@ Georgelofi, Wow!, My interconnect, The Taralabs Zero Gold's capacitance is 4 pf per-foot!, then the new Taralabs Evolution Grand master interconnect is 2pf capacitance per-foot, I'm good with the capacitance specs then!, thankyou for your reply Georgelofi. |
Audiolabyrinth:
Thanks for the invite, but cables and how they sound are such a subjective thing, and very system dependant.
All I say that for all passives and high output impedance tube preamps, one should make sure that the capacitance of the cable is low, as not to form a HF (high frequency) filter if the capacitance of the cable is too high.
Luckily good quality cables are nearly always low capacitance, and just to be certain you should ask the manufacturer.
A good worst measurement case is 100pf (pico-farad) per foot or lower good ones are much lower, for a 1mt interconnect this worst case capacitance would be 300pf, this equates to with a passive and many tube preamps to have a HF (high frequency roll off at around -3db at 76khz.
But if you pick an quality interconnect that is 50pf per foot, then the HF roll off is -3db at 152khz.
Cheers George |
Has anyone heard any of the LDR products from Tortuga? They have addressed the need for multiple inputs and remote volume control at prices that are not unreasonably higher than George's, so I'm curious how the stuff sounds in comparison. |
03-03-14: 4hannons
Drubin, I wouldn't use the Pardo;the 12V/2A will fry it. The LSA takes 1A max I beleive. I'm not an expert, maybe others with more knowledge will chime in here... Sorry but just to correct this, it will work fine, so long as the plug that goes into the Lightspeed Attenuator is 2.1mm and centre positive. Voltage can be between 9vdc-18vdc. True 2amps is way way over kill, but the amperage does'nt matter so long as it's above 100mA. Cheers George |
Drubin, I wouldn't use the Pardo;the 12V/2A will fry it. The LSA takes 1A max I beleive. I'm not an expert, maybe others with more knowledge will chime in here... |
I have a Teddy Pardo 12V/2A PS here. Can I use that safely with my LSA? |
I came across this thread in my mission quest to find linear, regulated power supplies. I have a non-LSA application and need 5V @ 3A output with a 120V input. However the specs listed on the site seemed to be just what I need since it indicated
"DC output: 0.25V-9V adjust (Default DC 9V 1A)"
though I am not sure what the maximum amperage is if not the 1A indicated.
Need to wait and see if my "proof of life" inquiry gets a response. ;-)
IF anyone knows of another linear, regulated alternative to the TeraDak other than the pricey and overkill KECES D-116, I would love hear about them. |
I also see that Output Voltage is "adjust" between 0.25V and 9V. Is output voltage adjusted by user...or preset by the vendor to user requirement? There's nothing to adjust on mine--at least not on the exterior. I bought mine from their bay store, but I see that they have nothing presently for sale...hmmmm. |
AB Systems was off for the Chinese New Year which ended a few weeks ago I beleive. Just before that, on January 10, I ordered the TeraDak U9VA for use with my LSA. It arrived within a few days from China, kind of surprising how fast. Very happy.
There was no need to specify the voltage for the U9VA, it came PnP for the LSA; all I needed was to use my own PC.
This model doesn't have an adjustable output voltage. Nevertheless, it's not necessary when using with the LSA. I am supremely happy with my purchase and highly recommend AB Systems.
About three days ago I sent AB Systems an e-mail about and have not heard back. I hope all is well.
~Tom in Sacramento |
Have been reading with interest the comments about the TeraDak and keces DC-116 power supplies and am encouraged that users are happy with the TeraDak given its considerably lower cost.
Is AB Systems (source of the TeraDak) still in business? I have written emails to the Contact@ listed but have not received any responses over the past several weeks. As expected, I am reluctant to order anything blindly.
I understand that Input Voltage must be specified.
I also see that Output Voltage is "adjust" between 0.25V and 9V. Is output voltage adjusted by user...or preset by the vendor to user requirement?
Also would like to know what the DC connector barrel dimensions are...5.5mm/2.1mm or other?
Anybody have any experience with their other products, e.g., power cords?
Thanks! |
Georgelofi, It would be an honor for you to come to the thread I requested, there is a need there for your vast exsperience, comment on all subjects, as you can see, this thread is unlike most others, we talk about all audio, not just the subject of the thread, please. |
Hi, Audiolabyrinth, tell him to come over here and read this.
I had a quick read of that thread, and there are those that like to be on the preamp merry-go-round, spending lots of money and are addicted to it.
They say that their preamps aren't coloured. But keep changing them for "different sounding ones" (odd I thought they were uncoloured).
I have yet to hear them use the statements like "straight wire with gain" or "true to the sound of the source" as these statements are describing a preamp the is truly transparent, dynamic, uncoloured and invisable to the sound of the source.
Cheers George |
What do you mean by your post Ebm? |
So So no big decal HELLO!!!!! |
Hi Georgelofi, come on over to the cable thread,Taralabs 0.8 versus the one, there you will find a member friend of mine that is interested in your product, His name is waxwaves, read the last few post, if you could agree with my findings and back me up concerning all that I said about active pre-amps versus source direct to amps, and addresse waxwaves about your product, I would be grateful, thankyou George. |
update
wow, what a different it make,after I change wallwart to terdak, the lightspeed became more slam & dynamic. frankly this got to be the best hifi investment I ever make. |
i found the lightspeed more detail,musical &neutral compare with my other preamp(sonic frontier sfl2 & placett audio rvc) with lightspeed my system never sound so good before, on rare occasion i found lacking is through full classical orchestra music with rapid & continues power punch & slam. just my 2 cent. |
Found it and answered.
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1392847679&&&/Pre-amp-or-cd-direct-to-XA30-5-
Cheers George |
You found it, very well done, thankyou. |
Audiolabyrinth, I tried, but couldn't find the thread, which forum is it in?
Cheers George |
Hi Georgelofi, I believe the thread cd player direct or preamp that is new, needs your help., you can answer better than I can, so I did not post |
Hi Lacee
Its in the detail you miss out, DBX type 1 (not type 2) is very relevant today, works wonderfully with CD sources.
Quite correct on the description, however the post question is also wrong then.
There is far more to the NSL32SR2s and feeding it DC sadly this little car you perceive so much faith and interest in is parked and frozen in design , step across to the next garage, otherwise you will never find out.
|
And DBX was the best there was in the 80's,until you bought one and couldn't stand to listen to the music any morebecause of all the pumping noise issues.
If you try an LSA in a system that is devoid of shapeshifting devices and listen to a high resolution system, you'd understand what all the folks who own one are talking about.
It is as far away from processed sound as the Cortina is to a Bugatti.
I'm quite sure your folks were proud of that Cortina and where it took them,and for them it was the best car in the world.
Strictly speaking I would agree that the LSA is not the "best preamp ever".
It's not a Pre-Amp.
It's a volume control. |
No its NOT, Same as a Ford Cortina is not the best car ever.
feeding a pair of shunt and series LDR's from a fixed voltage then into a potentiometer with all the consequences of ridiculously low current and some trimpots at the other end when the pot swings to maximum. I have nothing against Cortina's mum and dad drove one |
Photonman, good news that you prefer the Teradac, am I reading right that you think it's a little better than the wall wart you have, if so in what way? And do you know if your wall wart was linear or switch mode?
As for Nelson Pass and that buffer. Many thanks to him as he first developed it for the Lightspeed Attenuator back in 2008 so that it could then drive some of his amps that had low input impedance that customers owned who wanted to use the Lightspeed with it. Those amps for memory had around 10 or 20kohm input impedance.
Here is the link to the 2008 post and circuit diagram for the Lightspeed he developed.
http://www.diyaudio.com/forums/analog-line-level/80194-lightspeed-attenuator-new-passive-preamp-137.html#post1521766
http://www.diyaudio.com/forums/attachments/analog-line-level/109114d1211904694-lightspeed-attenuator-new-passive-preamp-atten-sch.jpg
Cheers George |
I hid my unit under my bed and my wife stepped on it and sliced up her toes very bad... I am not going to ask because I don't even want to know. |
Hello again George, still loving m LSA and I did add a TeraDak PS to the mix.
At first I thought I heard a big difference vs. the wallwart but now I am used to it but I am staying with the TeraDak. Yes that red led is BRIGHT and be carefaul as the face plates are sharp. I hid my unit under my bed and my wife stepped on it and sliced up her toes very bad...
Curious how this Nelson Pass unit compares to the LSA...here is a link to some circuit diagrams:
http://www.firstwatt.com/pdf/prod_b1_man.pdf |
Thanks George,I am quite happy with the unit as is,maybe down the road I'll try the new RCA, so that all contacts are rhodium to rhodium,just the OCD part of my brain talking out loud.The tips about what to do are most appreciated by me and anyonelse thinking about mods. |
If it's a new one, far as being fixed under warranty, ah, yes that would be out the window.
If you decide to do it, do not use the nylon insulating washers that come with rca's. You must make sure that all 4 x of the metal bodies of the new rca's are in electrical contact with the back panel.
And be careful the black anodising on aluminium chassis is an electrical insulator, so leave the burrs of the rca holes sticking up as they contact the rca's body.
Cheers George |
Replacing the RCA with the same ones as my amp is a move I might make,but I am hesitant as I haven't had the LSA for a year yet.
If something goes south that's not related to the RCA mod,would I still be covered or would I be on my own?
Nothing holds me back from simple mods if the gear is out of warranty. |
Most modded LSA: don't know.
Probably need to follow DIY.com to get a sense of yes or no.
Maybe the power supply is the big one! |
Off Topic but I wanted to say I switched from a Classe CA-150 amp to a Prima Luna Prologue 5 lastnight and the lightspeed works great on both. No problem whatsoever with using the lightspeed with the Prima Luna; it sounds great! I secretly thank George everytime I fire up my rig. His piece is one of about four that changed my rig from mid-fi to hi-fi. |
John47: you must have the most heavily modded LSA in existence. It would be interesting to a/b it with a stock version. |
OK for US and Canadian owners of the Lightspeed Attenuator, I just did a search for definate linear wall warts that are all suitable.
First three are regulated, last two are unregulated, it does not really matter, so long as they are linear 9-12v with a 2.1mm plug that is center positive which they all are.
Or you can get the Teradac http://www.ab-system.hk/index.php?route=product/product&path=73&product_id=64 Cheers George
110-115v linear wall warts from Jameco, payment by COD, Paypal or Credit Card
All are suitable.
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_null_220898_-1
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_null_1953639_-1
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_null_162996_-1
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_null_2192712_-1
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_null_2197484_-1
|
Thanks for your comments George: no I didn't have a wall wart, I would have bought the package, so can about guarantee mine is a 'George' psu.
Banquo
"John47: did replacing the rca's make an appreciable difference?"
I would like to say yes, but being semi ancient and not keeping notes I don't remember. It was some time ago, but can say that my system sound has gone incrementally forward (over time). If there was no difference, or worse, assuredly I would have a big mental red alert.
Of note - I've used Nextgen Ag throughout, to match my silver ICs, and that I discovered (by removing) gold plating adds warmth, ie colouration I don't want. Expensive, but a oncer. Best RCA? I cann't say, but I read heaps before I bought.
Further: WBT Nextgen are not a direct replacement in the LSA, the mounting holes need enlarging, not straight forward.
Sorry if above seems like a non answer, but I don't recall, even subliminally, thinking I should restore the original RCAs. |
John47
That is unless you had your own wall wart, and just ordered the Lightspeed without wall wart, I had a few who've done this.
Cheers George |
John47
I supply 220v-240v linear wall warts to the rest of the world. US and Canadian owners purchase their own 110v ones from within North America. Who knows what they are getting from their suppliers, as linear wall warts are getting very hard to find, smp is the norm now.
You need not worry John47 being from New Zealand I would have sent a linear to you.
Cheers George |
No worries, B_limo.
John47: did replacing the rca's make an appreciable difference? I've been wanting to have that done for the longest time. I wish I possessed your soldering skills. |
Sorry part of my earlier post was premature.
"I’m using the original supplied wall wart psu, so your discussions re power supply are v interesting. Seemingly its sm according to George's suggested AM radio test, which gets noisy brought close to it."
I believe I misinterpreted noise: George's info says he supplies a linear 12vdc supply - thats what I've got. Please ignore my "Seemingly its sm," line. |
Hi guys: haven’t viewed this thread for a couple of yrs at least (since I bought a LSA, after the gracious, generous help of Pubul57, Clio09, and George).
Maybe you are interested: I upgraded my LSA by wiring the power supply direct to the board (removing the psu connector). It was beneficial, but relatively so long ago I can’t be specific about what difference I heard.
Oh, I also replaced the RCAs with WBT NextGens to (supposedly) impedance match my WBT NexGen/ICs, and added a separate earth lug to the LSA chassis, that is wired (separately), directly to the green mains Earth wire behind a dedicated mains outlet (so the LSA is like a star earth in my system. I tried in vain to get George to add an Earth lug when I purchased).
(It gets worse! I also rewired my LSA with the same silver litz of my ICs.
But other than the psu wired direct to the board, it’s all far too laborious – I’m not even sure I should mention it!)
I’m using the original supplied wall wart psu, so your discussions re power supply are v interesting. Seemingly its sm, according to George's suggested AM radio test which gets noisy when brought close to it.
Thanks guys for the interesting posts. |
Thanks Clio!
Well put Lacee. I'm no skeptic when it comes to upgraded power supplies or power cords; they've all made improvents in my system, so I don't know why I'm skeptical over an upgraded power supply for the lightspeed (maybe because someone (George?) said that rubbing two sticks together is enought to power the lightspeed, lol. I'll be getting a teradak next month to compare to the battery pack I'm currently using.
Now if there was a way to harness all the damn static electricity in my house, I could power all my equipment for free... |
Thanks Lacee. I am glad George recommended this PS and that you and Banquo263 have used it. So now hearing about its positive effect it is on my list to get as soon as I get my new innerconnect, Amadi Maddie Sign., in my system and broken in. Thanks again. |
This is a strange hobby, and the hobbyists are a strange breed.
Some folks are content to listen to their music collection and not worry themselves if a power cord or a PSU will make an improvement to what they have.
They are the ultimate music lovers,while some of us, myself included,fuss over the smallest of details trying to squeeze that last drop of performance out of our systems.
Such types are mostly frowned upon,their enthusiasm about superior performance when changing one type of wire for another is met with more than a bit of scepticism.
"Don't such people know that if two wires measure identical they should sound the same not different?"
"The only difference between a stock fuse and an upgraded fuse is the cost.Soundwise there should be no difference."
On and on it goes.
The endless "I heard it" and the response"no, it just can't be".
Some of us have heard the improvements the TeraDak makes over an off the shelf wallwart, which as stated by someonelse, probably is a SMP device,the linear ones seem to be harder to find.
Battery power would appear to be, in theory ,to be the ideal.I once owned a Sutherland PHD battery power phono stage, my friend has a Nighthawk battery power phono stage.
Yes, getting off the grid does have it's benefits,but battery power isn't the magic bullet, ticket, to sonic nirvana.
It takes more than a battery power supply to bulid a good anything.
Not trying to disparage any of the above products, or anyone's based on battery power, but there is a lot to be said about how those batteries are implimented into the design and how good the design of the product is in the first place.
Running a device that is well made, and designed with top components will trump an inferior design with cheap off the shelf parts.
Because both are battery powered, doesn't mean they will be on the same playing field, and sound the same.
I would think that there are the same quality variations between such battery power supplies as there are with anythingelse.Some better than others.
Or you may feel that they should all sound the same.
The PHD doesn't sound like the Nighthawk,or my Steelhead, nor should it.
Yet the non battery powered unit with tubes,doesn't send any kind of hiss or residual noise thru my system, so it's as dead quiet as the battery unit was.
If that was the only thing to consider, then you could say that there is no difference between battery power and grid power.Or that it makes no sense to spend any extra money if the Nighthawk is as quiet as the PHD.
A SMP is said to be noisier, inferior to a linear unit, and the linear unit is said to be the equal of a good battery supply.
The LSA demands such little juice that how one can hear any differences at all between any of the devices is hard to believe.The power supply shouldn't really be of importance, just as long as it meets the specs.
Less would be bad, but more is overkill.
I'm not sold that it's the noise from a SMP supply that was robbing me from all the dynamics that I now enjoy.
The system sounds as noise free as before.
Just like the Steelhead is a noise free as the PHD was.
There are other things to be considered,not just noise cancellations.
I'm just a listener,not a techie.
But I'm not suffering from tunnel vision either or am I the slave to measuring devices.
And yet here we are discussing those very differences and merits between a cheap wallwart or a bit more expensive PSU being used with an entry level priced volume control.
Chump change to the those who play in the big leagues and ponder if another ten grand on interconects over and above the ten already spent,would have made the difference they were looking for.
I have no idea what the cost is for a decent battery power supply for the LSA, and what the lifespan/cost is to keep one running at it's optimum.Or if it gradually powers down or abruptly shuts down.
So I would think that if a linear supply sounds close, then that would be the one to go for.
I have no ideas why the TeraDak performs so well in my system.
Granted it's getting more support from what it's plugged into than most other LSA in use.
But that's getting back to the top of my rant.
The LSA is not priced as a High End performer,so the systems it maybe used in, perhaps reflect the cost constraints of the owner.In other words,it's cheap, but in cost only.But it's cheap, why throw any money at it?
I think if the thrifty music lovers, (who are always looking to cut corners to free up more cash for music software),and buy the LSA, will most likely partner it with gear in the same price spectrum.
And for those folks,expensive power cords and power supplies are unjustified for musical satisfaction.
So in essence, they are selling the LSA short from my perspective.
And in my opinion,so are the folks who own the LSA and power it with a SMP wallwart into a power bar.
From my recent experience it deserves to be treated with the same regard for power demand as any of the mega buck high end components, and will benefit just as much.Eventhough it only requires a minimum amount of power to work, don't take it for granted that it can not be made to work even better.
It's power demands are few but don't hold that against it.
Given a better power supply, the LSA is an even better giant killer. |
I think it will work fine with the Prima Luna, but at 600mV you might not get too far around on the volume control. With my Music Reference RM-10 that is 800mV I get to about 11 o'clock before I reach my preferred listening level. |
B_limo
George,Another quick question: would the lightspeed attenuator work well with a prima luna prologue five tube amp?
Input impedance 100 kohm
input sensitivity 600 mv (the man. site said 600mv on one page, 775mv on another...)Thanks in advance, George!
Perfect match! and just about any source will give out more than 600mV. Most give 2000mV (2v) or more.
Cheers George |
It would need to be electrically conductive, the only paint I know of that is, is rear window demister paint. Better off lining the whole inside with aluminium foil then it needs to be earthed to all 4 x rca sockets so it gets a system earth. All too much if you ask me, just enclose the Lightspeed as it is with the wood of your choice, that way all is still RF shielded.
Cheers George |
George,
Another quick question: would the lightspeed attenuator work well with a prima luna prologue five tube amp?
Input impedance 100 kohm
input sensitivity 600 mv (the man. site said 600mv on one page, 775mv on another...)
Thanks in advance, George! |
Thanks George.
What about painting the exterior chasis of the lightspeed with automotive paint? Yes, no? |
01-15-14:
B_limo: George, two questions: does the lightspeed ever need to be recalibrated? It seems like my volume control may be adjusting in larger increments than before...
Question 2: is it okay to dress it up a bit? I was thinking about a small wooden case or having it professionally painted.
B_limo
Q1: Only if any part of the rest of the system has changed with a different gain to it source amp or speakers. As it's impossible for the Lightspeed Attenuator to change gain as it has none.
Q2:As the Lightspeed chassis is part of the RF shielding, puting it into a wooden case may introduce rf noise into the system.I advise against it.
Cheers George |
My bad Banquo, didn't see the link, didn'tknow you looked into it at all, let alone actually digging around a bit. I apologize. I'll check the link, but like I said, I'll probablyend up just buying the terradak to back up my battery pack and will report back.
George, two questions: does the lightspeed ever need to be recalibrated? It seems like my volume control may be adjusting in larger increments than before...
Question 2: is it okay to dress it up a bit? I was thinking about a small wooden case or having it professionally painted. |
