16-10-2014, 08:33 PM
We have the warts and all start of a restore here.
I intend these to pair up with a very nice pair of valve mono block amplifiers that have been running a large pair of domestic speakers for a couple of years. These sound a little bit distressed at times.
These 1970s units will sink the power easily even if the valve amplifiers get turned up flat out
So there is no risk of the domestic speakers ever failing open circuit if these commercial units replace them.
They shall not be tested as acquired on a valve amplifier with a an output transformer like a coal scale weight until there electrical integrity has been established
The assessment is that both cabinets have been rewired poorly and have also had a latching input connectors added. I will retain these as I already have mating cable mounted female plugs for them and enough Plessey MK4 cable mounted males for the amplifier ends.
The original loft insulation like stuff is missing and something else has been substituted. I have got some rock wool so this can also be sorter out.
The cabinet with slightly less tatty wiring has had one of the drivers replaced with one with a little flair around the dust cover. This makes little difference to the sound if any at all.
The capacitor on the tweeter was not tinned at all what so ever and there was no contact to the tweeter.
Perhaps this replacement driver with the extra bit was added to overcome the dry joint.
The tweeters are branded Motorola and are both good as are all the main drivers.
The DC resistances of the voice coils are not much to go by but are 6 ohms on the 3 identical drivers and 10 ohms on the different one. I would guess that these are two 15 ohm drivers in parallel per cabinet.
Those green capacitors will be visited by a 250 volt Megger.
The only shortage looks like it is a carry handle end cap. I am tempted to remove these anyway as they will no longer be lugged about.
I might be tempted to paint them to match the amplifier cabinets as these are dove grey so showing off the big round black driver cones through the child proof grilles. No poked dust covers in these speakers
I intend these to pair up with a very nice pair of valve mono block amplifiers that have been running a large pair of domestic speakers for a couple of years. These sound a little bit distressed at times.
These 1970s units will sink the power easily even if the valve amplifiers get turned up flat out
So there is no risk of the domestic speakers ever failing open circuit if these commercial units replace them.
They shall not be tested as acquired on a valve amplifier with a an output transformer like a coal scale weight until there electrical integrity has been established
The assessment is that both cabinets have been rewired poorly and have also had a latching input connectors added. I will retain these as I already have mating cable mounted female plugs for them and enough Plessey MK4 cable mounted males for the amplifier ends.
The original loft insulation like stuff is missing and something else has been substituted. I have got some rock wool so this can also be sorter out.
The cabinet with slightly less tatty wiring has had one of the drivers replaced with one with a little flair around the dust cover. This makes little difference to the sound if any at all.
The capacitor on the tweeter was not tinned at all what so ever and there was no contact to the tweeter.
Perhaps this replacement driver with the extra bit was added to overcome the dry joint.
The tweeters are branded Motorola and are both good as are all the main drivers.
The DC resistances of the voice coils are not much to go by but are 6 ohms on the 3 identical drivers and 10 ohms on the different one. I would guess that these are two 15 ohm drivers in parallel per cabinet.
Those green capacitors will be visited by a 250 volt Megger.
The only shortage looks like it is a carry handle end cap. I am tempted to remove these anyway as they will no longer be lugged about.
I might be tempted to paint them to match the amplifier cabinets as these are dove grey so showing off the big round black driver cones through the child proof grilles. No poked dust covers in these speakers
