Tube Bass Preamp reco.

[fusionbear]

I would like to build a nice tube preamp for my son's bass. It would be Bass>Preamp>QSC Stereo Power amp> 2- Mesa EV15 Theile cabs. Any ideas where to look for schematics? He likes a variety of tones from old school blues tones to modern bright slap tones. He plays 5 string with a Low B. I appreciate any help...

[Alexo]

The Ampeg B15 preamp has a nice, classic sound.

[selloutrr]

Fender dual showman with Alembic mod.
B-15
or just purchase a trace Elliot preamp for $300 or a hartke 3500/7000
gallien kruager 800, swr studio 220
swr 900 Eden World tour ashdown aquilar

I understand the desire to build something for him but from a cost to performance stand point the solid state bass amps above are both professional and cheaper to buy then build.

[LOUDthud]

The Fender tone stack is the FMV type and the Ampeg B15 uses a James network (frequently mistaken for Baxandall). It would be nice to have both in one preamp. Traditional tube front ends are easily overloaded by modern basses. That is also an issue that should be dealt with. Sorry I can't offer a solution. Kevin O'Connor addresses these issues in his book Tonnes of Tone but doesn't combine them into one preamp.

[Cliff Schecht]

Padding the input is not hard and will compensate for the extra volume from modern basses (active stuff really). Just use a Fender style input where one jack is normal and the other creates an input voltage divider to pad down the input signal by whatever amount you need. Or you could even put an input impedance knob (pot to ground) on the input to attenuate input signals by whatever amount you need.

[roberto]

I suggest you a baxandall eq like the one we developed on this thread:
http://ampgarage.com/forum/viewtopic.php?p=97467#97467

and just a 100k 1k5//22u stage before and one after the eq

[fusionbear]

Thank you Roberto. That looks like the ticket. I am getting a B15 this weekend that a friend asked me to repair. I will test it out and see if I like the tone.