Exposure X
Data[edit]
General
- Manufacturer: Exposure Electronics,
- Model: X - "integrated regulated amplifier"
- Years of manufacture: ca. 1987 - 1995
Type: Integrated amplifier
- Remote control: No
- Power consumption: idle approx. 10-15 W, mainly by the preamp supply, max. approx. 80 W
- Dimensions: 85 x 430 x 310 mm (HxWxD)
- Weight: approx. 9.0 kg
- Colour: Black
- Original price approx.: 2000 DM
Connections
- Number of inputs: 5, Chinch
- Phono, alternatively ex works as MM or MC, as supplementary board
- CD
- Tuner
- Video
- Tape
- Number of outputs: 2
- Loudspeaker, 4mm socket
- Tape-Out, Chinch
Technical Data
- Continuous power:
- 8 Ohm: approx. 35W
4 Ohm: approx. 35-40W Supply voltage
- power amplifier +-32V regulated with zener diode circuit of +-37V power supply voltage
Preamplifier +-18V, individually regulated with 1x LM317/337-ICs each for line and phono stage, derived from main power supply winding
- Attenuation factor: ?
- Input (sensitivity/impedance)
- Phono (MM): 47 kOhm, 470 pF, 3.0 mV
- Phono (MC): 470 Ohm, 6800 pF, 0.15 mV
- High level sources: 10 kOhm, 150 mV
- Tape output (level/impedance): 600 Ohm, 5V max. (passive)
- Frequency response: 0.5 Hz - approx. 35,000 Hz
- Tone control: not available
- Balance control: not available
- Loudness: not available
- Subsonic: yes, fixed in phono stage (15 Hz, 6 dB/octave)
- Mute: not available
- Direct/Line-Straight: not necessary
- Ripple distance (short-circuited): ? (rather moderate)
- Stereo channel separation: ?
- Signal to noise ratio: ? (rather moderate)
Special Equipment
- Holden and Fisher 160VA transformer 2x37V sec.
- Epoxy printed circuit board, double sided traces, hand soldered
- volume control ALPS RK27112 (blue)
- regulated output stage voltage via Exposure assembled power transistors, 1x for both channels
- Exposure assembled 10000µF main power supply capacitors
- use of higher quality Philips (BC) capacitors for all eletrolyt capacitors
- gold plated chinch sockets in the phono input
- floating ground in the preamplifier section
- very low quiescent current of the power amplifiers, very wide Class-B range, low idle power, nevertheless low distortion
- very high quality aluminium enclosure made of extruded profiles with very low construction tolerances
- Tape Monitor
Notes[edit]
About 2000-3000 units of this amplifier were produced, it is the first integrated amplifier from Exposure, designed by John Farlowe. The Exposure 10 is a typical English amplifier and has very conventional, discrete amplifier circuits, in his case with bipolar transistors. Special attention was paid to the load- or frequency response-independent power supply of the individual stages, moderately high negative feedback, a defined grounding and the use of as massless as possible, small components in the signal path (e.g. 10µF coupling capacitors). The sound can be described as very musical, in view of the low continuous power incredibly (!) powerful and dynamic, this more than consoles over the moderate signal-to-noise ratio, caused by the preamp voltage regulation. For operation, the manufacturer recommended in-house loudspeaker cables (similar or identical to Naim, Linn K20 etc...). This makes sense from a circuit point of view, better control of the LS chassis is achieved due to the low cable capacitance.
Transistors Used
- Phono, Line stage:
- ZTX214, ZTX384 high-noise type, similar/same BC214/BC384 design.
- Power supply:
- ZTX452,ZTX552, 100V;1,5A;hfe approx. 100, for drivers, replaceable by BC639/BC640 (less voltage resistant, as only 80V!).
EXP8N, EXP8P, for power amplifiers, similar to MJ15003/MJ15004 Power amplifier:
- BC414B hfe approx. 200 for current source differential input, high-noise type.
- BC414C hfe approx. 450 for differential input, high-noise type
- ZTX452,ZTX552, for voltage amplifier, driver, see above.
- EXP1N, EXP1P, for power amplifiers, similar in design to MJ15003/MJ15004
Other models of the same series:
- Exposure XV (own transformer winding, rectifier and capacitors for preamps).
- Exposure XX (identical in construction to Exposure XV, but without phono section)
Pictures[edit]
Inside view of an opened Exposue 10
Inside view of an opened Exposue 10