Stereo Vacuum Tube Amplifiers

Hi-Fi Valve Amplifier

         The photograph below shows a 'one tuber' - a single ended, stereo, power amplifier utilizing just one 'spud' per channel.  Designed exclusively by ourselves - a small-scale, Buckinghamshire based audio engineering crew - this model, which is hand crafted entirely within the U. K. & produced to order, is of the type in which just three components lie in series with the audio signal path to attain near optimum musical reproduction.  The output transformers * (also designed in-house) are of premium grade, British made, with windings elegantly interleaved in several sections to secure adequate magnetic coupling.  The amplifier can deliver an average power of 5W ** into a pair of 8 ohm loudspeakers & has an input sensitivity of 1Vrms. *** The design is such that the second harmonic component is promoted whilst higher order harmonics are attenuated; the overall characteristic sound reproduced has been likened to that which was ubiquitous during the era of vintage wireless.

        Note that the product described is a chassis assembly & as such will require an appropriate enclosure - see below for further details.  We have introduced an attractive, smokey grey tinted, toughened glass plinth to complement the amplifier (see 'Photo Gallery'...11 of 16).  This plinth is offered at no extra charge if requested at the time an amplifier is purchased through this website.

        We offer the options of anodized black chassis, & 4 ohm output impedances.  We also produce a 'Tetrode Tube Amp' version.

        The amplifier can be driven directly by a laptop computer, a disc player with integral volume adjustment, a solid-state micro jukebox, a radio or the audio outputs of a television set.  For vinyl record playback, a suitable pre-amplifier comprising RIAA equalization is required.  A high quality lead & connectors should be used to couple any chosen source to the amplifier.

        The electronic component parts of the assembly are connected by method of point-to-point & its stylish, 'in-line' design is such that it could sit neatly on a bookshelf.  Solid carbon composition resistors are used with good reason.  Please visit the 'Photo Gallery' to view some examples of the product described.

        Liquid insulating tape is applied to the transformer terminals prior to dispatch (see 'Photo Gallery'...4 of 16).

        Power Bandwidth (DIN 45-500):  2.5Wav + 2.5Wav over 30Hz to 16KHz into 8 ohm loads with 3Vrms input signals. 

        Defined by the output transformers, the upper cut-off frequency quoted is adequate for low power, hi-fidelity amplifiers & allows for betterment in other areas of output transformer design.  We find no perceptible furtherance in having power bandwidths extending beyond the audible range.  Use of fine quality materials & good design techniques are the key to achieving best results.

        Tubes:  EL84 Output Pentodes (not included).

        Zin:  > 150000 ohms.

        Feedback:  0dB  (decreasing distortion complexity).

        Tube Biasing Method:  Cathode. 

        Output Transformer Lp 24H @ 30Hz. 

        D. C. Fuse250mA, anti-surge.

        Power Consumption:  55 Watts.

        The power supply RC filter reduces ripple voltage to 1/30 of that across the reservoir capacitor.


                            NOTE THE FOLLOWING: HIGH VOLTAGE WARNING!

        The entire assembly is constructed on an aluminium chassis & delivered thus (as shown) within 21 days of purchase.  Under no circumstances should the unit be operated in this rudimentary form owing to exposed live parts measuring in excess of 300 Volts.  The product has been designed specifically to be set in a personalized enclosure as desired by the individual purchaser - so making the overall finished article unique in appearance & safe to operate.  We do not provide this service.  A qualified technician must undertake to complete the installation prior to operation of the amplifier in order to ensure users' safety, albeit we have no objection in giving some related guidance.  Adequate venting is important.

        Unit dimensions:  W 14 3/4" (375mm), D 4" (102mm),  H 4 3/4" (121mm).

        Input socket:  5-Pin/180 DIN (preferred over RCA for earthing considerations).

        Loudspeaker sockets:  2-Pin DIN.

        The amplifiers are sold without vacuum tubes (type EL84 & type 6V6).  We leave brand selection & other tube preferences to each individual purchaser, since they all have their personal favourites; however note that 'one tubers' are highly sensitive to vacuum tube performance - we have experienced vast, all 'round improvement in sound quality when utilizing premium grade n. o. s. tubes.  

        A one year warranty is given, covering any production defects, & every unit is tested prior to being packed & dispatched.  Postage is recorded/tracked.   As a consumer you are entitled to a full refund should the amplifier fail independently within thirty days of receipt.  We sell this product almost exclusively to U. K. residents - we do not export other than to a limited number of selected destinations.

        Our objective is to contribute the principal constituent of what will become a uniquely personalized, fine sounding, high quality, audio component.

        If not completely satisfied, a customer may return his amplifier within fourteen days of receipt for a full refund in accordance with 'distance selling regulations'.  The assembly must arrive back in pristine condition; & please note, we do not refund the return carriage. 

        To purchase one of our vacuum tube amplifier assemblies, please select 'Buy Now - Tube Amp.'.  The price of a single assembly is £590, which includes packing & delivery charges within the United Kingdom.    Alternatively we will accept a £100 non-refundable deposit, the balance of £490 to be paid on completion of the order.  We forward photographs of the finished article for approval prior to full settlement.  When making your purchase, please specify which model has been selected, ie. EL84 or 6V6.

        Do 'Contact' us with any questions you may have. 

    *  Select 'Output Transformers' for further details.

   **  Select 'Audio Power Output' for more information.

 ***  For (in our opinion) best tonal quality (as a result of additional, hysteresis generated harmonics) yielding 350mW.



                                                                                                                       Grippeaz-UK / Ilissus Audio