EL84 Push-Pull 10W Output transformer 8000 Ohms 43% UL taps (Mullard 5-10)

(1 customer review)


EL84 10W Output transformer – Mullard 5-10 etc

8000 Ohm primary. 43% Ultra linear taps for improved distortion.

Earn up to 114 Points.

5% discount on 2 or more


A high quality 10W at 20Hz Push pull ultra linear output transformer. Designed for the Mullard 5-10 amplifier but may be used in any single ended design with a valve having an output impedance of 8000 Ohms anode to anode, such as an EL84.

This is similar to our 6600 Ohm 20% ultra linear tap design, but results in an improvement in distortion of around 0.1% as described in the Mullard “Circuits for amplifiers” book.


Multi section winding, for reduced leakage inductance.


Inductance 35H at 25Hz.
Leakage inductance 3mH


Wide bandwidth, 10-50KHz. (-1dB)


Output impedance 4,8 and 16 Ohms.


High quality Grain Orientated M6 0.35mm.
Hand laminated for the best stacking factor, and accuracy.

Winding wire

Double coated Grade 2 enamelled copper wire.
Wound using CNC winders for highly accurate wire placement and turns count.
Layer wound for excellent wind consistency and alignment resulting in reduced leakage inductance.

Connecting wire – stand up only

High quality PVC 600V
Primary : 24AWG UL1015
Secondary : 20 AWG UL1015


Frame, Drop through or stand up versions, all with flying leads.



Additional information

Weight 1.6 kg
Mounting type

Stand up, Drop through, Frame

Output Impedance

4, 8 & 16 Ohms, 4 Ohms, 8 Ohms, 16 Ohms


Here are dimensional diagrams for this transformer.
Please refer to the relevant key below for the dimensions.


Shroud With Feet Drawing Key

Label Description Dimension (mm)
A Width 64
B Height 78
C Depth 83
D Mounting depth 48
E Mounting width 57
F Hole width 5

Frame Drawing Key

Label Description Dimension (mm)
A Width 79
B Height 67
C Depth 70
D Mounting height 54
E Mounting width 54
F Mounting depth 54
G Overall depth 70
H Mounting hole width 5

Drop through Drawing Key

Label Description Dimension (mm)
A Width 64
B Length 76
C Height 60
D Cutout width 58
E Cutout length 61
F Fixing length 64
G Fixing width 51
H Mounting hole diameter 4.1


1 review for EL84 Push-Pull 10W Output transformer 8000 Ohms 43% UL taps (Mullard 5-10)

  1. Gabriel Schembri (verified owner)

    I’ve bought 2 for my stereo armstrong 220, essentially a mullard 5-10 with an ecc83 at the front end. They worked with the stock circuit values, producing a good square wave, no ringing and a good frequency response. They replaced 2 “guitar amp grade” transformers that were smaller, and which required changes to the lead and lag compensation values to stop ringing and overshoot, with a consequential loss of HF.
    Buying two of these (stand up version) got me a 20% discount.

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