LL2785C: Lundahl Output Transformer
The Lundahl LL2785 C-core output transformers for tube amplifiers have a primary impedance of 3 kω and secondary impedances of 4 kω or 8 kω, depending on how you wire them. There are options for circuit topology and core material, which you select when you purchase. suitable for the popular 300B electron tube
The transformers are highly segmented with harmonically sized sections, resulting in minimal leakage inductance. Combined with a low-capacitance coil-winding technique, this results in a wide frequency range. The transformers have a special audio C-core from Lundahl's production, gapped for the desired DC current. This would depend on the current draw of the output valves. The transformers are open-frame and suitable for mounting inside an amplifier housing.
The LL2785C AM 60mA Single-ended is used in the Elekit TU-8900VK.
The LL2785C is available in 3 versions. (The air-gap is adjusted during manufacture to suit)
- 60mA Single-ended
- 70mA Single-ended
- 90mA Single-ended
N.B. The purpose of the airgap is to accept the DC current of the output valve without saturating the core, leaving enough headroom for the sound signal.
There are two additional versions, depending on the C-core material you require.
- Silicon-iron
- Amorphous-iron (AM)
Depending on how the transformer winding sections are wired together via the exposed solder pins, the constructor can adjust the following primary and secondary impedances.
Primary impedance: Secondary impedance
- 3K: 5R or 8R
We currently have stock of the LL2785C AM 60mA, single-ended versions, as used in the Elekit TU-8900VK
Overall dimensions including pins - 115mm x 87mm x 77mm
STARTING PRICE (1 off)
£252.25 +vat +p&p
Non-Stock Item - Please allow 4-6 weeks for dispatch