Amp Power Supply



Power Supply Parts Description No. Supplier Stock No. USD ea. Total
T1 TRNS, 300VA, 40V, Center Tap 1 Antek AN-3240 36.00 36.00
T2 TRNS, 25VA, 18V, Center Tap 1 DK 237-1288-ND 15.41 15.41
BR1 RECTIFIER BRIDGE 200V 25A D-34A 2 DK 26MB20A-ND 8.87 17.74
CP1 CAP 12000UF 80V ELECT TUP SERIES 4 DK P10032-ND 12.07 51.48
CP2 CAP .1UF 250VDC METAL POLY CAP 4 DK EF2104-ND 0.34 1.36
AC1 AC Receptacle IEC 320-C14 1 DK Q210-ND 0.70 0.70
PC1 Power Cable, NEMA 5-15P to IEC 320-C13 1 DK Q125-ND 4.1 4.10
FH1, FH2 HOLDER FUSE 3AG .500"L 1POS 2 DK 3536K-ND 1.55 3.10
FH3-10 HOLDER FUSE 3AG 2.375"L 4POS 2 DK 3539K-ND 5.28 10.56
F1 FUSE 8A 250V T-LAG GLS MD 1 DK 283-2755-ND 1.00 1.00
F2 FUSE 1A 250V FAST AGC GLASS 1 DK 283-2619-ND 0.70 0.70
F3-F10 FUSE 5A 250V FAST AGC GLASS 8 DK 283-2635-ND 0.70 5.60
R52 RES 3.9K OHM 2W 5% METAL OXIDE 4 DK OY39GK-ND 0.25 1.00
R53 RES CERAMIC COMP 100 OHM 2W 1 DK OY101KE-ND 1.28 1.28
TS Terminal Strip 3 NA Generic 5.00 15.00
S1 SWITCH TOGGLE DPST 5A SLDR 5PCS 1 DK 360-2087-ND 7.65 7.65
Total NA NA NA NA NA 169.48


ESP Project 05-RevA

The schematic above shows the ESP 05-Revision A regulated power supply. The version used in Pi-Amp Bi-Amp is Revision B. The Revision B schematic cannot be shown due to copyright protection.

The table below shows the total cost of ESP 05-Revision B (PCB and on board components)

ESP P 05-RevB Description No. Supplier Stock No. USD ea. Total
D1-D10 1N4004 10 DK 1N4004-E3/54GICT-ND 0.47 4.7
U1 IC REG ADJ 1.5A 3 TERM TO-220 1 DK LM317TFS-ND 0.71 0.71
U2 IC REG 1.5A NEG-ADJ TO-220 1 DK LM337TFS-ND 0.71 0.71
Q1 TRANS NPN GP 30V 100MA TO-92 1 DK BC549CG 0.45 0.45
Q2, Q3 TRANSISTOR PNP 1.5A 80V TO126 2 DK BD14016STU 0.45 0.9
C1, C2, C3, C4 CAP ALUM 2200UF 25V 20% RADIAL 4 DK 493-1306-ND 1.03 4.12
C5, C6, C7, C8 CAP .10UF 25V CERAMIC 4 DK BC1148CT-ND 0.44 1.76
C9, C10, C12, C13 CAP ALUM 10UF 100V 20% RADIAL 4 DK 493-1372-ND 0.3 1.2
C11 CAP ALUM 1UF 160V 20% RADIAL 1 DK 493-1384-ND 0.32 0.32
R1, R2 RES 10 OHM METAL FILM 1W 5% 2 DK PPC10W-1CT-ND 0.34 0.68
R3, R5 RES 100 OHM 1/4W 1% METAL FILM 10 DK 100XBK-ND 0.13 1.3
R4A/B, R6A/B, R8, R9 RES 2.2K OHM 1/4W 5% CARBON FILM 10 DK 2.2KQBK-ND 0.08 0.8
R7, R10, R11 RES 22K OHM 1/4W 5% CARBON FILM 10 DK 22KQBK-ND 0.08 0.8
ESP Project 05-RevB PCB 1 ESP 05-RevB 18.00 18.00
Total NA NA NA NA NA 36.45

Tip For Soldering Wire Leads to Small Components
  • Measure and cut the wire leads. Include enough excess to route the lead from that component to the final connection.
  • Strip the component end of the lead back, twist the strands together, apply flux and tin with a generous amount of solder.
  • Secure the small component gently with a bench vice, locking pliers, mount point, masking tape, etc.
  • Apply flux to the component lead and tin with a generous amount of solder.
  • Attach the lead to the component by touching the tinned leads together and then applying the soldering iron tip. As soon a the solder flows between both leads, remove the iron while holding the lead steady until the solder hardens.
  • It is generally not necessary to twist the leads together or insert the lead through a hole in a solder lug because the solder is strong enough. De-soldering components that have been mechanically joined before soldering can be time consuming.
  1. Solder the snubbing capacitors (CP2) across the AC terminals of the two rectifiers (BR1). Wrap and solder the leads as close to the body of the rectifier as possible to avoid interference with the slip on terminals.
  2. Solder the bleeder resistors (R52) across the terminals of the four reservoir capacitors (CP1). Wrap and solder the leads as close to the body of the reservoir capacitor as possible to leave room soldering leads.
  3. Remove the Power Supply Distribution Unit (PSDU) from the chassis. Lay out and drill 5/32" holes for the two terminal strips and four fuse holders and one 5/16" hole for the bridging rectifiers. Mount the terminal strips and fuse holders with #6 machine screws and bridging rectifiers with one 1/4" machine screw.


  4. Position the Passive Crossover transformer (T2) and regulator PCB (ESP P-05B) on the toroid cover and mark the mounting holes. On the rear panel, layout the square hole for the IEC-14C socket and mark holes for the rear panel terminal strip (this strip, not shown in the wire schematic for clarity, makes the power supply components modular). Remove the toroid cover and rear panel and drill 5/32" holes for T2, regulator PCB, and rear panel terminal strip. Drill 3/8" holes in each corner of the square laid out for the IEC-14C socket and finish cut out with a jig saw. Attach T1, PCB, IEC-14C socket and terminal strip with #6 machine screws.


  5. Reattach the rear panel, toroid cover and PSDU.
  6. Position the four reservoir capacitors inside the base of the PSDU (they will fit snug) and secure with two wire ties in series.

  7. Mount the toroid transformer to the toroid bracket. A new transformer will come with two round rubber disks and steel washer for mounting. One disk is placed between the transformer and bracket. The other is placed between the transformer and washer. Since the transformer is mounted on edge, place a small piece of foam or cardboard between it and the chassis base to protect the windings. The primary and secondary leads should face toward the bracket. The center bolt (or all-thread) should be cut so no excess is protruding.
  8. Install the power switch on the controls panel.
  9. Wire the circuit according to the schematic above. The wiring on the primary and secondary side of the transformer should be 14 AWG stranded copper hook up wire. The wiring from the DC side of the rectifier should be 18 AWG stranded copper hook up wire.
  10. Central ground is shown below. Note: The regulated power supply DC ground terminal connects to chassis or central ground during supply testing. This ground is then disconnected from central ground and then connected permanently to the ESP active crossover power ground later in the hookup process.

  11. Power up each supply circuit and measure the voltage between each terminal strip lug and central ground (chassis). The power supply connections to the Leach amp should measure +58V and -58V DC. The power supply connections to the active crossover should measure +15V and -15V DC