Electron Engine ™
Printed Circuit Boards by Emissionlabs

Update:

TIN PLATED PCB

EE29 Universal Matrix board for:

LL2765, LL2774.

To choose a transformer, click here for a technical bulletin.


EE29 with 2.5mm pin holes. Order Number 310-029-85



The programming is easy to do:

This table corresponds to the Lundahl data sheet connections.

LL2765 Transformer Output impedance
12:1
 32 Ohms with 4k6 tube 10+9, 9+3, 3+2, 8+7, 7+5, 5+4
6:1
 150 Ohms with 5k4 tube 10+2, 9+8, 7+5, 4+3
3:1
 600 Ohms with 5k4 tube 10+5, 9+8, 4+3

 

LL2774 Transformer Output impedance
13.6:1
 16 Ohms with 3k tube 10+9, 9+3, 3+2, 8+7, 7+5, 5+4
6.8:1
 64 Ohms with 3k tube 10+2, 9+8, 7+5, 4+3
3.4:1
 300 Ohms with 3k5 tube 10+5, 9+8, 4+3

 

This would also be possible: (more options added) .

LL2765 Transformer Output impedance
12:1
 27 Ohms with 4k Ohms (tube: EML RS242)
16 Ohms with 2k3 (tube: C3g Triode connected)
11.6 Ohms with 1670 Ohms (tube: 45)
8.8 Ohms with 1265 Ohms (tube: EML PX25)
6 Ohms with 875 Ohms (tube: EML PX4)
5.5 Ohms with 800 Ohms (tube: EML 2A3)
10+9, 9+3, 3+2, 8+7, 7+5, 5+4
6:1
 111 Ohms with 4k Ohms (tube: EML RS242)
64 Ohms with 2k3 (tube: C3g Triode connected)
46 Ohms with 1670 Ohms (tube: EML 45)
35 Ohms with 1265 Ohms (tube: EML PX25)
24 Ohms with 875 Ohms (tube: EML PX4)
22 Ohms with 800 Ohms (tube: EML 2A3)
10+2, 9+8, 7+5, 4+3
4:1
 250 Ohms with 4k Ohms (tube: EML RS242)
143 Ohms with 2k3 (tube: C3g Triode connected)
104 Ohms with 1670 Ohms (tube: EML 45)
79 Ohms with 1265 Ohms (tube: EML PX25)
55 Ohms with 875 Ohms (tube: EML PX4)
50 Ohms with 800 Ohms (tube: EML 2A3)
10+3, 8+5, 4+3, 9+5
3:1
 444 Ohms with 4k Ohms (tube: EML RS242)
255 Ohms with 2k3 (tube: C3g Triode connected)
185 Ohms with 1670 Ohms (tube: EML 45)
140 Ohms with 1265 Ohms (tube: EML PX25)
97 Ohms with 875 Ohms (tube: EML PX4)
89 Ohms with 800 Ohms (tube: EML 2A3)
10+5, 9+8, 4+3

 

LL2774 Transformer Output impedance
13.6:1
 22 Ohms with 4k Ohms (tube: EML RS242)
12.4 Ohms with 2k3 (tube: C3g Triode connected)
9 Ohms with 1670 Ohms (tube: 45)
6.8 Ohms with 1265 Ohms (tube: EML PX25)
4.7 Ohms with 875 Ohms (tube: EML PX4)
4.3 Ohms with 800 Ohms (tube: EML 2A3)
10+9, 9+3, 3+2, 8+7, 7+5, 5+4
6.8:1
 87 Ohms with 4k Ohms (tube: EML RS242)
50 Ohms with 2k3 (tube: C3g Triode connected)
36 Ohms with 1670 Ohms (tube: EML 45)
27 Ohms with 1265 Ohms (tube: EML PX25)
19 Ohms with 875 Ohms (tube: EML PX4)
17.3 Ohms with 800 Ohms (tube: EML 2A3)
10+2, 9+8, 7+5, 4+3
4.5:1
 198 Ohms with 4k Ohms (tube: EML RS242)
114 Ohms with 2k3 (tube: C3g Triode connected)
82 Ohms with 1670 Ohms (tube: EML 45)
52 Ohms with 1265 Ohms (tube: EML PX25)
43 Ohms with 875 Ohms (tube: EML PX4)
40 Ohms with 800 Ohms (tube: EML 2A3)
10+3, 8+5, 4+3, 9+5
3.4:1
 346 Ohms with 4k Ohms (tube: EML RS242)
200 Ohms with 2k3 (tube: C3g Triode connected)
144 Ohms with 1670 Ohms (tube: EML 45)
109 Ohms with 1265 Ohms (tube: EML PX25)
76 Ohms with 875 Ohms (tube: EML PX4)
69 Ohms with 800 Ohms (tube: EML 2A3)
10+5, 9+8, 4+3

 

Headphones Impedance Explained

With both the Lundahl tables, and the tables with specific tubes in it, make good note of the impedance you get. The specified value is the output impedance of the head phone amplifier itself. This is NOT the impedance of the head phone which you need to connect to it. Just to give an example, a 300 Ohms headphone should be connected to a 50 (or so) Ohms output.

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