You can apparently modify Dr. Lava's MicroBoost to be modulated by TTL.
I don't have a link to the document, but it is somewhere here on the forum.
If you place the Micro boost on a work surface, with the B+ connection in the upper right corner, and the POT up, you will see a sorta "L" shapped pad just above the B- connection. According to the document, you cut the upper leg of the 'L' (leading to the 6 pin chip, just below the B+ connect) and scrape the mask off of the broader lower leg of the 'L' (that becomes your TTL+ modulation input pad).
I have tried to attach a copy of the doc.
The real problem may be getting your hands on a microboost. I think Dr. Lava is out of them for the moment. But, I think, Bogartman has them for sale @ $38. He may have some in stock.