Electron Engine ™
Printed Circuit Boards by Emissionlabs

Update:

EE24. To add XLR input to RCA amplifier.

LL1527, LL1527-XL, LL1570, LL1570-XL, LL1540, LL1545, LL1578, LL581-XL.

Introduction

EE27 boardThe EE24 board adds a balanced, symmetric XLR INPUT to an amplifier with standard (unbalanced) RCA input.
Or, only with LL1540, it can be used in both directions, adding a symmetric XLR OUTPUT to a pre amplifier which has only an unbalanced RCA output.
Order nr: 310-024-89

This board uses 1:1 transformers, which have an attractive price.
Just connect the board, and it works. Tuning with LL1540 is not needed. With other transformers, tuning is optional, to expand frequency range.

The board can be used with a few different transformers, each with it's own advantages. (Listed below here). The difference of those is signal level or frequency range.

If signal level is not much higher than 1V, also Board EE31 can be used, which uses an attractive priced transformer.

   
Frequency Range
Distortion
Maximum Signal
Typical Advantage
Output possible?
Tuning
1
LL1527
 10Hz-150kHz 0.1dB 0.1% 6dbU 16dBU HIgh frequency range at good price. Yes R=3k9, and a wire link at the capacitor position
2
LL1527-XL
 10Hz-150kHz 0.1dB 0.1% 9dbU 19dBU Twice the signal level of above type. Yes R=3k9, and a wire link at the capacitor position
3
LL1570
 10Hz-200kHz 0.5dB 0.1% 6dbU 16dBU

Higher frequency range than LL1527, and higher noise immunity.

 Yes R=8k2, C=680pF
4
LL1570-XL
 10Hz-200kHz 0.5dB 0.1% 9dbU 19dBU Twice the output voltage of above type Yes R=22k, C=1000pF
5
LL1540
 5Hz-50kHz 0.2dB 0.1% 20dBU 30dBU High signal, low cost, low distortion. No tuning needed. Can be used also as RCA to XLR converter. No no R, no C.
6
LL1545E
 5Hz-45kHz 1dB 0.2% 22dBU   Very high signal. Yes R=6k7, C=470pF
7
LL1579
 10Hz-25kHz 0.5dB 0.1% 22dbU 30dBU Very high signal. Lowest distortion of all. No R=22k, C=1000pF
8
LL1581-XL
 10Hz-100kHz @0.5dB 0.1% 3dBu 13dBU

Exceptional good noise immunity.

 Yes R=10k, and a wire link at the capacitor position.