Lightspeed Attenuator
- Thread starter Tech Guy
- Start date
Well this "amateur" your talking about who doesn't listen to audio circuits, has designed several commercial uber high end discrete output stages for some of the biggest names in audio. This is why I chose him for this design. So if you can show me a more impressive resume, maybe I'll fire him and hire you instead.
How do you know anything is real? Repeated listening tests backed up by other peoples findings is certainly one way. Cynics are cynical....doubters are doubtful....lovers are happy. I like happy.
I did not call him an amateur......you are exaggerating, as you tend to do. I just said he has not done critical listening tests to resistors in the feedback path. Many, many high end designers are not very tweaky. They do not listen much to parts or subtle ways or implementation. That does not make them not good designers......just not great tweakers. I am done with this conversation. Please, lets move on here....or do you always have to have the last word?
I did not call him an amateur......you are exaggerating, as you tend to do. I just said he has not done critical listening tests to resistors in the feedback path. Many, many high end designers are not very tweaky. They do not listen much to parts or subtle ways or implementation. That does not make them not good designers......just not great tweakers. I am done with this conversation. Please, lets move on here....or do you always have to have the last word?
You got me.......let's make that.....He has more than likely not done critical listening tests to resistors in the feedback path. I have done these tests and I always hear the "sound" of the resistors.
Maybe 25 years ago I had a Theta Gen III in for tweaking. I changed the 75 ohm load resistor on the digital input to different brands of resistors. The whole sound of the system became colored by whatever resistor brand I used. My friend who was there with me listening said "It is the same as if it were a resistor load on a moving coil cartridge"......really blew his mind. This game is so cosmic, infinite and subtle. Everything changes the sound.
Maybe 25 years ago I had a Theta Gen III in for tweaking. I changed the 75 ohm load resistor on the digital input to different brands of resistors. The whole sound of the system became colored by whatever resistor brand I used. My friend who was there with me listening said "It is the same as if it were a resistor load on a moving coil cartridge"......really blew his mind. This game is so cosmic, infinite and subtle. Everything changes the sound.
So you think this guy is just spouting off reccommendations without having any actual experience? As I mentioned in my last post, if you have a better resume than he does, let me know. Let's hear one of your discrete class A preamp designs, and we will compare with his.
I figured that is where you are going. It does for some people. I think I am pretty open minded.....ie.....what I hear is in the now.....not preconceptions. I have had my mind blown so many times thinking this "magnet wire" cannot sound good, etc. Things are as they are, not as we would like. It is certainly a skill to stay in the open possibilities of things. Open mindedness is a good thing. Since we all "create" our own reality.....if you hold on to things being "just so" then that is what you will experience. If you hold the universe as completely open in each second then you can experience what is real in this moment. There is a saying " don't believe everything you think"......it should be "don't believe anything you think". What you think is not a reality. They are just thoughts in your head. However, thoughts held strongly and intensely will manifest in the physical reality. This is why holding loving and positive thoughts creates happiness. Love creates love. Joy creates joy, etc. What do you want to create? How do you want the world to be? Become it and radiate it out......Bless everyone....no exceptions.
What I expect is that I will experience more and more love and joy and share it with more and more people....helping to heal the planet. That is my "bias".
What I expect is that I will experience more and more love and joy and share it with more and more people....helping to heal the planet. That is my "bias".
so if my direct experience (and that of many others too) is that I suffer from expectation bias, then that's the reality I'm creating and it's all good.
Right?
Right......
I think I've lost interest already after visiting the sites. I'll never understand why these small shops can never seem to find the money or time to post up any useful specifications or measurement data on their products
I guess a working website, friendly demeanour and a smile is all that’s needed nowadays to sell audio equipment
I think I've lost interest already after visiting the sites. I'll never understand why these small shops can never seem to find the money or time to post up any useful specifications or measurement data on their products
I guess a working website, friendly demeanour and a smile is all that’s needed nowadays to sell audio equipment
Hi all, I was sent an email and asked to join and answer some questions on this forum,
Hi cfj, don't know about the other clones, but my specs are listed everywhere, these are about the only specs you can do for a passive.
Lightspeed Attenuator Specs
Frequency response: 0hz – to almost Infinity "Lightspeed" (interconnect capacitance is the determining factor here) so good ones are recommended, from 1-3mts long.
Power Amp Input Impedance: Should be more than >33kohm which most are
Source Output impedance: Should be less than <1kohm (1000ohms) which most are.
Here is the circuit if some members have the skills to make one. And if help is needed, you can post questions here, and I will answer you asap.
Cheers George
Attachments
Last edited:
Hello,
The Specs/Measurements I would be interested in seeing are those related to Frequency Response DB vs Frequency at MAX & Lower Volume Control intervals across the whole Freq Range up to say 50kHz. Looking for any odd behaviour. Channel Separation/Cross Talk DB vs Frequency to see how well they match each other. THD+N vs Frequency ...etc...etc
I get that in "Theory" the Frequency Response could be up to infinity but how do the actual measurements look? If none of the above measurements apply to a Passive of this type then how do you measure it to know its Freq Resp should be good up to infinity?
Is there any documentation online that would be a good resource to look at for someone interested in knowing more about why a Passive Pre of this type can't be measured the same way a traditional active Pre is?
Thanks
Frequency response does not vary from min to max, it is 0hz to many MHz even ghz. The HF limit is only governed by the interconnect capactitance. EG: if we have 100pf per ft cable capacitance, (good ones are even lower) and we have 1mt attached the -3db point is 212khz!! (212,000hz)
The only distortion with 2v line level input is 2hd, the nice sounding tube one, and it is below .1% mostly .01% because line sources never give out full 2vrms continually.
Cheers George
The only distortion with 2v line level input is 2hd, the nice sounding tube one, and it is below .1% mostly .01% because line sources never give out full 2vrms continually.
Cheers George
Attachments
Last edited:
Sorry, and you also asked "Frequency Response could be up to infinity but how do the actual measurements look?"
Here are the square wave screen shots at 10hz 1khz 20khz and 100khz.
The 100khz screen shot is only limited by the scope's test lead capacitance.
To give this kind 100khz square wave frequency response is well over 500khz!!! (Lightspeed'ish)
Merry Xmas to all and a Happy New Year, Cheers George
Here are the square wave screen shots at 10hz 1khz 20khz and 100khz.
The 100khz screen shot is only limited by the scope's test lead capacitance.
To give this kind 100khz square wave frequency response is well over 500khz!!! (Lightspeed'ish)
Merry Xmas to all and a Happy New Year, Cheers George
Attachments
Last edited:
I can't give you any comparison details, but this Lightspeed Attenuator owner did some comparisons with the Townsend one. And there are a few others in this thread that did them with other TVC's and passives.
https://forum.audiogon.com/discussi...ator-best-preamp-ever/post?postid=77348#77348
https://forum.audiogon.com/discussi...ator-best-preamp-ever/post?postid=77345#77345
Cheers George
Similar threads
