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BC1 Xover upgrade

 

It was a pure coincidence when Darren contacted me regarding a service for his Croft Amplifier that he had also seen my posts on the Spendor group about internal rewiring for my SP1's. When he asked me if I would work on his BC1's I was happy to oblige. Below are the photo's click on any image to see it full size.

I would urge anyone to consider changing the original wiring on the older Spendor units as the gains are worthwhile. Darren's BC1's responded to the rewiring more than my own SP1's. I think this is because the original wiring was poorer on the BC1 and maybe the fact that his bass drivers had the Alnico magnets.

 

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Before opening up

 

 

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The standard wire was installed at a time where wiring, speaker cables and interconnects was not the issue it is today. The current S Series Spendor speakers uses VDH wiring as standard.

 

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Notice that the black wire is on the red post. I tested the phase on the bass driver and found that the black post was in fact positive and red negative. The voice coil was in fact upside down with reversed phase. The bass unit was not rejected so this was the factory solution.

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The crossover incorporating polyesther capacitors. I have modified the crossovers also and will be posting a page showing this work shortly.

Crossover Modification here!

 

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Ready to rewire with flat foil copper for the hf units. I have since experimented with various wiring configurations in the HF section and now use LC-OFC signal cable here. The bass driver is wired with Hitachi LC-OFC copper cable which has a particularly neutral sound. In order to achieve tighter bass QED silver anniversary or other silver plated cable is used.

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Wiring complete! I am now ready to install the new binding posts and solder the connections.

 

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Binding posts soldered in. I always turn the driver through 180 degree's and make sure it is bolted back ultra tight.

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All connections are now soldered

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The new binding posts

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The job done just now need to put the front panel back on. I screw it down as tight as I dare.

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The other speaker unit completed!

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I have always had teak BC1's and I just adore the rosewood veneer on Darren's speakers..

See here for the latest work on Crossover Modification.