Trouble shooting
Hello,
I just tried to adjust the bias on my amp camp. On the 20v setting of my mm I can mostly read 0.02v no matter how I turn the pot, sometimes it jumps to 2v. The LED stays on for a while after shut off. What's a good method to trouble shooting? Here's a picture.
Y
Hello,
I just tried to adjust the bias on my amp camp. On the 20v setting of my mm I can mostly read 0.02v no matter how I turn the pot, sometimes it jumps to 2v. The LED stays on for a while after shut off. What's a good method to trouble shooting? Here's a picture.
Y
Attachments
For ACA amp with heat sink of size : 190mm*100mm*30mm each, which of the below options be better:
1. with 19v 90w laptop power supply for both the channels, without 6w 2.2k R15 mod.
2. with above power supply and with 6w 2.2k R15 mod.
3. with 24v SMPS power supply without 6w 2.2k R15 mod.
4. with 24v SMPS power supply with 6w 2.2k R15 mod.
Will the 2.2k R15 mod be significantly better than normal circuit without it or will it be more of unnecessary heat generated for the given heat sinks?
1. with 19v 90w laptop power supply for both the channels, without 6w 2.2k R15 mod.
2. with above power supply and with 6w 2.2k R15 mod.
3. with 24v SMPS power supply without 6w 2.2k R15 mod.
4. with 24v SMPS power supply with 6w 2.2k R15 mod.
Will the 2.2k R15 mod be significantly better than normal circuit without it or will it be more of unnecessary heat generated for the given heat sinks?
Just completed my ACA's with slightly larger heatsinks (200x100x40) and tested it with and without R15 mod and on 18V and 24V. That is the minimum size heatsinks I'd be happy with in my ambient temperature of 28-30 deg Celsius at 19V.
Going to 24V raises the temperature considerably. Therefore, your option no 1 is the only one I'd recommend, unless your ambient temperature is way less. The R15 mod also raised the temperature by a few degrees.
Going to 24V raises the temperature considerably. Therefore, your option no 1 is the only one I'd recommend, unless your ambient temperature is way less. The R15 mod also raised the temperature by a few degrees.
Apart from temperature, how is the sound output quality and quantity among the options ..
Your first concern should be temperature. However, I did not hear any difference in sound quality. The 6W mod and higher voltage just resulted in higher volume levels. That's my opinion. Others may feel otherwise about sound quality, which by the way is amazing.
I have ordered Vishay RN60 Series B14 Axial Metal Film . I ordered this from RS component. When I ordered it wrote 0.25w but when I received it the packaged wrote 0.125w.
for R14 use whatever you have in drawer , from 470R to 4K7
it's easy to calculate peak power through it ;
presume 24Vdc supply , peak current is then I=24V/R
power is P=U x I
that's "just" bleeder resistor , there to prevent output cap having floated output side , so no POP! while you're connecting speaker wires
it's easy to calculate peak power through it ;
presume 24Vdc supply , peak current is then I=24V/R
power is P=U x I
that's "just" bleeder resistor , there to prevent output cap having floated output side , so no POP! while you're connecting speaker wires
Ok will bear in mind.
I'm building another set of ACA, like you said using 24Vdc, that means the Vac transformer is 18v, rite?
