UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - 120W PP EL34 amplifier re-born.

Diabolical Artificer · 28th Sep 2018, 7:02 am

"I reckon Chris has it, foldback limiting." It has to be it DC, however the I max of a LM317AHV is 2.2A, see attached "Does that fit with reality" With a 5ohm load, it goes into current limiting mode.

My winding is beefy enough 16AWG = good for 3.7A less a bit @ - 10v (13.4v), I'm using a 2200u reservoir cap.

In the end I used a TIP3055 as series pass Q, no more issue's.

Andy.

28th Sep 2018, 7:02 am	#19
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,657	Re: 120W PP EL34 amplifier re-born. "I reckon Chris has it, foldback limiting." It has to be it DC, however the I max of a LM317AHV is 2.2A, see attached "Does that fit with reality" With a 5ohm load, it goes into current limiting mode. My winding is beefy enough 16AWG = good for 3.7A less a bit @ - 10v (13.4v), I'm using a 2200u reservoir cap. In the end I used a TIP3055 as series pass Q, no more issue's. Andy. __________________ Curiosity hasn't killed this cat...so far.