Guide to Amps

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Notes Learn about amps, tube amps, Half Stacks and Full Stacks ...

GUIDE: Different Amplifier Types & Half Stack vs. Full Stack

So you want a half stack or a full stack??

The Bottom Line Start with a half stack and add an additional cab later if necessary. Choose a guitar head based on the sounds and tone you prefer.

Why would anybody want a half stack or a full stack when he could probably get by with a powerful combo amp? I'll tell you why, because he wants to have the balls to shake the world around him, literally! No, seriously, many choose half stacks because they like the flexibility, the power, the headroom and volume that only 4 speakers can provide, and finally the statement that only such a set up can make on a stage, etc...

I can't begin to talk about half stacks and full stacks without first giving a little more information regarding guitar amp types.

Basically, there are four types of guitar amplifiers: Solid State, Tube, Digital, and the hybrids such as the modeling/tube or SS/tube amps. There are also the guitar pre-amps. These units include only the tone section and not the actual amplifier section. Pre-amps are geared mainly for professional rack units, you need to buy a power amp and speaker cabinet to use them.

Solid State Amps

Solid State amps use transistors for their pre-amp and power sections instead of tubes. They are more reliable and seldom need repairs because there are no tubes to change or go bad. They often have a very clean tone and most come with a distortion channel as well. The distortion you get from SS amps can vary greatly. Transistor distortion CAN BE harsh especially when pushing the amp into clipping. If you keep the amp volume knob under 5 or less than half way, the distortion sounds may be quite pleasing. With the volume knob at 10 or at full throttle, you may damage your amp! Some of the newer amps with tube simulating circuitry may provide a variety of good distortion sounds and tone. If distortion is important to you, you will need to use your ears and compare models when you buy a solid state amp. These amps are very popular with country and jazz players who want a clean sound or with metal head bangers looking for a sturdy and reliable touring amp.

Tube Amps

Tube amps are also known as "valve amps", and to clear things up, they are the same exact thing . Tube amps were the first type of guitar amplifiers and are the preferred choice of many guitarists for their warm tone and smooth distortion sounds. When you overdrive the pre-amp tubes or the power amp tubes, you create very pleasing distortion sounds and tone. Furthermore, the distortion sounds created is also related to how hard you play. Most tube amps have separate channels that can switch from clean to distortion sounds instantly. There are numerous types of pre-amp and power tubes, and each type has their own unique sound qualities. You will need touse your ears to find the tube amp that sounds best to you. Tube amps are more fragile than solid state amps due to the fact that tubes are made out of glass. Tube amps need maintenance, changing tubes occasionally, always keep some spare tubes on hand. Many studios prefer tube amps for their rich, warm tone. Likewise, most high-end studios use tube microphones for the same reason. As a general rule, solid state amps sound very very good. Tube amps sound better. You will usually see this on the backside of a tube amp (and an example of tubes that go with):

tube amp


Examples of tubes:

tube 1 tube 2 tube 3 tube 4

Digital Amps

With computer technology advancing at an alarming rate, some amp builders use the power of digital processors to simulate the sounds of old-fashion tube technology. Using software that models the sound of one or more tube amplifiers, these amps end up sounding like numerous amps all in one box. At this moment, some succeed more than others and as technology advances further, the sounds are only getting better with every new model. Discriminating tube users may notice the difference immediately but most people won't. Digital amps have the advantage of being programmable, allowing you to save numerous preset tones that can be called up with a foot-switch. Moreover, they often have built-in digital effects such as delay, chorus, etc..., and most include digital or analog outputs with speaker emulation for direct recording

The hybrid Amps - modeling/tube or SS/tube:

A few creative builders have started combining the best of each type of amp into one package. Johnson amplifiers use 12AX7 pre-amp tubes in combination with digital modeling technology to effectively simulate different tube amps. Fender's Cyber Twin does the same. Marshall Valvestate amps use a tube in the pre-amp section and solid state circuitry in the power section to create tube tone without using power tubes.
Vox has created the new Valvetronix - a digitally controlled, power-tube signal-processing modeling amp - very nice unit with very nice sounds!

Configurations

Amps come in different configurations. Combos (short for combinations) are self-contained units containing the amplifier and speaker all in one unit.

The amp Head and Speaker Cabinet (Cab) configuration is what this review is all about! This set up allows you to use any amp head with virtually any speaker cabinet. This also means that you get two units (the head and the cab), making each unit lighter and some say easier to carry than many 2 X 12 combo amps. Combining two cabinets and a head is called a stack. A half stack is when you combine one head with one cabinet.

Half Stack Fullstack
halfstack fullstack




A third option or configuration is the rack mount amplifier. These typically require a pre-amp, though some units contain both the amp
and pre-amp, and a cabinet. An example of a rackmount: 

Rack mount

An example of how the above rackmount piece is used in an actual rack:

racks


In the above picture, he (john petrucci) has more equipment that you will probably ever have in your life... but besides that, he keeps his amplifiers in his rack (in the right hand piece, the very bottom two Mesa/Boogies are some of his amps)..., he has recording preamps, tuners, wireless systems, and everything you can only dream of owning. More professional artists use setups such as these, so they arent carrying around hundreds and hundreds of seperate pieces while they tour, moving from place to place... they set it up all into a rack, and just move the rack. Rack mounts are mostly used by professional musicians and I doubt very much that a pro will be reading any of my articles... Well, anyway...

Before moving on to shopping for an amp head, I want to discuss the issue of CABS.

Cabs come in the following configurations: one speaker units, 2 speakers and 4 speaker cabs. Most guitar cabinets usually have 12 inch speakers, so you will generally hear terms like 1x12 ([1] 12 inch speaker), a 2x12 ([2] 12 inch speakers), and 4x12 ([4] 12 inch speakers). Examples of these:

1x12 Speaker Cabinet 
2x12 Speaker Cabinet
(what a beautiful cabinet!) 
1x12 2x12
4x12 Speaker Cabinets
4x12 Cabinet
4x12 4x12


One and two speaker units would be good for home and band rehearsals, including gigging in small clubs. A four speaker cab for practicing in your home may be a little much. Choosing the right cab for you is a matter of needs and overall preference. Depending on the sounds you are looking for, the choice of speakers loaded in the cab is the most important and perhaps the only factor to consider besides for aesthetics.

Furthermore, one speaker cabs are usually designed as extension cabs for combo amps. Two speaker cabs can also be used as an extension cab for more powerful combo amps. 2x12 cabs can also be used very effectively with an amp head for those occasions when a half stack is too much.

So, what to do? My suggestion is to compare speaker sounds...check out various models from Celestions, Sheffields, Jensons, Eminence...and when you find a speaker you like, look for a cab loaded with nothing but your favorite speakers.

Extension speaker cabinets are designed to be operated at 16, 8 or 4 ohms. It is very important to always make sure the cab and head are set to be operated at the same ohms. Some heads can be switched to operate at 16/8 or 4 ohms. Most cabs are wired to operate at either 16, 8 or 4 ohms but NOT all three. For instance, Avatar cabs can be ordered wired for operation at 16, 8 or 4 ohms, but NOT all three at once. Most models are factory set to operate at 8 ohms, some at 4 ohms and others at 16 ohms. Just be sure to check in order to make sure the ohms of your cab matches that of your amp head! You could seriously damage your 8 ohm head if you are going through a 4 ohm cab. The safest rule here is to NEVER mix a head and cab set to operate at different ohms!

Here are a few selections to give you an idea of available options:
(Information provided in the following manner - make & model - rated power handling - speaker - average price in US dollars):

1. Single Cabs - 1 x 12" speaker:

* Mesa Boogie 1x12 Recto - 70 watts - Vintage 30 - $299
* Mesa 1x12 3/4 Back - 90 watts - Celestion Custom 90 - $299
* Fender DT112 - 100 watts - Celestion G12T - $299
* Peavey 112SX - 75 watts - Sheffield 1230 - $299
* Traynor YCX12 - 50 watts - Celestion 70/80 - $279
* Avatar G112 - 120 watts - Vintage 30 or G12T - $180

2. Dual speaker Cabs - 2 x 12" speakers:

* Marshall 1936 - 150 watts - Celestion G12T-75W - $419
* Mesa Boogie 2x12 Recto - 140 watts - Vintage 30's - $499
* Mesa Boogie 2x12 3/4 Back - 180 watts - Custom 90's - $499
* Fender Tone Master 212 - 140 watts - Vintage 30's - $699
* Randall R212CS - 120 watts - Celestion Vintage 30's - $455
* Tech 21 2x12TM - 200 watts - speakers U/K? - $350
* Carvin C212E - 120 watts - Celestion Vintage 30's - $329
* Traynor YCX212 - 80 watts - Celestion 70/80's - $319
* Avatar G212 - 240 watts - Vintage 30's or G12T’s - $323 

3. 4 x 12" speaker Cabs:

* Marshall Mode Four 280 - 280 watts - Celestion MF - $850
* Marshall Mode Four 400 - 400 watts - Cleestion MF - $1000
* Marshall 1960 - 300 watts - Celestion G12T-75W - $769
* Mesa Boogie 4X12 Recto - 280 watts - Vintage 30's - $799
* Mesa Boogie 4X12 3/4 Back - 360 watts - Custom 90's - $699
* Fender DT412 - Celestion G12T/100 - $599
* Peavey 412M - 300 watts - Sheffield 1230's - $599
* Crate GX412S - 200 watts - crate speakers - $455
* Laney GS412IA - 200 watts - HH50 Invader Vintage - $549
* Yamaha DG S412V - 240 watts - Vintage 30's - $699
* Tech 21 4x12TM - 400 watts - speakers ? - $795
* Randall RA412XLT - 280 watts - Vintage 30's - $679
* Carvin C412T - 240 watts - Vintage 30's - $529
* Avatar G412 - 320 watts - Vintage 30's or G12T’s - $448

If you did not notice it, popular name brand cabs are often more expensive than your average brand. My point here is that the speakers are often the same as those found in less popular brands. Furthermore, the construction and quality of say an Avatar speaker cab is top notch, and that cab may last you just as long as any of those expensive popular name brand ones and perhaps in some cases much longer. So if aesthetics and having a popular name brand is important to you, its your money. Otherwise shop wisely! If it’s only a matter of aesthetics, Randall make sturdy beautiful looking cabs at a very reasonable price compared to popular name brands. I`m waiting to get the new Randall R212CS extension cab loaded with Celestion Vintage 30's to add to my collection...just love that vintage look. Great for bedroom practice and band rehearsals, including those small club gigs where a 4X12 cab is perhaps a little too much.

Now, say your overall preference in speakers is the Celestion Vintage 30, and by the way this is a very nice choice, so when you go out to compare amp heads make sure the cab your playing though is loaded with Celestion Vintage 30's! If not, the sounds will be very different from those you’d expect to hear.

Obviously, the best way to pick an amp is with your ears. Visit all of your local music stores and pawn shops and try as many amps as you can, name brand or no name brand. Try everything, including types you might not have considered. Hearing the difference between solid state, digital, hybrids and tube amps will help you narrow down your search and give you a better idea of what you actually want. You may even be surprised by something you never thought youd like. Start in your price range but don’t forget to compare it with more expensive models and to some of lesser value. How do you know if that $500 SS amp head wont sound just as good to you as that other $1200 tube amp head if youve never heard one? That goes for digital amps, too. If you’ve never played a Mesa/Boogie, how would you know if the digital simulation is not bang on?

Make sure you try the amps out with the same model guitar you own. Pick-ups and body construction make a huge difference in an amp’s tone. What sounds good with a Les Paul may not sound quite as good with a Strat or a Telecaster. Try out all the channels, effects, and foot-switches to see if they meet your needs.

Play the amp quietly...setting volume knobs (and master volume knobs) any higher than 2 when going through a 4X12 cab may be VERY loud. If it has a good tone when played softly, it most probably has good tone when set a little higher. Yes, you need to crank it up also, but listen for
bothering hissing sounds. Then play for one or two minutes, loud enough to tell if the amp sounds good when pushed hard (at least ½ to 3/4 full throttle). Some amps are made to crank, but dont forget about clean tone. A good clean tone should be available if you need it for chorus, delay, or other clean effects.

Just like buying a guitar, buying an amp head takes lots of shopping and comparing. Here are some recommended models to test and compare before you buy:

1. Marshall Amp Heads:

* Mode Four - hybrid - 350 watts - 4 channels - $1200
* AVT50H - hybrid - 50 watts - 2 channels - $449
* AVT150H - hybrid - 150 watts - 4 ohms - 4 channels - $699
* TSL60 - tube - 60 watts - 3 channels - $1099
* TSL100 - tube - 100 watts - 3 channels - $1429
* DSL50 - tube - 50 watts - 2 channels - $1049
* DSL100 - tube - 100 watts - 2 channels - $1149

2. Mesa Boogie Amp Heads:

* F100 - tube - 100 watts - 2 channels - New $?
* Single Rectifier Solo Head - tube - 50 watts - 2 channels - $1099
* Dual Rectifier Solo Head - tube - 100 watts - 3 channels - $1499
* Triple Rectifier Solo Head - tube - 150 watts - 3 channels - $1599

3. Peavey Amp Heads:

* 5151II Series - tube - 120 watts - 2 channels - $999
* Tripple XXX - tube - 120 watts - 2 channels - $999
* Ultra Plus - tube - 120 watts - 3 channels - $849
* XXL - modeling - 100 watts - 3 channels - $529 

4. Laney Amp Heads:

* GH50L - tube - 50 watts - single channel - $639
* GH100L - tube - 100 watts - single channel - $759
* VH100R - tube - 100 watts - 2 channels - $900

5. Rivera Amp Heads:

* KR50 Knuckhead - tube - 55 watts - 3 channels - $1495
* KR100 Knucklehead - tube - 100 watts - 3 channels - $1579

6. Soldano Amp Heads:

* Hot Rod 50+ XL - tube - 50 watts - 2 channels - $1849
* Lucky 13 - tube - 100 watts - 2 channels - $2149
* Decatone - tube - 100 watts - 3 channels - $2469
* SLO100 - tube - 100 watts - 2 channels - $2999

7. Hughes and Kettner

* Puretone Head - tubes - 25 watts - single channel - $1799
* Duotone Head - tubes - 100 watts - 2 channels - $1849
* Warp 7 - SS - 100 watts - 2 channels - $700
* Vortex - SS - 100 watts - 2 channels - $679 (half stack)
* ZenTera Head - Modeling - 2x100 watts - 11 models - $2399
* Attax Series Tour Reverb Head - Solid State - 100 watts - 3 channels - $489

8. Crate Amp Heads:

* GX1200H - modeling - 120 watts - 3 channels - $319
* GX2200H - modeling - 220 watts - 3 channels - $455

9. Randall Amp Heads:

* RH100 - SS - 100 watts - 2 channels - $289
* Titan - SS - 300 watts - 2 channels - $599
* Vmax - hybrid (one all tube pre-amp + one SS pre-amp + SS power amp) - 300 watts - 3 channels - New $?

10. Yamaha Amp Head:

* DG130H - Digital Modeling - 130 watts - 8 amp types - $699 

11. Tech 21 Amp Head:

* Trademark 200 - Analog tube emulation - 200 watts - 3 channels - New

12. Carvin Amp Heads:

* SX200H - digital modeling - 100 watts - 2 channels - $299
* MTS3200 - tube - 100 watts - 2 channels - $599
* VL100 - tube - 100 watts - 2 channels - $799

As you have probably noticed, the more powerful the amp head, the more expensive the amp head. The price of Amp Heads vary from $300 to $3000 for high end "boutique amp" models. There are many more models to choose from as well. The Randall RH100 at 289$ is a very decent SS amp head with good clean tone to high gain metal sounds ?a Pantera (Dimebag). Is it for you? Compare it to other models for fun! You never know, you might be pleasantly surprised? Add an Avatar G412 and for the total sum of 750$, you have a decent half stack set up loaded with 4x12" Celestion Vintage 30's! Anyway, good shopping...

Text: Greg (LVShorty610)