Hi all,
I had some spare time so i made more mods in my little circuit.
I made several mixes. I fitted different kinds of ampop in left and right channel and the results are:
Opa604 and opa604 circuit worked.
Opa604 and LM6181 circuit worked.
Opa604 and AD811 circuit worked.
AD811 and LM6181 circuit not worked I listed only noise.
AD811 and AD811 circuit not worked I listed only noise.
What could I try more?
PS: I burned one lm6181.
Katapum
I had some spare time so i made more mods in my little circuit.
I made several mixes. I fitted different kinds of ampop in left and right channel and the results are:
Opa604 and opa604 circuit worked.
Opa604 and LM6181 circuit worked.
Opa604 and AD811 circuit worked.
AD811 and LM6181 circuit not worked I listed only noise.
AD811 and AD811 circuit not worked I listed only noise.
What could I try more?
PS: I burned one lm6181.
Katapum
Attachments
Hi,
I burned a LM6181 because I inserted a parallel cap with feedback resistor.
I hear you but:
Now the stage is working. Its sounds better then my previous jfet stage. I didn´t like opa604 they are a little unreal. AD811 has an impressive micro detail but the mid band is a little aggressive.
I wiil buy one LM6181 and ….. two OPA134??? and maybe two opa637 (they very expensive)???.
More options please?
Katapum
I burned a LM6181 because I inserted a parallel cap with feedback resistor.
I hear you but:
Maybe later.
Now the stage is working. Its sounds better then my previous jfet stage. I didn´t like opa604 they are a little unreal. AD811 has an impressive micro detail but the mid band is a little aggressive.
I wiil buy one LM6181 and ….. two OPA134??? and maybe two opa637 (they very expensive)???.
More options please?
Katapum
Katapum, if you check the 78xx datasheet from National, the absolute max. input voltage these regulators can take is 35V (ex: LM7815).
With 32V trafos your DC voltage will be around 44V.
It doesn't smell good that you say you have 31V after the 3.3 ohm series resistors, after the rectifier diodes, as printed on your schematic. (?)
Another thing, just 470uF capacitance before the regs?
With 32V trafos your DC voltage will be around 44V.
It doesn't smell good that you say you have 31V after the 3.3 ohm series resistors, after the rectifier diodes, as printed on your schematic. (?)
Another thing, just 470uF capacitance before the regs?
Hi Katapum,
run just one secondary winding through the bridge rectifier to create your 45Vdc to 50Vdc supply.
Now create a false ground using a splitter made from caps and resistors or even an active ground using an opamp. Lots of circuits to do this.
Then you will have +-22Vdc to run into the two + & - regulators.
You are throwing resources at the wrong end of the circuit.
Sort the PSU before you waste even more money on toasted opamps.
run just one secondary winding through the bridge rectifier to create your 45Vdc to 50Vdc supply.
Now create a false ground using a splitter made from caps and resistors or even an active ground using an opamp. Lots of circuits to do this.
Then you will have +-22Vdc to run into the two + & - regulators.
You are throwing resources at the wrong end of the circuit.
Sort the PSU before you waste even more money on toasted opamps.
Hi,
B1 is totally wrong throw it away quickly.
A1 is almost there.
Add balancing resistors after the rectifier.
1k0//470uF and 1k0//470uF. These resistors will run pretty warm so 1W or 2W might be better.
I think you should remove or reduce 3r3 series resistors before the caps.
I also think you should add a lot a capacitance to the PSU. eg. ceramic and PP or PES across the electros, spike suppression across the psu outputs and the rectifier AC and across the transformer mains side and before and after the regs.
Like I said earlier, invest some resources in the PSU BEFORE wasting money on expensive opamps. The PSRR of the opamps helps reduce all the HF hash coming from the mains and rectifier diodes but you should not be relying on that alone.
Have you fitted spike suppression cap across the opamp supply pins?
B1 is totally wrong throw it away quickly.
A1 is almost there.
Add balancing resistors after the rectifier.
1k0//470uF and 1k0//470uF. These resistors will run pretty warm so 1W or 2W might be better.
I think you should remove or reduce 3r3 series resistors before the caps.
I also think you should add a lot a capacitance to the PSU. eg. ceramic and PP or PES across the electros, spike suppression across the psu outputs and the rectifier AC and across the transformer mains side and before and after the regs.
Like I said earlier, invest some resources in the PSU BEFORE wasting money on expensive opamps. The PSRR of the opamps helps reduce all the HF hash coming from the mains and rectifier diodes but you should not be relying on that alone.
Have you fitted spike suppression cap across the opamp supply pins?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.