Electron Engine ™
Printed Circuit Boards by Emissionlabs ®

EE20 Moving Coil Applications. Version 2.8

  1. Introduction
  2. Moving Coil Applications (You are here)
  3. Audio In/Out, with or without gain.
  4. Tuning the EE20 Board

Possible Movoing Coil transformers:
LL1636, LL1678, LL9206, LL9226, LL9226XL

The MC cartridge is connected to L+ and L-, with the options to connect the cable shield, ground, etc. The best sounding step up ratio can be found, just by trying out, and adjustable damping of the tone cartridge is possible as well.

All Lundahl options, and some additional step up ratios have become possible, all of which can be tried out conveniently, just by setting the Switches. For hard core audiophiles, the switches can be replaced by wire pieces as well. Yet the contact resistance of the switch is only theoretical, because we switch the transformer windings, which represent a great length of very thin wire, with 1000x more resistance than the switch.

Line
Gain

Name

Piano Switch Numbers
Set to "On"
With External Switch Option2

Low / High is the switch position
#1
#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)

 

LL1636 has an internal shield between each layer of inter sectioning, which increases the noise suppression a lot. The price for this, the room this takes internally, and so the wire diameter had to be slightly thinner, compared to LL9206. This increases the copper resistance of the LL1636 secondary from 395Ohm to 415 Ohms, however when loaded with 47k, like the standard for RIAA, this is insignificant.

LL9226 has lower copper resistance, which is better for low impedance inputs, but it fails the internal shielding of LL1636. The failing shield also increases the frequency range from 90kHz to 100kHz. Personally I prefer LL1636 because hum is something I can hear, but the difference between 90kHz and 100kHz I can not hear. Also, LL9226 has a very minor increase in output signal with very low impedance MC systems, but the trade off between this, and better shielding, goes into the direction of the LL1636. (This Just my personal opinion).

LL1678 is the gain master, maximum 32x is really very much and there is no alternative if this gain is needed.

Connection Schemes


Yamamoto Floating Ground RCA (Cinch) Connector

Ways to use this scheme:
  • Create a Moving Coil RCA input with a MM amplifier, while the board EE20 is build inside the amplifier. This requires floating ground connectors.
  • Not recommended, but you can try with standard (grounded) connectors, if these are already mounted and you have no option to change something. In that case, make a link from L- to G, and only the RCA center pin is connected to L+. Yet if it is humming, you need to install a floating ground RCA chassis connector. (like the picture above).
  • Create a separate box, with RCA input and RCA Output. With a metal case, connect it to where it says Ground on the schematic. The input is a floating type connector, the output is a grounded type.

Ways to use this scheme
  • Create a Moving Coil XLR input to an MM amplifier, while the board EE20 is build inside the amplifier
  • Build a separate box, with XLR input and grounded RCA Cinch connectors at the output.
  • In both cases, 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.

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.


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.


All Schemes are possible, using the EE20 Board stand alone, or wit the EE22 Board.