Lightspeed Attenuator - Best Preamp Ever?
@georgehifi, on a pot the middle tab is the wiper or output if I understand correctly and if I understand you correctly this is positive. Based on the physical layout the positives of each switch are connected with a red wire and then there is a red wire from one of the switches to the board. Well I installed the stepped attenuators using the same method. I believe I hooked up the other wires correctly as well, but here is my issue. With the original pots the Lightspeed never fully attenuated the sound, the pots in full counter clockwise positions still resulted in some low level sound coming from the speaker. I get the same result with the stepped attenuators, only the sound is much louder, in fact I could just listen to the music without moving the switch clockwise. If I do move the switch clockwise the volume does increase, but not very dramatically. In full clockwise position the sound level is still reasonable. Something is amiss. Any ideas? |
First off clio, are you 100% sure the new ones you bought are 100kohm logarithmic and not 100ohm logarithmic or even linear??? @georgehifi, on a pot the middle tab is the wiperYes on the dual mono it is, and where the + of the power supply goes. But not on the stereo if you look at the circuit. With the original pots the Lightspeed never fully attenuated the sound, the pots in full counter clockwise positions still resulted in some low level sound coming from the speaker. I get the same result with the stepped attenuators, only the sound is much louderThis is correct, all Lightspeeds Attenuators can never attenuate to absolute zero, as the LDR’s can never go to 0ohms, or complete open circuit I get the same result with the stepped attenuators, only the sound is much louderIf all was wired up as the original/s were, the problem must be that the pots you bought are either not 100kohm, or not logarithmic but linear. If they are 100kohm and logarithmic, then the first step up in volume must be way to high. If I do move the switch clockwise the volume does increase, but not very dramatically. In full clockwise position the sound level is still reasonable.If 100kohm value and log curve are correct ,this says to me you’ve wired it up wrong. The only thing I can suggest then to do is put back the original pots and see if it all goes back to normal, if not you’ve wired it up incorrectly Cheers George |
To all the "Lightspeeders" here at Audiogon and any new ones OK, time to let all here know that Lightspeed Attenuator has been acquired by a most avid audiophile, and who will do it proud. His name is Scott Campbell who also resides in Australia in the Sydney country side town of Green Point. He’s been very committed hi-end audiophile for as long as I can remember. As for his component history I’ll let him tell you. It was time to let it go after all these years, because it was starting to feel too much like “ground hog day” to me producing them. He also won’t be doing any orders for the time being, because of the Covid outbreak here, and he will also need to setup his production premises. His present email is [email protected] but no doubt will have another soon, more akin to Lightspeed Attenuator name in the future. I will still be around for tech assistance, till he finds his feet. Cheers, and a very big thanks for all your support George |
Thanks George & thanks for the kind words. I’m a passionate audio guy of 60. I’m very proud to have this opportunity with a product I’ve used personally for over 10 years. George has kindly agreed to remain on in a support role & I'm fortunate to have his knowledge to call upon when needed. I have some future plans for the Lightspeed, but for now the focus is on supporting existing owners & getting production up & running, once Covid allows. Cheers Scott |
