Arcturus Audio Deco & 89


Arcturus Audio Deco preamp uses 27 or 56 triodes and also uses an 84 rectifier tube. All of the iron is courtesy of ISO. 

It provides either balanced or single-ended inputs and it’s available with various types of lacquered hardwoods based on price and availability. There are three inputs. The pre uses the widely respected ISO NP-126 line transformers. There are no circuit boards in either of these products.

Arcturus Audio 89 amplifier is a push-pull transformer-coupled design using Lundahl choke, interstage and output transformers. The power transformer is from Hashimoto.

The amplifier runs in class A and provides 15 watts per channel with very low distortion. The amp is dead quiet at idle. The 89 tubes were chosen for a few reasons. 

Firstly, it follows the legacy of 46, 59 in what ultimately became a 6.3v tube. The 46 was a directly heated 2.5-volt tube. 

The 59 then followed as an indirectly heated 2.5 tube and it was the 89 which is a 6.3v indirectly heated triple grid tube with a “grid” cap. 

Arcturus Audio runs these tubes in “triode”. The performance of this tube is excellent, and along with the other tubes it turned out to be an easy and inexpensive amplifier to re-tube. Arcturus Audio recommends this power amplifier with medium to high efficient speakers. 

Horn speakers are a dream and work exceptionally well with the amp. George from Arcturus Audio is using the new Klipsch LaScala’s on them at home and there’s plenty of surplus power for them. The amplifier has adjustable bias so you can dial the tubes in easily. Matching tubes is not necessary with the biasing arrangement although it wouldn’t hurt either. 

The amp uses a damper diode to bring up the voltage slowly. This ensures that the amp energizes properly. Reliability is a hallmark for our products and everything that we design spends a full year undergoing listening tests as we monitor the parts for reliability.