With over 15,000 of their distinctive blue boxes installed in studio racks around the world, Danish manufacturer Tube-Tech are one of the most respected outboard brands in the industry.


We talk with company founder and designer John G. Petersen....

You worked at the Danish Broadcasting Company before training at SSL, Studer and Neumann. Is that where your interest in recording equipment developed?

My interest in electronics came through music. I wanted to understand how an electric guitar worked and that led to my interest in pro audio equipment. In 1972 I had the opportunity to work for Danish Broadcast as a maintenance engineer. They made a lot of in-house recordings across many different styles - pop, rock, jazz and classical music - which gave me experience with a wide range of studio equipment, recording setups etc.

You collect old gear including tape machines, vintage radios and gramophones. What attracts you to old equipment?

The fascinating thing about old vintage gear is seeing how they solved various technical problems, not to mention the efforts they made to avoid each other’s patents and copyrights. Also the exterior design of eg. old radios from the thirties was almost Art Deco. Later in the fifties, they began to look more alike, both inside technically and outside - things have been like that ever since.

What inspired you to design your first piece, the PE 1A Program EQ, back in 1984?

The PE 1A came about while I was helping a friend to build a studio in the late 1970’s. He had bought some old Pultec equalizers in New York for less than $200 each, and they sounded fantastic. I could see that the price for these old Pultecs was starting to climb so I talked to AKG’s Danish distributor and he said that if I could make an exact copy, he would order 20 units. So I starting production in my own garage and made 30 units. I sent some to a company in New York, they really liked them and ordered some more. I only expected it to be a fad that would last maybe five years, but by 1990 the business had grown so much I realised that I had to choose between my job at Danish Broadcast and Tube-Tech - because I couldn’t do both. I chose Tube-Tech.
Take a look inside Tube-Tech's production facility
A LOT of Tube-Tech ready for recording!

If you had to choose one piece you’re most proud of, what would it be?

It would either be the EQ 1A or the SMC 2B. The EQ 1A was innovative in that it used op amps made with tubes. Most people think of op amps as solid state, but the very first ones were made with tubes for computers where they were used for calculations/operations (hence the name “Operational Amplifier”). The SMC 2B multiband compressor has a special dividing network between the three compressor channels ensuring perfect crossover points between the three bands.
PE 1C - the latest version of the original EQ 1A program EQ
SMC 2B multiband valve compressor

Have you ever been tempted to create products for 500 Series?

I have been asked many times through the years to make modules for 500 series. But there are some fundamental problems:
  1. There is not enough power in one slot to drive two tubes, so a tube unit will take at least two slots.
  2. There will be some power loss as the tubes runs on 12,6V and the rails in 500 series racks are 16V.
  3. You have to generate a high voltage (+250V) and such power transformers tend to be noisy. I think we already have enough noise surrounding us from computers, LED illumination, phones and switch mode power supplies.

How did the collaboration with Softube come about - the CL 1B opto compressor plug-in is particularly good?

I had been looking for someone to develop plug-in versions of the Tube-Tech range for some time, but couldn’t find anybody that I felt could capture the high quality of the hardware units. During a conversation with our American distributor (TC Electronic at that time) they recommended a young Swedish company called “Softube” that seemed to have a good understanding of how to digitize analogue systems. They did a splendid job with our equipment and have continued to do all our plug-ins since.
Softube plug-in collection

In an increasingly digitised recording world, what do you think it is about valve-based outboard that still attracts users?

First of all, the sound of tubes and transformers, but also the simplicity of having dedicated controls. My impression is that many users like the feeling of a knob that they can reach out and turn, instead of having to use a computer mouse.

Have you considered using your expertise in valve equipment to branch out into other markets - maybe guitar amps or hi-fi?

Actually, I have considered both these things! I made a prototype 250W mono block amplifier (with 8x KT88’s wired as triodes) and a stereo 2x 40W (2x KT88’s also as triodes), but it wasn’t really of much interest for the professional market and, in my opinion, the hi-fi market is too dogmatic! I also made a 50W/180W guitar amplifier, but that was more or less the same problem and as there are already a lot of great guitar amps around, I gave it up.

On the subject of guitarists, they’ll often obsess about the benefits of one valve brand over another - is that a critical issue for you?

It’s really two different things. In a guitar amp, the tubes are normally amplifying as much as they can. This means that even small differences in gain are noticeable and as the specification for e.g ECC 83 (12AX7) are so broad, different tube brands will sound different. With Tube-Tech units it’s a different matter because they use both local and overall feedback which levels out the differences. We’ve tested the units with Mullard, Philips, Telefunken, Siemens, Shuguang, JJ tubes etc and have not noticed any difference. Of course, some people say they can.

When you’re not managing the company, how do you like to spend your time?

At my workbench at home restoring old equipment, developing new Tube-Tech designs, and a lot of other things..!


For more information on Tube-Tech products: CLICK HERE