Electron Engine ™
Printed Circuit Boards by Emissionlabs

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EE21, EE23 Gold Plated Multi Purpose Board Series. V7.1

For LL1588, LL1592, LL1674, LL1676, LL1681, LL1684, LL1690, LL1922, LL1930, LL1931, LL1933, LL1940, LL1941, LL1943, LL1948, LL1949, LL1971, LL5402
    1. Overview (you are here)
    2. EE21 for MC Applications
    3. EE23 for Amplifier Input Applications
    4. EE23 for Amplifier Output Applications

EE21 or EE23 Board

Lundahl uses two internal wire schemes for this transformer family. For this reason why we have two boards, EE21 and EE23, and each transformer type can only be used with one of the two boards. If a transformer + Board is ordered, we add the right board, EE21 or EE23. Optically EE21 and EE23 look the same, only PCB tracks are different.

There are many applications and transformers. Just read only what matters for YOUR application. Like when you are only interested in an output Application (Part 4, above here) there is no need to read part 2) and 3).

Finally, no more hand wiring, and a good grounding method.

Gain, Attenuation, Phase splitting, Phase reversal, balanced to unbalanced or vice versa, using a termination network, use an external gain switch, all of this is possible.

As a minimum, only the gain has to be set with the jumpers J1, J2, J3, and the Board works. Impedance termination, if needed or wanted, comes only at the end.

Dimensions: Outside: 70x46mm. Hole distance: 3.8mm from hole center to PCB edge. Hole Diameter: 3.5mm. Hardware: 4x Metal space holders, and 4x M3 screws are supplied with the board.

Moving Coil, with EE21 Board.

  • Choose between two step up factors.
  • Transformers used: LL1681, LL1931, LL1933, LL1940, LL1941, LL1943, LL1971

Input Applications, with EE23 Board.

  • A totally different application as Moving Coil. Yet the pin lay out of these transformers are the same. So it was logical to make a combined board.
  • Transformers used: LL1588, LL1592, LL1690, LL1674, LL1676, LL1684, LL1922, LL1930, LL1948, LL1949, LL5402

Output Applications, with EE23 Board.

  • Consider parafeed with LL1930, or use LL5402 which is very low impedance, and intended to drive it with solid state. Choose the gain, connect input and output, and the board works.
  • Transformers used: LL1930, LL5402
Connections. The functionality can be changed very much, by the way the board is connected.
Gain Setting
Each transformer allows two gain factors, and some transformer can be used reversed as well. The gain is set with solder jumpers, or by the additional switch board EE22. This board EE22 can also be added later.

Gain Setting, not using EE22

Close J2: Low transfer Ratio. (J1, J3 open)
Close J1+J3: High transfer Ratio. (J2 open)

Variable Gain with Switch EE22

To use EE22, open Jumpers J1, J2, J3.

The switch is mounted with a 6mm hole, and this mounts also the small PCB conveniently.

 

Changes:

V7. Board dimensions and hole distance 3mm wider than V6.
V6.5 Gold plating. Piano switch at the bottom was replaced by the external Board EE22.