I'm trying to bring a CE-1 Preamp schematic to life. I found the schematic on the internets, and it is supposedly verified. The circuit centers around a SIP7 TA7136. Tracing with an audio probe, I get signal all the way to pin 2 and only faint, garbled mess at pin 6. The IC voltages seem a bit off to me, as well... no IC (w/IC):
1 = x (14.5V)
2 = input good (7? variable with vol pot)
3 = x (14.35)
4 = -17.6 (-17.5)
5 = 15.45 (15.45)
6 = output bad (14.87)
7 = 15.6 (15.4)
I'm not very familiar with the TA7136, and the only datasheet I could find seems to be lacking in critical info (http://www.datasheetcafe.com/ta7136p-datasheet-pdf-amplifi.../).
The power section of the schematic also seems odd. The author claims +/- 13V should feed pins 4, 5, and 7. Clearly, I'm a bit off from there.
My questions... is the TA7136P connected properly in the schematic? Also, how would I get the voltages to where they should be? Would a zener be better than 4001+resistor? Or would a higher resistor be the solution?
The power supply section is pretty close to what you'll find in the LT1054 data sheet as a doubler with negative as well. It won't have identical voltage for + and - pins, due to the drop across the diodes I think. It's worth reading the LT1054 data sheet to see what it is doing here.
If you think the +-13v is important to aim for, I'd add in some voltage regulators that give you exactly 13v. Or zeners as you suggest.
I've got a similar circuit with 4001 on one path and 5817 on the other, to even up the negative and positive sides, and it came out at about +-15v.
Interesting. Never noticed that configuration before on the LT1054. I'll have to give that a try.
Maybe this will help:
https://drive.google.com/file/d/1Dwtb4_tTKEtF0X1ESL6Ecg9upAne_Ljv/view?usp=sharing
The doc is for the TA7136AP instead of the TA7136P, I don't know how much difference that makes.