MY DESIGN L20D IRS2092+IRFI4020H 200W8R

[salvinci]

Originally Posted by ljm_ljm

Very enough. You want to know how much you need to use the power output.

the power output is 150/200w max.
I am interessed an a hi-end sound quality, not a big power.
I use the totem pole tube 6sn7 preamplifier, i hope in big combination tube (old system) + class D (new system amplification).

[rickedd46]

LJM,

The 2K2/1W resistor next to the D669 gets very hot and changing color on both boards even at idle. What should I change? Remember I'm running +/-70V.

[cOz]

Originally Posted by rickedd46

LJM,

The 2K2/1W resistor next to the D669 gets very hot and changing color on both boards even at idle. What should I change? Remember I'm running +/-70V.

Run less

[Bernie7]

Measured the L20D board for temp while music was playing using a DVM with thermocouple. I'm using linear supply +-63VDC and 4ohm rated speakers (speakers' impedance actually dip to 4ohms only at 100-150hz, most of the time they're above 6ohms for other frequencies).

Heatsink - 45degC
1.1K resistors (one of them beside LED) - 80degC
2.2K resistor (beside D669) - 100degC

This is with the chassis cover removed, and readings may go up another 10degC with cover in place.

Are these resistor temps too high, should higher wattage ones be used instead?

[ljm_ljm]

Originally Posted by rickedd46

LJM,

The 2K2/1W resistor next to the D669 gets very hot and changing color on both boards even at idle. What should I change? Remember I'm running +/-70V.

B: yes, I also found this phenomenon, in some time ago I this a few resistance are replaced by 2 W power.

In the IRAUDAMP7S IR noted in 2K2/1 W apparently is not so correct, because the resistance the power consumption of the above about 1.3 W.

If you are some time before buying it, I suggest that you put the two resistance to change is 2 K2/2 W.

If no hav, please contact suppliers, I can send you a few.

[ljm_ljm]

Now I have resistance change for 2 W power, military quality metal oxide film type.

It has a small change in temperature.


Today some L20 D I start with speakers as a test.
+ 77 V 4 OHM. Good work and almost no temperature.

[rickedd46]

Originally Posted by ljm_ljm

Now I have resistance change for 2 W power, military quality metal oxide film type.

It has a small change in temperature.


Today some L20 D I start with speakers as a test.
+ 77 V 4 OHM. Good work and almost no temperature.

Thanks for responding. I will get some 2W ones and replace them.

[Bernie7]

My 2.2k resistor is beginning to discolor after 1 day. Will be asking Zoe Tsang for a 2 watter as E14 doesn't carry this part.

Try changing the input DC blocking cap as well. Since my present sources are AC coupled, I shorted the input cap just to hear the difference. Significant gains - signal is just so much cleaner and less colored. Ymmv as some prefer the color of caps, in which case roll out your fave caps

[ljm_ljm]

This 2 W resistance can also, just a little bit big volume.
Metal film resistors.

[cOz]

My power supply outputs 56w. I assume that I can run L20D with no problems, correct?