VDV-4040-PPE (3A524-UL)

Description:
The VDV-3040/4040/5040-PPE transformers all are equal, except the primary impedance is 3 or 4 or 5 kΩ. They all are improved versions of the famous 3A524-UL push-pull transformer. These powerful output transformers can handle 40 Watt power. The Ultra Linear taps are at 40 %, while secondaries are 0/4/8 Ω. Their -3 dB frequency range is remarkable large. Many power tubes can be used with these transformers, ranging from 4xEL84 (guitar amp) up to 2 x KT150 in a high-end power amplifier. How to choose which type you should use? This depends mainly on the B+ supply voltage. If B+ = approx. 250 Vdc, then select 3 kΩ. For B+ = approx. 350 Vdc, use the 4040-type; for B+ environment 450 Vdc, use the 5050-PPE version. These OPT’s belong to my most applied designs (old number is 3A524-UL) with remarkable open and tube-warm sound quality.

Specifications: 
Application PP : 4 x EL84/2 x EL34/6550/KT66-150
Power : 40 Watt
Impedance-prim. : 4 kΩ
Impedance-sec. : 0/4/8 Ω
UL-taps : 40 %
Frequency range : 1 Hz to 48 kHz (-3dB 2 x 6550 in UL)
Dimensions : round 91 mm dia, height 35 mm
Weight : 1,3 kg

Download : Datasheet VDV-4040-PPE
Download : Application RB Elektronica, September 1985, pp.329-333