Has any of you fine gentlemen tried their hand at modifying the Hypex NC250MP amplifier modules?
Judging from the PCB layout these are using the same input buffer as used on previous modules and thus the NE5532 can be replaced with a more modern part (LME49xxx, OPAxxx), which also means the coupling caps can be removed.
Thoughts?
Judging from the PCB layout these are using the same input buffer as used on previous modules and thus the NE5532 can be replaced with a more modern part (LME49xxx, OPAxxx), which also means the coupling caps can be removed.
Thoughts?
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I'll just leave this here... 🙄
NwAvGuy: Op Amps: Myths & Facts
PS: How exactly would replacing the 5532(s) mitigate the need for coupling caps, exactly? 😕
NwAvGuy: Op Amps: Myths & Facts
PS: How exactly would replacing the 5532(s) mitigate the need for coupling caps, exactly? 😕
The coupling caps are there, as in the other Hypex modules using the NE5532, because that opamp has a high DC offset (by today's standards) hence replacing it with a modern opamp, with magnitudes less DC offset, removes the need for those caps. The same approach has been applied to Hypex UcD and NCore modules since the dawn of class-D in the early '00s.
So you can dispense with the 🙄 as clearly you're not familiar with the history behind these module amplifiers or what modifications were carried out to them in the past, alright?
Which caps are you concerned about? NCxxxMP inputs are DC coupled and these el-caps near NE5532 are used to power supply decoupling, not for signal. Performance of NE5532 in this application is perfectly fine and I don't think it is bottleneck for rest of the amplifier. I've actually replaced it for OPA1612 in one module without measurable (and hearable) performance increase (I don't have AP gear, though). After this change Hypex guarantee is unrecoverable voided.
Input is DC coupled, but that’s just the input buffer, the coupling between that and the 2nd NE5532 has coupling caps.
Which part numbers are you reffering to? I don't know if such a caps can be bypassed as it may be integral part of main control loop. I need further investigate this subject.
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