Are passive preamplifiers OK?
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- Опубліковано 5 вер 2024
- It seems like a passive preamplifier would have the least amount of sonic coloration. So, are they the best to use over an active device? Have a question you want to ask Paul? www.psaudio.com...
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I made a passive preamp once from parts sourced from Radio shack. While it's a bit lacking in dynamics it sounded pretty good...
I bought an Ypsilon autoformer and ran DS through it. A stunning preamp but has to be matched with appropriately sensitive speakers & an amplifier with sufficient gain. Highly recommended!
FWIW, it's best to have your gain stage built into the front end as close as possible to the source, in terms of signal/noise ratio. Each stage adds noise, why amplify the noise introduced by previous sections?
Thanks Paul for informations. You always answer my questions when I have one. I go to your youtube channel and always find what I'm looking for. Thanks for your professional advices.
Answer: It depends on the signal source and the amplifier. Some combinations of these components work well because the source has low impedance AND the amplifier's input has low capacitance. Another thing to consider is the impedance of the passive preamp: The lower the impedance, the higher the bandwidth. Finally, as our host said, the output voltage of the preamp is critical to drive the amp to its full output.
Thanks for the straightforward explanation, Paul.
I have a couple of Alps pots on a box I put together decades ago.
Using this "pre" direct to the second input of my amps: I find the sound quite transparent, but lacking drive. I prefer my jfet preamp for the "added" body on most recordings ( does this make me a bad person?).
I also have several Musical Fidelity tube buffers.
You have given me the info I needed for an experiment or two ;-)
10k volume pot will only have 5k output impedance, max.. Think about it.. if you mesure the impedance of the output you will see two varisble resistors between 0-10k but to you on the output these will look like they are in parallel.. so the resistive midpoint of the pot will be one varisble resistors going up and one going down..
With a 10K pot meter you get a maximal output resistance of 2.5K. Of course Paul is right that passive preamps are not the best way to go. I wouldn't know about the exotic transformer based volume controls, I suspect that they do better in such a case.
That's it, I'm going for the Schiit SYS to let me switch between my mixer and DAC.
Hi Paul,
Thank for you answer! I took your advice and got myself a tube buffer. I am now in process of upgrading the tubes, opamps and capacitors. Just with better tubes the sound quality went through the roof.
I used a quality passive pre-amp for several years, then on a whim, I borrowed a BAT pre-amp from a dealer. The sound stage doubled in size. The sheer dynamic scale of an orchestra increased significantly. I bought the BAT on the spot. Later on, I bought a Benchmark DAC with a headphone amp and tried connecting that directly to my speakers. Everything shrank back in size. So once again, back went the BAT.
Well in my understanding keeping things simple is better for sound quality
I’ve found active preamps (especially a good one) always seems to add something more than passive.
And that can be a problem if it adds colour . It may sound nicer to your ears , but also less faithfull to the original signal of the source
@@gerritgovaerts8443 Well, it probably changes it less than just adding a variable resistor. If you want that, you should just hook up your source directly with as short a cable as possible. But multiple sources with such a setup would be a huge pain.
@@wellivea1 I only listen to one source , my digital lossless library on my PC . Speakers are 4-way active with a digital Mini DSP Xover . Once you have that active digital Xover , it's easy to use the digital volume control that is integrated . No need for active preamp , nor passive pot . Problem solved
Okay, well that makes sense in your case, but our systems are very different. I run my turntable into a 12AX7 based phono pre to a 6SN7 based pre to my SS power amp. We’re just dealing with different sources, so we can still be friends. 🙂
@Larry Niles So what ? I dissagree with Paul and Arnie Nudell on their speaker designs . I rather follow in the footsteps of a guy like Siegfried Linkwitz with a PhD , multiple papers published on acoustics and electronics plus a few patents . If you study the mathematical dipole theory that he devellopped , you cannot escape the conclusion that the Infinity IRS is a big design blunder . I can't really blame Arnie for it , because that dipole theory was not known at the time , but the new IRS killers have the same design fault , having a too wide baffle for mids and highs that prevents perfect dipole dispersion and thus constant directivity . The use of a U-frame also baffles me and surely only degrades the polar response even further. The often raised arguments against digital volume control (decreased resolution ) can be raised against analog control too : you loose some detail as your signal steadily falls deeper into the noise floor of your active electronics . In practice , both can work really well . I am sure , Paul can design a good class A or AB amp or a preamp, but I would never buy a speaker from him . And for amps , I am more of a Bruno Putzeys and Nelson Pass fan : these guys also support the DIY community with free designs , and affordable kits . Bruno also being the guy who made the breakthrough Hypex class D amps (UcD and nCore). Nelson Pass needs no recommendation
I accidentally made my Stellar gain cell DAC a pass through DAC skipping the volume control. Holy smokes it was loud. I didn’t realize what I had done and I can’t believe I still have speakers. That corrected I now rarely get passed 35 on the volume knob.
Beautifully explained.
So are you saying a passive circuit is not as good as an active?
Related question, but would the same issues apply where a CD player (for example the Marantz CD63 KI Signature) which has a variable output, which can therefore be plugged directly into a power-amp? I did that for many years when it was my only source, and I preferred the sound, far more clarity, than first routing the CD player thru a pre-amp. Today, streamers such as the Cambridge Audio CXN V2 can also act as a passive pre-amp (and a DAC), meaning I can route a CD transport thru it, as well when using the streamer itself. Again, to my ears, the sound is pretty good without using an active pre-amp (altho mine is not a high-end system).
Some preamps come with a bypass output. Doesn't that turn them into passive preamps?
Hi Paul. I have Leak 20 with Harbeth p3esr. I use iphone 4s witch I like better then new ones. The sound is clear and voice forward to me but I feel some time drums and voice and the end to sharp like ts...... Somebody advice to buy passive preamp. Will i get some different sound? As I understand passive only volume control and inputs. I have a doc iphone to Fatman tube amlifier with remote even but need to be repaired. Is doc can be like some preamp? I use ipone 4s with my Denon AH D7200. It is perfect, I dont need any amp.Thanks for videos.
Mike
Passive preamps certainly CAN amplify the input signal if they are transformer based. A well design source output don't need active preamplification.
wow cool
You need to look at how things work technically to understand things. The sound out of a preamplifier should be completely equal to the sound right out of a CD player. This is the perfect preamp. Many use a pre-amplifier or op amp ic as an equalizer to get the proper sound out of speakers that do not have such good sound quality. The main problem many times is the speaker which is not good or sound source which is not good.
Paul, I have a suggestion for a name for your new studio. Either Paradigm Studio or Paradigm Records. I think Paradigm is the perfect word that describes what you are trying to do with the studio--and with PS Audio.
Just a suggestion.
Mark in Ft. Smith, Arkansas
My Tisburry passive has zero ohm impedance, And costed me। atiny fraction of a regular pre amp. In this case, it does not create any impedance issue between source and the power map, does it ?
i have mine with my Rotel x2 with cd with more transparent detail, if you put the rac in the output it's even better but at the volume 1 its ver loud
Yes, I had a passive pre years ago and a a friend came by with a Dayton Wright pre amp, night and day difference. Bass slam and well everything, I was 16 old old at the time. Paul is correct in saying a buffer can work well. Running a nice tube pre now. :)
would it be a good idea to use a passive preamp between an AVR and a separate DAC for 2 channel, used as an AV bypass. It seems you just turn up the volume on the preamp and use the source volume controls to run the amplifier. I've looked at preamps w/HT bypass and I cant seem to find one that isn't loaded with features that I don't want or need. I have one room for entertainment so my system must be combined. I pretty much only stream music and my AVR does a decent job at two channel, but I would like to get back to a real two channel for music.
They are absolutely ok. With so little as possible components inside it :)
Of course they're okay, I have one, it's the best sounding piece of Hi-Fi gear I have ever heard, and it's made from an old integrated amp that died, anybody that says they aren't acceptable clearly hasn't heard one.
I too am using passive and very happy
@@ixfxi me too more detail n clean acoustic
Couldn't imagine my setup without my micro iTube2! I use it at 0dB gain so technically it's in passive mode, but what it does to my audio is pure magic!
A pot in a box with a buffer? Isn’t that a pre?
Great Paul.
well hey now i understand preamps
all im getting these days is sellsellsell
Go integrated!
so a preamp is a unit that comes before the amp that primarily is used to switch the different inputs.
I was just thinking about this topic when it popped up in my recommended
The term "Passive Preamp" itself is an oxymoron. If there is no gain, there is no "preamp". You cannot play vinyl or open reel tape because of very low signal and no equalization applied. For records, I guess you could use a ceramic cartridge, but do you really want to go there?
Yes , but that only applies to RIAA boost and correction for the weak vynil source . Tapes , DAT , CD , SACD , DAC's etc ... do not need any correction or boost (except for the power amp gain)
Older open reel tape machines had a direct "tape head" output which required NAB or IEC equalization, but you are correct in that ALL of the tape machines since the late 1950s, have these preamps and equalization built into the tape deck. So, with no pre-amplification you would have to buy a separate RIAA phono preamp or use the lowly ceramic cartridge with your turntable.
And what do you call the device you use to connect your computer to the Internet? A modem, or a router? What most people call a modem these days does no modulating/demodulating of analog audio signals whatsoever.
I call mine a router. I am not sure how this relates to anything else in this thread.
I guess what you are saying is that people tend to hang on to older terms even as the technology advances.
(Such as saying they will "tape" a TV program when they mean DVR, or calling a video "filming".
@@swinde "I guess what you are saying is that people tend to hang on to older terms even as the technology advances."
Correct. And I'm not sure what you have against ceramic cartridges. My Decca Deram was certainly "transcription quality" as claimed by Decca:
Tracking force: 2.5 gm. Frequency Response: 18Hz - 18kHz =+/- 3dB. Separation: better than -20dB at 1kHz. Output 200mV at 5cm/sec.
Shure M55e "Tracking force: 2 gm. Frequency Response: 20 - 20 kHz
. Output voltage: 6.2 mV per channel. Separation: >22 dB at 1 kHz.
I remember being quite disappointed that the promised "dramatic improvement" of moving from the Decca to a moving magnet cartridge wasn't at all evident to my ears at least. The Great leap Forward came with the acquisition of a Decca ƒƒss along with the realisation that there are a lot of shitty recordings out there. The BBC were still using Deca Deram cartridges in their broadcasting studios in the early 1970s.
"Lyubo shimich" is how to say the name.. good try hehe
I have a Nelson Pass B1 buffer.
It is the perfect pre-amp in my opinion, it has a gain of 1 :)
No
The term "passive preamplifier" is a misnomer. To amplify is active by default. passive would only be an attenuation never an amplification of power.
If someone invented the "something from nothing" amplifier theyd be pretty F"n rich!
If you drop the J out of that name and pronounce it Lubo you get close to the proper pronunciation of that name. LJ is an approximation for a letter and sound that does not exist in the English alphabet.
Ps 4 owners here?
Mine is the Ps 5.
PSIV in the house
@@excessivity 🙏😁
And a 6.2 :) no phono though :(