Weber Copper Cap Replacement for 5Y3GT Rectifier Tube in LSS

[axman53]

Any using one of these in the LSS? What are your results, sound-wise and reliability-wise? I'm mostly concerned about any ill effects doing this will have on my amp long-term. Any info appreciated. It's getting expensive replacing the 5Y3 every couple of months. Thanks.

 

[twally]

Hey,

Have you contacted Mesa about their 5Y3 Mod? If your amp's still in warranty they will do the mod for free. If it's not, it may still be cheap enough to off set buying tubes as often as you have to.

As far as I can tell it doesn't affect the amp's mojo.

TW

 

[axman53]

Have you contacted Mesa about their 5Y3 Mod? If your amp's still in warranty they will do the mod for free. If it's not, it may still be cheap enough to off set buying tubes as often as you have to.TW

Ah, didn't know about this. Thanks for the pointer! And my amp is still in warranty! Can anyone offer any details about this mod? I guess I'll have to find a MESA authorized shop somewhere too. Thanks.

 

[axman53]

So I talked to MESA tech support today. There is indeed a 5Y3 mod for the LSS. The tech pointed out that since approximately serial number 4000 the mod was incorporated into production units. My serial number just above the 4000 mark, so he suggested I bring the amp into the local authorized shop and have them check it out, which I will. I'll keep you posted on my experience with this. I have two 5Y3's from MESA on the way, plus I also ordered the Weber Copper Cap because I need the amp for an upcoming gig and there's no way to know when the 5Y3's will arrive. The Copper Cap I was able to get FedEx'd to me so I know I'll have it if needed.

 

[Crowey]

Excuse my ignorance, but why would we want this in our LSS'? From their (Weber VST) web site it appears to be a solid state rectifier, and I thought one of selling points of the LSS was its tube rectifier (well at least at 5 & 15 watt).

I'm not criticising, I'm genuinely interested - especially as a) I'm in Oz and so getting such upgrades is probably not as straightforward as in US; and b) my serial number is just under 4100 so I may/may not already have this mod ...

 

[axman53]

Excuse my ignorance, but why would we want this in our LSS'? From their (Weber VST) web site it appears to be a solid state rectifier, and I thought one of selling points of the LSS was its tube rectifier (well at least at 5 & 15 watt).

It's a little more thought out than just a solid state rectifier replacement. It's that plus a resistive component that is meant to emulate the voltage sag of the tube it replaces. I bought it just so I know I'd have something that will work until I get to the bottom of the 5Y3 failure problem. I will keep it on hand while using (or should I say, burning out) 5Y3's so I can at least play the amp when I need it. Based on what I've read, it's a pretty subjective thing as to any difference you might hear between the copper cap and the tube, but whatever it is, it has to be better than the amp not working at all.

 

[Steve73]

Interesting, I'd never heard of this 5Y3 mod either. My LSS head is in the 2600 range so it's definitely before the mod. I don't have any problems with my rectifier tube though. I've had the same one in for at least a year now.

Anyone know exactly what they do on this mod? I'll email Mesa and get the lowdown maybe.

 

[Don]

You can get an NOS 5Y3 for about $20. It will out last a new "5Y3".

 

[MrMarkIII]

So I talked to MESA tech support today. There is indeed a 5Y3 mod for the LSS. The tech pointed out that since approximately serial number 4000 the mod was incorporated into production units. My serial number just above the 4000 mark, so he suggested I bring the amp into the local authorized shop and have them check it out, which I will. I'll keep you posted on my experience with this. I have two 5Y3's from MESA on the way, plus I also ordered the Weber Copper Cap because I need the amp for an upcoming gig and there's no way to know when the 5Y3's will arrive. The Copper Cap I was able to get FedEx'd to me so I know I'll have it if needed.

If you are experiencing repeated 5Y3 failure, it just might be safe to say you don't already have the mod, the purpose of which is to stop the 5Y3 failures.

 

[axman53]

So I talked to MESA tech support today. There is indeed a 5Y3 mod for the LSS. The tech pointed out that since approximately serial number 4000 the mod was incorporated into production units. My serial number just above the 4000 mark, so he suggested I bring the amp into the local authorized shop and have them check it out, which I will. I'll keep you posted on my experience with this. I have two 5Y3's from MESA on the way, plus I also ordered the Weber Copper Cap because I need the amp for an upcoming gig and there's no way to know when the 5Y3's will arrive. The Copper Cap I was able to get FedEx'd to me so I know I'll have it if needed.

Update to this thread. The Weber Copper Cap works great! It doesn't fail at least, and no discernable change in tone to my ears. So I used that for a couple gigs no problem. I have a break to my next gig, so I brought the amp into the local authorized MESA shop and they are going to see if my amp has the 5Y3 mod or not. I'll update this thread again once I hear back from them.

 

[Don]

I just put a Weber Copper Cap 5Y3 replacement in a Fender tweed Deluxe (5E3) clone that I built for a friend. The voltage drop is to be about the same as it is with a real 5Y3. I also put a Copper Cap 5AR4 replacement in my Super Reverb with similar results as the Mullard 5AR4 in my Vibrolux Reverb. They work great. They get hot as heck, though!

 

[Rockin_Ron]

So I talked to MESA tech support today. There is indeed a 5Y3 mod for the LSS. The tech pointed out that since approximately serial number 4000 the mod was incorporated into production units. My serial number just above the 4000 mark, so he suggested I bring the amp into the local authorized shop and have them check it out, which I will. I'll keep you posted on my experience with this. I have two 5Y3's from MESA on the way, plus I also ordered the Weber Copper Cap because I need the amp for an upcoming gig and there's no way to know when the 5Y3's will arrive. The Copper Cap I was able to get FedEx'd to me so I know I'll have it if needed.

Can you tell me what exactly they do to "fix this"? I have an LSS well below 4000 and I haven't had any problems since changing over to NOS tubes. Bought some off the bay for cheaper than GC was charging for the garbage MESA ones which might only last ~ 1 year.

 

[axman53]

Can you tell me what exactly they do to "fix this"? I have an LSS well below 4000 and I haven't had any problems since changing over to NOS tubes. Bought some off the bay for cheaper than GC was charging for the garbage MESA ones which might only last ~ 1 year.

I'm going to try to get as much out of my tech as he'll tell me. When I get the amp back I'll update this thread.

 

[ricardo loma vista]

you don't really need the mod if you buy a NOS 5Y3GT. I bought one after blowing a couple of Mesa (Sovtek) 5Y3's, and have used it for several years with no problems.

That said, I was in Mesa Hollywood last summer and asked the tech about the 5Y3 mod. He said it was very simple and he could do it in about 5 min. I brought my amp in a few weeks later and while he wouldn't say exactly what he did, it took only a few minutes and afterward he handed me two clipped resistors from my amp. He said that the mod reduced the amount of current the rectifier pulls. I opened up the amp later and it looks like that's all he did--clipped two resistors from the circuit board. No change in tone or response to my ears.

I'd recommend getting it done since it's quick and simple and you can probably safely use any 5Y3 tube. However, I'm still using the NOS rectifier tube.

 

[axman53]

So I talked to MESA tech support today. There is indeed a 5Y3 mod for the LSS. The tech pointed out that since approximately serial number 4000 the mod was incorporated into production units. My serial number just above the 4000 mark, so he suggested I bring the amp into the local authorized shop and have them check it out, which I will. I'll keep you posted on my experience with this.

OK, the verdict is in. My amp was found NOT have the factory 5Y3 mod in it. The tech did the mod for me, so it does now. Now we'll see how long a MESA 5Y3 will last. I have another MESA 5Y3 and some fuses for backup, in addition to the Weber copper cap.

 

[Thundersteel]

I opened up the amp later and it looks like that's all he did--clipped two resistors from the circuit board.

For those who have had this mod done--is it possible to post pics, so we know which resistors to clip?

 

[ricardo loma vista]

the two resistors clipped are R101 and R103 immediately on either side of the ribbon cable.

I understand that newer LSS models do not have R101 and R103.

here's a pic of before. I didn't have a camera at hand when I checked what the tech did, but if I get ambitious, I'll take an after photo.

I couldn't see anything else that was done to the board.

 

[Thundersteel]

the two resistors clipped are R101 and R103 immediately on either side of the ribbon cable.

Which ones are R101 & R103?

 

[ricardo loma vista]

two resistors, one each on either side of the ribbon cable

the numbers should be stenciled on the board

 

[Thundersteel]

So, after those resistors are clipped, than I can safely use 5Y3s without fear of them blowing?

Or would you recommend I continue to use the 5V4?