Lightspeed Attenuator

[Tripmaster]

at the moment im getting a lot of volume even at zero on the pot? will that fix that?

make it simple guys... rob made it so i dont really know what im doing

Yes it should. Just solder a resistor like in the picture between the red and blue wires

[The Vinyl Adventure]

ta ... thats what rob said, was just checking i understood really

[Tripmaster]

ta ... thats what rob said, was just checking i understood really

No worries

[Puffin]

It won't neccessarily fix the "volume at zero" problem. What it will do is give more control over the volume pot range.

[Tripmaster]

It won't neccessarily fix the "volume at zero" problem. What it will do is give more control over the volume pot range.

I'll second that. You should find the volume control within the medium...to medium high range acceptable.

[john blackburn]

Just as a matter of interest has anyone had any light leakage on their LDRs?

I put a lightspeed together on stripboard to see if I liked them and all seemed well until darkness fell. I noticed that one LDR was illuminating the board with a good 8mm ring of light emanating from the led end of the unit. The other 3 just show 2 pinpoints of light around the photocell wires, I assumed I had neglected to cut the strip under the 100r resistor to that one and was shoving too much power through it. The left channel was dropping out and sounded troubled to add to my concerns.

I checked it over the day after and all was well with the build, the supply voltages matched and I was very puzzled to say the least. Running a lens cleaning disc through the playstation sorted the channel loss out and it's done a good few hours since with no issues other than the light leakage. It doesn't seem to be causing any problems, I just wondered if anyone else has seen this.

John

[Tripmaster]

Just as a matter of interest has anyone had any light leakage on their LDRs?

I put a lightspeed together on stripboard to see if I liked them and all seemed well until darkness fell. I noticed that one LDR was illuminating the board with a good 8mm ring of light emanating from the led end of the unit. The other 3 just show 2 pinpoints of light around the photocell wires, I assumed I had neglected to cut the strip under the 100r resistor to that one and was shoving too much power through it. The left channel was dropping out and sounded troubled to add to my concerns.

I checked it over the day after and all was well with the build, the supply voltages matched and I was very puzzled to say the least. Running a lens cleaning disc through the playstation sorted the channel loss out and it's done a good few hours since with no issues other than the light leakage. It doesn't seem to be causing any problems, I just wondered if anyone else has seen this.

John

I haven't noticed any leakage, but it has been reported in the past. I guess you could add some sealant to the LDR.

[john blackburn]

Hi Tripmaster

I think I will just ignore it and chuck it into its enclosure. It was in traditional test mode, screwed to a piece of wood. It was just alarming when only one was lit up like a christmas tree. We will see if it gives an early failure but all seems well currently.

The only amp I have tried the lightspeed with is my point to point LM1875 which has a pot and only 22k input. Even with this less than ideal setup I would say there is an improvement in fine detail. It gives a little "niceness" boost if that makes any sense, the music is just "nicer" to listen to.

All told I'm a happy camper and may well pitch in for a matched set in the future, it may get better still.

John

[Tripmaster]

Hi Tripmaster

I think I will just ignore it and chuck it into its enclosure. It was in traditional test mode, screwed to a piece of wood. It was just alarming when only one was lit up like a christmas tree. We will see if it gives an early failure but all seems well currently.

The only amp I have tried the lightspeed with is my point to point LM1875 which has a pot and only 22k input. Even with this less than ideal setup I would say there is an improvement in fine detail. It gives a little "niceness" boost if that makes any sense, the music is just "nicer" to listen to.

All told I'm a happy camper and may well pitch in for a matched set in the future, it may get better still.

John

Hi John

I have put my name down for the next group buy. Rob (Puffin) built his first Lightspeed with the same unmatched LDRs I have. He has just received his matched set so it will be interesting to hear if they are any better. I find the sound through the LS to be a crisper, cleaner sound if slightly lacking a little bass when compared to my previous pre.

I think its definitely a keeper though!

[john blackburn]

I had noticed a slight reduction in bass with my setup too, but everything has tightened up at the same time. I hope that makes sense, I'm no good at this audiospeak.

I'm on with a new LM3875 jobbie that will be taking over from the 1875s on there currently. That will be just a power amp so it will be interesting to see how the sound changes when the 1875s redundant volume pot is removed from the equation.

I'm after a matched LDR set when the project budget has picked up again. There have been 2 amps, a pair of Bib speakers, a phono stage and the lightspeed built this year.

I can happily live with the sound I've got for the time being. If there's more to be got in the future, so much the better.

John