Manufacturer of  Ultra High Quality Audio Transformers
		Introduction (the Part number below, is the same as in the pricelist
Part 1		Tube Power Supply Chokes)	Part14..21		Tube Output transformers
Part 2		Filament Chokes / High Current Chokes	Part 22		Tube Mains transformers with DC cancellation
		Plate (anode)  Chokes	Part 23		Mains Cleaning transformers with DC cancellation
Part 4		Grid Choke	Part 24		Transformer Covers (Housings)
Part 5		Interstage	Part 25		Various transformers, not mentioned here
Part 6		Signal Input
Part 7		Signal Output
Part 9		Moving Coil
Part 10		Guitar Input	Tech1		(technical info) PPZ transformers
Part 11		Microphone	Tech2		(technical info) Product Storage
Part 12		For Digital Audio. Finest Quality	Tech3		(technical info) Amorph Cores
Part 13		Interconnect Solutions	Tech4		(technical info) DATASHEET DOWNLOAD

Plate (anode) chokes

Technology

the Lundahl plate chokes have a windings technology with the sectioning as maximized as can be. What does that mean? Plate chokes are made of very thin wire. Suppose you have 40000 windings. You can section it as two coils of 20000, or as 10 coils of 4000, etc. You reach a limit since the smallest section you can make is of one layer of single (!) wires. It is just this what Lundahl is doing, and as far as we know they are the only one.

NOTE: Due to the dual coil construction, these plate chokes can also be used as PP plate chokes, as found in some of the legendary ALTEC amplifiers. Any PP stage must allow for some offset between the tubes. (No two tubes are identical). It is recommended to use the 5mA Version for PP stages. That provides you an incredible 810 Henry, and you have 5mA offset for just in case your tubes require that. .

Detailed pictures of LL1667-7mA plate choke. All plate chokes are constructed this way
	Here you see how extremely fine the sectioning is done. You have to look here for a full resolution picture, and you will see the foils are there like the pages of a closed book. Each foil you see represents one layer of very fine wire.
	This picture is the outside (final) layer. Click here to see the detail. So this shows you best the coil is not a randomly wound package.
	Here you can see they double the sectioning by splitting the coil in two. As you can see the core is almost round shaped. So here all good things of the technology of ring-core is combined with the technology of C -core. Remember a plate choke is not only for increasing the gain of a tube, it also is very elementary in reducing the tube distortion. (It changes a tube from a not-so-ideal current source into an almost ideal one) So this MUST be a highest quality element, and we think Lundahl made exactly what we need: The BEST. The symmetrical construction also results in lowest mechanical noise, since the two coils work with opposite orientation to each other. Detailed picture