Dont they do the same thing, just that the preamp like tech21 sansamp does so on a smaller scale ?
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Difference between a Preamp and a Head
- Thread starter bassbrother666
- Start date
A head is a preamp and a power amp all in one unit. If you just have a preamp then all you have is the first stage of the amplification chain. Preamps are used to properly adjust the input signal to levels appropriate for more powerful amplification later. They are also where most or all of the tone shaping and eq'ing are done. The gain, bass, mid and treble knobs are all a part of the preamp on a head. Compressors, effects and pedals go here as well.
Some preamps have on-board features but many offer effects loops. Effects loops are generally positioned in between the preamp and power amp and typically provide the primary connection point for pedals and other processors. Their unique position also allows exporting the preamp signal to another amp or bringing another amp's preamp signal into the power section. Many heads also offer a DI connection which can export the signal from the preamp section to other equipment (e.g. mixers and power amps). Dedicated preamp units will sometimes have more options in this area since they are specifically designed to be hooked to external equipment. Some are very simple, however.
To give you some examples, I have several preamps and heads. My SVP-Pro, SVP-CL, DB 659 and DB 680 are all preamp units that require some other amplifier to attach to a speaker cabinet. I generally use my AG 500 for this. The AG 500 is a typical 500W bass head. It has a preamp and power amp all in one and I can play through it directly into a cabinet. However, when I play one of preamps I plug them into the effects return so my preamp tone comes out of the cabinet instead of the AG 500's. I can also hook any one of my amps to the power amps I have (SVP-1500 and DB 728). The power amps have no tone controls and just have signal in and speaker outputs. The only adjustments are to the volume.
Some preamps have on-board features but many offer effects loops. Effects loops are generally positioned in between the preamp and power amp and typically provide the primary connection point for pedals and other processors. Their unique position also allows exporting the preamp signal to another amp or bringing another amp's preamp signal into the power section. Many heads also offer a DI connection which can export the signal from the preamp section to other equipment (e.g. mixers and power amps). Dedicated preamp units will sometimes have more options in this area since they are specifically designed to be hooked to external equipment. Some are very simple, however.
To give you some examples, I have several preamps and heads. My SVP-Pro, SVP-CL, DB 659 and DB 680 are all preamp units that require some other amplifier to attach to a speaker cabinet. I generally use my AG 500 for this. The AG 500 is a typical 500W bass head. It has a preamp and power amp all in one and I can play through it directly into a cabinet. However, when I play one of preamps I plug them into the effects return so my preamp tone comes out of the cabinet instead of the AG 500's. I can also hook any one of my amps to the power amps I have (SVP-1500 and DB 728). The power amps have no tone controls and just have signal in and speaker outputs. The only adjustments are to the volume.
Yup. If you have a pre-amp, you're going to need a way to power your cab. A head does both.
A lot of people use a head with a preamp in front of it (like the Sansamp) to sculpt their tone.
A lot of people use a head with a preamp in front of it (like the Sansamp) to sculpt their tone.
English is not my first language, but if i understood, the preamp BY ITSELF does not produce sound? for example with a head i can put some headphones and hear the sound, as that with the preamp i nedd another source ?
A proper amplification chain is preamp (signal processing and impedance adjusting) + power amp (amplifies signal)+ speaker (makes actual sound).
They come in all sorts of arrangements but you always need the 3 of them.
Combo amp = preamp + power amp + speaker
Head = preamp + power amp
Active cab = power amp + speaker
A preamp compared to a head misses the power section.
Note that Tech21 also makes heads.
They come in all sorts of arrangements but you always need the 3 of them.
Combo amp = preamp + power amp + speaker
Head = preamp + power amp
Active cab = power amp + speaker
A preamp compared to a head misses the power section.
Note that Tech21 also makes heads.
The preamp produces a low level signal (sound). Some preamps allow you to use headphones. It completely depends on the feature set designed into the equipment. A preamp will not drive a large speaker cabinet or enclosure like a 1x15 or 4x10. For that you need a power amp or a head.
Okay i think i have inderstood it quite well, also while we are on it, what do you think are the best brands of amps?
