One day maybe, as for now the Lightspeed Attenuator is still taking pride of place, when the time is right I may do a glitzed up version, as it is, it is in it's purest form
Cheers George
I am building one of Maximus's VCCS remote control units but have been unable to obtain one of the 455khz ceramic resonators; does anyone have a spare to sell?
Apologies if this should be in the swap meet.
Apologies if this should be in the swap meet.
One of my lightspeed units seems to ramp up the volume to quickly (and max out). Should I use a linear or log pot with it? What else can I check for?
Thanks.
Thanks.
Joe,
Shoot me your phone number and good time to call. Let's hook it up to a dmm while I'm on the phone with you.
Uriah
Shoot me your phone number and good time to call. Let's hook it up to a dmm while I'm on the phone with you.
Uriah
How about some time next week. I'd like to finish hooking up my system (actual stereo).
I'm going to be using my Wharfedale bookshelf speakers with my F5 with a lightspeed & CD player.
I'm might use a buffer inbetween, not sure yet.
I'm going to be using my Wharfedale bookshelf speakers with my F5 with a lightspeed & CD player.
I'm might use a buffer inbetween, not sure yet.
No problem. Looking forward to our chat.
You really are going all out. Your system will sound better than anything you could buy for 20grand easily. I listened to McIntosh amps/B&W803's and a McIntosh pre. Not sure of the source, but felt great going home and listening to my own system. Felt also kind of bad for folks who will spend that kind of cash on that kind of system. It wasnt crap but the Dynaudio speakers driven by some mid end amp they had WAS crap. Had a Peachtree DAC which I have heard and I can be sure the source/pre was not the issue. Anyway, we dont waste our time DIYing.
Uriah
You really are going all out. Your system will sound better than anything you could buy for 20grand easily. I listened to McIntosh amps/B&W803's and a McIntosh pre. Not sure of the source, but felt great going home and listening to my own system. Felt also kind of bad for folks who will spend that kind of cash on that kind of system. It wasnt crap but the Dynaudio speakers driven by some mid end amp they had WAS crap. Had a Peachtree DAC which I have heard and I can be sure the source/pre was not the issue. Anyway, we dont waste our time DIYing.
Uriah
I havn't posted here, or followed this thread for a couple of years now, so please excuse me if this has already been covered . . .
Has anyone compared these light controlled Jfets with regular LDRs ?
and by that I mean subjective comparisons.
Fairchild H11F1M, H11F2M, H11F3M Photo FET Optocouplers.
http://www.fairchildsemi.com/ds/H1/H11F1M.pdf
cheers
mike
Has anyone compared these light controlled Jfets with regular LDRs ?
and by that I mean subjective comparisons.
Fairchild H11F1M, H11F2M, H11F3M Photo FET Optocouplers.
http://www.fairchildsemi.com/ds/H1/H11F1M.pdf
cheers
mike
Mike,
Jackinnj did some tests with those. THD was really good. Might not have been same PN but similar devices. My only other experience is that my buddy Vlad from Audio Mirror told me he tried volume control with photofets before and it was not a great result. That was a while ago and technology may have improved though. I think its worth a shot to try!
ps Mike, look for some that go real low in min resistance. Important for low volume.
Uriah
Jackinnj did some tests with those. THD was really good. Might not have been same PN but similar devices. My only other experience is that my buddy Vlad from Audio Mirror told me he tried volume control with photofets before and it was not a great result. That was a while ago and technology may have improved though. I think its worth a shot to try!
ps Mike, look for some that go real low in min resistance. Important for low volume.
Uriah
The specs say less than 100 ohms to greater than 300 meg ohms. The question in my mind is, how much less than 100 ohms?
The spec table doesn't seem to give a 'typical' on resistance. Will it consistently reach 40 ohms?
What does that mean for a realistic attenuation range and system Z?
OK thanks,
I'll make a a new preamp & do a comparison.
I don't need very low resistance - that doesn't bother me - just the sound.
I'll make a a new preamp & do a comparison.
I don't need very low resistance - that doesn't bother me - just the sound.
Hi, I am writing here for the first time so I apologize if I say or do something out of policy, hope not. I am interested on the attenuators subject because I very recently bought a 150 watt power amplifier (still has to arrive to my home) and I would buy/build a simple quality attenuator for line signal, possibly not too expansive. I already own a Sm Pro Audio Nano Patch +" that is a honest device but PA, and wish something better quality for the main stereo equipment. I am not skilled in DIY but I can find help for the project.
Thanks,
Klakmuf
Thanks,
Klakmuf
I suggest building a cheap two gang log law potentiometer into a passive pre-amp as your first experimental volume control.
Learn how to connect the various wires.
Learn how to make simple cheap twisted pair interconnects.
Learn how to solder.
Learn how to select appropriate values for the components.
At this stage you do not use mains power and that "SAFETY" lesson can be saved for a little later.
Once you have this running and can listen to your stereo, then start reading about the advantages that switched and metal film and relay and high precision resistors can bring to the Sound system. Read about buffers and why in some circumstances they cannot be done without and in other cases bring extra complexity that is simply not required.
Read the first thread on Lightspeed - this one!
Then decide which attenuator route you want to take. You will almost certainly want to carry out further experimental research to help make that informed decision.
Learn how to connect the various wires.
Learn how to make simple cheap twisted pair interconnects.
Learn how to solder.
Learn how to select appropriate values for the components.
At this stage you do not use mains power and that "SAFETY" lesson can be saved for a little later.
Once you have this running and can listen to your stereo, then start reading about the advantages that switched and metal film and relay and high precision resistors can bring to the Sound system. Read about buffers and why in some circumstances they cannot be done without and in other cases bring extra complexity that is simply not required.
Read the first thread on Lightspeed - this one!
Then decide which attenuator route you want to take. You will almost certainly want to carry out further experimental research to help make that informed decision.
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Match LDR
Hello
Can anyone tell me where is the link with the instructions to match the LDR?
thank you very much.
Jose
Hello
Can anyone tell me where is the link with the instructions to match the LDR?
thank you very much.
Jose
Jose
Keep room temp perfectly the same and do your matching quickly AFTER giving them some time to come up to temp. Try not to hold them by the body, but only by the leads. Temp really will throw off your matching quite a bit. No breezes, no dinner breaks. All must be subjected to exactly the same voltage/current.
Uriah
Keep room temp perfectly the same and do your matching quickly AFTER giving them some time to come up to temp. Try not to hold them by the body, but only by the leads. Temp really will throw off your matching quite a bit. No breezes, no dinner breaks. All must be subjected to exactly the same voltage/current.
Uriah
You can add to that Jose, once you have match the quad set as I have outlined, set them up in so they are in close proximity to each other, then pot them together totally in hard wax,. This will keep them at a constant temperature to each other and any inter channel or series to shunt drift problems will be eliminated.
I get so many diyer's of the Lightspeed getting this problem and emailing me how to fix it, and it is always fixed in the end by potting in hard wax and then when cooled doing the final calibration once again.
To show you how a good set of quad matched NSL32SR2S's stays calibrated, my prototype that I still use for myself done over 7 years ago and is switched on 24/7 is still in perfect calibration.
Cheers George
Looks good idea and is new for me put wax, then is more interesting, but I´m not sure how can I potted. I had thought make the same of serbian´s diyers.
