LL2611
LL2611 is a line output transformer with turns ratio 2.75 : 1Radiometal lamination core.Pin configuration (as seen from PIN side) 1, 2, 3, 56, 7, 8, 9, 10 Usage (2.75:1)In+ 1In- 3Out+ 7Out_ct 8 (should normally not be used)Out- 9
February 2023
September 2019
LL5607
LL5607 is a C-core line output transformer designed for Calrec Audio, probably used as a 1.5 : 1 transformer. LL5607 has an internal Faraday shield and a mu metal housing. Pin configuration (as seen from PIN side) 6, 5, 4, 3, 2, 1 12, 11, 9, 8, 7 Usage (1.5 : 1): in+ pin 1 [...]
April 2019
LL2612
LL2612 is a line input transformer, 1:1, with double Faraday shields. LL2612 pin-out (pin side) 4, 2, 1 8, 7, 6, 5 In + 1 In - 4 Shield in 2 Out+ 8 Out- 5 Shield out 6 Housing 7
January 2018
LL1522
LL1522 is a high impedance line input transformer, normally used 2:1 It has been discontinued for many years. LL1522 pinout (pin side) 4, 3, 2, 1 8, 7, 6, 5 For high impedance line input, 2:1 use as follows: In+ 4 In- 2 Connect 1+3 Out+ 8 + 5 Out- 7 Ground (shield) 6
December 2017
Calrec line output LL5608
LL5608 is a line output transformer designed for Calrec Audio, turns ratio 1.55+1.55 : 1+1 Pin configuration (as seen from PIN side) 7, 6, 5, 4, 3, 2, 1 14, 13, 12, 10, 9, 8 Usage (1.55 : 1 ) in+ pin 1 in- pin 5 connect pin 7 + 3 out+ pin 8 out- pin 12 connect pins 10 + 14 Housing [...]
November 2016
I have bought some LL1673/10H from you, but the measured inductance (with my inductance meter) is only 6H. What is wrong?
Our power supply chokes are designed to work at 100/120Hz and with voltages around 100V. Most induction meters work at a few volts or less, at around 1kHz. This is not the correct operating point for a power supply choke, and the reading on the induction meter is usually around half the specified value of [...]
September 2016
LL5006
LL5006 is a line output transformer designed for the Danish company NTP Turns ratio 1.2 : 1 + 1 5 4 3 2 1 10 9 7 6 Usage (for 1.2 : 2 line output) in+ pin 5 + pin 1 in- [...]
November 2015
Is there a CAD library for Lundahl Transformers products?
EAGLE CAD Lundahl library (created by Bob Starr of RTZ Audio): https://cadsoft.io/resources/libraries/?query=lundahl CADSoft EAGLE PCB Design Software is a CAD software available for a number of different platforms. A limited function version is available free of charge for personal use. Please see http://www.cadsoft.io for downloads.
October 2015
What could be the possible disadvantage to use LL1540 (line input transformer) as output transformer?
An audio line is a cable transferring an audio signal from the output of one device to the input of another. Normally the input impedance is fairly high, >1k for mic preamps and >10k for line inputs. If the impedances in both ends of an audio line are high, any noise current picked up by [...]
September 2015
What is the sound difference between mu metal and amorphous core transformers?
Many customers ask us for the difference in sound between our mu metal lamination transformers and our strip core amorphous transformers. We have forwarded the question to Kevin Carter at K&K Audio. Here are his impressions: “When I first encountered the Lundahl LL1544A and LL1545A line level transformers, which use the same coils, but these [...]