Introducing a pair of BBC Loudspeaker Amplifiers in for service/refurbishment. They were originally manufactured by a company called Sound Sales back in circa 1954. There is evidence of this as an original smoothing capacitor has the date of 1954.
They are in a terrible state of disrepair. Poorly maintained and even the rectifier valves have been replaced with silicon diodes. This will be rectified (pun intended) and returned to the original working condition.
A time consuming job that is very rewarding to see an otherwise piece of junk fully working again.
I will update this page as I get on with the work. I have other repairs to do as well, so fitting this in, as and when.
They are in a terrible state of disrepair. Poorly maintained and even the rectifier valves have been replaced with silicon diodes. This will be rectified (pun intended) and returned to the original working condition.
A time consuming job that is very rewarding to see an otherwise piece of junk fully working again.
I will update this page as I get on with the work. I have other repairs to do as well, so fitting this in, as and when.
The mains input sockets will be updated to comply with BS7671 making it safe to use in a domestic environment. They each have an eyelet board that the components are mounted on but as the boards have been repaired with epoxy resin in the past, I will make new boards and fit modern components for reliability. The valve line up is as follows; Rectifier CV378, Output CV1075 x 2, Phase splitter CV455 and pre amplifier CV2135. There is at present a phono socket held onto the side of the chassis with one screw, that will be replaced with a Neutrik chassis mounted phono socket. Here are a few photos as I progress.
What was the last "techie" thinking!
Seen better days. Let's take it all out and start again.
Two amplifiers like chalk and cheese.
To the drawing board to produce a drawing to work from and then mark out the Paxolin for drilling.
Eyelets in and components being fitted.
Old board has epoxy resin holding the rear portion together so a new board and new components is in order.
New Paxolin Boards made and components fitted.
This is a very time consuming job when done properly. The exterior will be left as it is now with new components internally. The reason there appears to be more components on the board I manufactured is because on the dirty and damaged side, there are a number of components dangling from the board, straddling the board and valve bases.
Both BBC Amplifiers rebuilt to the original specification and going back to the collector for use in the studio.
Fully tested to the original specification.
Schematic reference
