The results of heat on PCB mounted tube sockets...

[allynmey]

Hi all, AES does have them and I just ordered two. They are $7.95 ea.

I think this could be a good way to end the "Flame wars" what a minute.........I think I have at tile for a George Lucas movie!

Allynmey

[Pepi]

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[csbradley]

If there are truely heat issues with any of the PCB mentioned..., anyone of the guys working with a PCB house to do the boards may want to ask what the cost is to move up from FR4 material to FR5 material. The FR5 is a higher temperature board material. I think 185C versus 135C. Not my expertise, but I sometimes have to deal with this stuff when submitting products to UL.

Also, for most of us using G10 for our turret boards, FR4 (typical PCB material) is actually a safer material when it comes to heat. FR4 and G10 are pretty much the same thing, but the FR4 uses flame retardants to get its 94V0 flamability rating. I'd rather have FR4 exposed to high temperatures than G10.

I can easily do the heat measurements if anyone really is worried about these things. The offer still stands. Otherwise, I assume people just need something to talk about, and I'll sign off on this stuff too.

CSB

[allynmey]

Pepi, I hope I didn't turn you off to PCB. I just bought a board from JA and have heard his PCB TMB in person. It sounds good! I'm collecting parts to build the PCB TMB and am waiting for JA to get his chassis in. I think you can build a great PCB. The problem is, and has been discussed ad nauseum, is the power tube heat transfer to the board. I mentioned the extenders because I found them online and was being helpful. I don't know that it needs them but, I bought two and will check out the heat issue on the board and if I feel its hot, I will install them and try again. There seems to be many advantages and few disadvantages to the PCB TMB. I'll report back with my findings and will bring it to ampfest and to the NJ weekly jamfest!

as always I think people should let the amp do the talking!

Allynmey

rant over!!!!

[EBE]

Also, for most of us using G10 for our turret boards, FR4 (typical PCB material) is actually a safer material when it comes to heat. FR4 and G10 are pretty much the same thing, but the FR4 uses flame retardants to get its 94V0 flamability rating. I'd rather have FR4 exposed to high temperatures than G10.
CSB

How many people are doing eyelet boards with on board tube sockets? Not me.

[csbradley]

Ok, well I guess that not what I meant. Probably the only thing that gets hot on most turret boards are power tube cathode resistors, and any parts that might fail. Turrets also help keep the components directly off of the board, so that an advantage too if heat is a concern. There are benifits and disadvantages to almost any method.

But one person that used to do turret boards with onboard tube sockets is Hoffman. Take a look at the pictures of his amps on his website. I think those look pretty cool. Then you can do most of your wiring outside the chassis. Pretty cool, especially is you sold pre-made and wired boards.

CSB

[loverocker]

deleted

[Pepi]

Pepi, I hope I didn't turn you off to PCB. I just bought a board from JA and have heard his PCB TMB in person. It sounds good! I'm collecting parts to build the PCB TMB and am waiting for JA to get his chassis in. I think you can build a great PCB. The problem is, and has been discussed ad nauseum, is the power tube heat transfer to the board. I mentioned the extenders because I found them online and was being helpful. I don't know that it needs them but, I bought two and will check out the heat issue on the board and if I feel its hot, I will install them and try again. There seems to be many advantages and few disadvantages to the PCB TMB. I'll report back with my findings and will bring it to ampfest and to the NJ weekly jamfest!

as always I think people should let the amp do the talking!

Allynmey

rant over!!!!

Just kidding. I really think JA has a good thing going here. I'm thinking about buying his full kit. JA's board look heavyduty. I don't think anyone will have issues with this board

[Plexi]

Just curious,, Steve said..

"""I am going to stop for a while to eat, I will have it finished tonight """

Steve how did it turn out? I see JA doesn't use 68k resistors on the inputs
or 33k for the one input MV side.

The Carvin amps also have alot of problems..and the heat off the Leagacy you could have a cookout,the chassis gets so hot you can hardly touch it,and the tubes sit flush above the chassis. Its not so much the discoloration of the board,its the hot /cold over and over. When you push or change tubes,the socket solder joins can crack or become loose.

Any of the heat things like the cathode resistor,could be placed on seperate boards to keep the heat off of the main board.
But still any power tubes sockets direct to the board,your going to get heat. Some amps do use long extended leads to raise the tube off the board. But should also have some way to mount,that keeps any flexing of the board when changing tubes etc..less likely to crack a solder joint.

Things can be improved, and may find better ways of making it better.

Richie



Richie

[jersey_aaron]

Actually, Kingcrimson should get the commission, being that he first injected the JA TMB PCB into this thread.

There are 1M resistors on the inputs.

[Plexi]

"""There are 1M resistors on the inputs."""

I was meaning to pin 2 or 7..you don't use the 68k input resistors. no big deal,just wondering. The stock 18 didn't use them either.


Richie

[HeeBGB]

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[stevesuk]

Richie,
I am going to start a seperate thread for this. This one is getting too hot.
Steve