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TC Electronics Booster/Line Driver Help

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9/3/1999 7:28 AM

TC Electronics Booster/Line Driver Help

I've got one of these pedals and I find it to be useful for boosting a signal w/out overdriving it too much, but it has two problems which may or may not be related.

1)The pedal turns on too slow, it takes 1/4 to 1/2 a second to engage, just long enough to be annoying sometimes.

2)After being engaged the led fades out after about 30 seconds, the sound is unaffected.

The input/output jacks are soldered directly to the circuit board, and I think I will have to unsolder them to remove the board. My guess is that the board is made deliberately hard to get at to make it harder to reverse engineer.

Any ideas on this?

Andrew.

9/3/1999 9:07 AM

Hi!

Regarding question 2, this is perfectly normal battery operation, probably a solution to preserve the battery. However, the LED will lit steadily if you run it on external power.

I have no idea about question #1, but I guess the problem is in the bypass flip-flop circutry. I think all TC's had a 4011 CMOS where two gates made up the flip-flop and another one was involved in the LED fade out function.

Maybe a bad cap somewhere?

I was able to pull out the PCB from my TC XII phaser, even though it was a bit tricky. Unfortunately TC used the chip grinding method to prevent reverse engineering.

9/3/1999 12:54 PM

The LED fading out after a few seconds is normal. This is done to preserve battery power as anonymous mentioned.

Your switch problem could be due to a drifting cap or wrong value cap. There is a 1 uF cap on pin 7 of the 4007 ( one of the 14 pin ICs), look there and confirm its value and replace it if necessary. It is a 1uF tantalum cap. I should mention there is a 10k R in parallel with this cap and check its value too.

Good luck,

CJ

9/3/1999 1:29 PM
Anders Westerberg	I'm responsible for the anonymous posting, I simply forgot to fill in the field. CJ, you maybe remember me. You helped me with the schematic for the TC XII Phaser, thanks a lot once more! I spent a lot of time and research to get that box in working condition but it was certainly worth it. Most versatile phaser I've ever tried and probably one of the best sounding.

9/3/1999 2:57 PM
CJ Landry	Yes, I remember Anders. I wanted to ask you if you have seen any where in Europe sources for the Reticon ICs like R5101 or SAD512? CJ

9/4/1999 6:26 PM
Anders Westerberg	I guess these chips are even more rare in Europe than in the US. But if I ever find a stock of those or the SAD1024, I'll certainly buy the entire stock . I'll let you know if it ever happens.

9/4/1999 11:02 PM
R.G.	That's how I got my SAD1024's. However, another five years of looking has not turned up even ONE SAD512D.

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