Gibson producing amps again

[SFIV1967]

Falcon 20:


Source: https://www.thegearpage.net/board/index.php?threads/gibson-falcon.2528551/post-38308191

Ralf

 

[GGJaguar]

Ugh. PCB and the tube sockets are directly mounted to it. No thanks.

 

[GAD]

Nothing wrong with a PCB if it’s done right.

Ugh. PCB and the tube sockets are directly mounted to it. No thanks.

Sigh.

 

[chazmo]

I was a little confused by these comments too...

GG, what did you mean? How else would you want the tube sockets other than mounted to the PCB?

 

[SFIV1967]

TheGearPage had many discussions about that tube sockets on PCB issue and I found two nice photos of other amps there:





Ralf

 

[SFIV1967]

How else would you want the tube sockets other than mounted to the PCB?

If I might answer, have a look in GAD's recent built:

https://letstalkguild.com/ltg/index.php?threads/project-jcm800-build.219890/post-2139270

Ralf

 

[chazmo]

Oh, I see. Can't see how that's preferable to mounting to a PCB, but OK. There's a whole lot about tube amp construction that makes little sense to me.

 

[SFIV1967]

Can't see how that's preferable to mounting to a PCB, but OK.

I'd say try wiggling older tubes out of their sockets and you will see why that could be potentially not good for a PCB in the longterm...But obviously others have other opinions. A chassis mounted socket is definitely stronger in my opinion.

Ralf

 

[AcornHouse]

Oh, I see. Can't see how that's preferable to mounting to a PCB, but OK. There's a whole lot about tube amp construction that makes little sense to me.

Each time you change the tubes you are stressing and flexing the PCB which increases the chances of breaking a solder joint. Having sockets on the chassis with leads running to the PCB removes that stress.

 

[GAD]

Each time you change the tubes you are stressing and flexing the PCB which increases the chances of breaking a solder joint. Having sockets on the chassis with leads running to the PCB removes that stress.

This is the right answer. In theory that risk can be mitigated by properly supporting the PCB around the sockets, but usually sockets on PCBs is a means to lower cost. Once the “lower cost” mindset wins then “things that happen inside the case where people don’t see them” start to go away and you get modern consumer crap.

It’s like how PCBs themselves aren’t bad *if they’re done well* but many of them aren’t so PCBs also get a bad rap. Those Gibson amps look like they were designed in such a way that they could be *assembled* by someone and then they could call them “hand wired”.

 

[AcornHouse]

And bad (read: cheap) PCBs, which can be found on amps at ANY price point, have very thin traces, I.e. the copper lines that act as wires between components. Thin traces are prone to heat damage and if broken, can cause a tube overheat and the amp to self destruct.

 

[GAD]

And bad (read: cheap) PCBs, which can be found on amps at ANY price point, have very thin traces, I.e. the copper lines that act as wires between components. Thin traces are prone to heat damage and if broken, can cause a tube overheat and the amp to self destruct.

And PCB design is an art form just like clean wire dress is. Wire traces can form parasitic oscillations and stray capacitance issues just like wires can, but so many PCB designers just seem to throw the schematic into a PCB generator and go with whatever comes out. Suhr amps have a good reputation of great PCB design. Psionic Audio has a great vid on a Suhr Hombre where he talks about a great PCB design - and it has PCB-mounted tube sockets! (14:30 for discussion about tube sockets).

 

[Rocky]

And bad (read: cheap) PCBs, which can be found on amps at ANY price point, have very thin traces, I.e. the copper lines that act as wires between components. Thin traces are prone to heat damage and if broken, can cause a tube overheat and the amp to self destruct.

Aka modern Fender and Marshall

 

[GGJaguar]

The PCBs that Ampeg used in the late '60s through the '70s were pretty beefy.

 

[Walter Broes]

Oh, I see. Can't see how that's preferable to mounting to a PCB, but OK.

Next time you're close to a tube amp that's been on for a couple of hours, fondle the tubes a little with your bare hands (or rather DON'T!)
That kind of heat + thin "throwaway" pcb = trouble

 

[AcornHouse]

Next time you're close to a tube amp that's been on for a couple of hours, fondle the tubes a little with your bare hands (or rather DON'T!)
That kind of heat + thin "throwaway" pcb = trouble

Roger Daltrey has talked about using the amps to dry out mics that got a little too much, shall we say, moisture.

 

[Charlie Bernstein]

Ugh. Forgot. Damn Gibson site demands cookies. Deal-breaker.

 

[GGJaguar]

 

[chazmo]

Roger Daltrey has talked about using the amps to dry out mics that got a little too much, shall we say, moisture.

Also, great for baking pot brownies for a little après-show action.

 

[GAD]

Ugh. Forgot. Damn Gibson site demands cookies. Deal-breaker.

Most sites use cookies, including this one.