Audio Alchemy DDP-1Preamp/DAC/Headphone amp


From the website: Inside the machined aluminum chassis are four core components: an all-analog preamplifier, a 32-bit/216-kilohertz DSD-compatible digital-to-analog converter, dual digital signal processors and a headphone amp.

The digital section of the DDP-1 incorporates dual 32/216 PCM/DSD AKM DACs (one per channel) with seven digital inputs: USB, AES/EBU, two RCA coaxial, two Toslink optical and an I2S connection for use with the Audio Alchemy DMP-1 Digital Music Player and other sources that support the Alchemy I2S format, including legacy Audio Alchemy products and some from Cambridge Audio and other brands. XLR and RCA outputs are provided, as well as a headphone amp that delivers 1 watt into 32 ohms.

The DDP-1 employs sophisticated digital processing. You can select from four output filter profiles and you can also select the output resolution. A multistage phase-locked loop (PLL) circuit reduces jitter to the picosecond level. The preamp section employs a discrete FET driver and output stages.

The DDP-1 is equipped with an external AC power supply, and can be upgraded by replacing the stock power supply with the PS-5. The PS-5 is a balanced power supply with separate feeds for analog and digital/control circuits, separate positive and negative rails for analog circuits, well as large banks of storage capacitors for better filtering of AC ripple and improved dynamics. A USB connector on the back of the DDP-1 makes firmware updates easy.

Key Features
· Internal 32/216 PCM DAC with native DSD capability
· All-analog preamp stage
· 7 digital and 3 analog inputs
· XLR, RCA and 3.5mm headphone outputs
· Remote control
Frequency response
+/-0.05 dB, 20 Hz to 20 kHz
+/-0.1 dB, 10 Hz to 80 kHz
Nominal THD+N (1 volt)
<0.001% at 10 volts output from analog input
0.009% at 7 volts from XLR output, 3.5 volts from RCA output
Signal-to-noise ratio (1 kHz) 103 dB unweighted
Maximum digital input sampling rate/bit depth:
32-bit/216-kHz on PCM
2.82 MHz (DSD64) on DSD
Headphone amp output 1 watt at 32 Ω
Input impedance 50 kΩ
Output impedance 75 Ω
Digital inputs:
AES/EBU, 2 RCA coaxial, 2 Toslink optical, I2S, aux USB for firmware updates
Analog inputs stereo XLR, 2 stereo RCA
Outputs stereo XLR and RCA, 3.5mm headphone jack 3.5mm 12V DC trigger
Digital filter profiles:
Linear phase, fast roll-off
Linear phase, slow roll-off
Minimum phase, fast roll-off
Minimum phase, slow roll-off (apodizing)
3.0 x 10.5 x 11.6 in (hwd)
8 lb

Cambridge Azur 851E Preamp

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Cambridge Azur 851E Preamp

THD (unweighted)
< 0.00045% @ 1kHz < 0.00057% @ 20kHz
S/N (unweighted)
< 110dBr < 90dBu
Frequency response
10Hz – 100kHz ± 0.1dB
Crosstalk @1kHz
> 110dB
Maximum output
8V RMS unbalanced 8V + 8V rms balanced
Output impedance
100 Ohms (Unbalanced or Balanced)
Subwoofer output
Flat or 200Hz 2nd Order Butterworth LPF
Max power consumption
Bass & treble controls
Shelving type
Max bass boost/cut
± 10 dB at 10 Hz
Max treble boost/cut
± 7.5 dB at 20 kHz
Standby power consumption
Black and silver
Dimensions (HxWxD)
115 x 430 x 385mm (4.5 x 16.9 x 15.2’’)
8.1kg (17.9lbs)

Wyred 4 Sound mPRE preamp

The pre-amplifier is often the unsung hero of the music lover’s audio system. Its job is to provide attenuation while remaining as transparent as possible. The existence of noise, distortion, coloration or other aural ugliness prevents your investment from meeting its full potential, so make sure you select with your needs and the needs of your amp in mind.

wyred4sound_mpre mpre_amp_back

Here’s an offering from Wyred 4 Sound, the mPRE. For more info:
It doesn’t possess a readout of any type, but instead has marked buttons for functions. It does have a remote though.

mPRE Features:
Fully balanced, Dual mono design
Next generation input and output buffers
Built-in ESS DAC which supports 24 bit 192 kHz on all digital inputs
Galvanically isolated, asynchronous USB input which supports Windows machines, is driverless for Mac, and supports Linux
Headphone amplifier
Remote Control
12V DC trigger input and output
Efficient (no heat)
Fully balanced input to output
Discrete input and output buffers
Unbalanced to balanced conversion (when RCA input selected and XLR outputs are being used)
Robust construction
Machined and anodized aluminum front panel, top, and sides
100kΩ input impedance
1 set of balanced (XLR) inputs
1 set of balanced (XLR) outputs
2 sets of unbalanced (RCA) inputs (one is selectable as HT bypass)
2 sets of unbalanced (RCA) outputs (one is selectable as a fixed 2.0V output)
Home Theater Bypass
External selectable voltage mains 115/230VAC
High grade Schottky Bridges
Compact size (8″W x 3.5″H x 8″D)
8 lbs.
Covered by a 5 YEAR WARRANTY