Lonestar Special 5Y3 rectifier alternatives, anyone?

[thinskin57]

i'm wondering if there's anyone out there with FIRSTHAND long-term experience with substituting the 5Y3 rect tube in the LSS. I've read of people recommending the 5V4, but they weren't LSS owners. MB tech support told me what works in another amp (Maverick?) won't work in the LSS... however, i'm skeptical so here i am. i've had mine for a month now (212 combo) and blew my first rect tube last night along w/the fuse. shortly after, i found this site and became a bit freaked by the frequency of this issue w/mesa's 5Y3's so here i am. i'd also be interested if anyone has any success stories of using any NOS 5Y3's long-term. thanks to anyone who can help.

 

[RR]

...I've read of people recommending the 5V4, but they weren't LSS owners. MB tech support told me what works in another amp (Maverick?) won't work in the LSS... however, i'm skeptical so here i am. ...

First of all you do realize that the LSS special only uses the rectifier tube (5Y3) in the 5 watt mode. The other modes is using solid state rectifier. I'm not familiar with 5V4 rectifier tube (not a technician) but you do realize a Maverick is 33 watt amp and uses a 5AR4 in rectifier tube mode and that's because it has to supply more voltages unlike a 5Y3.

So if you are considering using a more powerful rectifier tube in the LSS 5 watt mode you maybe doing a lot of harm than good to your amp.

Maybe you blew up your 5Y3 tube because of an unusually circumstances. You are not the first to do this. Now if you keep blowing up 5Y3 tubes then you should considering getting your LSS check than blaming on 5Y3 tubes.

You asking if there's a substitute for a 5YA is an excellent question but questioning MESA Tech support?

For one thing I would not questioned MESA tech support, that is like going to doctor and he tells you may have cancer so stop smoking and you question his diagnose and have ask others.

 

[thinskin57]

actually, you're wrong RR. the tube rectifier works in the 5 AND 15 watt mode. the only reason why i mentioned the Maverick as an example regarding rectifier tube substitution, was because there is a forum member here who does a substitution with his maverick- also an EL84 amp.

you mention that maybe it blew under unusual circumstances. such as? my power source was/is clean.

i shouldn't question tech support?! why not? should i instead bow down and kiss their ring? please! do you know how many tech support people literally read out of books or a computer while they've got you on the phone? if you listen carefully, you can hear them flipping pages or typing a search in their computer! i don't think that's the case w/boogie though.

according to tech support, they've never had a case where the recto tube blowing was due to a problem with the LSS amp. i was told flat out that the problem is with the poor quality of the current day 5Y3 that is available. so if the tech said this, it MUST be true, right? don't forget- Mesa was built on doing things to an amp that you weren't supposed to do, so why not question the techs who, for warranty reasons, are likely not allowed to take the liberty of telling you that you can try something else. there are a few people on this site who say you can, but even that's not good enough for me until i hear of someone who has been doing it successfully for a good amount of time with no repercussions to his LSS. for now i've decided to play it safe as i just purchased a NOS 5Y3 by RCA. according to KCA, it should last 10 years if used under proper circumstances. we shall see...

 

[RR]

thinskin57:

http://forum.grailtone.com/viewtopic.php?t=20609

Yeah, I forgot that tube rectifier is also 15 watts mode.

I guess I was little premature and MESA had to cover their tracks.

Sorry, My bad.

thinskin57:

I know you have good taste in amps (besides the LSS, those two Carr!), I'm not sure if you live in a small or large town but try to find yourself a reliable and trustworthy technician locally if possible.

I'm finding out more that there's a lot of egotistical technicians on-line that may mislead you given wrong suggestion and advice. So I was afraid someone may give you bad advice little did I know (above) ...

:wink:

 

[thinskin57]

no worries. i appreciate the concern. i know what you're talking about when it comes to techs. i DO have one who fortunately knows his stuff, but unfortunately he charges heavy for his services. i really don't anticipate having problems w/my Carrs. they're pretty much bullet proof, and built with nothing but the best components. that said, i DO prefer the sound of my LSS. some people will argue, but i DO think the difference is the tube rectifiers. soooo squishy! great for clean tones. best quality parts doesn't always equal superior tone i guess.

 

[fdesalvo]

I love the 5V4- less voltage drop across it = slightly higher volts on the plates of the power tubes...a littel more headroom and a little tighter/less sag. Perfect plug & play.

 

[BobL]

I would use caution when substituting a rectifier for the 5Y3 with anything that handles higher current. Higher voltage/current handling rectifier tubes stiffen the B+ supply, much like silicone diodes, and can actually allow the circuit to supply more voltage. So the question is, will the circuit handle the additional stress.

Quoted from source;

5U4GA Rectifier Converts A.C. to D.C. in high-power applications.

5U4GB Rectifier Converts A.C. to D.C. in high-power applications. This is a plug-compatible replacement for a GZ34 and can be used to enhance compression/sag in amps that come equipped with the more efficient

GZ34. The reverse substitution should be performed with caution as it may result in higher plate voltages reducing the life of other tubes.

5AR4 Rectifier Converts A.C. to D.C. in low-to-medium-power applications.

5Y3 Rectifier Converts A.C. to D.C. in low-power applications. This tube can be used as a plug-compatible replacement for a 5AR4 to enhance compression, but will generally have a shorter life than a 5AR4 in the same application.

5V4 Rectifier Converts A.C. to D.C. in medium-power applications. This tube is plug-compatible with the 5Y3, but has a lower internal impedance and is therefore somewhat more efficient than the 5Y3. Use of a more efficient rectifier will generally make an amplifier louder and brighter. The trade-off is that it will also degrade the amp's compression characteristics. Replacing a rectifier with a more efficient tube can also result in higher plate voltages which can reduce the life of other tubes.

 

[fdesalvo]

The 5V4 will not increase plate voltage to the point where the power tubes will be jeopardized in any way. Swap it out and enjoy. You will not see a huge difference in compression, rather, you will notice a little more tightness and less flab. You will still have gobs of touch sensitivity and dynamics.

If you are uncertain about the differences between the two rectifier tubes, compare the spec sheets on the 5Y3 and 5V4. This simple swap will not alter the characteristics of your amp the way a SS rectifier will. In a medium power/low gain application, I find that overly stiff power supplies crush a tube amp's dynamics and feel resulting in a very flat and stiff feel.