The Korg TP-2 ($699) is a dual-channel tube-mic preamp with built-in optical compression. It provides 24-bit, 96 kHz conversion and offers analog and digital outputs. Mounted in plain view on top of a sturdy all-metal chassis, two 12AX7 tubes provide the amplification and compression through feedback from an optical photo-coupler. Resembling a part from the robot on Lost in Space, the TP-2 glows a nifty blue color when powered up, enabling it to perform double-duty as a mood lamp.
From the (Table) Top
The tabletop unit lies flat, and the manual recommends maintaining that position for the meters to function properly. The top panel has two Mic/Instrument inputs on Neutrik combo connectors. Each channel offers phase and phantom-power switches and gain trim control. Underneath the trim knobs are the switches to select high impedance, a -26 dB pad, fast or slow compressor mode, and a -6 dB-per-octave 70 Hz low-cut filter. Under the circular VU meters in the center is a compressor-sensitivity knob for each channel and a switch to link the compressors for stereo operation. On the far right are two 60 mm output level faders to control the analog output.
The rear panel supports the 9V DC power connector and switch and two pairs of +4 dBu balanced analog outputs — one on XLR, and the other on ¼-inch TRS connectors. The unit provides S/PDIF output on Toslink and RCA connectors. Next to those is a 3-position switch to select 44.1-, 48-, and 96 kHz sampling rates (no 88.2 kHz, unfortunately). All of these rear-panel connections are labeled for easy identification from the top.
When the TP-2 was lying flat as suggested, it was difficult to see the meters, and the status, and the labels of the switches unless I was directly over the unit. It was also difficult to see the position of gray buttons against the gray chassis in dim light. (I typically work late at night with a single desk lamp in a common home-studio environment.) After using the TP-2 for a while, I decided to ignore the manual and prop the unit up at an angle. I would have preferred indicator lights for most of the other switches in addition to the lighted phantom-power indicator.
I recorded acoustic guitar and vocals with a large-diaphragm condenser mic while recording electric bass directly, using primarily the digital output for both channels. Getting the right levels and the proper amount of compression was challenging. Trying to get a proper input level often created tube-induced distortion, something I would prefer to introduce after getting a good working level. The fast setting on the compressor was a bit heavy, imparting too much attack, and the slow setting was too subtle. It wasn't clear from the manual if the attack and the release times were affected, but it sounded as though they were.
The ratio was not adjustable, and setting the sensitivity (threshold) was tricky. I like to start “by the numbers,” and then use my ears for tweaking. After a bit of knob twiddling, I got a sound I could use. But achieving it took longer than it should have, and I wasn't completely satisfied. The controls interact to clearly affect the sound, but because many parameters are out of reach of the user, obtaining sonic adjustments that were more refined was somewhat difficult.
That being said, the quality of the sound was quite good, and the unit delivered the warmth factor. The preamps have a decent range, the tubes impart some heft, and the compression has a creamy quality to it. If you are looking to fill out the sound of some source material, you can get that job done with ease.
The Korg TP-2 offers to give “analog tube warmth and richness,” and succeeds in that capacity. Sold as an add-on for Korg's D32XD and D16XD hard-disk recorders (TPB-2), it adds a unique feature to those units. I found the unit frustrating to operate, while trying to perform and engineer simultaneously. I might have had better luck if I were recording someone else. I would suggest, however, that you try it out for yourself to see if its design, user controls, features, and sound are right for you.
Overall Rating (1 through 5): 2.5