Review: Coleman Audio TC4

A few months ago Coleman Audio announced the TC4 Transfer Console & Insert Switcher designed by Glenn Coleman and based on suggestions from legendary mastering engineer Bob Katz. We put the TC4 through its paces and report back...

TC4 Mastering Transfer Console
When Coleman announced the TC4 last September, I was quite excited as I was on the lookout for monitor and insert switching capabilities and was already looking at Coleman's existing offerings such as their MP3H MkIII to serve some of these functions. The Coleman TC4 is a mastering transfer console and consists of four stereo inserts and a monitoring section with headphone output based on their MP3H which it resembles remarkably. It takes a single space in a 19" rack so it can integrate any mastering rack leaving more room for additional outboard. Despite its diminutive size, the TC4 manages to pack a lot of functions.
Insert switcher section
The Stereo insert section consists of four white switches which illuminate red when the insert is engaged. A fifth switch flips the order of insert 1 and 2 and lights up orange when engaged. Being able to flip the order of insert points is crucial in mastering applications and is often used to switch the order between an EQ and compression. These switches are not the same kind as other Coleman products and are easily engaged or disengaged with a light touch. A Pre/Post Inserts switch lets you monitor the signal before or after the insert points for A/B comparison. Unfortunately, it doesn't include a level offset, so there is no way to compensate for level differences if your outboard doesn't offer a way to adjust the output volume.
Monitor section
The monitoring section looks very similar to the one found on Coleman's MPH3 MkIII monitor controller, with toggle switches for Left and Right Mute, Mono, Polarity reversal of the right channel, Monitor input and Alt Speaker selection. Just like on the MP3H it is possible to combine the Mono switch and polarity reversal (both in red) switches to solo the side, something that most mastering engineers use regularly. It also includes Coleman's distinctive 47-position Main level attenuator and headphone Level control.
Main level and headphone controls
On the back of the unit, two DB25 connectors handle the four available balanced inserts. Coleman has configured Insert 1 & 2 I/O’s on the first connector and Insert 3 & 4 I/O’s on the second - wired to Tascam AES/EBU digital spec ( This had us confused at first as we were expecting all inputs to be on one connector and all outputs on the second. However, in use, this makes complete sense and results in neater cabling as any unused terminations aren’t left dangling at the back of your rack. The rear panel also features connections for two sets for speakers, two monitor inputs, one master output and a meter out for a VU meter or any metering setup you may have.

In Use

TC4 hook up diagram
The Coleman TC4 is extremely easy to use with every function clearly labelled. The switch buttons feel great and are completely silent, and the volume controls are straightforward to set with precision. While it is mainly utilitarian, the TC4 brought vast improvements to my workflow. The possibility of simply removing a processor for my chain at a flick of a button allowed me to make more accurate decisions, much faster. I could instantly check if adding each piece of outboard was beneficial or detrimental to the sound, and I would choose not to use a particular piece of equipment. Flipping the order between the EQ and compressor was also a revelation, opening up my ears to the benefits of either configuration. The monitoring section first appeared a little primitive compared to some of the more established transfer consoles, but in practice covered most aspects I needed, and its smart way to monitor the Mid (Mono) or Side elements of a song was invaluable. The Main Level control also made it a breeze to set the ideal monitoring level and recall it accurately after any changes. The headphone section is the only active element in this unit and has plenty of headroom to spare - even with high impedance headphones such as the Focal Clear Pro. Using a passive design, the TC4 is remarkably transparent and quiet. When measuring for noise levels, I was pleasantly surprised to see that no increase in noise occurred even with all switches and the Main Level turned to the maximum, remaining at the level of my AD/DA converter at -117.3dB. The only noise introduced was by my processors when engaged not the TC4. This is another strength of using the TC4; If you have some noisy equipment, you can easily bypass them when you don't need them, significantly improving the quality of your audio at the touch of a button.


The TC4 is pitched primarily at mastering engineers, and it certainly delivers sonically. Some users may miss a monitor input level offset and M/S width control, and possibly find having only 4 inserts limiting in larger setups. However, the number of features crammed into a 1U unit at this price point is very impressive. If you are looking for a comprehensive, simple, transparent insert switcher with monitor control, the TC4 is a great choice and mastering engineers with less outboard, or with an existing insert switcher, will undoubtedly benefit from the unit’s sonic transparency and very low noise. It is also worth remembering that more established players like the Dangerous Music Master, SPL DMC or Maselec MTC-1X are twice to four times the price of the TC4. The TC4 is also a great tool to add on the mix bus, offering improved workflow removing the need for patching and unpatching cables. Engineers using outboard on their mix bus should seriously consider it as it will not only free up connections on their interface or AD/DA converter, it will also greatly enhance their experience and workflow. For info on the Coleman TC4, click <>