Disclaimer: I took some electronics classes 25+ years ago, but I am not an electronics engineer, so use this solution at your own risk. Moreover, it is not certified nor approved by Takamine in any way. I tested it in one configuration only as described in this article.
The easiest (but not the cheapest) way to power up the CTP2 from the external power source was to use a Takamine DI+. I said “was” because Takamine doesn’t manufacture it anymore. It’s a great device – I tested it! It provides several essential DI functions, plus it works as an external power supply for CTP2. Its retail price was around $200. However, I didn’t need a DI and thought that $200 is too much for a power supply. So, I decided to find a less-than-$20 and easy DIY (Do-It-Yourself) solution.
DIY solution – the idea
I had DI+ at my disposal for a while and looked how it powers the CTP2. DI+ connects to the guitar via standard 1/4 TRS stereo cable, uses one wire for passing the signal and another one for powering CTP2 (+6.7 volts on the ring connector).
Here is what I realized:
- CTP2 has a circuit for disconnecting the battery if there is some voltage on the external power connector (aka comparator)
- An external power supply providing 6.7-7.5V should be ok. Probably even 9v (typical power supply for guitar pedals) will work just fine, but I was afraid to grill my CTP2 and never tested it.
- 0.5-1A current should be more than enough for CTP2
- I did not want to change anything within the guitar (wiring, connectors etc)
The picture below shows the idea:
I found an inexpensive ($6) and compact Y-adapter Hosa YPP-491. It connects two mono signals from two 1/4″ TS connectors to a stereo TRS female connector. This is how all parts are connected:
The modern transformer-less lightweight power supplies are SWITCHING power supplies and are very noisy for audio applications. Don’t repeat my mistake – they WILL NOT work well in this solution.
Instead, I went to the nearest electronic recycling store and picked a relatively bulky used 6V/800mA RadioShack 273-1761 LINEAR wall wart for five dollars.
Then I simply cut the old connector from the power supply, found ‘+’ and ‘-‘ wires, and soldered them to the 1/4″ TS connector. The ‘+’ wire goes to the Tip and the ‘-‘ wire – to the Sleeve terminal on a 1/4″ TS connector.
The result is: it works just fine! I even recorded it via my audio interface and compared the level of noise with battery and external power – it was the same, no differences.
This project cost me about $20 with all connectors and about 6-8 hours of fun. But please take into attention the disclaimer from the beginning of this post 🙂
Thank you and please leave your comments below.