Single Ended headphone amplifier with 5842 triode (2)
First a description of the components used. All these components are bought at flea-markets and/or by trading except from the JJ-capacitors which can be bought at Angela.
I've used a powertransformer with only one^6V3 filament winding. Both the rectifier and the 5842's are fed from this one. This is possible because the rectifier used here, the EZ80, is indirectly heated. This means that filament is separate from the kathode thus no B+ is seen on the filament. If you decide to use a directly heated rectifier, it is better to seek a transformer with separate filament windings.
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The parts. Millerioux powertransformer and supplychoke, GE paper-in-oil and JJ capacitors. Small output transformers with 32ohm tap, 5842 and EZ80 and some loose parts. |
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The Amperex 5842. This small 9-pins tube has a mu of 43, a transconductance of 25mA/V, low plate resistance of 1K8 at reasonable current. Perfect tube for use in this concept! |
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Philips EZ80. An indirectly heated rectifier providing in a slow turn on. This means that the B+ is supplied at the 5842 after a 5 seconds delay... |
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The output transformers. They come from an old SE amplifier, brand unknown... They're relatively small, with laminated iron and a small air-gap. When used at 20mA, like here, they must feel comfortable and will not saturate. |
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Nice potted French made transformer and choke. These were meant for 220V mains i.s.o. the 230V now-a-days.. No problem except the 6V3 has become 6V8... |
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The ripple-killers: Paper-in-oils from GE and electrolytics from JJ. These light weight elco's are referred to as "good" by Angela, so I thought to give them a try... |
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