Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => AmpTools/Tech Tips => Topic started by: pullshocks on March 22, 2021, 12:47:37 am

Title: Mini breadboard.
Post by: pullshocks on March 22, 2021, 12:47:37 am
Some of you on this forum have breadboards bigger than my whole house. 


Here's a "kinda sorta" breadboard in an Judybox amp chassis I got years ago.  It has a PT with 265-0-265 and 320-0-320 taps, and an available 45 volt bias tap, if I ever venture into fixed bias circuits.


My goal with this is to try a few different preamp circuits 


The circuit board is in 2 layers.  The longer, lower layer has a generic 6v6 push pull cathode bias power amp soldered in place.


The upper layer consists of  4 rows of terminal strips, one of which is wired up as a ground bus.  Leads are soldered to the tube sockets and can be connected t the screw terminals.  It will accommodate all the preamp circuits I had in mind (thank you DIY LC for helping me confirm that)


It takes a fair amount of time to wire it up initially, getting the leads bent to fit the spaces.  But disassembly and temporary connect and disconnect is a lot quicker for me than desoldering and resoldering.


Once wired up, a lid can be screwed on the shell. and within reason, moved around like any other amp head.  I wouldn't take it on a world tour,  but the assembly is secure enough to move from the shop to a playing area for playing tests. 


First up is the Benson Monarch. 







Title: Re: Mini breadboard.
Post by: acheld on March 22, 2021, 09:23:11 am
I like the approach. 

With a similar goal in mind, I put together a set of pre-configured PCBs from Merlin's website.  These boards are engineered well, BUT are a pain in the neck to tinker with as you have to dismount the board from the chassis in order to desolder any component. 

In addition, it's a bit difficult to keep track of  what trace connects where . . . 

So, your idea is the winner.     Merlin's idea -- and my implementation of it -- not so much.