Twinings/Jensen Tea Box Preamp

Jensen copper, paper and oil capacitors from Denmark, large and all as they are, fill the small timber Twinings Tea box preamplifier. Two preamp component-2-component modules are joined to the input and output gold RCA connections via pure silver wire. The wire is prepared by covering pure silver wire with heat shrink. French Solen capacitors form part of the feed back network. Both capacitors have pure silver leads. Expensive components to produce a very natural sounding, high detail valve preamplifier.

The timber enclosure is lined with bituminous Al foil. Alps attenuator is topped off with a heavy 4oz solid brass knob. An external valve rectified power supply delivers a very quiet 260 volts to the Tea Box components. Golden Dragon 12AX7 valves are installed but any similar valve can take its place. A truly unique preamplifier and part of the retro-thermionic range.

Twinings Tea Box Preamp PS and 5Y3

Fortunately I have been able to acquire a number of Australian made rectifier tubes. This one being a 5Y3. When purchased today a much difererent looking tube. The 5Y3 and 5U4G(s) I now own are all in excellent working conditon. Most looking at 50 years of age with many years of service behind them.

If any single component is going to make an impact on the overall sound eminating from your speakers, it is your preamp. Many hard core audiophiles "roll" (change) thier rectifier valves to change the tonal balance and voicing of their system. This may engender a more natural and sonic balance.

Well aged Australian made valves and exceptional sounding Danish capacitors, in a light timber box, with a remote valve rectified power supply. Not only good sounding but who else has one. retro-thermionic.

Twinings Tea Box Preamp rear view

As with the Merlot power amplifier the Tea Box preamplifier can have switchable inputs. The power from the remote power supply is delivered by a fix cord which terminals on a metal XLR plug. The power supply has a XLR socket to connect the two sections: preamplifier and remote power supply.

Twinings Tea Box Preamp

Twinings Tea Box preamps are genuinely made from Twinings Tea boxes. Four fine and lightly scented teas come with the well presented box. Though the box timber is light weight and velvet lined, the adding of bituminous Al foil to the inside increases box weight and provides a RFI and EMI shielding.

No screws scar the the timber box top by the use of internal adhesive "stand offs" to mount the component boards. The two circuit boards are component-2-component wired. In a preamplifier, keeping the signal path as short as possible is essential. Only clean DC power enters the preamplifier section. With a remote power supply and valve rectification a very quite and detailed sound reproduction can be ensured. Not to mention the addition of a very cool looking timber preamplifier.

Fostex FE206E back loaded horn

Retro-thermionic not only produces valve amplifiers and preamplifiers but also some finished speakers. Currently retro-thermionic is having constructed the back loaded enclosures to accommodate the Fostex FE206E drivers. After evaluating the the Fostex driver in a simpler two chamber enclosure, retro-thermionic, decided to have the more complex labyrinth style enclosures made. A CNC cutting machine was employed to make the most efficient cuts from the expensive and heavy 21mm multiply timber. Some panels are double layers of 21mm multiply. Panel bracing is extensively carried-out to control box colouration.

Sandbags can be layed in the bottom of the horn to tailor the bass to the listening room. Sandbagging can also be performed in the driver chamber to alter the level of other low frequencies. With efficiencies of the drivers reaching 96db the retro-thermionic amplifiers can produce high sound levels easily.

Fostex FE206E back loaded horn

At this point the enclosures have not been stained. It is easy to see the excessive bracing which goes into these speakers. A large amount of internal dampening is used and the cabinets are held together with stainless steel screws, doweling and glue. Large clamps were used when two panels were attached to ensure a rigid and tight fit of all panels. These speakers will be stained a dark teak.

Sound stage is pin-point. Stage depth is is very evident. Bass weight can be tuned by placing the speakers closure or further from the wall. Placement is critical.