We love John East's bass preamps.
If you need to give your old (or new) J Bass added punch and flexibility, this is in our opinon the absolute best option available in the market today.
Ultra low noise and extremely musical EQ thanks to the top grade components and John's expertise at electronics design.
This is a direct replacement preamp with (usually) no modification of the instrument needed. The 9 Volt battery is located under the controls. Also this is one of the few preamos out there that works beautifully with just any type of pickup, be it active or passive.
Contols in this case are:
Volumen + Volume + 2 band EQ + Passive Tone
John East J Tone Vol-Vol-Tone