LSS - newbie type questions

[Marc99]

Been reading here for awhile, learned alot. So far after a year no big problems, some minor tube issues.

Which power tubes are used in 5 and 15 watt modes, looking at back- left to right?

What does phase inverter and phase inverter tube do? um, i guess phase inv. tube drives phase inverter.

What kind of tubes should i replace 12AX7's with? it has been a year, when should i replace them?

Sometimes i use GT8, only for overdrive (pedal models), delay and wah. I go through front input, is this best? The gain on LSS sound better natural (page, ZZ, killer blues etc) but sometimes looking for more "recto" type...Metallica, petrucci etc. GT8 works fine but

If you think a different pedal would be better which one? i may try out either EHX here-

http://www.guitarcenter.com/shop/pr..._metal_muff_with_top_boost?full_sku=103840526

http://www.guitarcenter.com/shop/product/buy_electroharmonix_graphic_fuzz_pedal?full_sku=153321

My last question. What do the metal covers on preamp tubes do? I had one explode after i took cover off for a look (he he) still dont know why it broke. But i left it off and dont see any issues.

Thanks, i will post more questions when i have some.

oh, got one-

What does Mesa charge for external cab? I want to use an Eminence Red Fang Alnico, around how much $ (either 1x12 or 2x12) and will mesa put this speaker in or will the only use Celestion? I know Celestion Alnico is good but more money. aaaahh, i dont know maybe i should just keep cab like Mesa makes it. My amp is black and it's beautiful/

 

[ylo]

The phase inverter inverts the signal going to one side of a push-pull output stage so that one side is pushing while the other side is pulling. Some amps use a small transformer to do this. Most Fenders, Marshalls, Vox and Mesas use a tube with in a particular way to do this, hence you will see "phase inverter tube" or "PI tube."

The metal covers on the preamp tubes sheild them from radio frequency interference, especially hum induced from AC power lines.

Not sure which tubes are used in 15 watt mode, probably either the inner or outer pair.

The 5 watt mode actually uses two tubes, but only one is amplifying the guitar signal. The other serves as a sort of DC balance to the other. This is the genius of Mesa's design for the LSS, single-ended (one tube) amplification using the same transformer as the push-pull 15 W and 30 W modes.

Do a search of this site for lots of information on tube brands.

I have a black LSS too. I like the Eminence Red White & Blues in mine, similar sound to stock C90, but a little brighter.

 

[Ducky]

When i called mesa, they told me that in 5W mode, only the tube beside the rect is used. in 15W mode, the 2 beside are used.

I use the stock speaker in the combo, and i have a 1x12 tone tubby ext cab.

As for 12ax7 tubes, I like the tung-sol's
For El84 i like the TAD(The JJ's would blow my rect in about 5 mins)

 

[drunkdolphin]

Hi Guys,
Im using a LSS Limited edition from Long & McQuade in Canada, (same amp, just black tolex, tan grill and a mahogany front pannel, real classy)
I added a Red Fang, Tungo Sol preamp tubes and a matched PI and El84s's from Groove and it sweetened the amp right up. I use the drive channel in 5w and 15w in the clean. I have been contemplating getting the 410 ext cab for a bigger sound.
S

 

[Marc99]

Thanks. The reason i ask about which tube in 5 watt mode is because i play for hours (usuall after midnight-ha ha ha) using one tube and figured it would be good to rotate every few months. but of course i use 15-30 watts often too.

Preramp tubes- Good to know about the tung sol, guess i will change the preamp tubes in a few months.

Power tubes- i also use TAD also, very happy with them. Heck i allready blew rec tube with the EHX tubes in there, so far so good.

As far as cab guess i will call around on that but wish there was a place where i live (New York) so it doesnt need to be shipped from Ca. Not readyu to buy yet but in the end i will probably just order fr. Mesa or Avatar, seems the easiest route. Good speaker suggestions/

GT8- It is not ideal but changes the sound, drive and gain from Mesa alone are incredible for classic rock and blues but only use GT8 for when i have the urge to play some metal - right now it is my only option but one good thing i discoverd is that plugging into footswitch with GT8 does change channels :lol: on the Mesa. Some good FX too.

 

[Ducky]

Thanks. The reason i ask about which tube in 5 watt mode is because i play for hours (usuall after midnight-ha ha ha) using one tube and figured it would be good to rotate every few months. but of course i use 15-30 watts often too.

The reason i asked mesa about the tube layout was for that same reason. When he told me, he also said it doesn't matter, cuz all the tubes were "on" all the time anyways ??

I forgot to ask if we are able to pull tubes if we only use 5 and 15W mode.

But from what he said, my guess is no.

 

[ylo]

I think the guy at Mesa meant that the power tubes are on, with high voltage on the plates and the heater grids cooking, even with no guitar signal in on the grids. Even though a tube ages faster when pushed, it ages even when at idle. At all but the loudest settings, I bet the difference in rate of aging isn't that great.

 

[Ducky]

I think the guy at Mesa meant that the power tubes are on, with high voltage on the plates and the heater grids cooking, even with no guitar signal in on the grids. Even though a tube ages faster when pushed, it ages even when at idle. At all but the loudest settings, I bet the difference in rate of aging isn't that great.

ahh, That's true, duhh.

I knew class A runs at 50% when idle .

But my brain thought that they "disconnected" the last 2 tubes when not in use, didn't even think about heater ...