{"id":233,"date":"2018-01-11T14:25:18","date_gmt":"2018-01-11T14:25:18","guid":{"rendered":"http:\/\/www.wiredwood.co.uk\/wordpress\/?p=233"},"modified":"2018-01-17T16:53:11","modified_gmt":"2018-01-17T16:53:11","slug":"valve-headphone-amplifier","status":"publish","type":"post","link":"http:\/\/www.wiredwood.co.uk\/wordpress\/valve-headphone-amplifier\/","title":{"rendered":"Valve Headphone Amplifier"},"content":{"rendered":"

Vinyl after dark denied because m<\/span>y Mission Cyrus amplifier has no headphone output. I need something to connect to the tape out RCA sockets. I considered DIY, but it would have cost as much as a bought one to make anything that looked half decent. Research showed that a valve amp could be had for the same price as a solid state one. So, for about \u00a330, I got me this.<\/p>\n

\"\"
Nobsound NS-08E Headphone Amplifier<\/figcaption><\/figure>\n

The valves seem to do something, because there is a delay at start up before you hear anything, presumably while the valves heat up. Also, when you tap them you can hear it. They are microphonic. Not so great.<\/p>\n

\"\"I took the valves out, powered it up and had a poke about with a volt meter. Found +12v, -12v and +6v. Obviously some sort of voltage multiplying going on inside the box. In here we have 24V available to the designer for the valve stage. Also, a nice split power supply for the op amps.<\/p>\n

A quick google revealed plenty of real life examples of using standard valves in circuits powered by just 12V. I found guitar effects pedals and Hi Fi pre-amplifiers. So Clearly it is possible to do this.<\/p>\n

Slow start up, dead without valves and microphonic behaviour. I could waste hours of my life reverse engineering the thing and working out exactly how it works. I won\u2019t though. I\u2019ve seen enough to convince me the valves here actually do the business. Oh, and somebody else did it and posted their experience on YouTube.<\/p>\n

Something which kept cropping up in my research was how poor the supplied valves are in these cheap amps. I managed to source some \u201cNew old stock\u201d British made Mullard E180F valves. A massive improvement to the already good sound was evident straight away and the microphonic behaviour was gone.<\/p>\n

\"\"
Tech team replace valves, while supervisor looks on<\/figcaption><\/figure>\n

Fed from the Goldring E3 cartridge on the Dual 505 via the Cyrus One MM pre-amp and feeding a pair of AKG Y50 cans, it sounds pretty good and looks the part. All in all, a good result.<\/p>\n","protected":false},"excerpt":{"rendered":"

Vinyl after dark denied because my Mission Cyrus amplifier has no headphone output. I need something to connect to the tape out RCA sockets. I considered DIY, but it would have cost as much as a bought one to make anything that looked half decent. Research showed that a valve amp could be had for … <\/p>\n

Continue reading “Valve Headphone Amplifier”<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14,13,9],"tags":[],"class_list":["post-233","post","type-post","status-publish","format-standard","hentry","category-amplifier","category-featured","category-valves"],"_links":{"self":[{"href":"http:\/\/www.wiredwood.co.uk\/wordpress\/wp-json\/wp\/v2\/posts\/233","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.wiredwood.co.uk\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.wiredwood.co.uk\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.wiredwood.co.uk\/wordpress\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/www.wiredwood.co.uk\/wordpress\/wp-json\/wp\/v2\/comments?post=233"}],"version-history":[{"count":5,"href":"http:\/\/www.wiredwood.co.uk\/wordpress\/wp-json\/wp\/v2\/posts\/233\/revisions"}],"predecessor-version":[{"id":241,"href":"http:\/\/www.wiredwood.co.uk\/wordpress\/wp-json\/wp\/v2\/posts\/233\/revisions\/241"}],"wp:attachment":[{"href":"http:\/\/www.wiredwood.co.uk\/wordpress\/wp-json\/wp\/v2\/media?parent=233"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.wiredwood.co.uk\/wordpress\/wp-json\/wp\/v2\/categories?post=233"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.wiredwood.co.uk\/wordpress\/wp-json\/wp\/v2\/tags?post=233"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}