How much do I need to spend to get a preamp that sounds better than no preamp?
Just an FYI.... Any F5 can be made to yeild 25 dB of gain very easily. Who cares. It’s not about you and your F5. The heading of the thread is: " How much do I need to spend to get a preamp that sounds better than no preamp? I think my system sounds better when I remove it from the signal path. " "you are such a kosst", new saying here for agitators take note everyone. |
That doesn’t even make logical sense. Read again sunshine, maximum master volume with minimum "tube gain" for loudest listening level. Will give lowest noise figures I forgot to mention that when you purchase an Axiom passive preamp the mfg will ask you what power amp you will be driving so that it can be configured to deliver the best sound.That would be say a 100kohm passive for amps like many Rogue Tube amps which are 1mohm input impedance. Or at the other end maybe a 5kohm passive for amps with 20kohm input impedance. And then some in between these. |
honashagen OPI would do it so the "master volume control" is around 3 o’clock for normal listening level. That gives you leeway up or down for louder listen or quieter recorded music. Cheers George |
Yes Audible Illusions are a very good active preamps, I owned an AI 3A and loved it. They did run the tubes very hard in it though, you don’t get much life out of them, I’ve always believed that’s why it sounds as good as the best active preamps I’ve heard. But the OP and me, going direct sounds the best for transparency and dynamics, and to me and many others a well implemented passive comes in a very close second. To me any active stages add colouration's and cannot improve on the dynamics against a well implemented passive, they can only detract as they have no dynamic range expander circuit in them, and they wouldn't want to as they sound rubbish. Cheers George |
Regarding Steve’s McCormack amplifiers, I believe all of them originally had a 100K ohm input impedance, up to the DNA-500, which was designed with a 10K ohm input impedance.Yes these lower (10kohm) later amps will not be a good match for passives. But! as the OP used it, direct from a 100ohm source to amps, no problems so long as the input sens is still 0.8v or even 2v for full output, it will to many still sound better than any active preamp, with or without gain. Cheers George |
c_avila1 Hi again Ciro. Your XA25 (very nice poweramp btw) is 47kohm input impedance and I believe you used a 50kohm Khozmo stepped attenuator as a passive pre? You really should of used a 10kohm Khozmo passive pre, it would have been a much better better impedance match to the XA25’s 47kohm. But your now going direct from source to XA25, even better again, so long as you don’t lower the digital domain volume control of your source below 75%, as you will start to "bit strip", 14bit resolution instead of 16bit ect ect. Cheers George |
Your really just not worth the effort, you live in denial kosst, and question everything Nelson Pass tells you. I’ll post it up again just in case you missed it. Nelson Pass: And this as well from him just for good measure.
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A lot of this is system dependent....i.e., electrical values of the source upstream, amplifier downstream If we look at what the OP has there is no issue, 100ohm > 2v source and 100kohm 0.8v sensitivity poweramp. And once again this goes for 90% of matches, only high impedance tube sources can have a problem or very low input impedance amps. Cheers George |
mitch2 Nelson Pass tends to disagree, with his Aleph L, he says when the active stage (which you would assume to be first class) is engaged on this preamp it takes a hit "his word suffer" in sound quality (3 o’clock or more) from when it’s in passive mode before 3 o’clock. Nelson Pass: Cheers George |
Your last post is classic cherry picking...No you are cherry picking and must more likely have your back up over the "snake oil" voodoo'ist statement I made. As I'm a great believer in measurements, as that's how all gear is designed and made, and then listened to. And those measurements can help buyers/users choose right amps for speakers and/or right speakers for amps, instead of the many "well serving" here but wrongly saying "buy this" it sound great, but don't have any idea if it will to the job measureless wise. Cheers George |
He couldn’t even bother to wait for JA to post a response to his question, he had to immediately come here and post a click-bait thread on the subject. Really!!!!, I was asking the question, " Looks like Stereophile may be cutting back on expenses" operative word being "may", as I’m not in the US and maybe others at Agon had some more info, if the tests going to be stricken,, as they are the most time consuming part and expensive of Stereophile and many mags are getting rid of them to save money in this diminished climate for this type of reading. And 3 days later I did post this, your the one that needs to be questioned not me. Maybe your a "snake oiler" and just didn’t like what I said in this post. https://forum.audiogon.com/posts/1555737 Cheers George |
you went off half-cocked, and initiated a thread on Stereophile no longer performing measurements even though it was completely incorrect. Are you serious!!! (is this because I asked if you were a fuser.) that’s not even worth a response, but I will, as I asked a legitimate question as John Atkinson’s response shows??? And the measurements/test were not done with two reviews. I simply asked "Tests???????" https://www.stereophile.com/comment/574783#comment-574783 JA Quote: "It wasn’t possible for Larry Greenhill, who now lives in California, to ship this amplifier to New York in time for me to measure it. John Atkinson Editor, Stereophile Read more at https://www.stereophile.com/content/mark-levinson-no534-power-amplifier#Ibp132Sl19pHjucP.99 Cheers George |
bestdiyguy1 posts That’s well put for a first time poster, I like your rationale behind most of what you said. I hope you can last in the "sometimes" cesspit of "snake oil" threads that pop up here. As there is too much "snake oil voodoo" on these pages that real designers/techs won’t endorse or go near. And you know if those "snake oil" claims were posted on a forum where the likes of Nelson Pass, John Curl ect, ect, ect hang out like diyAudio.com the poster would get a new one ripped within the hour, and disappear in shame like many have had to do that I’ve seen. Cheers George |
Regarding active versus passive preamplifiers, the world is big enough for both of them.Yes and I’ve always maintained that, and so does Nelson Pass But when someone of no acknowledged tech background put **** on what Nelson Pass says about passive preamp, of course I’m going to have a go at him, as should you! BTW: are you a "fuser"? I think I may have seen you be pro fuses in posts and what "magic" they can do . Cheers George |
Saying that everyone that sells active preamps is just in it for the money and somehow that someone selling passives isn’t is as hypocritical as it gets.Yes I was drawing a long bow there, yes there is a place for active preamps when, poweramps have stupid low input impedance, and if their input sensitivity is higher than 2v, eg FW F5. This is when active preamps are needed. I’ve heard the Lightspeed and it works fine in the right circumstances.I’m glad, and the right circumstances can be 90% of the time, if amps input is more than >33kohm and input sensitivity is less than <2v. I’ve got nothing bad to say about Nelson- he is a brilliant designer and I often point out in my posts that he makes some of the best solid state gear out there."I’ve got nothing bad to say about Nelson" And no you shouldn’t, nor should anyone else here who want to question what he’s said, if they want to then go to http://www.diyaudio.com/forums/pass-labs/ site and try to tell him there direct and see how long you last, as those technically superior like NP wouldn’t waist their time here with the BS that’s put forth on these forums . Lay off the crap.Ditto back at ya sunshine. Cheers George |
You need to back off.Sounds like a threat there sunshine. You are an agitator, as many on Audiogon have said, stop drinking or whatever your doing. Like I said. That’s the second time you’ve put **** on Nelson Pass, who do you think you are? better???, your not even his hang nail. As others have said, you built a F5 from "paint by numbers" "kit" that anyone that can hold a soldering iron can put together. http://www.6moons.com/audioreviews/firstwatt9/1.jpg And you think you know better than Nelson Pass, who gave that very amp to the diy’ers who can solder to make. Cheers George |
So true Samuel. That’s why I’ve always maintained, the most "transparent/dynamic sound" is going direct from source to amp if you can do it without the sources digital domain volume control doing any "bit stripping", it is the number one way for most transparent and dynamic sound, second is a passive preamp with good impedance matching, third is an active preamp, which you can add differing colouration’s with. Another gem from Nelson Pass: " We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more. Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up. Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control. What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection. And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp." Cheers George |
So how about you lay off? Others and I could have easily called you on it years ago; its become tiresome. I think your the one that needs to lay off the false claims about passives with blanket statements about their ability to drive ect ect. Every time they are bought up, your on it to protect active preamps. Here is a person you should kneel to as he is one who makes active preamps for a reason which I’ve outlined, yet he is man enough to tell what it is about passives that’s the real deal. You just deny them as a whole, just like the "detriments" of a certain autoformer. NELSON PASS: On one of his favourite premps, "which is passive" in it’s best sounding configuration. " The Aleph L is a single ended Class A audio preamplifier combining new design thought applied to traditional topology and the experience of twenty five years of amplifier design. Cheers George |
You make no sense, can't see the forest through the trees, as usual. Like I said: "We have the voltage from most sources at more than >2v. Most poweramps only need less than <1.5v in, (some even 0.5v) to make them give full wattage output to the speakers." There is no debate at all, as any **** can see. Cheers George |
Its not wise to assume that 90% of all sources can drive a 10K load. This is picking hairs and scare mongering, and just selecting a worst case scenario. 90% of amps are 33kohm input impedance or higher. Very rarely is an amp a pitiful <10kohm, which even many tube preamps won't drive let alone passives. In fact most amps are >33kohm or higher to 100kohm or more. The loose industry standard input impedance has always been 47kohm, though it's not adhered to. So the impedance ratio of those 90% of amps regardless of volume position with a 10kohm passive will always be better than the industry regarded minimum ratio of 1:10 source to passive for the input, or 10:1 minimum for the output, passive to amp. And with the voltage of most of today's sources again are higher at >2v, and the input sensitivity of most amps are <1.5v, the only thing that could "clip" is the amp with too much volume from the passive volume control, so more gain from an active is not needed, in fact it's a curse as then the volume control can only be used right down low in many cases. Actives are not needed unless you have an amp that is 10kohm or less and/or it's input sensitivity voltage is higher than the source volt can give out. Or the other contentious reason to use an active pre is, if you like the colouration of active preamp, to me it's a bit of a ban-aid fix for something else that's not right better to fix it, as no active preamp sounds like the proverbial "a straight piece of wire" only direct source to amp can do this or second in line a passive volume control. Cheers George |
The combined aspects of the control can thus make the source less able to make bass at the input of the amplifier. This is not correct in this case, as with most of today's systems with low output impedance and high input impedance. If the source is low in impedance and in this case it is at 100ohms. And the amp has high input impedance and in this case it is at 100kohm. It doesn't matter one iota where the volume control is positioned here, these figures have a perfect impedance match regardless of volume position. As do 90% of sources and amps out there when mated to 10kohm passive volume controls. So the only reason for a lack of bass in this case (if correct) is a coupling cap that's too small, and that 100ohms source output impedance is rising at low frequencies which "would" roll off the bass. Cheers George |
honashagen OP The only reason for lack of bass, which would also rob warmth, is if the source’s output is "capacitor coupled", and that capacitor is too small. It’s a simple fix to double the uF (microfarad) of the capacitor and at the same time use a better "quality" one, as most skimp here with average quality industry ones. Myself, all my sources, and everything else is direct coupled, which has the best bass, and no "sound of a capacitor" in the signal path. Cheers George |
+1 PHD. As this tested McCormack shows, absolutely no need for an active preamp, when most sources are >2v or more out, and this McCormack only needs 828mV in for full output wattage. Stereophile: " Input impedance at 1kHz was a calculated 99.5k ohms, consistent with the manufacturer's specification of 100k ohms. The DNA-1's gain was very high, this gain ratio corresponds to a decibel gain of 32.4dB, implying an input sensitivity of 828mV for full 150w output." Cheers George |
I have sometimes thought about constructing a version of NP’s B1 bufferNelson did make first the B1 buffer for the Lightspeed Lightspeed so it could drive my customers low input impedance First Watts and Pass Labs. It wasn’t known as the B1 then, that came latter when he did a diy around it for the masses. Here is a simplified circuit of his for the Lightspeed, before it was called the B1. https://ibb.co/choBZS Cheers George |
mitch2 The Allergri is nice, but being a TVC (transformer volume control) they are coloured, nice but not transparent to the source. Here is an A/B a member here Rob_j did between my Lightspeed Attenuator and the Allegri. https://forum.audiogon.com/posts/77350?highlight=Lightspeed%2BTownshend Cheers George |
bacheVery nice, a little expensive.$995 You get the same type of volume control in the $699 Freya from Schitt. Plus you can switch it from passive (as the Alexus is) to two different active buffer modes with a little gain for some added colourations, tube or solid state. And it has rca and balanced. http://www.schiit.com/products/freya Cheers George |
Don't worry mrdecibel I had to have Nelsons view again, so I emailed him, and asked under "ideal conditions" when only the passive (<3o'clock) is used what happens to the active stage, this is what he said again without revealing what the "patent" part of the circuit was. So as you can read at 3 o'clock and below in volume all you hear is the source. " Under ideal conditions, where attenuation of the tap point is exactly that of the active gain, the active stage disappears, and any setting below that is the source. Non-ideal case would include distortion, which is attenuated by the ratios of the source impedance, potentiometer impedance and load impedance, the active circuit being s current source." As I said, kosst had a nerve to question what he said, as he isn't Nelson itch spot. Cheers George |
Give it a rest, it’s like you get on your horse, when you got a few shots of something under your belt, and that turns you into some one that just need to create angst. Leave it alone no-one is going to believe you over Nelson Pass about his own product the Aleph L, any thing you say against him is immediately swept under the carpet by anyone with any sense. Cheers George |
I’m over you. Go back to your F5 with high gain active preamp and keep pushing it, because you can’t use this Aleph L when it’s at it’s best in passive mode, only maybe after 3 o’clock, and as Nelson says you’ll take a sound quality hit. And please stop putting **** on the man, your not his **** ****, and never will be. Cheers George |
kosst, go away, where ever you go angst follows. The same goes for this Aleph L preamp it’s one of his favourites, and it came to us audiophiles when it was needed, as he said "we way to much gain in our sources and amps" so it’s not needed at all in the preamps. And as you can see in the link the Aleph L in red, it’s a direct path from input to output with nothing but input switch and resistors ladder switch in the signal path, only when the head of the volume arrow goes to the left of resistor marked RV6 does this passive become active. https://ibb.co/j8uwJn And as he states in the specs of the user manual https://www.passlabs.com/sites/default/files/alman.pdf "It’s Distortion at full is < 0.1 % THD," and below 3’oclock it becomes passive. "The sound is as pure as you can get. The distortion and noise figures you will get at this position are not easily measured." He also asks you to perform an experiment to see if you can hear the differences the active stage makes when it comes into the signal path above 3 o’clock from being a passive state below 3o’clock. Cheers George |
Like so many things he’s designed, it’s a quirky component with a narrow appeal.It’s one of his pride and joys as he’s stated, and said it’s a wonder it hasn’t made him filthy rich, not that he’s not already. Give him a break? You’re banging on as if this thing is audio divinity.Your searching for anything to put it and him down, and nothing is correct, as I have to post what he says and has measured in published in specs, to counter now 3 times what **** you’ve said. The reason you don't like it and keep putting *** on it, is because your F5 only has 15db of gain and you need a preamp or source with huge voltage gain, and this is not it. I WOULD RATHER BELIEVE HIM THAN YOU, AND THAT’S A FACT! Cheers George |
Please give the man a break, he’s earn’t his dues and his credibility, more than you, I, Ralph and everyone else here put together. No wonder he doesn’t come here. Nelson Pass on the Aleph L preamp. "Less than <0.1% at full volume" (with active gain in the signal path). This is minuscule and it’s probably 2hd. Knowing Nelson it’s the nice (tube like) distortion . And it’s only when the active circuit is fully in over 3 o’clock. All active circuits have some small distortion. At below 3 o’clock when it’s passive it’s probably zero %. Pass Labs: Printed SPECIFICATIONS Aleph L (volume control full clockwise) Maximum Gain 10 dB Freq. Response +0, -1 dB @ 10 Hz and 100 kHz Distortion < .1 % THD Give it a rest. Cheers George |
However, it must then be considered what happens between the passive preamp and the amplifier, how long are the cables, and what is the input impedance of the amplifier? All of these are factors contributing to the successful use of a passive preamp IMO. Nelson Pass addresses this also, as I have always said with the Lightspeed Attenuator passive, interconnect to the amp should be good quality low capacitance, which nearly all are, use <100pf per foot at 2mts or less. Nelson Pass quote: "The output impedance needs to be low enough to drive the capacitance of a reasonably long cable. How low does it need to be? I would say that it should be able to drive a 1000 pF load out to 100 KHz. The worst case output impedance of the Aleph L will drive 1000 pF with a -3dB rolloff at 225 KHz!!." Cheers George |
Believe Nelson Pass, his creds far outweigh anyones here. I believe he says below the input impedance is 20kohm, and states it in the specs, also 99% of sources will drive that, just some silly (pitiful as he says) dac’s ect that have high output impedance, tube buffer stages may not. Pass Quote: " Input impedance, the Aleph L is a nominal 20 Kohms. From the standpoint of input impedance, I can only say that it is a very pitiful source that cannot come up with the 100 micro-amps of current needed to drive this input." Cheers George |
As you can see, I’ve highlighted in red from input to output, if the volume is kept below 3 o’clock it is totally passive and the signal only runs through the source selector and the switched resistor ladder volume control. https://ibb.co/j8uwJn Nelson is right when he said: "The only component in the signal path is wire and switch contacts. At positions below 3 o’clock, the volume control functions as a precision passive attenuator using discrete resistor ladders." "Above 3 o’clock, active gain is ADDED to the output signal in 2 decibel increments, for a maximum of 10 dB,As a result, you suffer the effects of active circuitry only when additional gain is necessary." If anyone want to get one of these Pass Labs masterpieces that he loves himself, good luck as they are very rare and if they do come up used go for quite a bit of money. Cheers George |
I’ve looked at most of the schematics Pass has posted or published. Typically when he means to leave something out he posts a "simplified" Please post a link to this latest Aleph L schematic of his, not Milan’s early version mod’d interpretation of it. As I can’t believe Nelson would say one thing and yet mean another. As we’ve conversed quite a bit, as he designed a buffer for my Lightspeed Attenuator many years ago (later to be know as the B1 buffer) so it could drive his customers low input impedance amps <20kohms This is "simplified", yet not stated as so by him. https://ibb.co/choBZS Nelson Pass quotes on the Aleph L "At positions below 3 o’clock, the volume control functions as a precision passive attenuator using discrete resistor ladders." "At the 3 o’clock volume control position, the Aleph L offers a direct path from input to output. The only component in the signal path is wire and switch contacts." https://ibb.co/iVXKon "The only component in the signal path is wire and switch contacts. At positions below 3 o’clock, the volume control functions as a precision passive attenuator using discrete resistor ladders." "Above 3 o’clock, active gain is ADDED to the output signal in 2 decibel increments, for a maximum of 10 dB As a result, you suffer the effects of active circuitry only when additional gain is necessary." Cheers George |
And for those interested, the manual of the Aleph L passive/active preamp. https://www.passlabs.com/sites/default/files/alman.pdf Cheers George |
It is a provisional patent, which has maybe been granted by now on this special circuit, he may not have given the secrete to how he bypasses the "active stage" in the the schematic so it runs totally passive, after all it is patented. I've seen other manufactures post schematics and leave out their special circuits. Why no Nelson. His words "The only component in the signal path is wire and switch contacts."This means nothing active in the signal path. Same goes for my Lightspeed Attenuator there is nothing active or any switch contacts in the signal path just a passive ldr, yet it is powered by the mains for the leds to function. Yet it is a passive preamp with no gain. Cheers George |
Ralph (atmasphere) is trying to counter my quote with other quotes. But it still doesn’t get around the fact, that a favourite sounding Pass preamp of Nelson’s is the Aleph L. And this preamp is a totally passive switched resistor attenuator as his statement shows, only becoming "active" after the volume control goes beyond 3 o’clock. This is a patented "active" circuit, that he introduced is for the use with a couple of his Aleph type ect low very gain power amplifiers, which have very little only <20db or so gain, so then the "active" part of this preamp has to make up for this low poweramp gain, but the sound does take a hit as he says when the active circuit comes in beyond 3 o’clock. Thankfully most power amps on the market are much more gain and the "active" circuit wouldn’t be used, and the Aleph L will stay totally passive. Nelson Pass:As far as impedance matching goes, over 90% of sources and amps have a fine match with passive attenuators. It’s only the very few tube output >1kohm dacs and very low input impedance <20kohm power amps that can take a slight sound quality hit. As for interconnects quality low capacitance which thankfully most are, at 2mt or less in length. And you have what Nelson Pass describes as the best way to get the sources signal to the poweramp/s, with control over the volume. Cheers George |
I’ve done a blind A/B with 30 of our audio club members using a 10kohm passive preamp. A source with 2.5v at 100ohms output impedance. We had a power amp with 1.5v input sensitivity for full output, the amp had a special switchable input impedance’s on the fly 10 x from 100kohm down to 10kohm Nobody could tell the difference from 100kohm all the way down to 33kohm, when we got to 20kohm 5 of the 30 members though they heard something but weren’t sure, then it added up from there the lower we got. During the whole time we made sure the level was spot on within 1 mV from the amps output using a 1khz sine wave. Cheers George |
