Moving coil input transformers


Type Turns Ratio Size LxWxH Application Applications / Comments
LL1678 1+1+1+1 : 16+16 30x22.5x14.5 MC input Moving coil input 1:8, 1:16 or 1:32 . For low and medium impedance cartridges
LL1681 1+1 : 13+13 48x29x20 MC input Moving coil input 1:13 or 1:26 . Mu-metal core. Internal Faraday shiled. For low and medium impedance cartridges.
LL1931 1+1 : 8+8 43x28x22 MC input Prestigious moving coil transformer, 1:8 or 1:16. Cardas Audio copper and Lundahl Amorphous strip core. For medium and high impedance cartridges.
LL1931Ag 1+1 : 8+8 43x28x22 NEW! MC input Super prestigious moving coil transformer, 1:8 or 1:16. High purity silver wire and Lundahl Amorphous strip core. For medium and high impedance cartridges.
LL1933 1+1 : 8+8 47x28x24 MC input Prestigious moving coil transformer, 1:8 or 1:16. Cardas Audio copper and classic Permalloy lamination core. For medium and high impedance cartridges.
LL1933Ag 1+1 : 8+8 47x28x24 NEW! MC input Super prestigious moving coil transformer, 1:8 or 1:16. High purity silver wire and classic Permalloy lamination core. For medium and high impedance cartridges.
LL1941 1+1 : 16+16 43x28x22 MC input Prestigious moving coil transformer, 1:16 or 1:32. Cardas Audio copper and Lundahl Amorphous strip core. For low and medium impedance cartridges.
LL1941Ag 1+1 : 16+16 43x28x22 NEW! MC input Super prestigious moving coil transformer, 1:16 or 1:32. High purity silver wire and Lundahl Amorphous strip core. For low and medium impedance cartridges.
LL1943 1+1 : 16+16 47x28x24 MC input Prestigious moving coil transformer, 1:16 or 1:32. Cardas Audio copper and classic Permalloy lamination core. For low and medium impedance cartridges.
LL1943Ag 1+1 : 16+16 47x28x24 NEW! MC input Super prestigious moving coil transformer, 1:16 or 1:32. High purity silver wire and classic Permalloy lamination core. For low and medium impedance cartridges.
LL9206 1+1+1+1 : 10+10 30x22.5x14.5 MC input Moving coil input 1:5, 1:10 or 1:20. For medium and high impedance cartridges.
LL9226 1+1+1+1 : 10+10 30x22.5x14.5 MC input Moving coil input 1:5, 1:10 or 1:20. Improved version of LL9206. For medium and high impedance cartridges.

For MC transformer usage, please consult the following K&K Audio paper: www.kandkaudio.com/mccartsetup.html



Transformers for input and DC-decoupled line output applications


Type Turns Ratio Size LxWxH Application Applications / Comments
LL1674 1+1 : 4+4 43x28x21 Line input/output Amorphous core line input/output transformer
LL1676 1+1 : 2+2 43x28x21 Line input/output Amorphous core line input/output transformer
LL1684 1+1 : 1+1 42x28x22 High level general purpose For high level, low impedance applications such as (DC-decoupled) line output. The transformer is not suitable for line input from high impedance signal sources.
LL1690 1+1 : 1+1 42x28x22 High level line input For high level, high impedance applications such as (DC-free) line input.
LL1948 1+1 : 1+1 43x29x23 Line input With Cardas high purity copper wire and Lundahl amorphous core
LL7903 1+1+1+1 : 2+2+2+2 66x32x21 Mic or line input 200 : 13 k ohms (used 1:8) This is the ultimate microphone input transformer, designed for high quality tube equipment.
LL7905 1+1+1+1 : 5.6 + 5.6 66x32x21 High stepup input High level 600 ohms tube amplifier mic/line input (used 2 : 11.2) Can also be used as a (DC-decoupled) line output transformer

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Anode chokes, interstage and line output transformers


Type Comment Turns ratio Primary inductance Recommended DC current Core Saturating DC current
LL1621 / 6mA Noninverting interstage / anode choke 1+1 : 1+1 130H 6 mA
LL1621 / P-P Noninverting interstage 1+1 : 1+1 300H -
LL1630 / 5mA Line output 7.2+7.2 : 1+1 130 H 5 mA
LL1630 / P-P Line output 7.2+7.2 : 1+1 300 H -
LL1635 / 20mA Interstage 1+1 : 1+1 30H 20 mA
LL1635 / 5mA Interstage 1+1 : 1+1 130H 5 mA
LL1635 / P-P Interstage 1+1 : 1+1 300H -
LL1660 Interstage and line output 1+1+1+1 : 2.5+2.5 Application dependent Application dependent Application dependent
LL1660s SE - PP and PP - PP Interstage Internal Faraday shields for improved balance 2.5+2.5 : 2 + 2 Application dependent Application dependent Application dependent
LL1667, LL1668 Anode chokes Dual coil 1+1 Application dependent Application dependent Application dependent
LL1671 High current interstage and line output 1+1+1+1 : 2+2 Application dependent Application dependent Application dependent
LL1677 / 80mA High current interstage transformer (For 300B driving tube) 1+1+1+1 : 4+4 24H 80mA (1.2 Tesla saturation 115mA
LL1680 / 5mA Line output transformer Based on UTC LS-27 specifications 9+9 : 1+1+1+1 210H 5mA 10mA
LL1689 Line output transformer Based on the LL1660 size and structure 9+9 : 1+1+1+1 Application dependent Application dependent Application dependent
LL1692a Interstage transformer Compromise between the LL1660 and the LL1671 1.75 + 1.75 : 1+1+1+1 Application dependent Application dependent Application dependent
LL1930 Mu metal core transformer for DC-free ("parafeed") line output 5.8 + 5.8 : 1+1 Not applicable Not applicable Not applicable
LL2731 Low impedance line output transformer 1+1 : 1+1 Application dependent Application dependent Application dependent
LL2743 Anode choke Dual coil 1 : 1 64H 70mA 110mA
LL2745/18mA Line output 2.8+2.8 : 1+1+1+1 90H 18mA 36mA
LL2746 Stepup 1:2 interstage transformer 1+1 : 2+2 45H (30mA version) 30mA (30mA version) 60mA (30mA version)

NOTE!


• All types above (except LL1930) can be gapped for other DC current than listed.


• We recommend LL1630/5mA and LL1635/5mA for push-pull preamplifier stages where some DC imbalance occure.

The LL1635 data sheet is updated to reflect some limitations in it's use.


• For most SE applications, the LL1660 outperforms the LL1630 and LL1635.




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Mains transformers


In our C-core mains transformers, a very small air-gap is used to compensate for any DC unbalance in the mains outlet. Secondary voltages listed are no-load voltages.


Voltage drop because of load is to be calculated from transformer copper resistance and load current. Electrical size is estimated to 250VA, which can be increased with good cooling. For optimal use, about 75% of power should be taken from secondary 1.


Primaries should be connected in series for 210 - 250 V, in parallel for 105 - 125V. Table entries are calculated for primary voltage 230 V.


Type Secondary 1 Secondary 2 3 Secondary 4 5 Secondary 6
LL1648 350V 5.9V 6.6V
LL1649 230V 6.6V 6.6V
LL1650 350V 6.6V 6.6V
LL1651 500V 6.6V 6.6V
LL1683 250V / 0.16A 6.6V / 3A 5.2V / 3A 48V / 0.1A
LL2748 443 V 5.4 V 6.7 V -

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NOTE!


• Please study a very smart hybrid power supply principle. This principle avoids the very high voltage of an all tube rectifier and uses the transformer more efficiently.



Chokes for tube amp power supply


Type Inductance Rec. DC current Saturating current DC resistance
LL1638 / 10H 10H 150 mA 215 mA 36 ohms
LL1638 / 4H 4H 400 mA 575 mA 36 ohms
LL1638 / 8H 8H 200 mA 290 mA 36 ohms
LL1673 / 10H 10H 200 mA 290 mA 60 ohms
LL1673 / 15H 15H 140 mA 200 mA 60 ohms
LL1673 / 20H 20H 100 mA 145 mA 60 ohms
LL1685 / 100mA 17H 100 mA 145 mA 130 ohms
LL1685 / 160mA 10H 160 mA 230 mA 130 ohms

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Filament current chokes


Type Inductance Rec. DC current Saturating current DC resistance
LL1694 / 1.5A 0.16H 1.5 A 2.2 A 2 ohms
LL1694 / 1.5A (parallel) 40 mH 3 A 4.4 A 0.5 ohms
LL2733 / 1.7A 0.4H 1.7 A 2.7 A 3.4 ohms
LL2733 / 1.7A (parallel) 0.1H 3.4 A 5.4 A 0.9 ohms

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