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.

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 highest class product.   The build-in honestly of these products is best seen  from the datasheets.  I 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, interstage, 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.

AH! So what else is so special about the Lundahl  transformers? The answer is, they have the most flexible in configuration.   As you perhaps know, audio transformers are wound in many  layers, where 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. Folks, it is simply impossible to tell 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.   Any good engineer will confirm this to you.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 sound 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.  Manufacturers don't care at all about that.  Also the impedance doubles below 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.  It is what you hear,  that counts for you. So try it out!   It cost you nothing extra but a little effort.  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!       Do you want to hear the same story for interstage transformers? Probably not..  but you wouldn't be the first who bought a "fixed ratio"  interstage transformer with the wrong ratio. Look at the Lundhal LL1660 interstage transformers, these are masterpieces of versatility.   With one transformer you get six recommended ways to connect them,  but when you look in detail,  you can find more.   Additonally they are available for Push Pull input or Single Ended input, and Single Ended versions are made for 10,18 and 25mA. Shielded "S" Versions, and now also Amporph core. It is an amazing product. This is simply THE tube insterstage transformer, and just one example of many!

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 to try your 8 Ohms speakers on the 4 Ohms output and vice versa.  (IN THE SAME WAY, CONNECT YOUR 16Ohms Speakers to the 8 Ohms input) Listen to the bass, and decide what you think is the best connection. And don't be surprized if your 8Ohm speakers sound better at the 4Ohm output. It doesn't have to be, but it is nothing special if it happens. At the latest after you had this experience, perhaps you want to know why things are not as you always believed, and why things are not allways as the wiseguys on the forums tell you. And you will read this text again ;)  


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