DIY Audio Projects Forum

My next project will be to build an RCA cable with LDRs built into it and a separate power supply. Keep watching
I am using Eichmann Silver Bullets and they are hollow which gives me room to store the LDRs in. So it will look like a normal set of RCA cables with a power inlet.
Ri

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DIY Lightspeed Passive Attenuator

I like that idea! What will you use to house the circuit?

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[ DIY Mains AC Power Cable Cord ] - [ Gobo LM1875 Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]

Dunno. Been scratching my head on that one for a while. Small and light? It moves around to much. Heavy as in a block of aluminum? Lots of work. Probably a small project box or something neat looking from ebay.
Ri

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DIY Lightspeed Passive Attenuator

I think those small black ABS enclosures at Radio Shack would work well and look ok too,

Boxes and wooden blocks and boxes are not all that uncommon on speaker cables.

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[ DIY Mains AC Power Cable Cord ] - [ Gobo LM1875 Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]

Has anyone attempted a balanced Lightspeed yet?

Has anyone tried a remote control setup?
Thanks
Bob

Hi,

I got here after a long search and registered.
It's quite a long story to tell want I want, but I will try to keep it short (I possibly will not succeed in that)

After building a few other sets of speakers I decided to build the Linkwitz Pluto's (see: www.linkwitzlab.com)
Those Pluto's have active filters and built-in power-amps. Maybe it was not wise of me to build the poweramps actually in the cabinets of the speakers and in fact I didn't yet, but I still want them there.

I was looking for a matching pre-amp that I can operate with a remote. Then I came across passive pre-amps and got interested. But I still want remote control for the source and for the volume-setting. I do not use an LP-player, just modern things like CD/DVD and a computer combined with a rather good chinese USB-DAC (with headphone and therefor pre-amp), so my input voltages should be no problem to a passive pre-amp.

However, my problem is I have all equipment physically in the middle of my speakers. This means from my passive pre-amp to any of the speakers is about 2.5 meters (say about 8.3 feet). Using the best (self-built) cables this still means I have long inter-connects to the poweramps that are built in the speaker-cabinets. So I was looking for a solution to that. I would rather not first weaken my signal in the passive pre-amp in the middle and have all distortion on the rather long cables fully amplified by the amps in the speaker-cabinet. I would like the weakening in the speaker-cabinet itself so all distortion on the cables is weakened as well. But I also would like remote control on volume and inputs. The inputs selection can be on the passive pre-amp in the middle of my set-up.

And there are all sorts of rather price-worthy remote-controls on e-bay, all chinese that is.
What if I use one of those POT-driven remote-controls to drive the POT on the passive pre-amp, but make an extra wire to the speaker-cabinets and build the LDR circuit into the pluto-speakers? My losses on the signal can be very low and I am still able to remote control the whole thing. Or am I now mistaken? Not seeing things clear?

kind regards.

Hi all,

I was thinking of combining the LDR with some chinese/HongKong remote volume control based on a motorized POT, like http://www.ebay.de/itm/110672789815

I am planning to use the motorized POT as the 100K stereo POT that regulates volume in the LDR.
Furthermore I can also choose the channel remotely.

I came to this solution because I am building the Linkwitz Pluto´s and I already choose to build the power-amps in the stands/feet of the speakers. This means I will have long interconnects between the passive preamp and the power-amps in the speakers (2.5 meters/8 feet). I reccon it will be better to build the LDR's in the speakers . In this way I will not only lower the sound-signal, but also the noise that is picked up by the long interconnects. It does mean however that I will need a third cable running to each of the speakers (power cable, interconnect and cable from the POT), but I don't care about the extra cables.

What do you guys (or girls) think of this solution?

regards,

Czar.

Hi Czar. That sounds like it should work. Lets us know how you make out.

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[ DIY Mains AC Power Cable Cord ] - [ Gobo LM1875 Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]

i was thinking about building this project but seems like not many have tried it even though it's been out there for a while. i've had really good results with alps and higher grade pots in passive attenuators used with tube power amps. will this project be really an upgrade from such volume control?

so, from http://buildanamp.com, i should order the $43 kit and it will include the matched optocouplers, boards, and all parts? i mean everything i need other than the rca, power supply, and chassis?

another question is for the power supply, can i use LM317 instead of LM78? maybe with a trimmer? i have a bunch of them left over from last project.