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So I want to buy a head, but am unsure of everything.

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(@michhill8)
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Joined: 20 years ago
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Topic starter  

I'm in the market, or will be soon, for a head and cab. I wanted to know about them, because I have no idea about amps and such. One thing I was particularly unsure about was the term "Slave Output". Keep in mind that I'm looking on ebay and pawn shops for used gear, because I'm not a millionaire, and can't afford new stuff. This makes descriptions harder, and even on company web sites it is unclear. Another thing I was curious about were the different channels and is it bad to have only one channel? What do you guys know about these boutique (might be the wrong word) manufacturers like Orange, Mesa Boogie, or Hughes and Kettner compared to more general brands like Marshall, Vox, or Peavey?

What about the cab? Do I need the Ohms of the head to match the cab? What if the head has different outputs like 50w and 100w settings?

Any input will help.

THANKS! :)

Thanks Dudes!
Keep on Rockin'

Pat


   
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(@diceman)
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A slave output is for connecting to another amplifier . So a short patch cord would go from the slave output to the input of another amplifier . This allows you to use the preamp section of the " Master " amp , i.e. , the amp connected to your guitar , to drive additional amps or power amps and the cabinets connected to them . The channels on an amp allow you to have different tone ,volume and effect settings at your disposal instantly without having to fiddle with all the knobs to achieve this . The channels are separate preamp sections that you can adjust independently of each other and with the use of a footswitch you can change between them at your convenience . You could have a clean tone on one channel and an overdriven signal on the other . Some amps have three channels .
Matching amps to speaker cabinets is very important . The speaker enclosure(s) should never have an impedance rating lower than what is recommended for your amplifier . Running a 4 ohm amplifier output into a 2 ohm speaker cabinet would make the amplifier try to put out close to twice the output and cause it to run hotter than it was designed to handle and potentially fry some interior components . Not good !
Lastly , the 50 watt or 100 watt outputs are generally how many power tubes that the output section of the amplifier uses . The preamp section is unaffected . These output jacks allow you to push the preamp section harder and by not using all the output tubes (50 watt setting) you do not have to play as loud to get the sound you want . Whereas you would probably want all 100 watts in a large room or outdoors , in small places (barrooms) 50 watts is plenty .

If I claim to be a wise man , it surely means that I don't know .


   
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(@michhill8)
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Topic starter  

Great, thanks for the help.

Thanks Dudes!
Keep on Rockin'

Pat


   
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(@ricochet)
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Matching amps to speaker cabinets is very important . The speaker enclosure(s) should never have an impedance rating lower than what is recommended for your amplifier . Running a 4 ohm amplifier output into a 2 ohm speaker cabinet would make the amplifier try to put out close to twice the output and cause it to run hotter than it was designed to handle and potentially fry some interior components . Not good !
That's true for solid state power amps and triode tube power amps (which are seldom seen today.) Pentode and beam power tube output stages have screen grids held at an essentially constant fixed voltage, and that's what controls the flow of electrons to the plate. The plate voltage, which varies with the current through the load, has very little effect. So the output power changes only slightly over a wide range of load impedance. The impedance chosen is arbitrary and usually reflects the point of lowest distortion (which also is usually about the point of maximum power output as well.) Changing the output impedance increases distortion. Running a lower impedance like a 4 ohm on an 8 ohm output probably won't hurt anything with a pentode or beam power tube amp. Running it at a dead short for a little while won't hurt it; that's a reasonable way to protect the amp from high voltage "flyback" spikes in case it's played with no speaker plugged in, by using a shorting jack to short the output with no cable plugged in. But running a lower than rated impedance increases the current flowing in the output transformer windings, and if the O.T. is a very small one for the amp's power it could get too hot with extended high power playing. Running a somewhat higher than normal impedance shouldn't hurt anything, but since it increases the peak-to-peak signal voltage range in the output transformer's primary winding, if the insulation for the O.T. is marginal it can cause problems. A fixed load resistance of about 20X the rated impedance is commonly installed on the output to protect the O.T. from the aforementioned high voltage spikes if the amp's played with no speaker attached. It's not unusual for guitar amps to have too-small O.T.s with inadequate insulation (both as cost and weight saving measures, and because many like the distortion from core saturation in an undersized transformer), so caution is advised. But you won't increase your tube amp's output power by mismatching the impedance.

:D

"A cheerful heart is good medicine."


   
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(@wes-inman)
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Great answers by both Diceman and Ricochet. :D

I think it is important to know how you are going to use the amp and the tones you are after as well. If you are in a loud Rock band where you need lots of power and image too, then you probably would like a nice 4 X 12 half stack, or even two 4 X 12 cabs for a "full stack". These look fantastic on stage and put out a huge wall of sound as well. The downside? These cabs are large and very heavy (often 80-100 lbs. each). So it is lots of work trying to stuff these in your compact car. :D

So if you just want a stack to play at home, or occasionally go to the Open Mic or a friend's house to jam, then probably a 2 X 12 cab would be better, or even a 2 X 10. You will still get a big full sound, and it's much easier to haul a smaller cab around.

I won't get into any arguments over impedence, but I think it is always best to simply match the impedence of the cab to the head. Now, some heads will operate at different impedence. My Epiphone Valve Jr. head has 4, 8, and 16 ohm Speaker Outs. This is very convenient as it will match up with almost any cab. Most multi speaker cabs are 4 or 8 ohms impedence, but some like Marshall (especially the older models) are 16 ohms. The newer Marshalls usually have switchable impedence.
So there is another factor, many cabs today have a switch on the back that allows you to operate the cab at 4, 8, or 16 ohms.

There is also the issue of open-back or closed back cabs. Open back cabs usually have a fuller sound with wide dispersion. Closed back cabs are more directional (you hear the sound directly in front of the cab) but usually have tighter bass favored by some. I personally like closed back cabs for the tight bass, but that's me. Neither is better, simply personal preference.

The speakers make a big difference too. If you are after that Marshall or British tone (Hard Rock, Metal), then you would probably want a cab loaded with Celestion speakers and closed back. If you are after a Fender type tone (Jazz, Country, Blues, Classic Rock), then you would probably like a cab with Eminence or Jensen speakers with open back. There are other good speakers by other manufacturers, but these are probably the most popular brands.

If you just want to jam around the house or at a friend's house, then a lower powered amp is probably best, especially if it is a tube amp. Then you can crank the amp to get some overdriven tones. A 5 watt amp like the EVJ is great for this, but you can even use a 1 watt amp. You will be amazed how loud these amps are.

If you are looking to gig, then you need more power. You usually want a tube amp at least 30-40 watts, or a solid state amp 50 watts or more. The reason you need more power is for clean tones really. A 50 watt amp will play clean to fairly loud volumes before distorting (actually overdriving). If you are into super clean tones like Country, then the more power the better as you do not want overdrive distortion. But if you like natural overdrive distortion and use it a lot, then a 25 watt tube amp or 50 watt solid state is pretty good. These will begin to break up fairly early. If you play large clubs or outdoors, you would probably want a 100 watt head. These will overdrive too, but they will be screaming loud. :shock:

So what kind of music do you like to play most, and where will you be using this stack??

If you know something better than Rock and Roll, I'd like to hear it - Jerry Lee Lewis


   
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(@ricochet)
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I think it is always best to simply match the impedence of the cab to the head.
Exactly. :D

"A cheerful heart is good medicine."


   
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(@michhill8)
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Topic starter  

Thanks guys for all your help.

Wes, I like to play blues and rock type music. I love clean sparkly tones, but also am attracted to the nice "snarl" of overdriven, distorted amps.

I guess I'm a little spoiled since my current vox AD30VT has lots of modeling on it, I can find what I usually am looking for. However, it has its limits and thats why I want the flexibility of a nice half-stack.

Thanks Dudes!
Keep on Rockin'

Pat


   
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(@ignar-hillstrom)
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Well, what kind of flexibility are you after? Or in other words, why do you want a half-stack specifically? Maybe I'm missing something but if I were you I'd worry about sound first and size later. All those brands you mention have all kinds of amps, in all shapes and sizes. Limiting yourself to just the half-stacks seems a bit odd.


   
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 vink
(@vink)
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I guess I'm a little spoiled since my current vox AD30VT has lots of modeling on it, I can find what I usually am looking for. However, it has its limits and thats why I want the flexibility of a nice half-stack.

Sort of along the same lines as Arjens question: what limits are you trying to get past? That might help everyone steer you towards the right solution...

--vink
"Life is either an adventure or nothing" -- Helen Keller


   
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(@michhill8)
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Topic starter  

Yeah I thought that might have been confusing when I wrote it, but I didn't want to go back and retype everything.

I guess when I said flexibility I was meaning that I could use an effects loop to get the sound I actually wanted compared to the modeling on my current amp that has some limitations. Now, I know that on my current amp I can have an effects loop, however, I need an amp with a little more power. Meaning, fully a tube amp for warmer tones, not just a tube preamp, and louder than I currently have.

And the reason why I want a half stack - It's much cheaper than a full stack :D

Thanks Dudes!
Keep on Rockin'

Pat


   
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 vink
(@vink)
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Now, I know that on my current amp I can have an effects loop, however, I need an amp with a little more power. Meaning, fully a tube amp for warmer tones, not just a tube preamp, and louder than I currently have.

And the reason why I want a half stack - It's much cheaper than a full stack :D

Lots of tube combos can get pretty darn loud. Even the tiny Epi Valve Junior combo is pretty loud. I think something like the Fender HRD would be really really loud, and that is a 1x12 combo. Nothing wrong with wanting a half-stack, but just wanted to point out that you can get plenty loud with a combo. (Actually, I would say that the VOX AD30VT is itself quite loud, in my book .. I can't really crank it up all the way at home).

A half-stack is going to be really hard to move around. One alternative you can consider is a head with a 2x12 cabinet. That would be a lot easier than a half stack with a 4x10.

Just wanted to point out one minor thing: the AD30VT has both amp modeling and some built in effects. The modeling is used to make it sound like different amps, and the effects are added on top. You can still use external effects with the AD30VT and bypass the internal ones, although you don't have an effects "loop". You have to put all the effects before the instrument input...

--vink
"Life is either an adventure or nothing" -- Helen Keller


   
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(@michhill8)
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Topic starter  

Yeah, I guess the reason I want a stack is that I have a feeling I'm going to be playing live a lot more. I also am looking at some of the Fender reissue combos though.

I agree, the AD30VT can get loud, when I first got it I think I almost put a hole in my wall, and I know I gave my neighbors a scare.

So, what are your guys' opinions on the different brands of heads? What do each sound like, what type of music do you play through them? all that stuff...

Thanks Dudes!
Keep on Rockin'

Pat


   
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(@ricochet)
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Stacks are bulky and heavy to carry around. Got roadies?

A combo is easier to deal with. You don't need enormous power. A 50W amp will play as loud as you need to in a big club or small auditorium. If you get to doing stadium gigs, you can put a mic in front of your combo and run it through the PA. I've seen that done by big well known bands on many occasions. I've also heard that sometimes the sound is coming from a miked little amp backstage that the guitarist really likes for its tone, the stacks onstage being there for show.

"A cheerful heart is good medicine."


   
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(@racetruck1)
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My favorite gigging set up is a Traynor Mark III, 100W 2x12 loaded with celestions (60 Watts each), on top is a Fender Pro Reverb combo with the guts taken out, (in process of being rebuilt) with the original 12" Utah's in it. The Traynor is rated at 100w, it has great headroom and it's a relatively cheap amp. Anywhere from $200 to $300, if you can find them. The advantage of the Pro reverb cab on top is that the whole thing acts like a stack, in one place that I play in the band is about ten feet from the bar front and anything down low is blocked, putting the Pro Reverb on top puts it above the bar and everybody can hear it.

Small bars and rooms, 50W's is great, Big halls and dance floors, 100W works for me. I'm actually thinking seriously about selling my stack setups as I don't really use them. I'm really getting into combo amps the more I play them.

On the effects chain issue, I've never really used them, or for that matter, really found ones that I've liked enough to hang onto, pretty much plug n play for me.

I'm looking forward to when the Pro Reverb is back together, only 45W but a friend of mine has one and it sounds great live in a small place cranked.

Wattage is only one part on how loud an amp is, other things are speaker efficiency, area of speakers, amp class type, etc...... Don't think that sheer wattage is the only factor when looking for a good un...

When I die, I want to go peacefully in my sleep like my grandfather, not screaming......
like the passengers in his car.


   
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(@ricochet)
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Wattage is only one part on how loud an amp is, other things are speaker efficiency, area of speakers, amp class type, etc...... Don't think that sheer wattage is the only factor when looking for a good un...
Absolutely! Amp power rating is not a well standardized thing. The well known adage that tube amps are louder than solid state amps of the same power comes from the fact that tube amps are normally rated at some arbitrary relatively low percentage of distortion, but are capable of putting out much more power at the high distortion levels electric guitarists like, while the power stages of transistor amps normally aren't run into heavy distortion and their rated power is pretty much what you get. But a 5W amp with a highly efficient speaker can easily be louder than a 100W amp with an inefficient one.

"A cheerful heart is good medicine."


   
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