Introduction to LUNDAHL Transformers

Lundahl transformers follow a long tradition...

Unnecessary to say this company is in good hands! Their success tells it all. Lundahl transformers was founded in 1959 by Lars and Gunnel Lundahl, and is located in the big town of Norrtalje, in the Stockholm region. Today the company is managed by Per Lundahl, the son of the founder, and has now 25 employees. Some well known companies using Lundahl transformers are: Manley, VAC, SPL, Sound Devices, Brauner, Whirlwind, DHD. Not to forget the Swedish Radio, it all started with this company. Originally being only a small part of the business, the HiFi part is gaining more and more visibility.

Nordic is what these people are. They are very pleasant and correct to deal with company. Not producing many "golden" words, but producing many golden products, and let the detailed specifications speak for itself. Lundahl is in the middle price field, but they are doing so with a top class product. The build-in honestly of these products is best seen from the datasheets. I also noticed they have great respect for their machinery. They pay a lot of attention to keeping those in best condition. Lundahl audio transformers are now the #1 choice of OEMs and DIY builders around the world. This company offers EVERY Audio transformer you can think of: Mains transformers, SE, PP, Chokes, inter stage, phono transformers, input transformers, line drivers, and some very special problem solvers!

Do yo know what in HiFi, the word transparency means? It is often used for anything that sounds very nice. What does this word really mean? It means, the product in question adds nothing "from itself" to the music signal. When something adds no coloring to the sound, it is called transparent. So what goes in, is what comes out. That is what is means, and let's be realistic, you wouldn't want to listen to some sound effects added by the transformer itself. Or like Per Lundahl likes to say it: When you can 'hear' a product, it is not ours!

AH! So what else is so special about the Lundahl transformers? The answer is, the flexible configuration. Audio transformers are wound in many layers, with primary and secondary are interleaved. Most manufacturers connect the layers already inside the transformer, and only supply to you the resulting "primary" and "secondary".

Lundahl works different. They provide you the connections to each layer. The user can now connect certain layers in parallel or in series, or a combination of series and parallel. You don't need to worry about this yourself, all possible way are listed in the datasheet, like method A, Method B, Method C, etc. By this, you can get a wide range of impedances and step up/down ratios with just one transformer! This method is ideal for the DIY user, because now you can actually try out what sounds best, and not need to believe what (so called) experts tell you. It is simply impossible to tell in advance, what primary impedance will sound best with YOUR speakers, in YOUR listening room, and YOUR personal judgment of what YOU want to hear. That is because the amplifier and speakers and the listening room interact. To get a first idea if this, try your 8 Ohms speakers on the 4 Ohms output or vice versa. Now you will notice a sound difference, and don't be surprised when the 8 Ohms speaker sounds better at the 4Ohms output. It doesn't have to be like that, but it's nothing unusual. It's very rare an 8 Ohms speaker is 8 Ohms indeed. They can be just as well 5 Ohms or 12 Ohms. Speaker chassis manufacturers do a good job, but speaker cabinet manufacturers often make a mess. Also the impedance doubles below some point, like 50 Hz, and will triple below 25 Hz. Just to make you aware!

So you see, the best impedance is the one you think sounds best. The way to go is, take a Lundahl transformer that offers this impedance, and choose it as the middle one. All big transformers offer additional one impedance below and one above. Then, try out each three impedances, listen carefully, and decide for yourself what you think sounds best. You can't beat this approach with calculations or what others say. Try it out! It cost you nothing extra but a little effort. (or use our Switch Boards) All big Lundahl transformers offer three primary and three secondary impedances!

Even more this counts for the Moving Coil transformers. The "experts" do not even know what to tell you. Specially manufacturers of expensive MC Transformers blow a cloud of smoke around the specifications. So just take the Lundahl MC transformers, these offer you two or three step up ratios. Choose the one that sounds best! (or try our MC Boards). Do you want to hear the same story for inter stage transformers? Probably not.. but you wouldn't be the first who bought a "fixed ratio" inter stage transformer with the wrong ratio. Look at the Lundhal LL1660 inter stage transformers, this is a masterpieces of versatility. With one transformer you get six recommended ways to connect them, but when you look in detail, you can find more. Additionally they are available as PP (for Push Pull) SE (for Single Ended), PPZ ( for Parafeed) AM (for Amorphous core), or Ag-Versions for Silver Wired. Such excellence!

Let me finish to recommend you, just check one of the datasheets, and you'll get the full picture what company you are dealing with.


Remember ALLWAYS try your 8 Ohms speakers on the 4 Ohms output. Just to hear the difference. (The same applies for 16Ohms Speakers, test them on the 8 Ohms input). Listen to the bass, and decide what you think is the better. Don't be surprized if your 8Ohm speakers sound better at the 4Ohm output. Because no, an 8 Ohms speaker does not always sound best the 8 Ohms Output. What should it? It is just louder at 8 Ohms, that is true. But better? That is another question. Besides when it comes down to loudness, try connecting an 8 Ohms speaker to 16Ohms. That will really sound louder. But better? Probably not. Make this compare, just correct the loudness with the volume control, so you compare at the same loudness. Latest after test, you will read this text again ;) The secret is called damping factor.

Impedance Switch - We sell those PCBs