Why amps, pre-amps, integrated amps???


OK, having thusfar asked questions on this forum that have exposed me to the odd raised eyebrow and snicker for my gross audio ignorance, I shall go farther still, and venture to ask: What, exactly, are amps, pre-amps, and integrated amps??. More to the point, what, exactly, is their purpose; what do they do? And why do pre-amps and amps still exist comfortably in the audio market when you can get them combined as an integrated amp?? I just don't get it. Would much appreciate your learned revelations - after, of course, you've finished with your hoots, knee-slaps, and cat-calls.
georgester
Separate preamps and power amps have a certain cache that dates back to the days when tube equipment was the only amplification option.

The stuff was big and heavy, especially so as an amp's wattage rating increased. A higher power integrated amp could quickly become too big and heavy to be practical as consumer gear.

There was also the issue of the high power components on the same chassis interfering with the small signals handled by the pre-amp (especially the phono section).

The ultimate expression was a separate preamp and two monoblock power amps.

In the 1950s and 60s, tube integrated amps were typically limited to lower power units. (The classic integrated Dynaco SCA-35 was 17 tube watts a channel.)

These days, especially with class-D amplification, weight and chassis size are no longer an issue for high power integrated amps. There are some who would argue that the improved signal isolation of a separate chassis for each section is still worth it, but even modern integrated gear is incredibly quiet.

However, if nothing else, the cache of "separates" remains a good selling point for high-end gear.
A receiver is a tuner (to get radio), a preamp (selects what input you want to listen to and controls volume) and an amp that drives the speakers. Basically 3 boxes in one box. If the receiver has a phono section and a headphone section then make that 5 boxes in one box.
An integrated is a preamp and an amp in one box, with phono and headphone depending on the model.
Preamps simply select the input and control volume. And some preamps include phono and / or headphone as well.
Amps just take the input from a preamp and amplify, drive the speakers.
Receivers, preamps, amps, headphone amps, phono preamps all exist because "different strokes for different folks".
Most people on this forum would say that the best sound would come from 5 separate boxes (if you were interested in all 5 functions). I run an integrated amp with a separate phono amp. I'm not interested in radio or headphones. I might get better sound from a separate preamp and amp, but it would also cost a lot more, I'd need another AC outlet, more shelf space, etc. so practical considerations also exist on why people choose what they have.
There are slight variations (example an amp can take a signal directly from a CD player that has a volume control, things like that) but for the most part I think I covered it pretty well.
Oh yeah, and a CD player is also a transport and DAC, so you can consider that 2 boxes in one box also.
I was led to believe that better performance from separates could be achieved with being able to better split up and manage the power supplies. Not sure if that is true or not. In a general sense, it is always better to have more options so the more you separate components, the more options you have to mix and match and upgrade, etc. To me, I like the integrated approach although I prefer to have a stand alone phono stage that offers more flexibility than you will usually find in an integrated with a phono. An integrated also means you have less to worry about in terms of interconnects and power cords.
Each separate component has its own sound, and capabilities sonically, and mechanically (flexibility).

An integrated, or receiver, can be good for someone who likes the sound of everything ( each individual section)and flexibility it does.

I'll try to keep it simple with the three you mentioned:

The preamp has its own sound, certain types of needed inputs for everything you want to connect to it. A preamp is needed whether it's separate, or part of the integrated, or receiver.

The power amp section has its own sound, and output power limits to drive different types of speakers, or more than one pair if needed. It can be picked out to drive very demanding speakers an integrated, or receiver can't. In some cases, a power amp may not need a preamp, but it would need a volume control, and possibly a selector for multiple inputs like a preamp would have.

Every tuner has its own sound, and signal performance, and other features whether presets, or other preferred items.

Then you can get specialized. If you need a super good tuner for distant stations, or live in an area where the station you like has another one interfering with it. The separate tuner may out perform a receivers tuner, if this would be the case.

For the amplifier section. A separate amp can be picked out
to drive very demanding speakers, a receiver or integrated can't.

Then you could get more extreme (or specialized/custom) and mix tubes and solid state for sonic reasons, plus more variable capabilities and limits each type has.

You could use a strong tuner for a distant station, and low powered integrated, if you don't need the power for loud listening, or certain types of demanding speakers, for one example of using separates.

The list could almost be limitless for our personal preferences for all of each of individual component we choose limits for our preference.

So, if a receiver does everything to your satisfaction, you shouldn't need more. The same for an integrated if you don't need a tuner.
If you have a company known for great amps, another known for great pre amps, yet others building better tuners than others and on down the line then seperates allow you to go in whatever direction you wish. The reciever or integrated locks you in but folks with seperates can get the sound, features or even cosmetics in any combination they wish.
If your speakers need much power, you need a bigger amp(s) than an integrated can accomodate. It is difficult to find an integrated which equals the performance of separates. They necessarily involve compromises due to size constraints. The arguments in their favor are that they potentially allow one to eliminate a whole bunch of expensive cables, and usually take up less space. However, some "integrateds" have a separate power supply, which negates the size advantage.

You see an awful lot of "reason for sale - downsizing" ads on the Gon these days, as the boomers age and move into smaller places. That usually means getting an integrated to replace separates.
"It is difficult to find an integrated which equals the performance of separates."

I would tend to disagree with this as a whole-sale blanket statement.

Integrateds are often overlooked as the 'value' component.

For a given price point, integrated amps can be the better value and performer. For a given price point, separates involve additional costs for separate chassis, power supplies, interconnects, and even power cords.

Take the same amount of money and you could easily step into a 'better' integrated over separates.

So, it depends.....
Why not.
Interviews with audio electronics designers often turn to the importance of power supplies. I've seen this in interviews with James Bongiorno concerning the Ampzilla in the '70s, Paul Gower of PS Audio, and several others.

Transformers vibrate and when you add several to the same chassis you are raising the noise floor or you are compromising performance by requiring amp, pre, phono, and tuner to share the same power supply. If you mount and isolate separate power supplies for each component you have a large unwieldy single component where all power supplies are still sharing a single AC source through a single cord.

I started with a receiver. I graduated to separate tuner, preamp (with phono) and amp. I tried to go back to a receiver (Outlaw RR2150) to my extreme disappointment, went to an integrated with outboard tuner and compact phono, and now have separate tuner, phono, line stage, and power amp, all in full-sized 17"w chassis. The power supplies in the phono and line stages are bigger than what you'd get in a wall wart or PS section mounted in a standard-sized integrated.

It's not for panache or status. I'm interested in one thing: the music coming out of the speakers and how much it emotionally involves me. In that arena, so far in my experience separates win. I'm confident that there are integrateds that could beat my humble stack of separates (e.g., Pass, Krell, AR), but at a price I couldn't afford.
Johnnyb53 has got it right. The power supplies are the big issue- that and the way the grounds are set up. It is very easy to get crosstalk in integrated amps, in a way similar to to the way ground loops occur.

It is possible to build an integrated that gets around this, and if it is done, you will see a separate power transformer for each channel. If you don't see that in the integrated then you will be able to find separates that out-performs it.

I find that the main advantage of separates is the setup of the system. Its to your advantage to keep your speaker cables short- it can have a huge effect on impact and definition. Monoblock amplifiers allow just that, and especially if your preamp can drive long interconnects, you can place the preamp and the front end components in the room where they are least affected by bass, have the best WAF, or are the most convenient.

Integrated amps force you to place the amp between the speakers, often with longer speaker cables which means that even a great integrated may not be able to strut its stuff simply on account of longer speaker cables!
^^^^^

You are talking about separate separates! :-)

Again...just saying "separates" are better that integrateds is meaningless (cuz there are mid to lo fi separates and hi end integrated) - everything matters so it all depends on specifics.

You gotta do your homework and you gotta get your ears on for real listening.

The big fat paint brush doesn't work in audio
all of the audiophile world exists to take as much of your money as possible. that would include the components you mention along with everything else we talk about here.

feel better now? =)
"Hi end" audio is all about diminishing returns. All separate and mono blocks yield the ultimate audio when this is what your ears require, and you listen to music enough to justify the expense.

I'm sure separate power supplies have a lot to do with this. Turning AC into DC is what "black silent" background is all about.

Georgester, these are some very good posts with few contradictions. I think they all contribute to the total picture.

12-07-11: Orpheus10
"Hi end" audio is all about diminishing returns. All separate and mono blocks yield the ultimate audio when this is what your ears require, and you listen to music enough to justify the expense.
It's not necessarily more expensive. The maturity of high end audio plus the rise of Chinese-sourced new components change the high end price/performance ratio.

Consider: My combination of Jolida phono and line stage pre's plus vintage tuner and 180wpc power amp cost me a total of $1007. You will *not* find a new receiver or integrated amp at that price that can touch the power, clarity, and musicality of this stack.

Even going new, you can get an Emotiva USP-1 pre (with phono stage) plus 125 wpc UPA-1 power amp for $658. You'd be hard-pressed to find a new integrated--let alone a receiver--that could approach its performance at that price. Entry-level separates are no longer the big jump in price compared to integrateds and receivers worth listening to. The only disadvantages are rack space requirements and the cost of interconnects.
I like vintage tuners. In regard to the 180wpc power amp as compared to the very same amp as monoblocks, from a price performance point of view the 180wpc would be the winner; but there's nothing like the 3D soundstage of monoblocks, this is a result of the channel separation. While this is over the top, if you ever get used to monoblocks, you're hooked.

12-08-11: Orpheus10
I like vintage tuners. In regard to the 180wpc power amp as compared to the very same amp as monoblocks, from a price performance point of view the 180wpc would be the winner; but there's nothing like the 3D soundstage of monoblocks, this is a result of the channel separation. While this is over the top, if you ever get used to monoblocks, you're hooked.
Well, it's interesting to note that the Heathkit's big brother, the AA-1800 (rated 250 wpc but more like 350) is a full dual mono design with two power cords. Single chassis, but true dual mono.

If I had the rack space, I'd love to get a second AA-1600 and bi-amp. Then I'd have a separate amp for each speaker.
If you're into "kits", you can also get deep into the "high end" by substituting parts. For example you could substitute better capacitors, of the same value of course; and other parts as well. This would give you a true "high end" amp.

12-09-11: Orpheus10
If you're into "kits", you can also get deep into the "high end" by substituting parts. For example you could substitute better capacitors, of the same value of course; and other parts as well. This would give you a true "high end" amp.
Actually, I'm not a modder or a kitter. My amp is a Heathkit because that's the name of the company and they made very high quality kits. But I bought mine used, which means it was already assembled. I agree about how--if you're handy with a soldering iron--you can upgrade the parts in a signal path to great effect. I've never done any modding except for some tube-rolling.

I have a Jolida JD-9A phono stage and there are slews of mods out there including capacitor upgrades, but I never learned solder well. However, there's a lot of buzz about replacing the factory socketed op amps (about $1.19 ea) with $18-22 ones made to greater speed and lower noise specs. I'll probably get a chip puller and pop in the upgrade replacements.
From what I have found with respect to upgrading the electrical components within a CDP, I had 2 done with year, yields an incredibly better product. That is assuming that you, or the modder, is experienced.

After experiencing the vastly better products for myself, I will never buy 'new' again, I will simply buy 'good' designs, used, and have them upgraded.
My amp is a Heathkit because that's the name of the company and they made very high quality kits.
Johnnyb53
I'm not 100% sure, but I think the "Heathkit" amps from that time frame may have been made by Harman Kardon.

There is no better way to buy, than buying good designs that have withstood the tests of time, and that is the reason the price is going up on the best used equipment.
OP, your questioned answered?

12-10-11: Hifihvn
I'm not 100% sure, but I think the "Heathkit" amps from that time frame may have been made by Harman Kardon.
Not Harman-Kardon, but Zenith, who acquired Heathkit in 1979, two years before the AA-1600 amp was produced.

12-10-11: Orpheus10
There is no better way to buy, than buying good designs that have withstood the tests of time, and that is the reason the price is going up on the best used equipment.
The Heathkit AA-1600 is the best vintage amp I had never heard of. Its big brother, the AA-1800, is better known and often fetches $500-600 on eBay. It's a full dual-mono monster rated at 250wpc but actually built to put out 350 wpc.
Johnnyb53, who do you think made the amp.
Then again, maybe not. The Harman Kardon were way more costly.
12-11-11: Hifihvn
Johnnyb53, who do you think made the amp.
Heathkit itself probably made the amp parts. It was sold in kit form only, so ultimate the purchaser assembled it. Heathkit had been around since 1912, and had started offering electronics kits in 1947, so by the time Zenith bought Heathkit in 1979 heath had a well-evolved design and manufacturing facilities. In fact, Zenith bought Heath to get a leg up on home computer technology as Heathkit had a thriving personal computer product line.

The AA-1600 was one of the first amps to take transient intermodulation distortion (TIM) into account. This type of distortion was so new to amp design that Heath's specs for TIM qualified the numbers as "after Leinomen, Otala, and Curl." This may have something to do with why it is such a departure in sound quality from the "classic" amps of the '70s and an intro the much better sounding amps of the '80s.
Heathkit itself probably made the amp parts.
Could have. But, in the past, they used transformers from companies like Acrosound, Peerless, UTC, and other upper brand transformers in their well known amps, that collectors seek. Sometimes they seek their old amps for these parts made by other companies. Not all of their products were kits. Even some of the speakers made by JBL.
The AA-1600 was one of the first amps to take transient intermodulation distortion (TIM) into account.
It seems they may not have been the leader in seeking ways to measure and work on this. [http://www.aes.org/e-lib/browse.cfm?elib=10255]
Maybe the good old no-feedback design was right in the first place.
Oh yes, Allied, Lafayette, Radio Shack, and others had amps and other products made for them also.
The 'TIM' amps of the late 70s and early 80s proved to be a dead end. What they proved was that you can go overboard chasing specs to the detriment of the final product.

12-12-11: Atmasphere
The 'TIM' amps of the late 70s and early 80s proved to be a dead end. What they proved was that you can go overboard chasing specs to the detriment of the final product.
There was a THD (total harmonic distortion) spec war starting in 1976 and continuing into the '80s, but I never heard of a TIM war. Effective Jan. 1, 1976, the FTC set a federal standard in amplifier measurement to put an end to the confusing power ratings claimed by using different measurement standards. There was RMS, EIA peak power, and there was IPP (instantaneous peak power), and often a bandwidth and variation tolerance was not specified. The FTC rules starting in 1976 started requiring a 1-hour warm-up at a steady 1/3 of maximum power, followed by power testing. The resulting power specs had to be for continuous RMS power over a specified bandwidth (e.g., 20-20KHz) into a specified resistance (e.g., 8 ohms), a frequency fluctuation tolerance (e.g., +0, -2 dB), and a THD distortion rating (e.g., 0.5%).

This prompted a THD war among lower quality amps. It was easy enough to lower the THD measurement by adding more negative feedback to the amp circuit. Although it made the amp measure better per FTC requirements, it altered the slew rate and limited the amp's ability to perform wide voltage swings. Also, the FTC rule only required testing into a resistor of a specific value. This resulted in some bad-sounding amps that had excessive negative feedback and low current designs optimized to measure well into a resistive load (an 8-ohm resistor) rather than into a reactive load (a loudspeaker). It got to where some receiver designers stopped listening to their products altogether and shipped their designs as soon as they met the bench test spec--which may have been set by marketing. The result was a generation of mid-fi electronics that sounded sterile, flat, harsh, and uninvolving, like all those bogus department store rack systems of the '80s.

If anything, TIM was first described by Finnish electronics engineer, consultant, and professor Matti Otala as an unpleasantly audible byproduct of too much negative feedback, a dissonance that went undetected by the steady state measuring methods of the '70s.

Designing to reduce TIM helps make an amp sound better and is still an important parameter in high end amp design today. See this recent review of a $12.5K pair of Electrocompaniet monoblocks. Also see this recent interview with Tim de Paravicini, particularly page 3, where Tim discusses the challenges and effects of TIM in amplifiers, particularly solid state ones where the negative feedback loops slow down the slew rate and allow transient overload.
Yes, excessive loop feedback has been a problem in the past! I concur with the THD wars, but amps built for low TIM back in the early 80s or thereabouts definitely got a bad reputation.

It does not surprise me at all that progress has been made in that department. I suspect that we should also be paying attention to transient forms of harmonic distortion as well.

12-13-11: Atmasphere
Yes, excessive loop feedback has been a problem in the past! I concur with the THD wars, but amps built for low TIM back in the early 80s or thereabouts definitely got a bad reputation.
Well, audio is certainly a balancing act and if you pursue one spec at the expense of others the overall sound will suffer. Still, taking TIM into account (a balanced approach) probably had a lot to do with why there were more good-sounding SS amps from the '80s than from the '70s.

Another guy who was very hip to this early on was Bob Carver. It probably helps that he's a physicist and not an electrical engineer. He had few preconceived notions and had his own way of tracking down and solving problems. I was just re-reading Absolute Sound's article about 10 most influential amps, and in its writeup of the Phase Linear 700, it mentions that Carver had noticed that tube amps were capable of far wider voltage swings than typical SS amps, so he designed the Phase 700 to make bigger swings like the tube amps. Excessive negative feedback narrows these voltage swings. That may be why Carver never joined the THD wars; his Phase Linear and Carver amps typically claimed .5% THD while his competition was trying to get below .1%.
The voltage swing thing that Carver noticed is not for the same reason that he may have been able to get from the Phase Linear stuff. More here:

http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php

-in short, tubes make more voltage because they tend to be constant power devices, whereas (in general) transistors tend to be constant voltage devices.