FENDER: Deluxe 5E3

Some notes on the 5E3, the most famous and widely copied variation of the Fender Deluxe, produced from about 1955 - 1960.

POWER

Transformer:  Triad 6452, 380–0–380 V

Rectifier:    5Y3GT

B+ ~360V  

Filtering:    B1 - 16uf,    B2 - 5k / 16uf,    B3 - 22k / 16uf

OUTPUT

OT:   8k P-P,  8ohm secondary.   Triad 108 (pre 60's).   Schumacher 125A1A.   Note the option to add another 8ohm extension speaker, which implies that the amp can handle a 4 ohm load

2 x 6V6

Va ~340 - 350

Cathode biased.  Rk 250hm, 50uf bypass capacitor

Grid stop: 1k5.  Grid leak:  220k

CATHODYNE PHASE INVERTER - 12AX7

First stage, boost:

Ra 100k,  Rk 1k5 ohms / 25uf bypass

22n coupling to grid of inverter

Second stage, invert:   

Ra 56k,   Rk 1k5 in series with 56k 

Rg 1meg to 1k5 / 56k resistor node

100nf coupling to 6V6 from cathode and anode of 12AX7

PREAMP - 12AY7

Ra 100k,  Rk 820 ohms shared / 25uf bypass.   (1,640ohms per cathode)

Grid stoppers 68k (in parallel, for high).   Standard Fender input wiring

Rg 1meg.  100nf coupling caps to volume

A1M VOLUME & TONE

A1M volume and tone pots.   

In tweed circuits, the volume pots are wired in an older style: the wiper (pin 2) is the input, while the outer lug (pin 3) serves as the output. Electrically, this is the same as the modern convention, just reversed in function.

A 500 pF capacitor from pin 3 connects back to the preamp’s coupling capacitor. This acts like a variable bright cap—its effect diminishes as the volume is turned up.

A 4.7 nF capacitor from pin 1 goes to ground, providing a simple treble cut by shunting high frequencies away.

Pin 2 (the wiper) carries the combined signal forward to the grid of the phase inverter (also connected to the output of the volume pot).

One hallmark of these amps is the interaction between the two volume controls. Both pots connect directly to the grid of the first phase inverter stage, so even if only one channel is in use, adjusting the unused channel’s volume will still alter the response of the active channel.

12AY7 x 12AX7

Parameter	12AY7	12AX7
Amplification Factor (µ)	40	100
Plate Resistance (rp)	22.8 kΩ	62.5 kΩ
Transconductance (gm)	1750 µmhos	1600 µmhos
Typical Plate Current	≈ 3 mA @ Va=250 V.  Vg = –2 V	≈ 1.2 mA @ Va=250 V.    Vg = –2 V
Max Plate Voltage	300 V	330 V
Max Plate Dissipation (per triode)	1.5 W	1.2 W
Heater Current	0.3 A @ 6.3 V	0.3 A @ 6.3 V
Typical Bias for ~1 mA	–2 V to –4 V	–1.5 V to –2 V

6V6

Parameter	6V6
Type	Beam power tetrode
Plate Resistance (rp)	~62 kΩ (effective in Class A)
Transconductance (gm)	~4100 µmhos
Typical Plate Current	34–45 mA (idle, Class A)
Max Plate Voltage	350 V (design centre)
Max Plate Dissipation	14 W
Heater Voltage	6.3 V
Heater Current	0.45 A @ 6.3 V
Typical Bias	–12 V to –15 V (Class A)
Typical Load Impedance	8 - 10 kΩ  P-P
Typical Output Power	≈ 14 W (push-pull, Class AB)

5Y3

Parameter	5Y3GT
Type	Full-wave rectifier
Maximum DC Output Current	125 mA
Peak Inverse Voltage	1400 V
Typical DC Output Voltage	~350 V DC (at 100 mA load).
Max Input Capacitance	20 µF (first filter capacitor)
Heater Voltage	5 V
Heater Current	2.0 A
Typical Voltage Drop	≈ 60 V at 125 mA load