After reading 63 pages on the DIY Audio forum and speaking to George I decided to pull the trigger on the Lightspeed. Also, I figure if Nelson Pass got into the mix on LDRs it is worth checking out. Dave, did you ever get them implemented in the active preamp. I can't remember if you posted the outcome on DIY Audio. |
Are you still using the Paradigm Reference Active 40 speakers? If so and I read the amp specs correctly the line in input impedance is 15k ohms. That is something to take into consideration when selecting a passive preamp. That being said the other posters have covered the gamut on the different brands. Personally I prefer the TVC models over the resistor models as impedance matching is less of an issue. Another consideration would be the new Pass B1 buffer preamp. It is a zero gain design with a buffer output that offers all the benefits of a passive but eliminates impedance matching issues. It's listed here on Audiogon for about $875 new IIRC. |
I believe Nelson Pass already posted the schematic on the Pass DIY site as well. I saw a couple built by Audiogon member Rawsonte fly out of here of late. As Pubul57 says the rsistor based design is much simpler. I'm tempted to break out my EVS nude attenuators and give them a test run in my new set-up. I looked at the Lightspeed thread and am curious about those attenuators as well. Anyone know a way to contact the manufacturer? |
Actually I would have preferred balanced, but the cost was prohibitive due to the added parts and work involved. George wasn't excited about tackling the project either. I was able to get him to build me one with dual volume controls so I could have a balance option. My DAC has an output impedance of 50 ohms and my amps an input impedance of 100k ohms. The Lightspeed should be fine I imagine. |
Received the Lightspeed and have had a chance to listen for a bit. This little piece is pretty amazing. Dead quiet and excellent dynamics. Better than my previous K&K TVC that used S&B transformers and better than any other resistor based passives I have heard. I've always been partial to transformer based passives, but the Lightspeed is quickly changing that opinion. |
Pubul57, I'm traveling on business but I can get you George's email address when I get home Wednesday. Go over to DIY.com (do a search with "lightspeed") and read the thread as well. Very interesting stuff. Also, if you'd like to try one out first let me know. I'm not using mine right now and I'm happy to lend it to you. |
George, you were indeed right. Also, I appreciate the fact you went out of your way to build me one with dual volume controls. I'm picking up these to compare to the Lightspeed as they are comparably priced and I always wanted to hear the Slagle's. http://intactaudio.com/module.html I'll post comparisons when I get around to it. |
