Hi, 
 
I purchased a Tascam US122MKII 3 or 4 years ago but never got it to work with my MIDI devices; there has always been a delay in both recording and playback functions. I put it in the drawer up until last week, when I purchased Sonar Professional and the MPK mini MK2 from Akai. 
 
I can record live instruments perfectly; the playback is all good, no clipping, no dropouts.
However, for some reason, there is a considerable delay between when I strike a key/pad on the MPK mini and when I hear it from the audio output of the Tascam US122MKII. I set the buffer times to 64 msec and the MIDI device manager in Sonar tells me that the Input/Output buffer times total 10 msec, but trust me, it is somewhere closer to 300 msec.
 
Did anyone experience something similar?
 
Thank you for your help and Happy Holidays.
 
Audio Input/Output: US122MKII through USB
MIDI Input: Akai MPK mini MK2
MIDI Output: Microsoft GS Wavetable Synth
 
System:

• Lenovo ThinkPad T460s
• Intel Core i5-6300U vPro dual core @ 240 GHz
• 8 Go RAM DDR3
• 118 Go SSD Sata 3 (30 Go remaining free space after DAW/Sound Card/MPK Editor install)
• 2x USB 3.0 ports + 1 x USB composite 

 
Phil Leonard

This issue is almost always caused by having certain plug ins in your project. Try bypassing any "look ahead type" processing. Sonar delays the audio which is OK for mixing and playback. But when you are tracking you should not use certain plug ins. 

In extreme rare cases, something get delayed on the way between the controller -> Windows -> Sonar. But that is easy to check: try play using virtual keyboard inside sonar by mouse/computer keyboard (or on screen in the synth, if it has some). If you have no delay in that case, you may have mentioned problem.
Otherwise follow the advise from Johnny.

I am not familiar with "look ahead type" processing; the delay can be heard in an empty project with no plugin selected. If they are active nonetheless then yes, I might need to bypass them. 
 
Have you got any clue for performing that action in Sonar?
 
Thank you.

Disable the MS GS Wavetable synth as start using TTS-1 for GM sounds.
Follow the instructions in the hardware setup guide for the interface. Then set the ASIO buffers in the software supplied by Tascam.

• 2x USB 3.0 ports + 1 x USB composite 
• MIDI Output: Microsoft GS Wavetable Synth

A lot of USB audio interfaces and devices don't work perfectly with USB 3 Ports. 
Possibly this is your problem. 
As scook said, disable the output to MS wavetable, you don't need that. 
 
I have an Akia Synth station 25 and one thing for sure, it did not come with a midi driver and because of this it performs badly compaired to my Roland keyboard. Sonar always disconects etc. And as well I get weirdness like double notes and there is definatly a bit of delay, but not enough to make it unusable. Probably about 5ms.