Let's build a Treble Booster

Step by step guide on how to build your own germanium treble booster.

Let's build a Germanium Treble Booster

Step 1: Choose a suitable germanium transistor

The original Dallas Rangemaster Treble Boosters used either OC44 or OC71 germanium transistors. It's good to use these transistor models if they are available. However, the characteristics of the transistor are more important than the actual model number. Information is available on the internet about suitable replacement options. One of the websites I use to determine replace ment options is this:https://www.radiomuseum.org/tubes/tube_oc44.html​

Before buying a transistor always look at the data sheet. There are three important parameters when choosing a transistor for a treble booster: 

- the general voltage that the transistor operates at. This is marked UCE or UCB and in the case of the OC44 is 15V. Somewhere up to 32V should be okay. Don't use power transistors!

- the current gain or amplification factor known as HFE or Beta. For the treble booster circuit an HFE over 55 is great. However, keep in mind that going with a higher HFE means it will amplify noise more as well, so it can be noisier. This is not the only factor determining noise but it is one of the factors.

- the current leakage marked as Ic. This should be as low as possible for this circuit. In general anything over 0.3mA is useless. For a treble booster stay under 0.1mA.

For this build a Tungsram OC1044 is used that has an HFE of 92 and virtually no current leakage as show below.