That is easy, just carefully read each post, and refer to your dictionary for the meaning of the word.
Are there passive attenuators that don't zero volume and only offer one input ?
I am not sure how many people would like those features, but its worth asking in case someone would try to sell such a thing.
Which is to say it is essential I should think to be able to zero volume, and have more than one input, do you agree ?
Which is to say it is essential I should think to be able to zero volume, and have more than one input, do you agree ?
64 responses Add your response
Not at all, if you check back through each post I have not mentioned other manufacturers product name, or personal names, and I have also avoided, as best I can, stating my own. This page being the exception. Think of other manufacturers of passives, rather than the one you refer to, and it all begins to make sense. Let's hope things improve, so all passive manufacturers move forward & cater for features that make passives, the only choice. |
@dbxrecord who cares. This has been a pretty useless thread. You are obviously trying to take a poke at another manufacturer's product with the hope you will get gobs of people to agree with your point of view while pimping your products feature set. Obviously it's not happening so give it a rest. People can make whatever decision they need to regarding the features they desire in an LDR preamp, or any preamp for that matter. I've made mine and I'm not looking back. |
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There is no doubting LDR passives for sound quality are the bargain of the century, surpassing every other device you can name. I am unsure if everyone would put up with one input and not being able to zero volume, particularly knowing that those two aspects can be solved. The product IMO must surpass with its features too, ideally one step ahead in all departments, making it irresistible. |
Not an issue to me. I just had a passive built for me that purposely had only one input for purposes of SQ because it takes one switch out of the signal path. If the volume doesn't go to zero then a mute switch would work fine. I run mine in front of a unity-gain buffer and having remote control of volume, and an easy to read display, were more important to me. |
Back to the topic, who agrees passives should be able to zero volume and have more than one input.These are trivial features and not important to me. What is important is that the passive preamp is well designed and gets out of the way. If in doing so it can zero volume and have more that one input fine, if not that is fine too. As I stated previously I have had many passive preamps in my system. Some zero volume and have multiple inputs, some were made by manufacturers and some I DIYed. In the end the Lightspeed Attenuator which doesn't zero volume and has only one input is the one that I keep coming back to. One of the best bargains in audio and one of the best purchases I have ever made. |
±0.1VDC 1mVDC ripple is hardly anything to sneeze at.No thyristors are ideal in this circuit as they exhibit much better complete switching. As you well know There are hundreds if not thousands of thyristors , each with different characteristics suiting different purpose, To which do you refer ? The main advantage with thyristors in rectifier circuits as you should know, is to conduct current only in one direction,this suits when the load requires DC. A diode in comparison always has a forward voltage droprelated to temperature so is always incomplete with its switching. In so doing it creates what is called dark current, also called reverse bias leakage current. With thyristors they too can exhibit forward voltage, however is related to the junction current, With 3ma being the load that does just not occur, But if large current is the load seen by internal junctions then the thyristor does such transfer to exhibit forward voltage drop slowly. Another major asset being that a thyristor is a controlled device vs uncontrolled |
Although the contributors seem very knowledgeable about passive control preamps I don't know if this is a good place to ask if the Townsend passive Allegri Reference preamp is the type of technology you understand and support and the type company and sound to consider replacing an ARC REF 10 preamp with the Allegri. I don't use a balance control, but have to have a remote, and only need an inbound balanced in and a balanced out. Is anyone up to speed on the Allegri reference and willing to relate it's pros and cons to the other approaches you were describing, and then the replacement of an ARC 10 with it. If this question is too off base just say hello and move on Thanks. |
I don't recognize any of the model numbers nor the technologies, but you guys seem to know a lot about passives. I have never tried a passive preamp, but i have been researching a Townsend Allegri Reference passive preamp to replace my massive two box ARC REF10 solution. Are I in the same ball park of Passives? Can anyone tie the more technical part of the discussion to if the Townsend Allegri REF to see if it might work in my system as a passive. All I run is a DAK/Streamer to monos and onto my Wilson speakers I'm digital as the only input, no balance control needed, nor TT or other inputs needed, I just need balanced output, a volume control and a remote control. Any advice for a newbe from the Passive camp as I'm just seeing If there room for my questions and ideas. |
I am happy to ignore that reason, as it has absolutely no relevance at all, relating to what customers want from passive attenuators. We each know LDR passives offer so much better audio than other attenuation methods, and the task ahead is to make LDR passives the number one choice, as nothing else, can do what they do. The good news is each issue, namely more inputs and silence are relatively easy to do. I am very sure your customers will welcome those new features, and thank you, for caring about their needs., on a wider perspective ... it will see see all other passives, .. eating dust. |
@dbxrecord OP Please deny again for the record 1: That you are Chris Daly 2: Have any associations with a: Stereo Coffee b: Java Preamps c: Opamp Pass transistors 3: That this you https://ibb.co/yqH11rj |
High quality DC supplies are 10 a penny today.Look inside the plugpack , it explains why they are 10 a penny. "A thyristor is a semiconductor device which can be used to switch current on and off. When used in rectifier circuits, thyristors allow current to be controlled more accurately than diodes, which can only be ON or OFF. A thyristor can be triggered to allow current to pass in a graduated manner, by firing (switching on the thyristor) at a precise time, therefore controlling the conduction angle." https://www.ppi-uk.com/news/thyristor-controlled-rectifiers/ |
Why an A/C supply when a DC wallwart would keep all hum outtadabox?Because you then avoid the cheap rectification components inside wall warts, all avoided by using a AC 12v supply. Rectification can then be achieved with thyristors, and jfets https://www.stereo.net.au/forums/topic/113297-comparison-lightspeed-diy-ldr-pre-vs-stereo-coffee-diy... |
He a shyster ieales, and known all over other forums All you have to do is see how he disowned his own name and product, in the proof I posted up. This was the best one he tried to sell on ebay and diyaudio he called a "Pass Transistor opamps" https://ibb.co/Db3yj9s see the little smd transistor squashed under the opamp with the "snake oil" he tried on https://www.head-fi.org/members/dbxrecord.192735/ Cheers George |
Just had a look @ OP Stereo Coffee LDR attenuator @ Stereo Coffee Passive LDR Preamplifier (wixsite.com) Why an A/C supply when a DC wallwart would keep all hum outtadabox? PCB looks like something a kid would have designed 40 years ago. TRIM POTS?!?!?!? WTF? Trim pots are the bane of high fidelity. "However, the real magic of the 2020 StereoCoffee is what happens after 40 to 50 minutes playing music." If a passive is changing, it's not passive. The whole point, at least for me for 40+ years, is PASSIVES DO NOT CHANGE!!! |
How’s that for a outright lie!! How does he live with himself? Chris! you are certifiable. If you choose to spell my name wrongly, I have no obligation to agree to that mistake, I would expect you to do the same, not acknowledge your name being spelt wrongly - as would anyone. Please once again, stick to the subject. If you have nothing to contribute then don't contribute. I can say, all my passive attenuators are able to zero volume, and I enjoy 6 contact less stereo inputs , that is if you need any further reminding of what the thread is about. Just this morning I enjoyed radio on one input, then switched to a jazz CD, and to a hard disc recorder for some Pink Floyd, I did not have to change cables at all. |
Please stick to the subject, rather than further libel, the subject is Are there passive attenuators that don't zero volume and only offer one input ? I am not sure how many people would like those features, but its worth asking in case someone would try to sell such a thing.Which is to say it is essential I should think to be able to zero volume, and have more than one input, do you agree ? |
testpilot636 posts04-10-2021 9:54pm@dbxrecords ....why not just disclose or post under your industry affiliation?There’s only one reason he is here, to promote snake oil he makes. georgehifi8,879 posts dbxrecord OP (aka Chris Daly)How’s that for a outright lie!! How does he live with himself? Chris! you are certifiable. From his Stereo Coffee website contact info https://ibb.co/hDwKkVV and him preaching his snake oil at the NZ coffee shop Java ldr release. https://ibb.co/yqH11rj Chris Daly has been criticize by some very knowledgeable electronic designers on many forums for his BS trying to get sales from the gullible, he’s even tried to claim the Lightspeed Attentuator, it’s about time he disappeared. Cheers George |
No. Is it HiFi or sonic wallpaper?If it is contact less already on the signal path then you can have as many inputs as required, and zero volume too. To do that arrange LDR anodes of each series pair to be switched on in turn - according with your stereo inputs. To zero volume needs your design to power shunt anode separate to series anode, it needs also NOT to ground the LDR cathodes, rather arrange a regulated jfet current sink. Your volume control is arranged between shunt cathode and series cathode. You then arrange via LM317, with a higher potential on its adjustment terminal, place its Vin to the series cathodes and adjust for silence with resistance from the higher potential to Adj. As lower volume positions are reached, the start circuit thus named influences the series resistance readings, and causes extreme resistance on series pair at lowest volume, creating ability for silence. The start circuit is accompanied with another circuit called the continue together they interact together to improve relationship of the entire circuit for excellent current delivery and resulting audio performance. |
@bigwave1 - The base Axiom uses a shunt to ground design that they indicate keeps the signal path away from the Alps potentiometer. I believe Joule did something similar on their preamps. The upper end Walker Mod models use Khozmo’s discrete resistor attenuators. I looked at both Axiom and Khozmo earlier in the year and went with the Khozmo. I liked the small form function of the Axiom but was ultimately able to have more/better features with the Khozmo, including L/R channel control, larger display (for each channel), and my choice of resistors. Khozmo also has an upscale brand, Hattor, with even more feature possibilities such as an active stage and more substantial chassis, but I am not convinced those would sound any better than the Khozmo line for a purely passive unit. If you want the choice of switching from passive to active using a high end op-amp or even a tubed stage then look at the Hattor line. |
@dbxrecords ....why not just disclose or post under your industry affiliation?If this thread is anything to go by, it is obvious a code of ethos is desperately needed. Until then, sorry but few would submit themselves to such abuse. Let alone give up personal information, to be potentially subjected, to more of the same. Here as example is a forum with a code of ethos, that is good to reflect on: https://theartofsound.net/forum/showthread.php?17-The-basics-of-Ethos |
You’ve been caught out sunshine, you want more posted up from diyaudio alsoMaybe deal with the topic instead , refer to post 1 if you need to. |
NZ shysters I have no association with either name, please stick to the subject rather than libel. You’ve been caught out sunshine, you want more posted up from diyaudio also https://robmid42.wixsite.com/diyaudiokits/stereo-coffee-preamplifier And this is the "Chris Daly" famous opamp "pass transistor" con job, which you use as an avatar!!!! here https://ibb.co/HKwPhsh https://www.head-fi.org/members/dbxrecord.192735/ These are my last words, I'll leave the rest to admin come Monday if you continue. |
I said.If you read the first post it asks a question. Am i right in assuming you are you somehow totally OK, with all passive preamps not being able to zero volume and offering one input ? The discussion points, that its not too hard to do, even with LDR types. I really hope not, rather hopefully your response would be on reflection, that would be much better for all passive preamps to have silence at zero volume, and offer more than one stereo input. The question is there for all to respond to, perhaps we can see from others contributing, that not being able to zero volume and only provide one input is really undesirable, in fact dreadful, now knowing its easy to correct. It remains for those marketing passive preamps, that it is quite easy to turn around, to be a success story instead, and that is what the thread is all about.... improving what is out there. |
Like I said. "Why did you start this thread, if you know all the answers" And add yourself to the list, https://robmid42.wixsite.com/diyaudiokits/stereo-coffee-preamplifier And the dreaded "pass transistor" https://ibb.co/HKwPhsh https://www.head-fi.org/members/dbxrecord.192735/ over and out! |
The S3 ’s are widely all over the place, almost impossible to get few "quad matched sets" to do a Lightspeed properly with close to zero volume low volume, unless they are forced matched with servo feedback arrangement and by over driving some which "raises the distortion substantially" to meet the others which will kill them over a very short period.I have no association with either name, please stick to the subject rather than libel. |
The S3 's are widely all over the place, almost impossible to get few "quad matched sets" to do a Lightspeed properly with close to zero volume low volume, unless they are forced matched with servo feedback arrangement and by over driving some which "raises the distortion substantially" to meet the others which will kill them over a very short period. Actually the SR3 are better in my experience than the SR2S for matching. There is no need either, to use servo feedback arrangements. Keeping current 3ma for the whole circuit is the key. Sweeping between lowest volume and highest should achieve variance of just 2.78ma to 3ma , for the entire circuit, encompassing the load of 4x NSL32SR3 There is no need to go any higher at all, which keeps distortion extremely low, and achieves much better stability with cell resistance. R(on) of 20ma per device, or anywhere near that figure, is thus neatly avoided . |
The S3 ’s are widely all over the place, almost impossible to get few "quad matched sets" to do a Lightspeed properly with close to zero volume low volume, unless they are forced matched with servo feedback arrangement and by over driving some which "raises the distortion substantially" to meet the others which will kill them over a very short period. NZ shysters Chris Daley? JAVA ldr passive preamplifier $3.5K!!!!!! |
This is BS, do your own homework. First off observe the incivility of language being used in the first paragraph, and the attitude of demeaning. He would do well to learn to tackle the subject, & not the writer. Lets look at the subject. The manufacturer Luna inc states for the NSL32SR2S " low distortion" , and for the NSL32SR3 " best distortion characteristics " best, in my dictionary The Concise Oxford has the following meaning: " of the most excellent, or outstanding, or desirable kind " The second part of his reply, its easy to assess that pricing of goods of any business relates to the number of units being sold. Indeed the SR2S is more expensive as a direct result of fewer being stocked and one would have to then think units sold, a weak point in his reply to raise. Trying as we see, to attribute higher cost, as being better. As example today DigiKey stocking 13611 of the SR3, and just 897 of the SR2S. but lets go on, he states as we see doesn’t go low enough in volume unless over powered/stressed and won’t last if done so.He refers here to 20 ohms of difference that the SR2S has when powered with 20ma of current, vs the SR3, his attribution being needed to go low enough in volume. Herein the problem, finally exposed, deep breath ... one does not need to raise current, to achieve low or zero volume with LDR's. In fact other designs achieve current draw of no more than 3ma total at all volume levels which includes the entire circuit, with the benefit of no stress at all, to the LDR's Another issue being lowering shunt resistance too low, appeasing to achieve low volume, does nothing, other than squashes available dynamics in music. It is far better to have a higher resistance to begin the shunt resistance range, with the NSL32SR3 its possible though to have 100 ohms at zero volume, and 56k by mid volume with the shunt pair , and to have 25 mega ohms at zero volume with the series pair and 18k at mid volume. That though does take quite a bit of design effort.... but it can be done. Other designers providing LDR attenuators worked this out many years ago how to zero volume, and to provide more than one stereo input, without using higher current , they even went to the trouble of publishing how to do it, for everyone's benefit. |
But what I observe is other LDR attenuators, based on what I have learned may be the NSL32SR3 type of LDR, apparently these can offer better audio characteristics, namely lower distortion, the manufacturer Luna Inc stating "best distortion characteristics" and also as I understand, providing wider resistance range.This is BS, do your own homework. The very best is the NSL32SR2S and is the most expensive, second is the NSL32SR2. The R3 is the cheap one and doesn’t go low enough in volume unless over powered/stressed and won’t last if done so.Cheers George |
True but it's not as pure a signal path. I have owned my LDR passive (Lightspeed) for over 10 years. I have also built/owned other resistor and transformer based passives. The simplicity of the Lightspeed and the ability for it to stay out of the way more so than the other passives is why But what I observe is other LDR attenuators, based on what I have learned may be the NSL32SR3 type of LDR, apparently these can offer better audio characteristics, namely lower distortion, the manufacturer Luna Inc stating "best distortion characteristics" and also as I understand, providing wider resistance range. Apparently they are also able to easily zero volume with a clever technique, and offer more than one stereo input, as I understand as many inputs that are needed, can be catered for. It would seem then easy enough to solve, not to have problems like not being able to zero volume, if designs, and designers, have motivation to do so. The one you mention appearing after so many years, to lack any motivation whatsoever, to overcome the two said issues. |
Here is a balanced attenuator that I just made for someone.....he loves it. http://tweakaudio.com/EVS-2/custom_modsultimate_attenuators.html |
I'm in agreement with mitch2 - the Khozmo represents exceptional dynamic transparency, and an attractive price. I use a stereo version, with three inputs and two outputs, Vishay Nude Z-Foils and Takman REX shunts (carbon vs metal film of the REY). I have two Khozmos, the older one using a stepped attenuator (with Takman REY and the same Vishays), and the newer unit which utilizes relays for volume control. Both are superb, but I think the relay based unit is the more transparent of the two. My previous "volume knob" was a set of Intact Audio/Dave Slagle autoformers, via a Shallco stepped selector and a Bent remote control kit. An excellent unit, which the Khozmos finally displaced. |
If you want to use LDR's , as I observe in other designs, they find it easy to both achieve silence at zero volume, and to also have as many inputs, as are required.True but it's not as pure a signal path. I have owned my LDR passive (Lightspeed) for over 10 years. I have also built/owned other resistor and transformer based passives. The simplicity of the Lightspeed and the ability for it to stay out of the way more so than the other passives is why it is the one that stays in my system. |
