Boards for Power Output Transformers

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Introduction

Lundahl Power Output transformers have a wired system to achieve 4, 8. 16 Ohms, because this reduces power loss, and increases the frequency range.

Most Japanese transformers work with "taps". However, with an unused tap, a large part of the winding is unused. Knowing, how much extra work has to be done, to get the windings layered nicely, and how to increase the copper filling factor, it is just not right, to let half of the winding hang in the middle of the package unused, causing performance loss. The Lundahl method gives better frequency performance, less phase error, en less power loss. The drawback of the Lundahl method is, impedance switching is not as easy as when using taps. To overcome this, PCB's can be made.

OUTPUT BOARDS. The PCB series EE16, EE18, and EE32, solve this issue! The desired impedance can be chosen in a few ways. The nicest is use the external switch board EE17 for this. At the same time, the EE17 board provides the speaker connections, making external wiring simple and short. Or, do not use the switch board, and make fixed connections on the transformer board, for a single impedance.

INPUT BOARD. Just for the nicer looks of the wiring, we have now also a primary board.

LL1620, LL1623, LL1627, LL9202 primary EE16. Secondary Board
Order nr: 310-016-48

LL1620, LL1623, LL1627, LL9202 primary EE18. Secondary Board.
Order nr: 310-018-69

EE16 and EE18.

SECUNDARY BOARD FOR:

LL1620, LL1623, LL1627, LL1679, LL9202.

GOLD PLATED.

How these PCBs are used.

These work with all Versions SE, PP and Parafeed (PPZ)

First of all, there is not need any more, to understand these "Alt" variations in the data sheet. So do not ask "how to make Alt-C...". Just look in the table, under the desired input- and output impedance, there you will find the transformer of your need, choose the PCB, and you are done.

More info

EE32. Secondary Board
Order Nr: 310-032-00

EE32

SECUNDARY BOARD

Special Version for LL1679

This works essentially the same as the above boards, only is does not have the option to mount the switch directly on the main board. However an external switch board can be attached still.

If the impedance is selected with the external board, do not use the solder bridges.
Or, leave away the external switch, and set the impedance with the solder bridges.
A primary Board for LL1679 does not exist.

More info