Subbing LSS 5Y3 with 5U4 Question...

[rabidinus]

(I can't find the post I skimmed using the search function)...

I read some LSS owners are doing that.

Anyone used a 5U4 with no issues? I like the idea, tired of blown recifier tubes - and the occasional fuse...

raf

 

[dpiratetim]

I just switched mine back to a 5Y3! I had some strange overheating problems that would burn up the power tubes on occassion. Could have been a bad rectifier tube, but I decided to play it safe. If you get a good 5Y3, it will serve you well for a long time. Boogie now provides NOS Phillips 5Y3 Rectifiers because their new "made for Boogie" version of the 5Y3 was unreliable at best.

 

[rabidinus]

Thanks for the response! Yeah what you said was my one hesitation - that it might run just a bit hot.
I'll check out the Boogie site and order up an NOS 5Y3.

Thanks again!

raf

 

[zm4]

Are the NOS 5y3's labled in any way, other than {MESA}? I ask because my LSS came with what looks like the same old rectifier as before. Even though I havent had trouble I swaped it for a NOS Jan/bendix. Is it just in my head or can you hear a diffrence?

z

 

[dpiratetim]

If you order the 5Y3 from Mesa, it will come in an unmarked plain white cardboard box, not the usual Mesa Packaging, although the tube will have the Mesa stamp. I did like the way it sounded with the 5U4 better. Channel 2 was tighter and more focused. The 5Y3 has the most sag of any of the rectifier tubes used in Mesa amps. The 5U4 was an attempt to get a more modern tone on Channel 2, although using the 30W setting (taking the rectifier tube out of the signal path completely) accomplishes the same thing. I can't tell you if the new 5Y3 sounds better than the original because I had the 5U4 in the amp for 6 months between the two.

 

[user 9654]

I had a 5U4 in for a while but got nervous about it. I put a few different NOS tubes in. All of them were very loose. I recently had my LSS in for service and the tech replaced the rectifier tube with a new one from Mesa (I assume something NOS). The bottom end tightened up considerably with a perfect amount of sag. I never imagined the LSS could get better but it is now amazing. I can actually use the 5 & 15W settings for rhythm and not just leads.