+ -50VDC Will not work.
I've tested + - 68 v. Can't work stable.
Show the blue flashing LED, sound increases, will go out.
Voltage increase to + 75-75 - v or + v. LED does not shine. Sound and stable.
If change k1 resistance 5k1 to 3k9 2w. So can work stable in + - 65 v voltage.
From now on I will change by default. So can stable compatible between 60 v to 80 v voltage.
So, voltage range does not change (60-80 - v DC)
From now on I will change by default. So can stable compatible between 60 v to 80 v voltage.
So, voltage range does not change (60-80 - v DC)
I had to decrease the value of the 2k2 to 1k8 to make this amp work on 75+0-75. also increased the osc frequency to 285khz and it sounds much nicer.
ljm what is the max frequency you recommend?
Greg
ljm what is the max frequency you recommend?
Greg
Ljm,
Have you made these changes (i.e. 5k1 to 3k9 and halfing the 2k2 resistor value) to your boards in your store yet?
Don't go to adjust the frequency.
Although L30D frequency is lower than L15D doubled, but filter capacitance can be twice.
L30D 1 UF, L15D 0.47 UF.
So their filtering performance is the same. L30D 210K =L15D 430 k
Low frequency will have a better efficiency, less heat.😀
After my test.
Only need to change a resistor. 2 k2 in parallel can be completely stable working above> + - 50 v voltage.
Of course recommended voltage is still 60-80 DC+-v.
From 10 days ago, all L30D in this way.
😀
Iraudamp 9 schematic recommend 300khz frequency, and they have 2.2uf in output filter, double what you have. my tests at 285khz have less heat in inductor and much better sound quality in the upper mid to high range. heatsink temperature is the same. Greg
@Greg32,
Just curious, are you talking about LJM's L30D board or the reference design board? In the reference design the output filter is designed for a 2 ohm load. Not sure what is the targeted load of LJM's board. May be that's the cause for the difference in the output filter cap value? Just guessing.
Lo_Tse,
I was referring to both. ljm's second post he says the L30D is based on the Iraudamp9 reference design, The L30D is different from the Iraudamp9 in that the oscillation frequency is lower and i was pointing out the output filter was also different.
I am quite happy with the way my l30d boards are performing now. i see no issues with the frequency at 285khz, the sound quality is good. Greg
I was referring to both. ljm's second post he says the L30D is based on the Iraudamp9 reference design, The L30D is different from the Iraudamp9 in that the oscillation frequency is lower and i was pointing out the output filter was also different.
I am quite happy with the way my l30d boards are performing now. i see no issues with the frequency at 285khz, the sound quality is good. Greg
IRAUDAMP9 Can be as a reference.
But actually, I tried.
There are some problems. So L30D with IRAUDAMP9 is not the same.
Thank you for the clarification. Glad to hear that the Iraudamp9 sounds good (as expected I guess).
Hi,
Can you please explain what problems you had when you tried to replicate the IRAUDAMP9?
Thanks
Neil
All the circuit is equal to the IRAUDAMP9 ＝L30D
Just adjusted in practical application, it can work stable.
OCP The same as the IRAUDAMP9.
Over-Current Protection (OCP)
The OCP internal to the IRS2092S shuts down the IC if an OCP is sensed in either of the output
MOSFETs. For a complete description of the OCP circuitry, please refer to the application note
AN1138. Here is a brief description:
Yesterday I have ordered this L30D from aliexpress
will this work at 60v +/- or do I need to change any thing?
L30D/300 850W Single Channel Digital Finished Amplifier Board IRS2092 IRFB4227 IRAUDAMP9-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
will this work at 60v +/- or do I need to change any thing?
L30D/300 850W Single Channel Digital Finished Amplifier Board IRS2092 IRFB4227 IRAUDAMP9-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
@comasus yes +/-60V will work but you won't get full stated power.
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