IS THIS OK: plug a guitar through a bass head, into a guitar cab.

[everdrone]

is it a good idea or bad idea to plug a bass-amp into a guitar cab and play guitar through it?  (guitar-->basshead-->guitarcab). 

Im not sure when Ill buy it but I would like to have a small backup head for gigs for bass and guitar in case a tube blows or amp short circuits.  I like the looks of Gallien-Krueger MB200 200-Watt Ultra Light Micro Bass Head.

I might use it at practice too with my Tech 21 Oxford pedal.  I just dont want to fry an amp or a cab doing it. 

[everdrone]

sometimes with ohm mismatches I read that it is half the wattage, sometimes twice as much

I wanna get a small backup head that is loud enough for gigs and practice with a loud band.

Here are the amps I am interested in:

GUITAR HEAD: Quilter ToneBlock 200 Guitar Amplifier Head (200 watts)

http://www.zzounds.com/item--QUITB200HEAD?siid=135575&-g_uIl0ERIFPnzSsmaAxoCWjHw_wcB=

BASS HEAD:
Gallien-Krueger MB200 200-Watt Ultra Light Micro Bass Head

http://www.sweetwater.com/store/detail/MB200?adpos=1o3&creative=54988012321&device=c&matchtype=&network=g&gclid=CjwKEAiAi4a2BRCu_eXo3O_k3hUSJABmN9N1X_dkMc8SKUkZGhbCHi48Se6flfvmhzu5VdVqUbPhMhoC7xrw_wcB


each of these heads can take 16ohm or 8ohm though according to their manufacturers

Im thinking I should save up for the quilter cause I am guitarist in a band currently so there are chances of me using it more

I use Orange 212PPC cabs and they are 120watt handling capacity, so Ill stay away from playing the high wattage bass-heads through it. 

My drummer says that because my Orange Thunderverb 50 head is new and I use Furman P-1800 PF power conditioner which is top of the line, that if a tube goes out the other tube will work, and I should not anticipate any issues otherwise.

Here is my Furman:
http://www.furmansound.com/product.php?div=01&id=P-1800PF

[jibberish]

an amp is an amp.  from basic theory, you could use a bass amp like a guitar amp. the amp doesn't care.

when you run a solid state amp, the current is determined by the speaker resistance(or lack of it). so 4ohms is only 1/2 the resistance of 8 and it lets more current flow.
generally 8ohm tap[sic] is 2x power of the 16 ohm connection, same deal.


regarding your thunderverb 50 tubes. if it has 4 tubes which is a redundant 25watt pair, you could pull one set of tubes to play at 1/2 power.
If you have 2 tubes only, the amp is probably symmetrical push-pull and removing one of that pair renders SILENCE.

i'm guessing there is a good reason your drummer is a drummer haha.

btw, you guys have something rare: a real live frontman. most of these bands put ZERO focus into their vocals and sound of the singing.

sorry sleep, fu Manchu, red giant, sandia man,  and a thousand other bands: your vocals genuinely suck and tarnishes the awesome music.

[everdrone]

thanks for the insights,

I have a 50 watt thunderverb 50, Im not knowing too much about it to confirm that if a tube fails the whole thing shuts down and that is what worries me!  I prolly should bring a backup then since I do not know how to change tubes on the spot or diagnose the problem?  Maybe my drummer thinks I have a 100 watter, I am not sure.  

the Gallien mb200 bass head and the Quilter guitar head both handle anything you throw at them, i.e. 4ohm, 8ohm, 16ohm. the Quilter scales wattage and I am in one band and play guitar in it so I plan on getting the guitar head over the bass head.

I play an Orange thunderverb 50 (50 watter) into 2 of the Orange 212PPC cabs. If one tube blows, does my entire amp shut down? I dont know how to change tubes or trouble shoot to find detect this problem, so maybe it is crucial that I have a backup amp. other backup amps I am considering: Orange Micro Terror, EHX Magnum .44, Orange CR120(maybe too big), maybe a Hovercraft Dwarvenaut but that is an expensive fragile tube amp.

[Lumpy]

Nobody replaces their tubes during a show.

Except maybe VOLVO)))).  

Re: IS THIS OK: plug a guitar through a bass head, into a guitar cab.

Yes. As long as the power rating isn't a big mismatch (between head and speaker cab).

Hopefully, your backup head sounds pretty close to your main amp (ideally, it would be the same model amp). However, I'd guess that only professional bands have backup heads. If your equipment fails before or during your set, borrow an amp from another band playing that night. (You should also be prepared to loan your head out too, if there's an emergency).

[jibberish]

everdrone, if you can peek into the thunderverb cabinet do you see something like this?
if so, that is 2 25watt pairs of 6V6's. this pic is a rockerverb 50 so you know...

[RacerX]

most of these bands put ZERO focus into their vocals and sound of the singing.

sorry sleep, fu Manchu, red giant, sandia man,  and a thousand other bands: your vocals genuinely suck and tarnishes the awesome music.

1) You have no idea of how much or little effort I put into my vocals, so please stop talking out your ass.

2) Don't ask me why, but some people love SANDIA MAN's vocals—they've even come up to us on the street & sung, "San-D-Ia MAN!!"

Just goes to show there's no accounting for taste—or lack thereof, for that matter. 

[jibberish]

hahaha.  I edited sandia man into my post just to troll you.


FISH ON

[RacerX]

  I've heard your shit—maybe you should devote more time to practicing and less to trolling?

[everdrone]

Nobody replaces their tubes during a show.

Except maybe VOLVO)))).  

Re: IS THIS OK: plug a guitar through a bass head, into a guitar cab.

Yes. As long as the power rating isn't a big mismatch (between head and speaker cab).

Hopefully, your backup head sounds pretty close to your main amp (ideally, it would be the same model amp). However, I'd guess that only professional bands have backup heads. If your equipment fails before or during your set, borrow an amp from another band playing that night. (You should also be prepared to loan your head out too, if there's an emergency).

thanks man, I wont worry about trouble shooting at a show then.  Ill see if I can save up for the quilter guitar head in a month or two, but borrowing an amp sounds like a great option, cheers  Jibberish Ill look under the hood soon of my amp, I have not yet though, Im more of a n00b when it comes to fixing this stuff.  thanks for the heads up.


I plan to stay away from plugging in a bass amp and I might get that quilter if I save up in a month or two.  I need more power than an orange micro terror. bass amps seem to be a bad idea, I am concerned about my guitar cab rated at 120 watts

I think that with my 16 ohm cab, there may be issues with the Gallien mb200 bass amp.  The quilter definitely is not intuitive and DOUBLES power with 16 ohms.  I am worried about the quilter 100 watt setting now...Ill call quilter with my concerns.  Here is what folks on the forum reported back:

http://www.thegearpage.net/board/index.php?threads/quilter-tone-block-with-16-ohm-cab.1632580/

i recently purchased a Quilter Tone Block 200 as an experiment in SS, and as a lightweight backup head in case one of my precious tube amps dies at a gig. The TB wants to run into 8 or 4 ohms, but most of my cabinets are 16 ohm. I contacted the company, and they informed me that running 16 ohms is fine but that the power wattage out to the speaker will be about double from running an 8 ohm cab. So that means that you'll be seeing about 80 watts out when you set the master on the 40 watt setting IF you are using a 16 ohm cabinet.


Ok, it does make sense to me .
Earlier I wrote the standard answer, which applies to 98% SS amps out there (the "normal" ones).

There is one SS amp design when Quilter answer is true, and that is that they limit power amp output by limiting power amp *current* to a preset maximum level, instead of conventional *voltage* limiting/clipping.

Or: they limit voltage, (say, a couple clipping diodes), then they feed that to a constant current power amp.
Both amount to the same end result.

Which is easy to calculate:
P=I squared * R so I=sqrt(P/R)
I=sqrt (40W/8 ohms)= sqrt 5 A = 2.24 A RMS which in practice means setting the limiter to 3.16A which would be the current peak .
Call it 3.2A limit and we're fine

That very same current setting will provide exactly twice that power into 16 ohms:
2.24A*2.24A*16ohms=5*16W=80W <-- in this case we used RMS values

Same result if we used peak values , we'd get 160W peak, which again translates to 80W RMS .

That said, the "power doubling with impedance doubling" effect will stay while we are still *within* the rated amp power, which seems to be 200W into 8 ohms (or 100W into 16 ohms) .

So the 40W setting will translate into effective 80W into 16 ohms, but, say, a 120W setting (into 8 ohms) will not translate into 240W into 16 ohms and so on.
Not a defect, quite the contrary, simply that load would be asking for a peak voltage beyond what is available at the Power Supply.

That said, a very clever design.
And I bet there must be a dozen other cool design tricks under the hood, that's for sure

[Danny G]

Guitar into whatever is usually ok

Bass into guitar speaker cab can lead to problems (I blew the G-75s in my Marshall doing this *once*)


Sent from a can on some string using Tapatalk

[everdrone]

  Thanks Danny G, Rock on!! 

[Corey Y]

Others have already covered the broad strokes. As long as you don't expect a bass amp to make it sound more bassy it's fine, assuming all impedance and power handling considerations are covered. I've played clean guitar through my GK MB800 at low volume just for fun (and recorded it) and it sounded fine, never tried it with heavy dirt. Most of my main guitar amps over the years have been vintage tube bass amps, but in general 70's and earlier stuff like that is just the same as the guitar version but no reverb or tremolo built in.

[Mr. Foxen]

The thing you need to do to not break stuff is not sound shit. Stuff sounds shit when its breaking, don't do that. What does break stuff is assuming stuff will be magically protected by labels like 'guitar', 'bass' or 'watts'.

[zachoff]

Rules...

Ohms: care
Speakers: care
Amps: don't care

[jibberish]

that was a very illuminating thread you linked from that other forum regarding that seemingly magic power block matching watts to the ohms rather than inversely proportional.

the posts said it all: max power is whatever you have when the  SS amp hits the rails

so at the rails, ohm's law dictates that as the resistance increases, the current will have to fall since the voltage is now fixed.
ie as the speaker resistance increases max power decreases

however, if you work down within the amp's power range, you can do trickery like make a constant current which then jacks up the voltage drop across larger resistances and makes more power.  power(Watts)=current(Amps) x electromotive force(Volts)

and a constant current will force higher voltage V=IR as the resistance is increased. the I just becomes a fixed coefficient. so it is a V:R ratio. but only as long as the voltage is kept below the rail limit(rail=clipping fwiw)

LED drivers are constant current supplies. sort of a mindfuck since we all relate to constant voltage much better.
A constant current supply is needed so a string of LED's always gets a set/proper/safe/constant amount of current. what you see change as you add LED's to the string is the voltage output changes. an led drops 3-ish volts no matter what, so you have to control it via changing the current through it. the supply just raises or lowers the voltage to give enough 3v chunks to whatever number of LED's is connected and maintain the set current.

***************************************************************************************************************

hey racerX, you speak the truth regarding needing more practice. I will always need more practice regardless of what level I reach, regardless of what music thing I am working on.

there is always the next level waiting for me.

also, I have been playing keyboards and singing in choir n shit since I was in elementary school.  this is a guitar place so you really don't have any idea what I can and can't do beyond my progress figuring out this whole guitar universe. No one cares about that other stuff..well marginally with cool synth crap , but that's it.
around here we buy keyboard plugins so the machine can play the keys because that is too alien to wrap your head around and figure out how to do it yourself.
Periodically I have thought about making a keyboard demo and volunteering to add keys to songs, but I stop because I know deep down that it will just be ignored, but I could if someone really wanted help with keys.

********************************************************************************************************

and yes, your friends like your vocals and it serves the caveman image.  that's great.

fwiw, it seems like every band on the radio has a vocalist who also happens to be able to really sing.  think about it.

[jibberish]

is there any way you can get your doctor to prescribe an amplifier so that medical insurance can buy you a 2nd thunderverb 50?
tell him the stress of possible amp failure is destroying your life and you need help STAT!

..and it has to be a duplicate for redundancy....

[everdrone]

haha!!!!  the prescription is MOAR CITRUS!  I love it.  It is my favorite amp, I do look at the used Orange OR100s since they go for the same price at $1200, they probably sound about the same though as mine with a fuzz pedal, just alot louder.

[everdrone]

regarding your thunderverb 50 tubes. if it has 4 tubes which is a redundant 25watt pair, you could pull one set of tubes to play at 1/2 power.
If you have 2 tubes only, the amp is probably symmetrical push-pull and removing one of that pair renders SILENCE.

great call brutha!  orange amp forum administrator said:

"A two output tube amp is going to be silenced when one of the tubes go. If you retube yearly, you shouldn't have to worry. Unless you get a faulty tube or one that fails prematurely, you shouldn't feel the need for a back-up. That said, it's always good to have a Plan B ready..."

my plan B for now will be to borrow someones amp, I do like that quilter amp cause its solid state and super light and small.  solid state to me means it could go on and on forever at band practice like my peavey tour 450 for bass and no new tubes or anything needed for me to buy.  I left Quilter amps a voicemail with my laundry list of questions just now lol 

I am worried about trying my Peavey 450 watt amp plugged into my Orange 212PPC rated at 120 watts or a Gallien MB200 rated at 200 watts so I will avoid running into trouble on that one.

[batsquatch]

btw, you guys have something rare: a real live frontman. most of these bands put ZERO focus into their vocals and sound of the singing.

sorry sleep, fu Manchu, red giant, sandia man,  and a thousand other bands: your vocals genuinely suck and tarnishes the awesome music.

[everdrone]

hmm...a batsquatch emerges.  who are you???!?!?!?!?