Dual mono class D power amplifier based on two PURIFI 1ET7040SA. Each module 1ET7040SA is supplied by one Hypex SMPS1200A400. The front-end board is the EV produced by Purifi, based on dual OPA1612 opamps. It is possible to bypass the pre-gain stage to have an even more neutral and transparent sound.
Compared to the 1ET400A module, the new Purifi 1ET7040SA achieves more power and dynamic and it is more musical and less tiring. The amplifier, like the Hypex NC1200, has a great authority in driving the most hungry speakers.
Purifi 1ET7040SA: preview of the new high-end class D amplifier
review by Franco Tassinari
NEUTRAL AND CLEAR POWER AMPLIFIER
PRE-GAIN STAGE SETTING
The pre-gain stage based on dual OPA1612 can be bypassed using special jumpers . When the pre-gain stage is bypassed, both the amplifier gain and the input impedance are reduced.
ACTIVE PRE-GAIN: total gain = 27dB, differential input impedance = 10.2kohm
PRE-GAIN DISABLED: total gain = 13dB, differential input impedance = 4.4kohm
RCB OPTION . It is possible to add, for each channel, the RCB (Rouge Connection Board) which allows to have double XLR and RCA inputs. It is a passive module made with quality components.
POWER SUPPLIES: 2 X HYPEX SMPS1200A400
The Purifi 1ET7040SA amplifier module is capable of delivering the maximum output power if it is supplied with +/-70VDC. The power supplies used in the STUDIO N8 are the HYPEX SMPS1200A400 whose output voltage, supplied to the modules amplifiers, is in a range from 49VDC to 72VDC, proportional to the mains line voltage (Min@180Vac, Typical@230Vac, Max@264Vac). The graph to the side shows the power supplied by the amplifier (output power 1% THD) as the supply voltage variation. Normally, with a 230VAC domestic network, you can have from the Hypex SMPS an output voltage of +/- 63VDC with an output power from the amplifier around 2x750W(2Ω), 2x400W(4Ω), 2x200(8WΩ).
2 x Purifi 1ET7040SA
Output Power: 2x950W(2Ω), 2x500W(4Ω), 2x250(8WΩ)*
Output Current (each channel): ~40A
THD+N: <0.00035% @ 200W, 4Ω, 1kHz
Dynamic Range: ~129 dB(A)
Output Noise: ~14µV(A)
Gain: 27dB (buffered))
Differential Input Impedance: 10.2 kohm (buffered))
Output Impedance: <13µΩ @ 1kHz
Efficiency: 94% @ 500W, 4Ω, 1kHz
Idle losses (output stage): 2.8 W
Inputs: balanced (+unbalanced with RCB option)
Mains: 190-250Vac (95-130Vac on request)
Casing: black metal with aluminium front and rear panel (2U)
Measurements: 435x300x80mm (435x400x80mm on request)
* The AC mains line voltage affects these general performance data