Newbie Question regarding amps

[rusty1285]

This is an extreme newbie question probably, but I was wondering if someone could please explain to me what exactly a "pre-amp" and how a regular amp work? What's the difference between them? When do you know you need to amplify your equipment? Just some basic explanation of the two would be great. Thanks!

 

[zumbo]

All signals have to be amplified.

A pre-amp is a processor. It has no power, and needs to be connected to an amp to power speakers. A seperate tuner is also needed for radio.

A receiver is a pre-amp, amp, and radio tuner all in one.

An integrated amp is a pre-amp and an amp all in one. A tuner would have to be added for radio.

 

[rusty1285]

Thanks for the answers. I guess my next question would be a little subjective maybe, I dunno, but is there an advantage to using separate components then to a receiver which has everything thrown into one casing?

 

[dpnaugle]

I wondered the same thing but was afraid to ask

TO *** to this question, IF one has a 7.1 Av Receiver and eventually wants to get an additional amp, what is the line of thought? I guessing that a 2 channel amp would be the way to go for stereo music and a multi channel say 5 channel would be for HT?

DN

 

[zumbo]

Seperates are better.(IMO)

A seperate amp can handle a load much better than a receiver. Ex.(4ohm)

Seperates cost more. Alot more. Many people use a receiver/HT receiver as a pre-amp, and add a external amp. This can save money. Ex. I have a Yamaha RX-V1400 HT receiver. I use it as a pre-amp. I have an Adcom 7605 5-channel amp to drive my 4ohm speakers.

NOTE: A receiver/HT receiver must have pre-outs for an external amp. Many don't.

 

[PENG]

For a general definition, visit:
http://en.wikipedia.org/wiki/Preamplifier

If your source produces a low level output such as some phono cartridges, you will need a preamplifier to amplify the signal to a level (say around 100 to 200mV) where a power amplifier can take over. The preamp will have the volume control, tone control, switching functions that a power amplifier typically does not have.

If your sources all produce high level output (say around 200 mV), then you have the option to use a passive preamplifer. A passive preamplifier is one that provides some or all of the functions a preamp typically provides but it does amplify the signal. It controls the volume of the signal by attenuating it.

Preamplifier in a pure sense is not a processor. There are however, many preamp/processor/tuner such a Anthem AVM30 that has everything in one box except for a power amplifier. Such all in one unit does amplify the signal, but only to line level (around 200 mV).

 

[gcmarshall]

rusty,

i had similar questions when i first got into all this over a year ago. here is what i learned.

using a good mid-fi all-in-one HT receiver is a very good way to go, especially for a modest budget or to keep things simple. HT receivers in the $600-$1500 range can be very good or excellent performers when mated to good speakers, in a good room, etc.

what i found, personally, was that separate amps gave a more dynamic and powerful punch in loud, complex, and "heavy" movie scenes and music. at lower to moderate levels, there was virtually no difference and i was just as happy with my HT receiver alone. separate amps (even entry level brands) are an expensive addition to achieve what is usually only moderate improvements. but, if that extra ooomph is important to you and it won't prevent you from using your money for more important things (ie, saving money, healthcare, family, food, transportation, roof, etc.), then it's worth a consideration.

there are some less expensive separate amps (audiosource, for example). unless you are someone who critiques every singles note or sound coming out of your speakers, my guess is that these would be a good choice. they do have some limitations and are cheap for a reason, but they seem to work well for the most part, if you're not splitting hairs.

 

[highfihoney]

if that extra ooomph is important to you and it won't prevent you from using your money for more important things (ie, saving money, healthcare, family, food, transportation, roof, etc.), then it's worth a consideration.

This is probabally the best advice ive seen on any forum ever,ive seen guys spend every last nickel they could muster up just to get an upgraded "whatever" in order to chase the perfect sound all the while the car they drive is a hoopty & the house they live in needs carpet,your doing the right thing by asking questions before you buy anything.

If i might add something about upgrading to seperate amplification ,im a firm believer in it but i punish my systems so i need it but others needs are not as drastic as mine but in any case if it does come to the point where you feel running exernal amplifiers is what you need try & take advantage of stores & established internet sites that offer no questions asked cash back return policies that way if you buy something that ends up giving you very little benifit in sound your not out a wad of cash.

 

[markw]

The best compromise is to pick up a good performing medium priced receiver with the features you need but make sure it has preamp outs to feed an external power amp if you feel additional power is necessary or you upgrade to hungry speakers in the future.

 

[Nick250]

I would like to add, that IMO, cheap out on any part of your audio system but the speakers. As Mark mentions above, if you buy a receiver with pre outs, you can always add amps down the road. If I had $2000 for amplification and main speakers, I would spend $1400 on the speakers and $600 on Yamaha or Denon receiver that had pre outs. As an aside, if you shop around some you can get a darn good Denon or Yamaha for $600 from an authorized dealer. Probably a 2807 for the Denon and the equivalent Yamaha.

Nick

 

[mtrycrafts]

I wondered the same thing but was afraid to ask
DN

That is not good. Just think if the poster didn't post this question. You'd be still scratching your head and no answers. Asking such questions may be embarrassing, but it only lasts a short while but you'll have an answer for the rest of life. And, you'll be amazed what you can learn from asking questions

 

[mtrycrafts]

If your sources all produce high level output (say around 200 mV), then you have the option to use a passive preamplifer. A passive preamplifier is one that provides some or all of the functions a preamp typically provides but it does amplify the signal. It controls the volume of the signal by attenuating it. .

The issue with many passive preamps is their variable output impedance that can go as high, or higher, than an amp input impedance, then, cable capacitance becomes a serious issue as it WILL roll off the upper end, audibly.

One of these has the calculations with some cables affecting down to 5kHz.

Hayward, James 'Beating the Bafflegab & Filtering the FooFooDust,' Part 1- Marshall's Audio Ideas Guide(Canada) Summer/Fall 94

Hayward, James 'Making the Connection. Part Deux: A Closer Look at the Role of Loudspeaker Cables,' Winter 95. Reprints available from Kimberkable.

 

[mtrycrafts]

For both of you

This is an extreme newbie question probably, but I was wondering if someone could please explain to me what exactly a "pre-amp" and how a regular amp work? What's the difference between them? When do you know you need to amplify your equipment? Just some basic explanation of the two would be great. Thanks!

Also, remember that the speakers are in the drivers seat. Their impedance and sensitivity dictates its power needs. Room acoustics, room size and your listening habits are also part of that equation. Some speakers and receiver will drive you insane with spl, others will shut down.

 

[rusty1285]

Thanks gents. I really appreciate the answers and advice. At the moment, I'm happy with my equipment I have. And if there was anything that I want to change regarding my setup it’s my god forsaken room that I'm stuck with using for the time being. I had just seen a number of places also mentioning pre-amps etc. and I wasn't exactly sure as to how they work, what their function was, etc. compared to a regular receiver. But, now I know. Gracias.

 

[PENG]

The issue with many passive preamps is their variable output impedance that can go as high, or higher, than an amp input impedance, then, cable capacitance becomes a serious issue as it WILL roll off the upper end, audibly.

One of these has the calculations with some cables affecting down to 5kHz.

Hayward, James 'Beating the Bafflegab & Filtering the FooFooDust,' Part 1- Marshall's Audio Ideas Guide(Canada) Summer/Fall 94

Hayward, James 'Making the Connection. Part Deux: A Closer Look at the Role of Loudspeaker Cables,' Winter 95. Reprints available from Kimberkable.

Agree, I wasn't trying to promote passive preamp, but I wanted rusty to know that such a thing exists. I just noticed I made a typo, I meant to say .........but it does not amplify the signal. It controls the volume of the signal by attenuating it.