Modular Tube Preamp System

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I've got the final front panel for the PSU today, so here are some more details:
I've designed two PCBs for the required voltages. Here is the HT PCB that bases on a schematic Michael Kingston published some time ago. It can supply up to 300V regulated. I've added a voltage divider for the elevated heaters I use in this project. The little toroid transformer is custom wound, it'a 28.8VA 240V transformer.

mspsuht.jpg


Next is the PCB that holds two SMPS, the large one is a MW LRS for the heaters, the small one is for 48V.
mspsuhtr.jpg


The two cards co into a large Fischer cassette that is able to hold several euro cards. Special rails for the cassette are required.
mspsubc1.jpg

Assembly
mspsubc.jpg

Assembled
mspsu.jpg

Complete
msfront1.jpg

Rear view
msback.jpg


Bottom
msbottom.jpg



I started in 2017. Still one module to build...



 
Wow, Hoger, I´m impressed. That´s a lot of parts crammed into little space. Does it heat up a lot?
In particular I´m interested if the heat transfer through these small tube pins to the PCB is a problem.
 
jensenmann said:
Wow, Hoger, I´m impressed. That´s a lot of parts crammed into little space. Does it heat up a lot?
In particular I´m interested if the heat transfer through these small tube pins to the PCB is a problem.
Tubes get a bed press for producing a lot of heat, probably due the that fact that the power tubes in guitar amps do get very hot. But mic pres are completely different. One of Holgers modules will probably consume less than 10 watts.  Its front panels will probably rise about 5 degrees above ambient. 10 of these in a 19 inch space is 100 watts.

Cheers

Ian
 

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