Lighter Note LDR attenuator

[HighFidelityGuy]

Just a mini update:

I've finished enclosing the torroid in it's own little case and bolted down the main PCB:



The dual gang potentiometer on the left is for the volume control. As with the standard Lightspeed attenuator the quality of this pot doesn't really matter much as the audio signal doesn't pass through it, instead it controls the voltage of the LDR's. The pot on the right is to allow fine tuning of the channel balance. Again, no audio passes through this so the quality doesn't matter much.

I've drilled lots of holes in the back panel. Most of them are just pilot holes which will need widening, or in the case of the IEC socket cut out I'll join the holes together with my Dremel's cutting disc.



I've also built up the rest of the case to help me measure things out make sure it all fits together.



That's about all I can do for now until I can get my drill stand and Dremel set up but I don't think I'll have time to sort that out until Wed or Thu....

[24bit]

nice!

[HighFidelityGuy]

Thanks.
I'm hoping to get some more work done on this tonight or tomorrow so I should have another update soon.

[Reid Malenfant]

Interesting looking critter that

Did you get the thing built like that or was it a kit? Did you get supplied with a circuit diagram for diagnostic purposes if something isn't right more importantly

Looking good so far

[HighFidelityGuy]

Hi Mark. It came as a kit and I had an enjoyable afternoon building it up. That's my favourite bit of the process. I don't mind making up cases but its a bit messy and time consuming.

I can't wait to get it all connected up and working. I've got a bit of a dilemma though as the designer is working on a remote volume control and input switching add-on that I want to include but I have no idea what that will involve as it's still in production. So I'm just hoping I've still got room to fit it all in.

With any luck the add-ons will get released around the same time as I've finished all the main bits. I'm sure it will all work out.

EDIT: I didn't get a schematic I'm afraid. I'm guessing the designer is keeping that to him self for now. To be honest the manual is so comprehensive that you're unlikely to run in to serious issues.

[john blackburn]

Hi Dave.

Is the polarity on your ldrs right? Just looking at the batch numbers stamped into them, one is 180 degrees out to the others.

If the dots are right it must be how they are, it just troubled me.

I have a lightspeed clone here, I think you will enjoy this when it is done.

John

[Reid Malenfant]

Is the polarity on your ldrs right? Just looking at the batch numbers stamped into them, one is 180 degrees out to the others.

Hi John, like standard resistors LDRs have no polarity, or at least none that i have ever heard of. The LEDs feeding them light certainly do though

Besides which they are carrying & attenuating an AC signal so i think that kind of covers it

[HighFidelityGuy]

Hi Dave.

Is the polarity on your ldrs right? Just looking at the batch numbers stamped into them, one is 180 degrees out to the others.

If the dots are right it must be how they are, it just troubled me.

I have a lightspeed clone here, I think you will enjoy this when it is done.

John

Hi John,

I've double checked and the LDR's are definitely installed with the correct polarity. I've run the circuit and it works properly, so everything is ok so far. I appreciate your concern though.

[HighFidelityGuy]

Just a quick update....

I made a temporary front panel out of wood as I don't know how many holes I'll need to drill in the front yet, so I thought this would give me some extra flexibility without any risk:



I've also finished drilling and cutting all the holes on the back panel and mounted the connectors I've currently got. I'll order some more RCA sockets soon. I couldn't afford a full set all at once as they're rather pricey:



This photo shows the output socket layout with my planed wiring layout indicated by the white lines. I've tried to get the shortest signal path possible. As you can see I've included two pairs of outputs to allow for bi-amping:



This photo just shows the overall layout as it currently is. I've left one of the side panels off to give me better access for soldering the RCA connectors:



I will temporarily wire one of the inputs directly into the board for now and then re-wire this once I've got the new input switching add-on.

That's it for now.

[HighFidelityGuy]

I forgot to mention; the volume knob in the photo's is just temporary. As I don't know how the new remote volume add-on will work I decided not get any knobs yet.

I'll hopefully finish off the soldering tomorrow and start doing some testing of the unit in my system.