Peter Daniel said:
Pete I know Tom should give you his answer to this as well, but what you asked is exactly how I have explained the sound to be, but only try it if your amps are low enough gain as not to blow your speakers to kingdom come and for god sake use a quietly recorded cd.
Cheers George
That is correct, and I have the opportunity to use such an amp presently: it is Zen v9 and if I connect my source directly I'm getting about the right volume level for normal listening. It's a very good tool to test attenuators, and I'm already changing my views about some of them: it's hard to make it as good as the direct connection ;-)
Peter is your TX102 the mk 1, 2 or 3 ?
I have a TX102 Mk3
I'm just burning in zero cables and interconnects and already after 3 days I am feeling that all my "edginess" has dissappeared.
If you have the mk2, IMHO, this does not have enough treble and sparkle to allow edginess !
I still think I will try a lightspeed - I'm too curious not to.
cheers
mike
I have a TX102 Mk3
I'm just burning in zero cables and interconnects and already after 3 days I am feeling that all my "edginess" has dissappeared.
If you have the mk2, IMHO, this does not have enough treble and sparkle to allow edginess !
I still think I will try a lightspeed - I'm too curious not to.
cheers
mike
Peter, I assume a direct connection would sound better, no? Mind you:
• the LDR might, by virtue of the H2 it generates, actually lower perceived distortion to thus sound better than a direct connection *if* in the system in question it modifies the distortion spectrum to one for which distortion-masking by the ear-brain is more active, *assuming* that that masking occurs at all;
• the LDR's resistance might be smearing the signal in a way that reduces edge.
As to any of this, who knows, ey? Ask Bear or Eddy, or match a few LDRs ....
• the LDR might, by virtue of the H2 it generates, actually lower perceived distortion to thus sound better than a direct connection *if* in the system in question it modifies the distortion spectrum to one for which distortion-masking by the ear-brain is more active, *assuming* that that masking occurs at all;
• the LDR's resistance might be smearing the signal in a way that reduces edge.
As to any of this, who knows, ey? Ask Bear or Eddy, or match a few LDRs ....
First of all, this is really quite fascinating... so simple, yet really clever. Great information all around. I think that I'll have to build one of these ASAP! Maybe replace the alps pot in my headamp.
But here is a quick, and probably foolish, question... could you drive the LEDs with PWM? Or would that produce noise/instability? It strikes me that controlling one of these with a very simple PIC has some interesting possibilities... particularly for home theater applications etc. PWM would make such a setup trivial with like a PICAXE or other beginner chip.
But here is a quick, and probably foolish, question... could you drive the LEDs with PWM? Or would that produce noise/instability? It strikes me that controlling one of these with a very simple PIC has some interesting possibilities... particularly for home theater applications etc. PWM would make such a setup trivial with like a PICAXE or other beginner chip.
Blip, I hypothesize, backed by a recent bit of experimentation on my part, that noise on the LED power supply will modulate the signal traversing the resistive unit. The transfer, I assume, would not be 1:1---the resistive unit has a certain memory or lag, probably frequency dependent, in how it reacts to changes in light. That said, if the PSU noise signal in question changes the light intensity, that change must, to some degree, transfer to the signal.
I suppose the task of keeping PSU noise from affecting the signal is much easier with an LDR, mostly because, apart from electrical separation, current required by the LED is quite constant---no changing demands to get the PSU hens flapping. For my part, I have noticed that cleaning up the LED power supply gives slightly better sonics. Worth experimenting with, for sure.
I suppose the task of keeping PSU noise from affecting the signal is much easier with an LDR, mostly because, apart from electrical separation, current required by the LED is quite constant---no changing demands to get the PSU hens flapping. For my part, I have noticed that cleaning up the LED power supply gives slightly better sonics. Worth experimenting with, for sure.
That's what I was afraid of... Maybe at a high enough frequency it wouldn't be audible? But either way PWM would seem like an unnecessary compromise. Hmmm... Have to ponder this further.
Anyway, I'm just blown away that some people like this better than using transformers... this is so much cheaper and simpler!
Anyway, I'm just blown away that some people like this better than using transformers... this is so much cheaper and simpler!
AC TVC
Serengetiplains/Tom,
Did you compare the LDR passive to the Audio Consulting Silver Rock TVC or to Serge's TVC with standard silver OPT48 traffos? I have 1:2 New Silver Rocks in the ouput stage of my CDP & they are as good as it gets with transformers. I've not heard the Silver Rock TVC, but if the LDR passive sounds better it is very good indeed.
Dave
Serengetiplains/Tom,
Did you compare the LDR passive to the Audio Consulting Silver Rock TVC or to Serge's TVC with standard silver OPT48 traffos? I have 1:2 New Silver Rocks in the ouput stage of my CDP & they are as good as it gets with transformers. I've not heard the Silver Rock TVC, but if the LDR passive sounds better it is very good indeed.
Dave
David, I also very much appreciate Serge's stuff. His transformers are the best I've used. Like you, I am currently using his 1:2 line level Silver Rock coupling transformers---in my setup as a phase splitting input to my parallel-tube single stage 6C45P amp (the tubes are run opposite phase and each's output transformer is connected opposite phase at the speaker, so a modified, if you will, PSU noise killing SE). The AC TVC against which I compared the Lightspeed is the Silver Rock version.
georgehifi said:
I think I can see what 'ackcheng' is getting at.
If you used both sides of a single pot (+5v to the wiper and use both ends), rather than connecting one side to the wiper, then when one side gets a lower resistance the other will get higher. It seems like it would work, but I could be wrong. I'm still very much a newbie, and I am very tired to boot!
As far as I have read connecting one unused end to the wiper is done to attempt to have some sort of safety incase the wiper momentarily loses contact with the internal resistive strip.
I guess it's alot more unlikely that both wipers in a dual pot, wired as you have, will lose contact at the same time... but if it did happen presumably the effect would be the same in both cases anyway?
EDIT: here's a picture, as I am generally a bit rubbish at explaining things.
An externally hosted image should be here but it was not working when we last tested it.
ackcheng said:
I dont think it keeps the impedance the same. The actual pot isn't part of the signal path, so I dont think it would have anything to do with the impedance.
It's quite clever. I like the idea! It did take me a little while to see what was going on though. It's difficult for me to explain, but if you stare at the way the pot is wired for a while you should get it
ackcheng said:
As far as I can see, george has wired the dual pot to basically be a single pot. But I do definately agree we should wait for a response from george, or any other more knowledgable individual (than me that is), before coming to any conclusions
