Synthesis Roma 98DC Mono Valve Power Amplifier

Synthesis Roma 98DC is a high output mono valve amplifier, made by a leading valve audio manufacturer, combining the beautifully warm sound of valves with a modern Italian design.

The amplifier uses a pair of KT88 output valves in an ultra linear configuration. This results in excellent sonic performance as well as high power - at 80W the Roma 98DC can drive the most demanding of speakers and offers a clean and pure sound.

In house designed output transformer

Perhaps the most important part of any valve amplifier is the output transformer. This has to be able to handle the power as well as deliver a wide frequency response. Synthesis make their own output transformers using modern materials. The core is made of iron silicon and the copper used for the wire is much purer and has less resistance than many designs in the past.

Heavy build quality

The 98DC weighs in at 16kg, mostly due to the high-power transformers needed by valve equipment. This amplifier is for the audio purist, it has a balanced XLR input as well as standard RCA inputs. It needs about 500mv for full output. There is also an input gain setting.

Additionally, the front panel boast an analogue power output meter. This allows you to monitor and tweak your system as needed

How valves work

Valves are thermionic devices that emit electrons from a heated cathode. The cathode and other elements are mounted inside an evacuated glass envelope. The simplest type of valve is the diode. These are usually used for rectification, with two inside the same envelope. However modern amps tend to use solid state rectification.

The most common type of valve is the triode. These are used for amplification. For example, the ECC82 is a dual triode. Electrons emitted by the cathode are attracted to the positively charged anode. This can be at several hundred volts. Inbetween the cathode and anode is the grid. This is held slightly negative of the cathode, to prevent current flow. An audio signal on the grid will be amplified, creating a larger signal on the anode.

Why valve amplifiers?

Valve amplifiers have been around since the early 20th century. In fact, it was the only way to amplify a signal until transistors were invented in 1947. Early radio sets often used five or more valves. Valve radio and audio equipment was still made well into the 1960s. However, the power requirements and heat generation made them less popular.

However, valve amplifiers have always maintained a following amongst audiophiles, thanks to their smooth warm sound and the “coolness factor”. They look and sound amazing and Synthesis make a wide range of valve equipment including other valve amplifiers, valve CD player, valve phono stage and valve DAC.