DLH Amplifier: The trilogy with PLH and JLH amps

Hi.

I think several have made their designs and uploaded it to the thread. In fact, they are very good. I don't have my own PCB design to offer you.

Thanks for your interest in the amp.

Good luck with the construction of your project.

There is also another amp you could build, which is very tempting: The NEZ Amplifier. It operates under a different concept than the DLH, although it has its charm as well.

Regards
 
Hi.

A quiescent current of 1 A would be necessary to be able to adjust to the two possible modes of operation (single ended or push pull). For this case, the total dissipation would be in the order of 30.87 W.

If you only want to operate in push pull mode, a little more than 0.5 A would be enough. For this case, the total dissipation would be in the order of 15.43 W.

Best regards
 
Hi Diego

I'd like to build your amp , and I did order Prasi pcb's as per post #320 DLH Amplifier: The trilogy with PLH and JLH amps .

Can I substitute IRFP250 for IRFP240 on this board without changing any values ? My local supplier is out of stock of IRFP240

651772d1513603858-dlh-amplifier-trilogy-plh-jlh-amps-pcb-dhl-amp-jpg


I also got the Johnson/Gtose CapMX pcb's also layed out by Prasi . Juma's Easy-Peasy Capacitance Multiplier
 
  • Like
Reactions: 1 user
My advise to you use two DMM one to measure the DC offset and one to measure the current (Iq). Before you start please Use a 40 or 60W light bulb at start up, that help not to blow up the amplifier at power up! I will include a circuit for that. If everything fine at start up, no smoke or buzzing noise start to adjust the trimmers one by one slowly and you will see which one adjust the offset and which one the bias. I am totally of the picture with this amp, it was a long while since my last involvement.
 

Attachments

  • DimbulbSketch.gif
    DimbulbSketch.gif
    25.1 KB · Views: 111
Founder of XSA-Labs
Joined 2012
Paid Member
It’s a Class A amp so the lightbulb will glow when it’s working right and cause too much voltage drop. Mostly have your hand on the power switch to turn off if the current exceeds 5A. Turn off and investigate. You literally have 1-2 seconds to flip it off if there is problem. Important to set pots to a state of low bias current and work way up slowly.