PERELANDRA BOOST / OVERDRIVE
6
BUILD NOTES
“AT” (Andy Timmons) and “Version 1.5” models
In 2007, Xotic changed the BB Preamp to add an extra clipping diode in each direction (which they
described as reducing compression). Andy Timmons was an early endorser of the BB Preamp and
preferred the pre-2007 version. Because of this, Xotic re-released the pre-2007 version as the Andy
Timmons signature model (sometimes called the “BB-AT”).
While there have been a few very minor circuit changes to the BB Preamp along its production run, the
only thing distinguishing the AT from the non-AT version is the diodes. The AT version has one diode in
each direction while the later version has two in each direction.
The post-2007 version is now referred to as the “v1.5” by Xotic and is still in production. There is no
version 2, but presumably they didn’t feel the pre- and post-2007 versions were different enough to
warrant a whole number change in version as with the V2 AC/RC Boosters.
The default parts list provided above is for version 1.5, the current production model. To build the AT
version, just jumper one of the two diodes in each direction (i.e. D3 and D4).
Bass version
The Bass BB Preamp was released in 2006. It’s mostly the basic circuit, but it has a single capacitor
added and several part substitutions.
To build the bass version, change the following parts:
•
C2
: 1uF
→
100n
•
C4
: 47n
→
10uF (positive leg should go in left pad; will need to position it overlapping R5)
•
C5
: omit (leave empty)
•
C6
: 220n
→
1uF
•
C7
: 1n (normally left empty on standard version)
•
C9
: 10uF (positive leg should go in left pad; easiest to solder it to the bottom side of the PCB)
•
C13
: 4n7
→
10n
•
C14
: 4n7
→
10n
•
C15
: 1uF
→
10uF (positive leg should go in left pad; will need to position it overlapping R16)
•
R5
: 10k
→
4k7
•
R6
: 4k7
→
10k
•
R11
: jumper
•
R14
: 47k
→
22k
