DYNACO PAT-4 User Manual

Page 10 of 23
Remove C7 Nothing goes in its place
 
Remove the jumper
directly below C7
Nothing goes in its place.
 
Remove Q1 Replace Q1 by the MPSA18. Match the
orientation of the flat to Figure 2.
 
Remove Q2 Replace Q2 with an MPSW45A. The flat side
faces the near edge of the board, see Figure 2.
 
Remove C16
2
Replace C16 with the supplied 47 µF 50 Volt
capacitor. Make sure to get the polarity correct.
 
Figure 4-Preparing C4 for installation
Cut a 2” white wire (22 AWG stranded) and
strip ¼” of insulation from both ends. Twist the
white wire around one lead of the new C4, a 3.3
µF 63 Volt film cap and solder it. See Figure 4.
 
Remove the old C4,
a 50 µF 25 Volt
capacitor.
Place the new C4 assembly into the board as
shown in Figure 2 and Figure 7. For now, solder
C4’s right hand lead on the back of the board,
but not the left-hand lead.
 
Solder the free end of the white wire from C4
into eyelet 6.
 
If your PCB has a location for R30, then solder
the unsoldered (left-hand) wire of C4 on the
back of the board, and you’ve completed the
PCB Modifications.
 
If your PCB doesn’t have a location for R30,
then see the next section for directions on
installing R30 on the back of the board.
 
2
C16 isn’t part of the phono preamp. It’s part of the high level stage. However, we’ll replace it because it
often goes bad due to its proximity to the heat generated by R20.

DYNACO PAT-4 Specifications

General

Brand	DYNACO
Model	PAT-4
Category	Amplifier
Language	English