Synthesis Roma 117DC Valve Pre Amplifier

Synthesis Roma 117DC valve pre amplifier is beautifully designed, offering great tonal balance and is well matched to the Roma mono valve amplifiers. The design is simple and elegant with great musicality. A remote control is included.

With over three decades of experience making high-end valve equipment, Synthesis know what they are doing. A process of careful design, choosing the best components and meticulous build quality has resulted in an unrivalled and well featured pre amp.

Two stage valve amplification

The Roma 117DC uses two pairs of ECC88 valves. There are balanced and unbalanced inputs, that each have their own input valve. This ensures noise is kept to a minimum. The output to the power amp is transformer coupled to best match the impedance requirements of the connecting cables. As a result the frequency response is very wide, stretching from 5Hz to 40Khz at -3dB. The valves are specially chosen to reduce microphonics and only metal film resistors are used. Furthermore, all the capacitors in the audio path are polypropylene, for a long life.

High end power supply

The heater power supply is DC rather than the usual 6.3v AC. This ensures that no hum or noise is injected into the valves. The rest of the power supply rails are also well-regulated with better than 0.1% deviation. There is an oversized transformer that is kept well away from the signal circuits. Additionally, the PCB design keeps signal paths as short as possible.

Excellent connectivity

There are also three RCA outputs including a tape loop. The main on/off switch is on the back as is the IEC mains connector. On the front is the standby switch and source selectors. There is also a built-in headphone amplifier with a socket on the front. 
The supplied remote control makes usability simple. Volume control and input selection is easy and there are four RCA inputs as well as a balanced input and output.

Why valves?

Valves have been around since the 1900s and were once the only way of amplifying a signal. They once dominated the audio market until the early 1970s, when transistor amplifiers took over. However, valves have always maintained a following with audiophiles. Modern valves are still made in China and Russia. Specialist companies such as syntheses focus on no-compromise valve equipment, in particular. The main reason for their popularity is their “warm” sound. There is also the “coolness factor”, they look amazing.

Valve advantages

Unlike transistors valves are inherently linear in nature. This means that intermodulation distortion caused by harmonics is reduced. Harmonics are created whenever an amplifier is non-linear. Valves have a cathode that emits electrons, and they always pass a small current. This makes them class A. The current is generated by a positively charged anode. This is usually held at several hundred volts. In between is a grid. The grid regulates the current and as a result, the valve provides amplification.