Cait’s Vintage Radio conversion – Part 2 – inside the Pye R31

The inside of case with valve chassis removed….

The fabric on the fascia was fully glue’d and no way to remove it. The brass-like trim wil be kept and refitted to the new fascia panel.

Using the old panel (5-6mm thick) as a template allowed me to cut a new panel from 9mm plywood. The oval loudspeaker will be removed and replaced by 2 x 3″ Faital Pro 3FE25 20W at 8Ω impedance.


New internal hardware


The new fascia cut from 9mm plywood…

9mm plywood fascia

The plywood baseplate – required for mounting any electrics etc to….

plywood baseplate


The speakers mounting holes, marked for the Faital Pro’s….

speakers mounting holes

The speaker holes cut with my Bosch 70mm hole cutter. T-nuts (M5x8mm) are used to mount the speakers to the fascia.

To fit the T-Nuts, it is better if they sit flush with the front panel when hammered-in. Start by drilling through a 1mm pilot hole, then on the ‘front‘ drill a 10mm recess, 1mm deep  with a 10mm Forstner bit. Finish by drilling through with a 5mm metal bit. Slightly widen with a round wood file before fitting an hammering home.

speaker holes
Faital Pro speaker
speaker fitted


The Baseplate

The plywood baseplate – required for mounting any electrics etc to….

plywood baseplate


How the fascia and baseplate sit inside the case…

fascia & baseplate inside the case













Cait’s Vintage Radio Conversion – Part 1 – The Concept

A Vintage Radio conversion for Cait’s birthday. Gail bought the case, I am buying the conversion bits and doing the labour.

The radio puchased was a PYE R31 Caprice valve radio, in turquoise. Looks like it’s hand-painted but quite nice and should fit-in with Caits cottage look.


A bit History….

Known as ‘Caprice’, the Pye Model R31 is a 5-valve AM/FM receiver in a Bakelite case that operates on AC/DC 200-250V, with MW/LW & VHF wavebands. The Caprice was made probably late 50’s to early 60’s.  A ‘1476’ Trader Publishing Co Ltd Service Sheet dated 1960 references differences between this version and earlier versions, thus giving an approx. date of manufacture.




The new amplifier – with Bluetooth…

I had previously bought a cheap all-singing, all-dancing Bluetooth Amplifier of Banggood (Mono Digital Amplifier Board 220V Car Bluetooth HiFi Bass AMP) for a sum of £8.28. This amp has 240v mains input (via a fig-8 connector), USB, SD card I/P, Aux I/P, DC 12-24V I/P, volume/treble/bass controls and small I.R. remote control. The stated impedance is 4Ω.


The Spec from Banggood…


Play MP3 music from TF card, U disk, bluetooth.
Remote control: Full function, with number key it can directly control.
Self-equipped with switch.
Fit for all vehicle.


Voltage: 220 V
D type amplifier
Output power: 30W
Maximum power: 50W
Impedance: 4(Ω)
Loudspeaker unit: 133(mm)
Sensitivity: 200 hv
Frequency response range: 20-20000

Package includes:

1 x Car bluetooth amplifier
1 x Remote control
1 x Power line
2 x Connecting line

The amp did not come with any docs and there is nothing available on the web, although the amp comes in a few flavours – Stereo, Woofer O/P, mine is the ‘Mono’ version.  Although it was stated to be Mono, it has two O/P’s on the rear panel. After testing for stereo, woofeer etc, it is indeed a Mono amp, but with two mono O/P’s. The problem is that the O/P’s MAY be parelled-up causing any connected speaker Impedance to be halved if two speakers are connected. If using two speakers, it may be better to use 2 x 8Ω giving 4Ω if they are parralled, else the 8Ω Impedance on each channel would be less of a load on the amplifier/s. Testing with the DMM tells me they are in parallel!

I did find a Youtube video on the BASS/(woofer) version where the author did a good tear-down showing the pcb’s etc. He did state that there was no real isolation gap between the Live AC and transform DC voltage parts, something that is a bit worrying in the event of a fault. It could though be powered from 12-24V DC, albeit the On/Off switch will then not work as in my own strip-down I did measure 240V across the ‘open’ switch.

I wil include pcb images of the Amp taking from my mobile in the next post.