Banana booster is one of the oldest TT DiY projects and it always fascinated me how simple it is. I must have drawn tens of different layouts for it. In preparations for my bigger (half finished) project G5, and waiting for some "sand" kits to arrive I took a cardboard box, an obsolete noval socket and looked for the parts in my drawers. 2 caps and 7 resistors in pretty common values - check! TT LoV PSU from past projects - check (and I had to add two monster caps instead of originals
) jacks, knob, led, switch, wires ... Not a thing someone wouldn't have
as remains ... Chassis, pot - missing > ordered (can wait). The
model in cardboard was made in approx. 2 hours. With direct PTP approach
- my way: messy as hell and hard to troubleshoot, also prone to
parasitics, but small. When the chassis arrives there is a complication,
because the insides are smaller than thought. When plugged in, sound is
great, practically no noise. This kind of tube booster on the begining
of sound chain is practicaly all the tube in it you need ... But I am left wandering: what does the "kick" option in the kit add ... A transistor (as in Vanilla)? Later I see it's a switchable cathode cap - and I am kind of dissapointed; also in me, for not getting the idea myself ... I am thinking of putting it in this project, but where ... Maybe.
Design:
- tube socket is mounted with two L brackets - belton noval chassis sockets are made for this mounting (and can prove a difficulty to mount from inside the chassis >> make hole a square OR use nuts as spacers)
- led is an oval sort (3,7x3mm) and so it is mounted noly by frocibly pushing in 3,5 drilled hole - not too cosmetic, but it works
- caps are (again haha) overkill, this time in the voltage, but I had those home
- DC input terminal is turned to the middle of PCB (so it can be directly at the chassis)
- as the later 14V power adapters from TT are DC, the diodes are replaced with corresponding jumpers
- on the other side of PSU PCB I used an old pin terminal (neither currents nor voltages are too high for that) - and the distance is just right
- oh, and the second overkill: wires - i used the remains of silicon ones from G5 project >> better use solid 0,14mmm, soldering those to the tiny connectors is nuisance
- 1uF cap goes directly from socket to pot
- all ground is wired directly to the input jack; I tested with multimeter, that contact with chassis is made there
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