The voltages don't look right, so you may have more than one problem. However, the first thing to check is the current through your voltage reference. Assuming R12 is 5k, what is the model of D10?
LM329
I built gled431 but I didn't understand where to connect.
Lm329 has 3 pins, if I connect + and GND,what to do with 3rd hole?
I built gled431 but I didn't understand where to connect.
Lm329 has 3 pins, if I connect + and GND,what to do with 3rd hole?
LM329 is 6.9V. You cannot use it for a 5V regulator without changing the circuit. You need a 2.5V reference like LT1009 or LM4040. You can use GLED431, it connects to the same pins as LM329. Note that only two pins on the board are connected. Make sure the polarity is correct.
@tamra, you can connect GLED431 as they are connected in this scheme, it is a Walt Jung shunt regulator but the right side is identical to a series regulator.
Instead of 2SK3557 you can use 2SK246 or similar jfet. Instead of zener diodes for D2 and D7, you can also use a red LED.
Instead of 2SK3557 you can use 2SK246 or similar jfet. Instead of zener diodes for D2 and D7, you can also use a red LED.
Attachments
It should be SMD ZTX951 but it is not quite like that, an even better choice for GLED431 would be ZXTP2041F.
Thank you grunf.
I put gled431 but nothing changed for voltage problem.
Dose led in gled lit?
I put gled431 but nothing changed for voltage problem.
Dose led in gled lit?
@grunf Thanks, it helps. The reference noise is audible in my system (not as noise per se, but affects the clarity of the sound). I am currently using the LTC6655LN series reference with a 100uF internal filter and no external filter (no R4/C9). It sounds great, but needs a bootstrap. I want to try GLED431 next to compare.
Just curious (for my education), when you say ZXTP2041F is better than ZTX951, what part of the specs are you referring to? Thanks again as always!
Just curious (for my education), when you say ZXTP2041F is better than ZTX951, what part of the specs are you referring to? Thanks again as always!
With GLED431, you should reduce R5/R12 to 499 Ohm. See "Addendum of March 8, 2016" here (notice R2 is 499).
Every reference improvement affects the regulator itself and R4/C9 are an integral part of it which also affect the sound and performance of the regulator and should not be omitted. I think it could be done with a bandgap voltage reference like the LTC6655, just reduce the Cout on the LTC itself.
I think that GLED431 with good CCS beats LTC6655 in terms of noise but not in precision and an improved version of GLED431 in impendance as well.
ZXTP2041F is better than ZXTP2027FTA in GLED431, but I have never compared them with ZTX951.
Yes, but it is not the cause of the voltage issue in your build.
You can use Toshiba TTC004B and TTA004B without problems. I think they are easily available in your country. 🙂