Lightspeed Attenuator a new passive preamp

Jump to Latest
#1,921
theophile said:


Tolu,
If you raise the input impedance of your poweramp,you might not need a tube buffer.
Try the Lightspeed without first.
Click to expand...

I don't have a problem between LS and power amp. It is 2k to 47k!
I will try the tube buffer as some kind of "effect device" because I wanted to try a CDP with a tube output but with the buffer it is more versatile!
 
#1,922
Yeah, I'm looking at the Alex Cavalli OTL that's a bit more "over the top" than it's predecessor, the "Heretica IIIl". VERY good buffers, dependent on power supplies, as usual.
Or maybe one of those "Moskido" hybrid amps to get some of that "valve magic" at the drive end. (It's got the Aikido front end, Mosfet O/P stage) - no buffer required for the LS at all.
 
#1,924
Lightspeed remote control

Hi folks,

I have finished building and testing the infra-red transmitter and receiver boards for the Lightspeed remote control now, and they are both behaving properly, so no layout errors.

Unfortunately I have a very busy week at work this week so it may be Saturday before I can finish the application notes. Now that all boards are verified I will also post a materials list on the thread so those of you who have ordered circuit boards can begin acquiring materials.

If all goes according to plan and I get the application notes finished on Saturday, I will start shipping boards on Monday and Module shipments should start the following week.

Regards
Paul
 
#1,927
hi george,

i want to thank you for sharing your wonderful preamp! all i can say is WOW! ive been running the lighspeed or a few months now and every time i take it off....thres just no comparison!it brought a huge improvement on my system! im running it on battery! my current system is a pp6v6 ala music machine, lightspeed, modified cheap cs4397 dac, and ob speakers!

i want to try the tube output stage for my dac but im afraid the output impedance is too high with 70ohm...is there any modification that can be done? here is the scheme of my amp and the tube output stage for the dac....


amp..... http://audiotropic.net/Projects/mmAudio.html

dac...... http://lampizator.eu/LAMPIZATOR/LAMPUCERA/MAX/IMG_5143.jpg



thanks to all who have contributed on this thread!


ivan
 
#1,928
tubo said:
hi george,

i want to thank you for sharing your wonderful preamp! all i can say is WOW! ive been running the lighspeed or a few months now and every time i take it off....thres just no comparison!it brought a huge improvement on my system! im running it on battery! my current system is a pp6v6 ala music machine, lightspeed, modified cheap cs4397 dac, and ob speakers!

i want to try the tube output stage for my dac but im afraid the output impedance is too high with 70ohm...is there any modification that can be done? here is the scheme of my amp and the tube output stage for the dac....


amp..... http://audiotropic.net/Projects/mmAudio.html

dac...... http://lampizator.eu/LAMPIZATOR/LAMPUCERA/MAX/IMG_5143.jpg



thanks to all who have contributed on this thread!


ivan
Click to expand...


tubo

would you be kind to share how does your battery powerd LDR look like and maybe the schematic....?
 
#1,930
Guys if you have one of my production Lightspeed Attenuators you can plug one of these straight in they have the right size plug and polarity and come with a fast charger, I've had mine on for days before needing a re-charge, As for the sound, (how did I know you were going to ask that) I and my friends are in two minds if we can hear much difference from the 12vdc regulated linear 300mA wall wart. we think there may be a ever so slight difference but none is game to put up their hand and say what.

http://cgi.ebay.com.au/12V-Lithium-...286.c0.m14&_trkparms=66:2|65:10|39:1|240:1318

Cheers George
 
#1,932
hey guys,

i have not tried the mains solution as i have a couple of 12v car battery laying around...... with regards to how long do i need to charge it, i have it powered up 24hours for a week! when i measured the battery its initial reading was 12.69vdc after a week of 24hr usage it measures to about 12.300 volts! so i guess once a week with the unit powered on for 24 hours!

my implementation is quite rude just a 7805 regulator with 1000uf on input and 470uf on output! no connectors just straight to the battery terminals!
http://www.tkk.fi/Misc/Electronics/circuits/psu_5v.html


thanks,

ivan
 
#1,933
tubo said:
hey guys,

i have not tried the mains solution as i have a couple of 12v car battery laying around...... with regards to how long do i need to charge it, i have it powered up 24hours for a week! when i measured the battery its initial reading was 12.69vdc after a week of 24hr usage it measures to about 12.300 volts! so i guess once a week with the unit powered on for 24 hours!

my implementation is quite rude just a 7805 regulator with 1000uf on input and 470uf on output! no connectors just straight to the battery terminals!
http://www.tkk.fi/Misc/Electronics/circuits/psu_5v.html


thanks,

ivan
Click to expand...


so this will be 12vdc into 5vdc regulator....simple

what is the current value from the battery.....?

is it safe if the current of the source before regulation at 1000mA fot the LDR?

and do we need some kinda fuse protection with this kinda schematic....?
 
#1,935
i think the car battery has an ampere rating of about 200 ah. i guess it is safe cause ive been running the lightspeed 24/7 without any problems! i have no fuse protection on my supply! my build was just to try out the lightspeed it was a very crude build but when i heard it,
i didn't expect it to be that good.(awesome)! i just put a heatsink on the regulator!
 
#1,940
hey fellas,

i want to try a tube output stage for my dac and it has 70ohm output impedance! i know its in the high side and the lightspeed will have a hard time driving it. can i bump up the output cap of the output stage from say 2.2uf til 10uf..... i apologize for all the newbie questions!

thanks,

ivan
 
You must log in or register to reply here.
Top Bottom