On second thought when I check the datasheet on the transistors for the L25 I realize they're only 140v, therefore my guess is that it cant go over +-70v. my final option in my opinion is between a PR-800 amplifier board and a irs2092 board I've seen only good reviews online about.
https://www.ebay.com/itm/2843865471...+xxCwJJvVGNal9YMpmKl7Ihsl3|tkp:Bk9SR4yjtqPqYQ
https://www.ebay.com/itm/3840856822...kUZmCf6C9BrY4eAV1iu/4jhQ==|tkp:Bk9SR7T016PqYQ
or does anybody have some good suggestion for amplifier boards to work with my 78v power supply and stable at 4 ohms. Someone here suggested the sure boards but they way over my budget since my currency is very low. $2.8XCD=$1USD
https://www.ebay.com/itm/2843865471...+xxCwJJvVGNal9YMpmKl7Ihsl3|tkp:Bk9SR4yjtqPqYQ
https://www.ebay.com/itm/3840856822...kUZmCf6C9BrY4eAV1iu/4jhQ==|tkp:Bk9SR7T016PqYQ
or does anybody have some good suggestion for amplifier boards to work with my 78v power supply and stable at 4 ohms. Someone here suggested the sure boards but they way over my budget since my currency is very low. $2.8XCD=$1USD
L15D is ok and reliable and can give up to 300 W to a 4 ohm speaker (or 150 to an 8 ohm speakar). L25D is dedicated for an 8 ohm speaker and can give up to 250W to such a speaker.
Here my L25-D
In the first photo work at 55-0-55 without modification and in the second photo work at 70-0-70v with a little modification to limit the hot on some resistors
The 2W resitors has been replaced 5100 -> 2 x 12K in parallel and the 2200 -> 2 x 4700 in parallel
Probably in the future I will try to use the aux outputs of the switchg power supply to generate the +5, -5 and -12v in order to eliminate the hot generated on these resistors.
To drive this H-frame dipole subwoofer
In the first photo work at 55-0-55 without modification and in the second photo work at 70-0-70v with a little modification to limit the hot on some resistors
The 2W resitors has been replaced 5100 -> 2 x 12K in parallel and the 2200 -> 2 x 4700 in parallel
Probably in the future I will try to use the aux outputs of the switchg power supply to generate the +5, -5 and -12v in order to eliminate the hot generated on these resistors.
To drive this H-frame dipole subwoofer
Last edited:
L20 amplifier can be selected. Not L20D
It is L20 Class AB.
Then choose to use the ONSEMI NJW0302G 0281G transistor version.
You may need to consult the sales merchant.
I would like to share here a positive experience with the L30D, different from the experience posted here by @Zzalex. I had to replace the amplifier board for my JBL ES250P subwoofer and this spare part was no longer available from JBL. So I ended up choosing to use the Chinese board L30D, which is a hybrid solution between the IRAUDAMP7S (for the IRS2092S input circuits and power supply for Vcc) and the IRAUDAMP9 (for the IRS2092S output circuits). I had to make some modifications to this L30D PCB to reduce the temperature (since the entire JBL subwoofer amplification assembly is in a closed plastic box, without any ventilation system) and also to preserve the entire original JBL protection system. If anyone is interested, below is the link to the thread I created with more details.
https://www.diyaudio.com/community/...ration-and-thermal-improvements.426353/latest
https://www.diyaudio.com/community/...ration-and-thermal-improvements.426353/latest