5Y3 rectifier tubes

[LerxstLee]

I understand fast start up time is not the issue. Use the 5v4 and it takes more voltage, if something goes wrong
most slip the 5y3 back in and warranty it. Does'nt Mesa a fix for this by now ?
/cheers

 

[94Tremoverb]

Given these reports I would not risk a nice NOS 5Y3 in one of these amps - it's clear that the circuit demand is right on the edge of what they will take, and you may kill a perfectly good tube that will run fine in an amp which is more correctly designed to run with a 5Y3.

I would use a 5V4 or another of the higher voltage and current rated types, depending on how much sag you want - the 5R4 is actually the closest in forward voltage drop to the 5Y3, but is rated for double the current and voltage (actually more than double the voltage, for the GYB variant), and draws the same filament current. This should be bombproof in a 5Y3 application. You could also use a 5AR4 (GZ34) although you'll get a lot less sag. Of the other fairly common types I would avoid the GZ37 and 5U4, even though they have plenty of voltage and current capability, because they draw a lot more filament current.

For what it's worth I do like the 5V4 too though, I have a pair of NOS Sylvania ones in my Tremoverb - which is just OK on current (350mA total for both tubes, at the upper limit when it's really cranked), and they sound great and have been totally reliable.

 

[212Mavguy]

My Mav has run a 5v4ga Sylvania blackplate for years and hundreds of hours with zero issues...that amp is the LSS's daddy, and it runs 4 el84's all the time in a very hot class AB. Lots of current draw. GE 5v4ga is an awesome tube as well.

In my tube searches on eBay I managed to snag some Bendix 5r4's. They look similar to the Chatham "tater masher" ones, I run one in my Siegmund, nice tube. Also have Chatham, can't go wrong unless the size of the bottle is an issue. Some 5r4's look to be of similar size and shape bottle wise to the 5u4.

 

[stokes]

Given these reports I would not risk a nice NOS 5Y3 in one of these amps - it's clear that the circuit demand is right on the edge of what they will take, and you may kill a perfectly good tube that will run fine in an amp which is more correctly designed to run with a 5Y3.

I would use a 5V4 or another of the higher voltage and current rated types, depending on how much sag you want - the 5R4 is actually the closest in forward voltage drop to the 5Y3, but is rated for double the current and voltage (actually more than double the voltage, for the GYB variant), and draws the same filament current. This should be bombproof in a 5Y3 application. You could also use a 5AR4 (GZ34) although you'll get a lot less sag. Of the other fairly common types I would avoid the GZ37 and 5U4, even though they have plenty of voltage and current capability, because they draw a lot more filament current.

For what it's worth I do like the 5V4 too though, I have a pair of NOS Sylvania ones in my Tremoverb - which is just OK on current (350mA total for both tubes, at the upper limit when it's really cranked), and they sound great and have been totally reliable.

There really isnt an issue with a NOS 5Y3,they can handle the extra strain,its only the current production 5Y3's.I believe Mesa found a supplier to build them a better 5Y3,forget offhand who,but that was Mesa's answer to the problem.