using a 2100 sl-x head and 1936 cab

[greendy123]

Hi guys,

I need some help with the setup of my first tube amp head and cabinet. I have searched around on the forum and other websites for information. I just want to confirm it with you guys to see if it is correct.

First for the connection to the 1936 speaker cabinet, http://www.marshallamps.com/images/products/cabinets/cabinetsspectable.html. all I need to do is connect from one of speaker outputs a speaker cable going the right speaker input, on the cabinet it says mono above it. From what I have seen in the forums, this seems correct and if I wanted the cab in stereo I just need another amp connected to the left. 1) Is this correct way for me to hook up my setup? 2) In mono I assume both speakers are both on right? 3) Oh I can use either of speaker outputs right?

Here's a link of the amp's handbook before going on to the next part.
http://www.marshallamps.com/images/handbooks/pdf/jcm900.pdf

For the settings on the amp, I should use the 8 ohm selection output, which is switch set to the right, as the cabinet on mono is 8 ohms. 4) Is this right?

If wanted to play with cabinet in stereo, I think I set it at 8 ohms, because the total in stereo on the cabinet is 16ohms, by this I conclude that each speaker is 8 ohms. 5) Is this correct?

6) Do you guys think it's safe for me to run the cabinet in stereo with that head on 50watt setting and use my other fender practice ss combo at like 15w, cause one speaker is 75w, I'm not sure if the 25w gap is playing it safe or not? For some more info, if I do this, I plan to be playing in a room with a friend so I would probably go as high as vol 1.

For turning on amp I assume I need to turn on the main switch, and wait like 2-10 minutes, then turn on the standby switch. At this point I can start playing. For shut down I just turn off standby then wait I think a couple minutes, and then shut down the main power switch. 7) I was wonder what I do when I take a break but will be playing in a couple minutes, do I just leave both switches on while I do this? 8) From what I read I assume you play only when the main and standby switches are both on.

Could you guys put the answers numbered and tell me if any of this information is correct? I don't want to break my expensive equipment I just bought. Sorry about the long post with multiple questions guys. I would like to be better safe than sorry about what I did without asking first.

Thanks in advance for your help guys.

 

[greendy123]

Re: using a 2100 sl-x head and 1936 cab

Can anyone help me with some of my questions? I really want to use this amp once it get next week.

 

[Rich_T]

Re: using a 2100 sl-x head and 1936 cab

1) Yes, from the speaker output, to the mono input
2) In mono, both speakers are blasting
3) Either speaker output will do the job
4) Yes, make sure the impedances match, 8 ohm output to 8 ohm cab.
5) im not great with electrnics, can;t answer that one, sozza
6) It won't damage the cab, but getting the fender anywere near loud enough will be difficult
7) When taking a break, turn on the standby, this keeps the tubes warm, but there wont be any noise
8) Both mains and standby switches must be on for there to be a sound

Hope that helps,

Richey

 

[FireBros.]

Re: using a 2100 sl-x head and 1936 cab

+ 1 on all that. It would be hard to break your new marshall by hooking it up wrong, so don't be intimidated. That's a pretty cool rig you got.

 

[DeadSkinSlayer3]

Re: using a 2100 sl-x head and 1936 cab

I'm not going to answer numerically, but I hope this helps.

Always match impedances. 8 to 8, 4 to 4, 16 to 16, etc. When you have two cabinets, say two 8 ohm cabinets, the load is halved, so you'd use a 4 ohm setting on the amp. For stereo operation, IE, more than one head into the cabinet, treat the inputs like seperate cabinets. So in you're case, if the speakers are 8 ohms, you'd have the amps both set to 8 ohms.

When you turn on the amp, have the standby off, and turn the power on. You only need to wait two minutes or so, not that long at all. Then, flip the standby to on. Play. If you're going to take a break but leave the amp on, just flip the standby off. When you want to power the amp off totally, flip the standby on for 4-5 minutes, and then turn it off.

 

[greendy123]

Re: using a 2100 sl-x head and 1936 cab

On question 7 do you also mean to turn off the main switch and just have the standby switch on.

Thanks for answering my questions, that helped me alot.

 

[greendy123]

Re: using a 2100 sl-x head and 1936 cab

Hey guys I'm getting my sl-x head in a few hours, can't wait to use it. Do you guys know of any good settings for it? I'll tell you guys how it sounds later tonight.

 

[NecroPolo]

Re: using a 2100 sl-x head and 1936 cab

Hey Greendy,

All the questions had been answered properly, I'd just add some misc info

First of all, it is pretty handy to get a cheap ($10) yet sure digital multimeter to measure the impedance of cabs if you're on the road. Okay, there is written 8 ohms here and 16 ohms there, but you can NEVER be sure about the modifications had been done by previous owners. Besides, most multimeters have cable break test beeper - the BEST diagnostic tool for a guitarist

Note that the ohms printed on amps and cabs don't refer to the actual physical direct current resistance that you can measure with a simple digit multimeter. Cab ohms refer to impedance that is something like resistance but it refers to the characteristics of coils in alternate current environment, e.g. speakers creating soundwaves with 100W "slaps" delivered by the amp. If you measure the DC resistance, you will get the physical resistance of the wire they used. If a signal runs through a coil, the number of hoops, their distance, their placement enter the game. So, physical DC resistance and impedance are different so if you hook your multimeter into the speaker cable and measure DC current it will show approx. 60-70% of the impedance printed on the cab.

approx. 3 ohms on the display -> set your amp to 4 ohms cab
approx. 6 ohms on the display -> set your amp to 8 ohms cab
approx. 12 ohms on the display -> set your amp to 16 ohms cab

If you play on a festival and use the in-house cab(s) ALWAYS measure them. It's a 2-seconds-test but you can avoid mis-matching your amp OT impedance and a modified cab into-something-with-no-warning. If you mis-match the setting on your amp and the cab, you MAY fry your output transformer. It is not an all-true general rule of mis-matching because for years I ran my old Selmer amp with a 8 ohms setting via a 2 ohms cab (mea culpa, there was written "8 ohms" on it but the previous owner replaced the speakers and I did not know that) and it worked (still works) beautifully. On the other side, I have seen some heads dying by a mis-matching. In general, solid state amps are more sensitive of mis-matching but you can fry your tube head OT tranny, too.


----------------------
The myth of connecting speakers is not a myth, it's way too simple. It works the same as in case of resistors

So, take two speakers, A and B. If you wire them in series, the sum of their impedance will be:

A+B


If you wire them parallel, you can get the the sum with a little formula:

(A*B)/(A+B)


In short, if you wire speakers with the SAME impedance PARALLELL, the sum of their impedance HALVES. If you wire SAME in SERIES, their impedance just DOUBLES.

8 + 8 parallel = 4 ohms
8 + 8 series = 16 ohms

It's pretty well described there:

http://professional.celestion.com/guitar/features/drdecibel/index.asp

select a secret: speaker wiring diagrams



Hints for a good SL-X setup:

- don't scoop mids or if you like that way don't do it too much
- never max both preamp gain controls, you just don't need to
- don't start searching for your tone with both treble and presence knobs maxed. The amp will blow your eardrums and carve patterns in the window For some reason, in the studio it works sometimes, anyway.
- a bad sound is 50% on bad playing, 30% on bad settings and just 20% on the gear
- always keep the gunpowder dry

Cheers,

Miki

 

[Rich_T]

Re: using a 2100 sl-x head and 1936 cab

ADMINS! VAULT THAT POST! I'm going to need that in the future i know.

 

[greendy123]

Re: using a 2100 sl-x head and 1936 cab

I tried out my amp on various settings and there is great amount of different styles I can play from the amp. I have on gotten use the master volume around 2 with the gain up. At volume 10 and the gain knobs I get very sweet clean sound. Do you guys think I would get alot more distortion if I turned the amp to volume 4 at the minimum? I know pushing tubes harder gets you more distortion, it's just I don't know how much more I would get. At volume around 2 I still get a bunch of nice distortion tones I like.

I have read that when you shut off the amp you should turn the master to off and leave the standby switch to on, so something is drained.
I read it here http://www.blamepro.com/marfaq.htm for the first amp question. A guy I talked to at Guitar center said that leaving the standby switch on than turning turning off the master switch does nothing.
Can you guys tell me if this the correct way to turn off my amp?

 

[Rich_T]

Re: using a 2100 sl-x head and 1936 cab

I just turn it all off at once. Dont worry about turing masters down and all that, i just switch off the standby, then the power straight after. Tube amps aren't as fragile as people make out, you dont need to be super careful with them, just dont chuck it around. Having said that, mine has been bashed about all over the place, still works fine.

These amps are designed with touring pros in mind, who dont have time to set it all up, let it heat up, then let it cool down after the gig. They have to switch it off, take it down straight away, chuck it in the van and drive to the next venue. There is no real need to worry. Marshalls are built like the proverbial brick sh!thouse on the main.

 

[greendy123]

Re: using a 2100 sl-x head and 1936 cab

Guys could you tell me how i could output from my fender ss practice amp to my new marshall amp head? The outputs for the fender are either headphones or speaker. Do I just put the headphone output to the input of my marshall?