Audio Transformers Top 5 Ways To Improve Music Production Pt 01
Audio transformers are vintage audio components that were used in many commercial and consumer audio products. These passive audio components bring color, detail, improved sonic image, spatial separation and harmonics to audio signals. Their heyday was between the 40’s and the 80’s, even in the 90’s they were a critical component within pro audio gear, used by many professional recording studios, engineers and musicians. They convert electrical audio signals into magnetic signals, then back again to electrical signals. In this article we’ll try to gain a better understanding of audio transformers.
The sonic and electrical advantages gained by this conversion are many. In a sense this is forgotten technology, responsible for the amazing sound heard on many vintage recordings from around the world. Audio transformers have been used on any and all genres of music, hip-hop, lofi hip hop, boom bap, rap, jazz, soul, funk, reggae, electro, up-tempo, dance, rock, pop, country… you name it, and audio transformers have played a part in shaping the sound we hear in our music. In part one of this article, we will discuss the basic implementations and advantages of using audio transformers within the signal path. We will define the top five best uses for audio transformers in regard to fidelity and sonic flavor. Practical examples of how to use transformers in your studio.
These are passive devices. Audio transformers can be found in all types of audio equipment, radios / tuners, mixing consoles, pre-amps, amplifiers, equalizers, compressors, limiters… the list goes on. They are primarily used in the input and output sections, or to connect circuit blocks within the equipment. Audio transformers come in many shapes and sizes, in regard to audio transformers the basic types are input, output, E/I core and Toroidal core. Input transformers typically come in a shielded metal can, output transformers can be shielded or unshielded. They both have Primary input winding’s and Secondary output winding’s.
What do these devices do? Transformers provide many electrical functions including; stepping signal levels up or down, they balance input and/or output signals, match impedance between audio connections, they eliminate ground loops and reduce noise and hum, block DC and unwanted low frequencies as well as providing galvanic isolation. Audio transformers also impart analog characteristics to the audio as the signal is converted to an electromagnetic signal and then back again. To put everything into perspective, take a look at the video below, Peterson Goodwin from DIYRE gives a brief overview of audio transformers.
What Are Audio Transformers? Why Do They Sound So Good? | DIYRE YouTube Video
Published in May 2019: DIYRE “What Are Audio Transformers? Why Do They Sound So Good?” featuring Peterson Goodwin, Released by DIY Recording Engineering.
An added bonus to the balancing of the audio signal is an enhanced sonic image. It has been stated that audio transformers provide a 3D effect to music. Listening with a studio grade audio system, it is said that without a transformer the music will seem to emanate from the direction of the speakers. Once transformers are introduced, the size of the audio can be enhanced significantly, making the sound appear to surround the listener within the room. The size of the enhancement is directly related to the size of the audio transformer, the larger the transformer the larger the sound. Check out the video below to learn how transformer core size directly relates to sonic image size. This may have something to do with the Hysteresis potential relative to core mass. More on this in part 02.
Do Bigger Audio Transformers Sound Better? | Paul McGowan PS Audio YouTube Video
Published in Febuary 2021: Paul McGowan at PS Audio “Do Bigger Audio Transformers Sound Better?” featuring Paul McGowan, Released by PS Audio.
Below are the Top Five ways to improve your music production sound using audio transformers. If you haven’t had a chance to hear what audio transformers sound like, you can hear an example on the Bandcamp audio player below.
01. Sampling & Recording: For sampling and recording, transformers optimize the connection between the source and the destination. Most samplers and drum machines today are digital computers using software to deliver DAW capability. As a matter of fact, a lot of today’s samplers and drum machines are USB and/or MIDI controllers that leverage computers to make music. The Akai MPC X, MPC One and Native Instruments Maschine are perfect examples of this. Users claim these new machines sound sterile compared to the 90’s era machines. Using an audio transformer on the input and/or output of your DAW, sampler or drum machine is a great way to improve the sound quality, analog flavor and size of your recordings. This is true for most types of audio signals.
02. Tracking & Mixing: After you get the sequences and tracks arranged the way you want them, it’s time to print the tracks and mix down your songs. Stereo groups, DAW tracks, analog tape recorders, digital multitrack recorders, stereo tracking units… All of these can benefit from the use of audio transformers placed in the signal path. As the mixed tracks pass through the electromagnetic medium, sounds are glued together in an ear pleasing way. Adding to the cohesiveness of the sonic components within the mix. By using audio transformers in combination with passive summing boxes like the SB2-EN, routing audio groups through the passive transformers and summing boxes, then back to a stereo mix bus (out-of-the-box), the sonic quality and size of audio recordings can be significantly improved, in comparison to “in-the-box” software only mixing. This technique has become popular in the last 5 years or so.
03. Summing & Mastering: The same principles apply in regard to summing and mastering. If you add audio transformers to the signal path, the result will be improved sonic quality, added analog flavor and size. Kick drum and bass frequencies will stand out in a way that is very pleasing to the ear, due to low end phase shift. Many professional studio and mastering engineers such as Bernie Grundman, have been using audio-transformers for mastering in the music industry for several decades now. They will sometimes use an audio transformer with a 1:2 step-up ratio to achieve enhanced low frequency response. Step up transformers have a side benefit of adding a subtle bass boost to the audio signal, similar to a shelving equalizer. You can hear this in the audio demo below.
04. Analog Flavor & Sonic Image Size: Audio transformers impart analog flavor to audio signals, adding harmonics and warmth to our digital recordings. The analog flavor that is imparted to the audio signal is a function of the size and material the core is made from. The larger the transformer core, the larger the potential for increased sonic image of the audio. Vintage audio transformers are typically constructed from iron and/or steel, and deliver warm sounding harmonics to the audio signal, due to the lower permeability of the core material. Modern transformer core materials are constructed from alloys containing nickel, delivering a much cleaner transparent audio signal, due to higher core permeability. Today core materials are chosen to provide a balance between sonic flavor and clarity.
05. Impedance Matching & Galvanic Isolation: Audio transformers allow maximum power transfer between the output and input devices, due to impedance matching of the input and output circuits. Because the audio signal is converted to an electromagnetic signal, there are no physical connections between devices, this is called galvanic isolation. This eliminates potential ground loops between audio units and optimizes current flow for a clean audio signal within the system. Also eliminating noise and 60Hz hum, due to multiple system ground connections created via audio cables. Transformers allow you to run long cables i.e. from the deejay setup across the room, to the sampler, without signal degradation or noise.
Audio Transformer Demo 1:2 Ratio Step Up Vintage Iron Core | Bandcamp Audio Demo
This demo illustrates the 1:2 step-up iron core transformer. The “Audio Demo” has been done in 4 Bar sections; the 1st 4 bars start with the transformer enabled. Four bars in you will hear the transformer switched off (disabled), 4 bars after that the transformer is switched on (enabled) again. This is repeated across the entire track.
In part 02 we’ll explore more technical details you didn’t know about audio transformers. We’ll also share examples from our best customers, how they are using audio transformers from Big Noise MPC to improve their music production results. Lastly we’ll share some of the audio transformers Big Noise has been designing and fabricating. Please stay tuned.