Electron Engine ™
Printed Circuit Boards by Emissionlabs

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EE20 Gold Plated Multi Purpose Board.
For LL1636, LL1678, LL9206, LL9226, LL9226XL

Using EE20 stand alone

With the EE20 board, there is no need to use the data sheet, finding out connections. Just choose from the table below here, the required gain factor. Set the Piano Switch as in column 'Option1'. Connect input and output as in one of the Circuits, and already the board is working.

Using EE22 with EE20 together

EE22 is an additional PCB, which can be attached to a working EE20. With EE22 you have the possibility to change between two gain factors. Which two factors that will be, is set by the piano switch. Settings for using EE22 are under 'Option2'

What you receive is a small PCB and a high quality switch (with silver internal contacts). EE22 is mounted on the chassis with the switch itself. So very easy to construct.

The order number for the EE22 + switch is: 310-022-29

Detailed explanation

The MC cartridge is connected to L+ and L-. Adjustable damping of the MC cartridge is possible as well.

All Lundahl options, and some additional step up ratios have become possible, which are not in the data sheet. All of which can be tried out conveniently, just by setting the the switch itself.

Gain
Set Switches
#1
Designation
 USE of EE20 without external switch board.

USE of EE20 with external switch board EE22.

Low / High is the external switch position

       
OPTION1
OPTION2
#2
4x
2.5x
New! Possible with EE20 board
1, 3, 7, 9, 11 7, 9, 11, Low
(High = twice the gain)
#3
5.3x
3.3x
New! Possible with EE20 board
1, 3, 5, 7, 8, 11 5, 7, 8, 11, Low
(High = twice the gain)
#4
8x
5x
Lundahl Alt A
 2, 7, 9, 11 7, 9, 11, High
(Low = half the gain)
#5
8x
5x
Lundahl Alt B
 1, 3, 5, 7, 8, 10, 12 5, 7, 8, 10, 12, Low
(High = twice the gain)
#6
11x
6.7x
New! Possible with EE20 board
2, 5, 7, 8, 11 5, 7, 8, 11, High
(Low = half the gain)
#7
16x
10x
Lundahl Alt C
Most recommended
 2, 5, 7, 8, 10, 12 5, 7, 8, 10, 12, High
(Low = half the gain)
#8
16x
10x
Lundahl Alt D
Only for very low impedance cartridges.

1, 3, 4, 5, 6, 8, 10, 12

 4, 5, 6, 8, 10, 12, Low
(High = twice the gain)
#9
32x
20x
Lundahl Alt E
 2, 4, 5, 6, 8, 10, 12 4, 5, 6, 8, 10, 12, High
(Low = half the gain)

About the transformers used:

Per Lundahl told me this by phone: Anything you change to a transformer, you do this to achieve something. A change however, will always cause other data to change as well. All produced transformers have a well balanced set of specifications. But it does explain, why some have the same transfer ratio, but have other electrical data still.

LL9226 is an improved version of LL9206. There is LL9226 and LL9226-XL.

LL9226-XL is wound with thicker wire, which increases efficiency. This reduces noise at the loudspeaker, compared with the same loudness. The thicker wire makes the windings package larger, which requires a larger core. Since this cobalt core is expensive, this reflects in the price. An additional advantage is lower distortion of the larger core. The trade off is a slightly smaller frequency range, but as we are out in the 90kHz range, this should play no audible role.

LL1678 is the gain master, maximum 32x is really very much and there is no alternative for the good price, and high frequency range.

LL1636 can also be used. It compares to LL9206, but it has an internal shield, which very much reduces the hum sensitivity, and it should be used for environments where hum is a problem. The price for this, is the space, this shield takes internally in the transformer. So the wire diameter has to be thinner. This slightly reduces the efficiency, which reduction is very little though. This makes Ll1636 the ultimate MC transformer for a hum sensitive environment. LL1636 can also be used as a microphone transformer, but this is a totally different application, not addressed by EE20.

Some possible Connection Schemes

Circuit #1
Most recommended for Record Players.
Works with all transformers, also LL1636.

This connection scheme is the most used. Basically everything is grounded to the PCB Ground plane, which is double sided.

This uses a normal, grounded RCA connector, all wiring is classical and normal, and little to say about it, with no complications or difficulties.

=> Mind the two small ground links, as you see on the picture!

Circuit #2
Works best with LL1636

LL1636 is the only transformer of this family with a real static shield inside, which makes it specially suited for floating input connection, as we are doing here. This MAY become a problem solver for hums problems for which the reason can not really be found. You can also try his circuit with any other transformer, though it targets mainly for LL1636. The only difference between with circuit #1 or #2 is:

  1. Circuit #2 does not use the small ground link from L- to G (as in circuit#1)
  2. A floating ground RCA connector must be used.
  3. Circuit #1 can be used with all transformers, also LL1636

Circuit #2 works best with LL1636, but MAY work with any other.

=> Mind the small ground link, as you see on the picture!


Yamamoto Floating Ground RCA (Cinch) Connector

Ways to use this scheme:

=> Mind the small ground link, as you see on the picture!

Ways to use this scheme

This is for an external box. Since the output is floating, the board ground should be connected to the record player chassis, via XLR-1.

=> Mind the small ground link, as you see on the picture!

This is for an external box. XLR is not floating, but is centered to ground, by connecting it's center (CH connection) to ground.

it has to be tried out, what is best for the Input XLR-1 ground connection, because this connects the record player chassis to the RIAA amplifier chassis. Try this out, and take what is best. When it makes no difference, connect Input XLR-1 to 'G'. To be universal, use a miniature external switch for this.

Attaching the small EE22 board.