Futterman H3a OTL amp for sale seen on on eBay!

Just saw a Julius Futterman H3a power amp listed for sale on eBay today. Great piece of audio history to own !

rdiiorio04-10-2020 5:56pm

noromance Details Discussions Posts This discussion Message User 9,404 posts 04-15-2020 at 01:42am Copy Comment URL Report Comment Edit Delete Don't they have a reputation for taking out tubes and worse?
rdiiorio OP Details Discussions Posts This discussion Message User 33 posts 04-17-2020 at 07:00pm Copy Comment URL Report Comment Edit Delete I can only tell you of my experience, so there is no spreading of rumors, myths being perpetuated or anecdotal accounts being said here. This Futterman has been driving KLH Model Nines since 1972. I don't know how that "reputation" came about, but in today's lingo i might even say its fake news.
noromance Details Discussions Posts This discussion Message User 9,404 posts 04-18-2020 at 02:26pm Copy Comment URL Report Comment Edit Delete Early ones had stability issues. http://www.atma-sphere.com/Resources/OTLs_Defined.php Reading more, it seems JF improved the circuit and fixed the issue.
stevecutler Details Discussions Posts This discussion Message User 20 posts 04-20-2020 at 07:05pm Copy Comment URL Report Comment Edit Delete Futtermans like high impedance and were designed for 16 ohm and above speakers. These were very popular in early hi-fi. Will work OK but the low limit is 8 ohms. They are much more efficient the higher the impedance. Never heard of them taking out output tubes. A very novel tranformerless design.