Aurora Audio 5120 Amplifier Build Overview

This isn’t a full build log like the Jupiter one but more of on overview of the Aurora Audio 5120 build process. All boards used in this build are available in the store.

First up this amp is only single channel by design and puts out roughly 20w from a push pull pair of 6V6. But the board is flexible enough to build this from 2w up to 100w if desired. Schematics included are for 20w 6V6 and 50w EL34/6L6GC.

At its core this amp is the preamp paired with my push pull power amp minus the parallel input stage as it isn’t necessary in this format. It retains the Bite & Feel switching along with the headroom control from the power amp.

I designed this board around the modulus amps SB50 smallbox chassis and the only adjustments needed are a few holes for toggles and the valve socket mounting if you don’t want to do the whole twisted pair thing.

First thing I do in any amp build is wire up the heaters so it’s done and out of the way. I opted to add the option to switch between 12ax7 & 6n2p valves using one of these boards to avoid the fiddly switch wiring.

Preamp filament wiring complete with 12ax7/6n2p switch

I then check and drill the board supports and do a test fitting.

Then after this it’s time to get the transformers mounted up. For this specific build I had to drill the chassis for the custom Musical Power Supplies transformer set. But for 50w builds you can just use the 50w set that Modulus amps sells that the chassis is pre drilled for.

Transformer test fitting

Also for this project I made some small input boards to save on the fiddly wiring as there are a few parts that need wiring to the input jack. These come with the boards for both the preamp and full amp.

5120 Input PCB

Then back in to start wiring things up. Seen as I didn’t take many photos of this build I will break down the order step by step.

  • Wire up Power & Output transformers
  • Install the board and wire up preamp valves + PI
  • Add the input board which goes to V1
Wiring mostly completed

Then after this its just onto wiring the pots. As with all of my boards I have added pads to make the wiring easier for people that are less experienced. You can ignore these and wire as normal if desired but it helps some. It also makes it easier to remove/change pots as you can just remove the one pot.

Wiring completed.

This is all for now as I am still to build the head shell but here is a photo of the faceplates that I will install once I have built the head shell and an obligatory audio clip.

5120 demo no boost.
Aurora Audio 5120 faceplates. The sharp eyed may notice I added a hole for an additional toggle to switch between variations of the 5150 inspired circuit.

Well it turns out I never ended up building a headshell and just ordered one from Modulus Amplification. Here is the finished amp.

Aurora Audio Complete amp photo
Aurora Audio 5120.

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