Lonestar Special 5Y3 rectifier alternatives, anyone?

[stokes]

I totally understand your concerns.Its your gear and it is always best to err on the side of safety.If you aint comfortable trying something,it dont matter what I or anybody else say,you are the one who has to live with the results.We all have our own opinions,based on fact or fiction,and a forum like this is a great place to air those opinions and get responses that help clear up a lot of the "misinformation" we see everyday concerning amps.I am sure Mavguy meant no offense with that statement,he was just reinforcing a comment I made earlier about some guys thinking there is some "magic" to these amps.He,like myself and many others here try to help and share what knowledge we have, when we can,but sometimes words are taken out of context,intentions get misinterpreted,feathers get ruffled.I know for myself,I am not a writer,so sometimes my choice of wording might not be quite right and is very easily misread.Anyway,I am sure we will have more discussions here,and I hope it is always positive.

 

[boogieman90]

Great comments. You guys have given me a quick education about my recto tube and porential issues I've just ordered a Mullard NOS and backup, but will keep the 5V4 option in mind if this does not work.

 

[boogieman90]

I got the Mullard 5Y3 and it looks great. During this time I located a local dealer and I picked up a Mullard GZ32/5V4 tube. As I underastand the previous posts, especially from stokes, I do not need to do anyhting else other than insert the 5V4? As a non-electrican person I want to be sure that my LSS 2X12 can handle any additional voltage that would result from this change in tubes. I don't want to fry my baby! In any event I'm covered and will move away from the stock tube.

 

[stokes]

I got the Mullard 5Y3 and it looks great. During this time I located a local dealer and I picked up a Mullard GZ32/5V4 tube. As I underastand the previous posts, especially from stokes, I do not need to do anyhting else other than insert the 5V4? As a non-electrican person I want to be sure that my LSS 2X12 can handle any additional voltage that would result from this change in tubes. I don't want to fry my baby! In any event I'm covered and will move away from the stock tube.

Without knowing what power tubes you have in there,I would just tell you to keep an eye on the power tubes and be sure they dont redplate,which is a warning I would suggest even when changing power tubes,even if you are using Mesa graded tubes.Unless you check the bias,you can never be 100% sure what the power tubes are doing.I still stand by my comments that the 5V4 is safe in that amp,but that is assuming you have the proper power tubes in there,even if using Mesa tubes,its still a good idea to know how the tubes are biased before making changes of any kind.Mesa tubes are biased on the cold side,which is some insurance that the power tubes will be okay,but that is assuming the guy checking the current draw on the day those tubes were selected wasnt drunk,or just got his pink slip.

 

[boogieman90]

Thanks for the reply. I have stock Mesa EL-84's thus far. I know that they bias cool, very cool. This may well be a cushion, but I want to be safe. I'm looking at retubing with GE NOS's in nthe near future. What should be bias be? Floor plate voltage etc? I'm a newbie at this. For what its worth Torres Enginering also recommends this switch as well. After readying your posts I think this will enhance my tone all the more. That's what I want; to get the maximum performance from my LSS.

 

[stokes]

Thanks for the reply. I have stock Mesa EL-84's thus far. I know that they bias cool, very cool. This may well be a cushion, but I want to be safe. I'm looking at retubing with GE NOS's in nthe near future. What should be bias be? Floor plate voltage etc? I'm a newbie at this. For what its worth Torres Enginering also recommends this switch as well. After readying your posts I think this will enhance my tone all the more. That's what I want; to get the maximum performance from my LSS.

You should be fine,but like I said,it is always a good idea to keep an eye on your power tubes to be sure they dont redplate whenever you make any kind of change to power supply or tubes.To use the GE's you will need to re-bias,unless you can find a supplier that will give you tubes that are tested and graded to be safe in that amp.As to what the bias should be,depends on the plate voltage,but in a nutshell you want the tubes to dissipate about 8watts at idle for class AB or about 10 watts for class A.

 

[boogieman90]

Thanks for the update. I'll need to get the volt-plate info from Mesa, gather the equipment to measure and get the set bias switched so it can be adjusted accordingly.

 

[Timbre Wolf]

I've got to hop in here with a related rectifier question:

Why isn't the 5R4 mentioned in these discussions?


The 5R4 voltage drop is between that of the 5Y3 and 5V4, and it can withstand higher current (-67v@250mA). Like the 5Y3, it is also draws 2 amps (not 3, like the 5U4). And like the 5Y3 it is fast-warmup (not slow-warmup, like the 5V4 and GZ34). NOS versions of this tube are quite cheap (less than $20).

I don't have a LSS, but I've enjoyed using Ken-Rad 5R4GY in my Richter 5E7+ (tweed Bandmaster-like) and Victoria Regal II amps. Seems like it is closer in spec to the 5Y3 than the 5V4 is.

What say ye, Stokes? Mavguy?

- T

 

[stokes]

The 5R4 is also a good choice.I happen to be a fan of it myself.I got a half dozen NOS JAN Phillips for around $25 on ebay a couple years back.In fact there was a thread a while back questioning the amount of capacitance it could take.The manual says 20uf,someone took the stand that it could only take the 20uf safely,but I have one in a Tweed Deluxe clone I have with 100uf,and it has been going strong well over a year.When I first got them I wasnt too familiar with the tube,so they sat for quite a while.Then after having a discussion with Gerald Weber about the 5R4,I started doing some tests with them,I was able to use up to a 220uf input cap,with no arcing problems so I put it in the Deluxe,which gets a lot of use around here and it works just fine.I actually think it performs closer to a 5U4 or even a 5AR4,I find it a little stiffer than the 5V4,I suppose that is why it didnt come to mind here,but it would do just fine.Good point,Wolf.

 

[212Mavguy]

Am a big fan of the Chatham tater masher 5r4, uh-huh. 8) Got one, like fast warmup rec tubes for amps with a standby switch for the B+. Very cold war beefy in it's build, overly thick glass envelope bottle sitting in a very sturdy base that wraps around the bottom quarter of the bottle and has a layer of shock absorbing insulating compound/adhesive between the bottle and base.

In my Frank-en-champ I will just socket the rec tube after powerup when the power tube has had appropriate time to warm up, sort of a poor man's standby switch. 5r4 has enough current capability to handle a pair of 6550's in class a, el34 or 6l6 types are a no brainer. Nice to have an alternative to 5ar4 with high current capability and pin compatible. Great prices secondhand, better build quality by far than current production rectifier tubes.

 

[stokes]

I just saw some of those Chathams going for $13 and change on ebay,guy has 5 available,NOS.That is one of the sturdiest looking tubes I've seen,looks like it was built to take a direct hit from some serious artillery.Could be a problem fitting that in some amps,tho.

 

[Timbre Wolf]

I actually think it performs closer to a 5U4 or even a 5AR4,I find it a little stiffer than the 5V4,

That has also been my experience - seem a bit closer to the solid state of being. They're also larger than 5V4G (or 5Y3G), being as big as a 5U4G.

Thanks, to both you and Mavguy, for your replies. I have not tried that 'tater masher, Mav - simply because the easily available 5R4GY types I've got have been so good (and cheap too).

- Thom

 

[Timbre Wolf]

Hey - Just had to add that, in my experiments with several 5V4Gs, in my Richter tweed Bandmaster-like amp, I found that the RCA 5V4G seems to have a greater voltage drop (more compressed and slow, but I didn't measure the actual plate voltage) than the GE (or Ken-Rad) 5V4G, which is much more clear/tight/fast. I had several samples of each, from the early-'50s. If you want a greater change from the 5Y3, I recommend the GE (older versions labeled "Ken-Rad" are from the same production facility).

Actually, the Ken-Rad/GE 5V4G, 5R4G, and 5U4G are not too awfully much different from each other in that amp. Just slight volume changes. But all three have a kind of clarity that I've not experienced with other NOS rectifiers (Sylvania, RCA, Tung-Sol, National Union).

- Thom

 

[stokes]

I've got a couple of those RCA 5V4's-the short,stubby bottle,and I found them to be "softer" than the batch of JAN-RCA "coke bottles"I have.And then theres a pair of Phillips,in the short,stubby bottle that are a bit stiffer than both of the others,have a much sturdier looking plate structure than the others as well.

 

[Timbre Wolf]

I've got a couple of those RCA 5V4's-the short,stubby bottle,and I found them to be "softer" than the batch of JAN-RCA "coke bottles"I have.And then theres a pair of Phillips,in the short,stubby bottle that are a bit stiffer than both of the others,have a much sturdier looking plate structure than the others as well.

Well, I was referring to the bulbous "ST"-shaped 5V4G, in both cases. The RCA is softer than the GE/Ken-Rad.

- T

 

[fdesalvo]

I really like Brimar 5V4s. They sound great in the 5E3 and I imagine they'd sound great in that circuit.

I've got a couple of those RCA 5V4's-the short,stubby bottle,and I found them to be "softer" than the batch of JAN-RCA "coke bottles"I have.And then theres a pair of Phillips,in the short,stubby bottle that are a bit stiffer than both of the others,have a much sturdier looking plate structure than the others as well.