Merlot - Diode Rectification Module

As with all retro-thermionic amplifier sections each part is modularised but no module contains any wire other than the component wire. The Diode Rectification Module is a full wave rectifier employing the centre tap of the large power transformer. A large 10H choke is also used as part of the rectifying and power smoothing network. When a large choke is used to reduce hum and noise in the amplifier smaller filtering capacitors can be used. Smaller power capacitors produce a better detailed mid-range this is one of the better traits of a SE UL design.

Wiring between modules is of the free style method. Copper hook-up wire runs the shortest and safest path to the next module. Internal wiring is loosely banded together for safety and to ensure minimum cross talk. By using the shortest wiring path, total signal path length is kept to a minimum.

I can provide these rectifier modules, or any other of the retro-thermionic modules, for the individual who would like to assemble their own valve amp. E-mail me for a quote.

Twinings Tea Box Preamp with Remote PS

The Twinings Tea Box preamp is very much retro-thermionic. Always the mix of timber, metal and valves presents, not only a strong retro feel and unique images but very much a desire to get back to listening to good music the way it was meant to be. Controlled resonance qualities in natural materials can add a certain earthiness or natural tone often amiss in modern, commercial audio equipment. One of retro-thermionic's goals is to construct audio components in a novel and organic way, most often using timber, Bakelite or metal in audio component construction.

The inexpensive Twinings Tea Box provides a natural looking enclosure in which to construct a preamplifier using high-end and carefully chosen components. To further add to the lofty concept of the build a remote, valve rectified, power supply was added. In the image you can see not only was valve rectification and enclosed choke filtering used but a rare Australian made 5Y3 rectifier valve was also employed.

The chassis, on which the remote power supply is constructed, is die-cast Al. Hammond enclosed power transformer and 10H choke sits atop. Other electronics are housed beneath the solid chassis, which, like the preamp itself, reside on solid brass cones. Connection between preamp and associated power supply is via a high voltaqge short cord and XLR plug.

The Jensen copper, paper and oil capacitors and associated components (including the enclosures) make this a unique sounding andlooking preamplifier. Either coupled with a solid state power amplifier or a valve power amplifier this original almost conceptional preamplifier offers an exceptionally unique insight into electronics and audio reproduction equipment not seen in commercial units. And for the engineers amounsgt us the distortion figures fall below 0.05%. The musical rating figures: 99+. Listen and be convinced.

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.