tough, and using the 50 watt setting with 6V6s and an 8ohm load on the 4ohm output is just fine. In fact, I've been doing this for months now and I couldn't be happier.

Most modern 6V6s can handle the full-power setting fine too, by the way. Tweed will help them last longer though, which is also true for 6L6s and the rest.