How to match a preamp to a power amp
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- Опубліковано 23 сер 2018
- What factors do we look for in the specifications of preamps and power amps to make sure we have the perfect match. Paul gives us a quick tour of the challenges and solutions to properly matching preamps to amplifiers. Have a question you want to ask Paul? www.psaudio.com/ask-paul/
I am getting close to publishing my memoir! It's called 99% True and it is chock full of adventures, debauchery, struggles, heartwarming stories, triumphs and failures, great belly laughs, and a peek inside the high-end audio industry you've never known before.
I plan a few surprises for early adopters, so go to www.paulmcgowan.com and add your name to the list of interested readers. There's an entire gallery of never before seen photos too. - Наука та технологія
@paul while most other channels focus on reviews of products, I find your channel providing the fundamental concepts of sound and electronics. This is what is needed to spread and grow the science of sound. Thank you for doing it the way you are. 👍
Nice story about rosé - Paul, I loved it!
This was a great question. I'm of the school of thought that while having everything from the same company ensures that all connects nice and synergy between the components is a given, the problem is that sometimes that is not necessarily good. Here is the problem I have in theory: Sometimes the company one is most interested in for say amplifiers has great ones, but the preamps from the same company do not meet needs or just aren't that great in some respect or visa versa. That begs one to mix brands in that case I would think. I don't see anything wrong with doing that to get the best of both worlds so to speak as long as the tech side matches up correctly. Now, yes, I can see a list of challenges or problems trying to tie a tube preamp to a solid state amp or visa versa even in the same brand and I personally question what that would really give one at the end of the day.
By the way, balanced or single ended, both are fine, I have no problems with either. If I had balanced inputs on everything along with single ended, I'd go with balanced if I could most likely, but that's me.
I would like to be more like you when I grow up. Knowledge is power!
Never had the chance to listen to PS audio pre and power here in UK but I generally reckon a valve Preamp from Audio research takes some beating but if matched with the same company's power amps sounds a bit clinical. Matching with a Constellation Audio solid state power amp is a match made in heaven - valve warmth from the pre and refined muscle from the power amp. I have tried Constellations own preamp and it is so neutral that I crave a bit of warmth. Mix and match carefully for me.
Thanks. Very helpful. Shouldve watched this before I bought my combo. :)
Sir....
what if i match "ampeg scr di" to "ampeg ba 108" does it suit for impedance requirement that you mentioned 10 time should be higher than preamp ?
Hi Paul!
I want to try using my Violectric V281 as a preamp for my Woo Audio Wa22 1st gen.
The impedance matching is fine for those two (0.2 to 100k) both have ballanced inputs and outputs, both are headphone amps.
My question is - since i want to use the V281s volume pot in which position do i want the Wa22s pot? Full throttle or somewhere in the middle?
Is there a possibility of magic smoke?
I have a 20w mini terror tube pre amp at 8om out put to a solid state 200w head running to 8om cab. Is the suitable or will the amp blow?
Hello Paul my question is.i have a pioneer 939 receiver and I’m using it as a pre amp and I’m using a NAD thx 218 power amp is this a good match
My Shindo Masseto preamp only had single ended connections, using those basic appearing Switchcraft jacks that Ken felt sounded best...
Hello Paul, I need your help. I have the Paradigm Studio 100v3 front speakers and paradigms surround and center speakers. I just bought my self the NAD S250 power amp, What pre amplifier would I require to match up with my power amplifier?.
i need to connect 6 stereo power amps to 1 preamp, do i need any modifications boss
is there an easy way to measure the output impedance of the preamp and the input impedance of the power amp?
Thanks for the explanation, with a caveat. You are assuming too much knowledge on the part of some listeners. I am trying to determine a correct match of preamp to a Crown Audio power amp. When you got to the part on balanced vs open ended, I have no clue what that means. So, now I have to start searching for an explanation of that.
I am new to this. But I have an emotiva xpa dr2 power amp. Will the schitt freya be a good match for that amp?
Hello; Can you use a solid state pre-amp with a tube power amp,
hi paul, thanks for your post on how to match preamps to power amps. coincidentally i bought a ps audio 6.1 several years ago along with a hafler 500 amp to power my polk audio tsx550 towers mainly to listen to music. i was pleasantly surprised to see that you are associated "PS" after watching your video because i'm in the process of researching the technology of my units so that i can refurbish them. i'm educating myself so that when i get them worked on i can feel confident that i'm making wise decisions in either investing in the units i have or finding a better synchronicity! the input impedance on the hafler is 47000, so if i understand your post correctly, the ps 6.1 and the hafler 500 are perfectly fine to hook together ?
What preamp goes with audire crescendo amp 350watt
Compatible signal levels are an important consideration, too.
What you think of the tube preamp and class D amplifier ?
Loved 3:56 Balanced all the way 👏 ...Sprite and Orange juice in a pinch when Sanpelligrino is unavailable
Then how would all those pre amp pedals work then? Your definitely using it with different amps.
I was wondering this as well. Most informative. Thanks.
Good info!!👍
5 that's right 5, high end audio designers and engineers beside Paul have also told me use the balanced outputs of my preamp to my balanced inputs of my amps. It sounds wonderful.
Why would it take 5-6 people to convince you that was correct?
the whole "impedance matching" issue has always been woefully unaddressed (or incorrectly addressed) in the audio community. paul has it right here! though there is a little more to it...when transmitting signals, your output z from one device and the input z of the next device will dictate whether you get the best voltage transfer, best current transfer, or best power transfer from one device to the next. the 10+/1 ratio is applicable to all modern solid state hardware, because solid state preamp and line level amplifiers are operating as voltage amplifiers, and best voltage transmission happens with a low output z to a high receiving input z. current transfer is rarely (never in my experience) a concern, as even current amplifying devices like power amps will still have line level voltage amplifier stages buffering the input. the only other real concern is power transmission, which is best achieved when the output z and the next input z are matching. this is why we match from power amps to speakers, usually at 4, 8, or 16 ohms, to maximize the power transferred from amp to speaker.
Paul, what about matching PS Audio's BHK pre amp with your Stellar M700 monoblocks? ...makes a lot of financial sense...but what about compatibility/synergy (sonically)?...thanks, greetings from Malaysia.
Hey Paul that was veryhelpful, liked the funny parts too, last thing...I tried with rcas instead of xlr and was much better.......NOT!!
I'd like to think that a good hi-end DAC, such as the DirectStream, has already put its best effort forwrard if it has XLR output that can supply the amp directly. Why rely on the pre amp? And if there is good reason, why isn't the DAC doing it?
Larry Niles That's interesting, thanks for the reply and I will look for the video. I suppose the proof is in the listening. I'm very hesitant to place another device in my pathway. I use an SOtM 200Ultra as a source with an expensive linear power supply. This feeds a Mytec Brooklyn DAC. So much care has been taken to control jitter. I've found a subtle difference even when moving my NAA farther away from its linear power supply. The thought of transferring it to another device makes me nervous.
Larry has mentioned one aspect of adding a preamp. The other issue is sometimes you need a preamp for more signal gain. There are two types of amplifiers you can buy. Integrated amps and power amps. Integrated amps are designed to run on just a few volts of signal. A dac usually outputs about 1-2v and this will drive most integrated amps. Power amplifiers on the other hand usually need much higher input voltages. I have seen a couple power amps require up to 6v input, and im actually building myself a tube power amp that would need 10v input. So a preamp is required to take a voltage from the dac and amplify it enough before the power amp (hence "preamp") to reach the desired input voltage.
This voltage gain is part of the reason why adding a preamp can improve sound quality to the system. By boosting the signal with a quiet, high quality preamp, you can turn down the volume on your main amp which decreases the amount of work it has to do.
@@tristanjones7735 For one given output level on the speaker outputs, the amlifier must do the same work regardless of how much gain the signal has. You might get higher noise floor if you must amplify it more. The preamp regulate the amplitude to be lowered from the full line signal which would be far too high to send into the power amplifier. The volume control cranks down the voltage, which is related to the volume the power amplifier produces on the speaker outputs.
@@oysteinsoreide4323 I think you may have misunderstood what I was getting at. There are actually amplifiers out there that need signal gain from a separate preamp in order to provide the max output level the amp is rated for. Its rather unusual to find amps that are designed like this in modern times, but they do exist.
@@tristanjones7735 Ok. But I didn't think of amplifiers that wasn't made to current line input and output specifications. Is it because they don't ampliy it enough if the line in level is too weak? Is it a special type of preamp you need in order to get enough juice?
In my experience a balanced cable will always sound like it has lower noise but i'd rather have a high-end single cable than a cheap balanced cable as long as noise isn't a real problem. The construction quality of the cable makes a difference whether is balanced or not.
My experience says the Stellar GCD -> Levinson 333 amp sounds much better with any of the balanced cables I've tried than with any of my choices I have for pretty high-end single ended cables.
Thank you sir
Can i connect any other amp till my integrated amp to give more power
Did you change the name of the channel ?
I disagree with the assumption that balanced always sounds better than single ended.
It very much depends on the configuration of the input stage of the power amplifier.
I have owned several power amplifiers where balanced interconnect sounds clearly worse than single ended and when measuring distortion from the input stage balanced differential connection might remove a lot of the even order harmonics which definitely changes the sound for worse.
The impedance "matching" discussion and the balanced vs. un-balanced arguments makes sense..But the "synergy" stuff is totally subjective opinion. I connected an old SONY TA-2000f (unbalanced) Pre-Amp (1k output imp) to an Ashley 15-band EQ (22k input imp) with balanced inputs and then fed the output to home-made unbalanced "distribution box" (25k input imp) connected to several power amps (unbalanced). It all sounds great with very little residual noise. Just use high quality (short) cables.
I like blending tobacco and whiskey. For amps and preamps, I prefer a proven path, as Pol said, one company.
I have no idea what your talking about, I’m hyper-fixating. But it was worth it to hear the story of your mother mixing wines.
Sound advice.
So running 1000 ohm resistor from your cable what has the resistor connected to it to your Poweramp will always be better?
John sweda You are joking, aren't you ? If that would indeed be 'better', would it not already be in place, and advertised as such, accompanied by a "slight" hi-end fee. ;)
Tubetinkerer no clearly it is not in place as Paul has said. If you've Got a mismatch system than 1000 ohms at least should do it some favours
John, the issue with most home stereo is the preamp is not designed to drive that low of a load impedance, so the overloaded preamp output will be distorted. In commercial audio where long interconnects is the norm to reach from the boot to the power racks, the output impedance of the console is designed to drive into lower impedance loads. For example of a typical mixing console is a Mackie SR32-4. It has an output impedance of 120 ohms on all outputs and can easily power 10 power amps daisy chained to drive a cluster for a concert each with 10 K input for a total of a 1 K ohm load on the mixer.
Most home gear is not built to drive this type of load. If you have a scope, try a 1 K termination and see of there is any resulting distortion. Some pre-amps can support this. If you get a service manual and schematic, you can look up the output section to find it's abilities from datasheets. If it is only a low power op amp, I would not overload it.
Tubetinkerer, most manufactures stick with best known practices and keep the inputs high so there are no problems when matched to other manufactures gear that can't drive into lower impedances. The industry standard for RCA audio termination is 47K ohms. Making an amp with a 1K or lower RCA input is going to be a problem when matched to other manufactures gear. The blame will be on the amp for the distortion from an overloaded preamp. Manufactures don't want this problem.
isettech I am with you. In guitar gear input impedances are usually at least 100k. (Yes, there are some exceptions) Anything less will load the signal and will cause an audible roll-off of the high-mids and highs. I merely wanted to highlight the mumbojumbo surrounding impedances.
People tend to generalise and there is no generalisation in impedances, just some rules of thumb. Impedance matching is an engineering job, not a "let me roll my resistors like I roll my tubes" kind of thing, right ? ;)
This is why guitar cords are always short. A long cord will change the sound drastically due to the capacitance of the cable per foot adding up. An on stage preamp to drive a DI, or a powered DI, is required for pro sound and studio recordings, while a dynamic mic on a 100 foot snake is no problem. Guitars and their pickups were designed for the input impedance of a tube which has carried forward into the solid state equipment. A guitar amp has high impedance inputs. Along with this input impedance comes all the cable limitations and hum and noise pickup when there are poor connections that low impedance mics simply don't have.
Here is a link to a good article on DI boxes for guitar. www.prosoundweb.com/channels/live-sound/di_boxes_for_guitars_different_approaches_for_acoustic_and_electric/
My integrated amp has pre-out. Does that mean I can also use it as a pre-amp if I bought a power amp?
You should be able to,I'm doing this on my Marantz AVR.
OK thx, thought I could, just wanted to make sure first.
Taffy O'Keefe No, you can use your integrated amp as a poweramp dude.
No, I can use it as an integrated amp or just a pre-amp.
And to make it more confusing, the output transformer on a tube amp should match the impedance of the speakers. For maximum power transfer the output should match the input - in power amps anyway.
Manard, Actually the output impedance of solid state amplifiers is a fraction of the speaker impedance to provide speaker damping. If you go too low in speaker impedance on a solid state amplifier, the excessive current will damage the amplifier. This is why the nominal impedance of the load is stated. If your amp has the damping factor listed, this is the inverse of the amplifier's actual impedance and is often in the milli-ohm range. For example an amp with a damping factor of 30 has the 1/30 impedance of 0.0333 ohms. Tube amps with their warm sound have much lower damping factor as their output impedance is much higher. Google damping factor of amplifiers for more on the subject. This is why a tube amp has nicer clipping than the harsh brick wall of a solid state amp. It has a warmer fuzz for guitar distortion.
great
Hmmm funny that Benchmark says SE is better than balanced.
Paul, I'm going to cover two points from an audio perspective and from an RF perspective because they are related.
First on the block is the impedance. The minimum of 10:1 is strictly for the benefit of low cost output drivers of the preamp. In commercial audio this amp input impedance permits daisy chaining either power amps or powered speakers for use in a cluster for concerts. Many powered amps have the pair of jacks built in for daisy chaining multiple powered speakers in a cluster. Sonically this actually is not the optimum solution, however at audio wavelengths the non optimal effect is negligible and is generally ignored by engineers. The design theory is a lightly loaded audio preamp can produce a clean waveform when it is not heavily loaded. This is fine for short cables and audio frequencies. For audio short is defined as under 100 feet.
From higher frequencies in RF and down to 100 KHZ is considered radio, and some radio is near the audio band. The considerations for RF is maximum power transfer on a cable with minimum reflected power. This applies to almost all high frequency applications such as twisted pair CAT-5 network cable, Cable TV, DMX-512 lighting control, and in audio, low impedance microphones and POTS telephone service. The driver is lower impedance or matching the impedance of the transmission line (wire, cable, interconnect) and the cable is terminated at the cable's nominal impedance. This match is required to send signal any significant distance without distortion. Examples of impedance not matching at higher frequencies thus limiting max cable lengths to very short distances include MIDI cable, RS-232 data, unbalanced RCA audio, and speaker cables. These cables should always be less than about 20 feet to function properly. The longer distance version of RS-232 data is balanced RS-485 which is terminated into it's impedance and can travel over 10 times the distance of RS-232. This improvement in distance is due to the cable impedance and it's proper termination.
In pro audio XLR line cables are about 80 Ohms impedance depending on the manufacture. Most consoles are stable into 100 Ohms and amps are either 10K or 20K balanced. Jumpering a bank of 10 amplifiers in daisy chain for a cluster is normal practice with a load of 1K or 2K which is well within the driver range of commercial mixing consoles. For example a Mackie SR32-4 mixing console is specified to have an output impedance on all outputs of 120 Ohms. Loading it to 600 ohms is not a problem at all.
POTS telephone service in the US is 600 Ohm. Works fine in rural areas with overhead lines.
Networks using twisted pair are terminated into 120 ohms on each pair. So is DMX-512 at the end of the line for long runs.
Cable TV on coax is terminated into 75 Ohms, same applies to old analog TV video cameras and monitors.
Baseband analog video was a signal that starts in the audio band and has to remain flat well beyond ultrasonic sound. An analog TV or CCTV signal was from 25 or 30 HZ to 6 MHZ. Most audio equipment interconnects won't pass this bandwidth of a signal without destroying it and it won't work if a long cable is not terminated into the cable impedance.
The same high bandwidth rules could be applied to high quality sound to carry sound from one place to another. For some critical applications I have put audio on RF cable and terminated it properly to run sound to a 2nd venue location.
Two way communications use antennas and coax with 50 ohms impedance. This uses coax, not twisted pair.
If the preamp was properly designed to drive a balanced line and had an impedance of 20 ohms or less, it could drive insanely long interconnects terminated into the nominal impedance of about 100 ohms with insane flat response well beyond the upper limits of audio, but as stated in another video, engineering is a trade off. Lower current drivers and higher Z loads are fine for lower cost and short distances which in a home are well under 50 feet.
Just my 2 cents worth from an engineering perspective regarding cable impedance and proper termination.
A quick note of speakers.. They are a complex impedance, not a simple resistive load. There is not a cable made that is perfect for a speaker other than very short. A dynamic speaker won't match the impedance of any cable at all frequencies. A long interconnect is no problem as it can be terminated close to it's nominal impedance. This is where I disagree with Paul. Higher impedance in an amp is not better for the input of amplifiers. Lower to match the cable is best for the cable and distance for frequency response and, higher is better for low current preamp drivers for lower distortion in the preamp. The best compromise for most home audio is 20-50K and keep the distances reasonable.
Well... I'm sure he will take that on board? I'm unsure of the point or your little essay here. Are you trying to educate Paul, or the rest of us who aren't engineers and just want ideas for well matched hifi?
It is an introduction to engineers for the separation of pseudo acoustics and solid engineering. This is specifically aimed at those selling $100 and up patch cords. There is not a TV studio in the country that needed exotic cable to patch an analog color TV camera to the video switching console. BNC connectors were the order of the day with 75 ohm impedance cable and equipment that terminated at 75 ohms carried video signals just fine from 30 HZ to 6 Megahertz. This was a 1 volt Peak to peak signal. Audio could have been designed to use the same bandwidth with the same response as video. Audio did not take this path because the higher bandwidth requirement does produce higher noise levels in amplifiers. Engineers working with OP Amps deal with balancing gain, bandwidth, and noise as they are related. Lower current drive from audio preamps and higher impedance inputs in amplifiers is a trade off for lower noise but a limited interconnect cable length. Pro gear drives balanced cable with a lower impedance and the amplifier inputs are lower input impedance input for use on longer cables than home equipment. Neither are designed to match the impedance of the cable except in digital snakes for digital mixing consoles which use 110 to 120 ohm network cable.
An example of this is the Behringer S32 with servo balanced XLR inputs and outputs all 32 channels on a CAT5 network cable up to 100 Meters long. This is the only analog portion of the system up to the output DAC to drive amplifiers. This keeps all analog cable into the system to under 30 feet.
Yeah, but your Mom LOVED the Wine concoctions (COLD) that she created for herself... and that's ALL that counts!!! All of us in this Audio hobby could Learn a thing or two from your Mom :)
It would be better, in my opinion, to refer to "compatible impedance" rather than "matched impedance" because there is a signal transfer technique that requires input and output impedances be equal, i.e. matched. This technique is not often seen these days but the potential for confusion continues.
Michael Kesti Impedance matching is only used for current driven devices, e.g. dynamic microphones (600 ohms) and of course loudspeakers.
A preamp is a voltage source and should therefore be loaded as little as possible. You really don't want your, say 50-100 ohms output to be loaded with a similar impedance, because the signal will be reduced to half the voltage being generated. Besides it will cause a significant roll-off of certain frequencies and maybe even clipping distortion. If you don't believe me, simply connect a 50ohms resistor across the two conductors (signal & ground and still connected to power amp of course) of your interlink and experience it first hand. (The 50-100 ohms also functions as a short-circuit protection, so you won't damage anything)
As much as I would like to have preamps there are so little reviews on them
Simple solution. Integrated Amp-"all inclusive with both digital and analog I/O"- plus DSP speaker correction and multi-channel operation. Separates constitute a recipe for mismatching: One exotic preamp to an exotic power amp and or wonky matching speakers all with different demands on Z.
Somebody bought a lot of Elac speakers there.
why do you have so many elac's in the room? :)
i wanna know too. in the past i've always seen him with elac speakers.
www.psaudio.com/products/sprout-elac-system-2/
Probably because they play very well with the Sprout and likely with the other gear too.
They sell Elac bookshelfs with Sprout as a combo system.
Based on your story, I would actually consider your mother a purist among connisseurs. Someone who isn't afraid to suit their taste against the "rules" and taking the time to suit themselves just right.. I like my coffee room temperature,, and if it's too strong, I can get cooled down quicker by adding a little bit of water. Right on to your mother.
I guess this is why many of the 'pro' reviewers seem to stick with matching pairs from the same manufacturer, esp when the power amp costs somewhere north of 50K USD. Your point re impedance is a good one - I often wonder just how successful some 'tube preamp into solid-state power amp' match-ups are when there appears to be no quoted output impedance for the pre : I guess some folk just get lucky. Replicating some of these combinations would require a Jeff Bezos' budget ;)
Thanks for the video.
Balanced vs unbalanced out- to input doesn't 'sound' different. Balancing is a method of suppressing stray noise.
A solution for a non-existent problem at 0dbu and 2 ft of well shielded cable. But... whatever.
I am not cursed with golden ears....
Larry Niles Thank you.
More gain, indeed. But if you say that it sounds different, I can only take your word for it. Technically, there should not be a difference other than more gain. How would you quantify "better" ?
It depends on the implementation. Look at the B.M.C pure dac for example
Danny Woods Why ? Please elaborate...
Perhaps the blend of white and red wines helped make you.....
Yes, fine wines are blended from different years and terroirs. And your mother was not wrong to put ice cubes in the red, ze French do it too. They even mix red with sugar or soda. So that their kids can become proper drunka... ahem, connoisseurs!
I can make this real simple buy pre from the same company that makes your amps (duh) 🥴
Shut up bitch I'll beat your ass
well his mama was a wino. but that was a long time ago.
Hahahahaha technically speaking.
You’ve got some good videos but you have a tendency to ramble on about other things and not stick with the subject at hand
The wine analogy was charming
First