Description
This tone control preamp uses the excellent and proven Baxandall tone control circuit still widely in use today with tube and solid state tone control Preamp,s. The tone control circuit is designed in such a way that with the controls centered, there is zero influence on the signal. This tone control preamp uses four 12AX7 Triode’s. The PCB is manufactured to FR4-TG standards with ground planes on both sides to improve screening as well as component screen printing to make assembly easier.
The TCLA will also work with most solid state amps, but, there will always be exceptions and we cannot advise which soild state amps may require an impedance matching circuit, as there are just too many variables.
Volume control MUST be 100K and balance control MUST be 250K!
NOTE: the tubes require a 24VDC supply for the filaments, not 6.3V or 12.6VDC!
A set of assembly instructions is also included. However, Tubes are not included. Please note that the photos are a general indication, and component colors and style can and will vary.
The Potentiometers used in this kit are only suitable for ‘set screw’ style knobs, the old push on knobs will not work!
An important note regarding the TCLA: since this preamp uses four tubes, the original Dynaco PA211 power transformer will not be able to handle the additional filament current demanded by the two additional tubes. You will need to use one of our regulated power supply kits, details of which can be found on our power supply kits page.
