I'm building a KT88 PP amplifier from a PCB which has the valve bases soldered in. The chassis I'm using already has the correct number of valve base cutouts but they dont align with the PCB. I dnt want to mess with the chassis so my question is would it be okay to use the existing chassis cutouts for the valves and link the chassis valve holders to the PCB valve holders with short links of wires. The longest link would only be about 5cm. I'm no physicist so I dont know whether the signal paths, voltages or the valve performances would be be affected. The links are so short I can't imagine they would be but I bow to the superior wisdom of the much more knowledgeable members of this forum. The question may be dumb but any advice would be appreciated.🙂
Using chassies mounted sockets will make the amp better.
-no head damages on the board
- no damage due to mechanical damage due to tube replacements
What could be done is to use resistors ( grid/screen stoppers) between the socket and the board.
Boardmounted tubesockets , especially for power tubes, is a fault waiting to occur.
-no head damages on the board
- no damage due to mechanical damage due to tube replacements
What could be done is to use resistors ( grid/screen stoppers) between the socket and the board.
Boardmounted tubesockets , especially for power tubes, is a fault waiting to occur.
Not a dumb question. A few things I can think of right off.
It's probably not a problem adding the extension wires but one question is whether the sockets are on the component side of the board or not. I'd want components to be accessible from underneath without having to remove board and sockets to get at them. Then the concern is if having to flip anything around , to make sure that you don't inadvertently reverse the pin-out.
. . .And, if there are bias adjustment potentiometers , you want to be sure you can get to them, either by adding holes through the top plate or switching them to the effective underside of the board so you can get at them.
Also, if the circuit uses grid stop resistors on any of the tubes it's probably a good idea to remove them from the board and put them directly on their associated socket pins. (Then of course, you'll need to put a jumper in the resistor's board position.)
An afterthought. As I see it , you'll have to put the sockets on the board before you mount the whole assembly to the top plate, so if you are going to buy new sockets to do this, make sure you get sockets that can be mounted from underneath but fixed from above. As I imagine it, you'll need either a captive nut or screw arrangement on the socket hardware as well.
It's probably not a problem adding the extension wires but one question is whether the sockets are on the component side of the board or not. I'd want components to be accessible from underneath without having to remove board and sockets to get at them. Then the concern is if having to flip anything around , to make sure that you don't inadvertently reverse the pin-out.
. . .And, if there are bias adjustment potentiometers , you want to be sure you can get to them, either by adding holes through the top plate or switching them to the effective underside of the board so you can get at them.
Also, if the circuit uses grid stop resistors on any of the tubes it's probably a good idea to remove them from the board and put them directly on their associated socket pins. (Then of course, you'll need to put a jumper in the resistor's board position.)
An afterthought. As I see it , you'll have to put the sockets on the board before you mount the whole assembly to the top plate, so if you are going to buy new sockets to do this, make sure you get sockets that can be mounted from underneath but fixed from above. As I imagine it, you'll need either a captive nut or screw arrangement on the socket hardware as well.
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Maybe wire the heater supply direct to sockets, twisted wires, close to chassis.
No point having potential hum waiting to be picked up.
No point having potential hum waiting to be picked up.
