About the characteristic of case that used 2A3 for A-08S

@Although A-08S has obtained the popularity after the launching, it is attached to the characteristic of case that used 2A3 for the A-08S amplifier from the customer and there be a question and ask to cause to report because the good result was obtained, as we checked the characteristic and tone quality in our company.

We are able to replace 2A3 and 45 physically because the heater voltage and pin arrangement are same. However, it assumed to come off from the optimal action condition of 2A3, in the case that 2A3 is driven with 45 action conditions because the plate impedance and optimal current value differ. However, it will be able to say that it is able to use sufficient it if those characteristics are fairly good.

Be able to promote as our company because the characteristic, tone quality over the expectation were obtained, although it is the result with judged. Those result are as follows.

A-08S output tube 45 4 ohms load distortion rate: Biggest output 2.25W at the time of 10%.

Biggest output 1.82W distortion rate at the time of 5%.

Output tube 45 8 ohms load distortion rate : Biggest output 2.76W at the time of 10%.

Biggest output 2.0W distortion rate at the time of 5%.


output tube 45 16 ohms load distortion rate: Biggest output 1.82W at the time of 10%.

Biggest output 0.90W distortion rate at the time of 5%.

Action situation of output tube 45: the substance plate voltage: 276V, 34mA, load impedance 5k ohms


A-08S output tube 2A3 4 ohms load distortion rate: Biggest output 2.72W at the time of 10%.

Biggest output 2.06W distortion rate at the time of 5%.


Output tube 2A3 8 ohms load distortion rate: Biggest output 3.92W at the time of 10%.

Biggest output 3.13W distortion rate at the time of 5%.

Output tube 2A3 16 ohms load distortion rate: Biggest output 2.48W at the time of 10%.

Biggest output 1.10W distortion rate at the time of 5%.

Action situation of output tube 2A3: the substance plate voltage: 266V, 37mA, load impedance 5k ohms

Although it is a little softer sound trend in comparison with RCA45, in the case that RCA2A3 is used the scale impression of the sound becomes big and be strong, could hear with the sound that has force.

We promote that you try once in the case that you use A-08S.