Only if it has a fan. You are about to burn 2.5A at 12V, I.e. 30W. For the T Amp there is no high constant bias that it burns it so to take the burden off the shunt, like a class A amp with big idle bias and chunky shinks does. It only burns dynamically from it when it plays. The shunt will be getting less heat the stronger the amp plays. When the T Amp idles, the shunt gets it all. You will need a 0.5C per W heatsink.
Tham, please let us know how your t-amp works with the new regulator, when you get a chance. Hope to finish my high current version soon too.
Hi stormsonic,
We may be talking about the same thing, we'll see tomorrow.
-Chris
Sure, no problem. I'm hitting the sack right ow, but I'll scratch out a diagram for you tomorrow.
We may be talking about the same thing, we'll see tomorrow.
-Chris
Hi all and I wish not to get any answer because you are all at vacations 🙂
For some months now, a pair of salas shunts have replaced batteries in my line amp with spectacular results. In order to clean up the mesh and close the chassis I would like your opinion on this.
The line stage consists of a opa627 buffer, a volume control and an opa627 output stage.
Now the shunts go where the batteries before them. That means per chanell per rail
- a small inductor
- 1000 uF
- and then to each chip with 1R/47uF on chip's rail pin
Should I leave it like this or remove inductor + 1000uF ?
For some months now, a pair of salas shunts have replaced batteries in my line amp with spectacular results. In order to clean up the mesh and close the chassis I would like your opinion on this.
The line stage consists of a opa627 buffer, a volume control and an opa627 output stage.
Now the shunts go where the batteries before them. That means per chanell per rail
- a small inductor
- 1000 uF
- and then to each chip with 1R/47uF on chip's rail pin
Should I leave it like this or remove inductor + 1000uF ?
Hi,Marinos said:
if the inductor version sounds spectacular, then why change it?
Only you can experiment and find out whether removing the inductor can make it more or less spectacular.
Marinos said:
Its OK as it is, although a coil smooths it up high just a bit, does not alter it, we had experiments, it is still perceptibly positive, if before the shunt. After the shunt it messes with its low output impedance. I don't know if it helps the chips more than what an impedance alteration can do as harm. Bypass and listen, compare.
Salas, canabalised a heatsink from my unused AV amp and tested my new v1 shiunt for T amp...the output without load measured only about 8V. Is something that I have done wrong?
Using a 14V 4A trafo and D15XB60 diode from the same av amp. With 8000uF of smoothing cap, the output voltage is about 18.6V ...could that explain why I only get 8V after the shunt?
I would expect >20Vdc from a 14Vac transformer when the load is disconnected.
Check the PSU.
But maybe it's a 12Vac transformer.
How did you arrive at 14Vac and 4Aac?
Check the PSU.
But maybe it's a 12Vac transformer.
How did you arrive at 14Vac and 4Aac?
10V6 drop across the regulator sounds way above a normal drop out voltage.
There is something else wrong.
There is something else wrong.
AndrewT, its a 60VAC trafo with single 14V secondary. I will have to recheck again if I have done something wrong with the built...
Tham, I suspect too much current being drawn. Measure the current drawn especially at 1) first resistor before the first series mosfet, 2) shunt mosfet, 3) load. For 2) and 3) I usually put a small resistor (0R2, 0R1 etc.) and measure the voltage across it.
Sorry guys, found the problem. I redo the grounding and the problem is solved. Running in now and will give it a listen soon 🙂 .
How much Vin-Vout and how many Amp? Amp Iccs = VR1/R1. OK with the sinks? Do they stay under 60C?
Salas, is it possible to use 2SK246BL FETs in place of 2SK170s, in your shunt regulator circuit, albeit with a small reduction in performance? Any component value changes? Thanks.
Not under the zener because of higher pinch off than 170BL. They will suffocate under Vbe. All other places yes. No changes. But you can add a 220R from BC550's emitter to ground. That will give space for -2.5V pinch off devices if BC550's collector load is a 8.5mA Idss Jfet. Your Vout becomes Vz+2.5V then. If your 6-9mA Idss 246s that are better to be applied here, have higher than -2V pinch off you scale the resistor higher and your Vout goes up accordingly. You rethink of Vz. And you must not squeeze the voltage across the BC550 too much. Say no less than 8V across or not less than double shunt Vgs in other words.
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