Replacing tubes in Mesa Boogie Single Recto

[Apex1Rg7X]

So I have a Mesa Single Rec I just recently got and it came with EL34B tubes. I have no idea how old they are but want to swap all of the tubes out to 6L6 "high gain" tube set from Euro tubes. Now the dumb question of the day...since these amps are fixed bias that's mean all I have to do is drop the new tubes in and just make sure the switch is moved over to 6L6 correct? No need to re-bias or anything?

What have been preferred tubes for recto users?
-6L65
-EL-34
-EL-34L

 

[Bad.Seed]

Correct, no bias necessary.

So you're doing preamp and power tubes through the Eurotubes kit?

I've never been happy with any amp I've owned that had all JJ 12AX7's in the preamp. Typically sounds buzzy, dark and dead. Just my 2 cents.

I like EL34B's in my rectifier, but that's the only tube I've tried other than the 6L6. It really comes down to personal preference, but most Rectifier users seem to stick with 6L6 for the signature Rectifier tone.

 

[Kevin11]

Fixed bias doesn't necessarily mean you can just pop in any tube, flip the switch and you'll be fine. It means the bias is fixed to a range and you should replace tubes within that tolerance range. The Mesa-branded tubes that come stock have a rating number on them to more-or-less denote the bias range that works with that amp. Yes, you should flip the switch to 6L6, but if your replacement tubes happen to fall outside of the fixed range the amp is set at, you could do some damage depending on how far outside of the tolerance it is.

If you have the manual, check that. Otherwise contact Mesa and see what they say to be safe.

 

[Bad.Seed]

Fixed bias doesn't necessarily mean you can just pop in any tube, flip the switch and you'll be fine. It means the bias is fixed to a range and you should replace tubes within that tolerance range. The Mesa-branded tubes that come stock have a rating number on them to more-or-less denote the bias range that works with that amp. Yes, you should flip the switch to 6L6, but if your replacement tubes happen to fall outside of the fixed range the amp is set at, you could do some damage depending on how far outside of the tolerance it is.

If you have the manual, check that. Otherwise contact Mesa and see what they say to be safe.

Eurotubes sell power tubes that operate safely in the range of the amp you request, and are quite popular with Mesa and Peavey amps for this reason, so he should be safe to order from there.

 

[Kevin11]

Eurotubes sell power tubes that operate safely in the range of the amp you request, and are quite popular with Mesa and Peavey amps for this reason, so he should be safe to order from there.

Good to know, thanks for clarifying!

 

[Apex1Rg7X]

Correct, no bias necessary.

So you're doing preamp and power tubes through the Eurotubes kit?

I've never been happy with any amp I've owned that had all JJ 12AX7's in the preamp. Typically sounds buzzy, dark and dead. Just my 2 cents.

I like EL34B's in my rectifier, but that's the only tube I've tried other than the 6L6. It really comes down to personal preference, but most Rectifier users seem to stick with 6L6 for the signature Rectifier tone.

What preamp tubes do you like? My amp currently has EL34B's but want to switch to 6L6's

 

[Bad.Seed]

Correct, no bias necessary.

So you're doing preamp and power tubes through the Eurotubes kit?

I've never been happy with any amp I've owned that had all JJ 12AX7's in the preamp. Typically sounds buzzy, dark and dead. Just my 2 cents.

I like EL34B's in my rectifier, but that's the only tube I've tried other than the 6L6. It really comes down to personal preference, but most Rectifier users seem to stick with 6L6 for the signature Rectifier tone.

What preamp tubes do you like? My amp currently has EL34B's but want to switch to 6L6's

I've just come to realize I'm an EL34 Tube type of guy, so they tend to be my preference is all.

For Pre-Amp, I run a Tung Sol 12AX7 in V1, Ruby Chinese HG+ in V2+ V3 and a Sovtek 12AX7 LPS in the PI. V4 and V5 are whatever I have laying around.

The Tung Sol tends to add a little clarity and bite, and the Chinese help retain the gain without darkening the amp, which is already dark IMO, unless the presence is cranked and then it sounds harsh.

 

[maddnotez]

Seems like they nailed it all. Definitely be sure your new tubes are rated to fall in line with the range of your amps bias.

IMO regarding pre amp tubes. Try as many as you can. Some may sound better in other amps. Same as Power Tubes I guess but I feel changing preamp tubes can make more of a sound impact where as Power tubes like changing from EL34 to KT88 will have more of a widening impact and a feel impact. just my .02

 

[311splawndude]

^ good advice maddnotez givez

I just got done doing a lot of preamp tube rolling in my Single Rec but I can't remember 100% what I landed on. I'll double check and post back but it was a full mix of stuff. I actually recommend doing this with the chassis outside of the shell. So much easier. If you have glove and are pretty good at swapping these in and out you can actually do it while the amp is on. Speeds up the process. Hit the pins with electrical contact cleaner once while you are at it.

I personally like EL34s in these amps I've experimented with several types.

But let me ask you this. WHY do you want to swap out the tubes?

 

[skullfxr]

Tung sol in V1, the rest jj and a sovtek LPS in the PI.

 

[Apex1Rg7X]

^ good advice maddnotez givez

I just got done doing a lot of preamp tube rolling in my Single Rec but I can't remember 100% what I landed on. I'll double check and post back but it was a full mix of stuff. I actually recommend doing this with the chassis outside of the shell. So much easier. If you have glove and are pretty good at swapping these in and out you can actually do it while the amp is on. Speeds up the process. Hit the pins with electrical contact cleaner once while you are at it.

I personally like EL34s in these amps I've experimented with several types.

But let me ask you this. WHY do you want to swap out the tubes?

Well I bought the amp used and have no idea how old the tubes are. I feel like its lacking oomph that a recto should have and just figured swapping some tubes would be a good start before I give up on it.

 

[311splawndude]

Yeah, don't give up on it. It has plenty of oomph. Are you using a boost pedal? What kind of cab/speakers?

But yeah, doing some tube swapping is always a good idea. Just don't do it for the wrong reasons. Download the user manual if you have not already. Get a handful of different preamp tubes (like some of the ones mentioned in this thread). Take the chassis out of the shell so you can swap more easily. Be careful not to touch the insides of the chassis where the guts are. Contact cleaner will do wonders too. Spray a little on the tube pins (never the sockets) and work the tube in and out a bit to clean all the contact surfaces.

Get a Tung Sol, JJ, Chinese something, LPS and maybe a 5751 and start experimenting based on suggestions in this thread and other sources.