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sellen

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have a Marshall dsl 401 combo. Have bought myself 1936 vintage extension cab for getting a richer sound. In my first practise with the band i plugged it with the extra loudspeaker output from my dsl to mono 140 watt 8 ohm input in the 1936 vintage cab and set the ohm to 8 on my dsl. I could then play with all 3 speakers. But here's what i can't figure out- I want to try use it in stereo. Want to try a split cable from my extra loudspeaker output and in the two input in the 1936 cabinet. But here's the tricky part. At the 1936 cab it says when used in stereo 2*75 watt ohm at 16. But my dsl instruction says when use of the extra loudspeaker output set at 8 ohm. Have anyone some good advice on this subject.

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to be used in stereo you have to use 2 amps, each one powering only one side of the cab, if you are using the same amp it wont be stereo is will still be mono, so using one amp and pluging into both stereo inputs will put you right back to the same 8ohm load as the mono input.

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You have an impedance mismatch to begin with. In other words, you can't use that cabinet with the internal speakers.

 

The internal speaker is a 16 ohm speaker. If you want to mix it with another speaker system, BOTH must be the SAME impedance. Hooking it up to an 8 ohm speaker cabinet and the 16 ohm internal speaker results in a 5.333 ohm impedance, which is not correct and could conceivably damage the amplifier. Also, due to the decreased resistance, more power will flow to the cabinet than flows to the internal speaker.

 

If you put the cabinet in "stereo mode" you could hook up the internal speaker from the combo with ONE of the speakers from the cabinet, but not both.

 

Also please make sure you are using SPEAKER CABLE to hook up the external cabinet. and also do NOT put a splitter in a speaker cable.

 

Your best option is probably to disconnect the internal speaker, set the impedance to 8 ohms, and hook the combo up to the cabinet.

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You have an impedance mismatch to begin with. In other words' date=' you can't use that cabinet with the internal speakers.

 

The internal speaker is a 16 ohm speaker. If you want to mix it with another speaker system, BOTH must be the SAME impedance. Hooking it up to an 8 ohm speaker cabinet and the 16 ohm internal speaker results in a 5.333 ohm impedance, which is not correct and could conceivably damage the amplifier. Also, due to the decreased resistance, more power will flow to the cabinet than flows to the internal speaker.

 

If you put the cabinet in "stereo mode" you could hook up the internal speaker from the combo with ONE of the speakers from the cabinet, but not both.

 

Also please make sure you are using SPEAKER CABLE to hook up the external cabinet. and also do NOT put a splitter in a speaker cable.

 

Your best option is probably to disconnect the internal speaker, set the impedance to 8 ohms, and hook the combo up to the cabinet.[/quote']

Tbone I always consider your opinion to be one of experience and expertise but reread what he wrote particularly toward the end. I believe all the speakers in question are 16 ohm and he is hooked up correctly. It is the same with my Marshall TSL and my B-52 ext. cab. If the cab runs at 16 ohms in stereo which is one speaker per input then the speakers are 16 ohms. When he runs both speakers at the same time he is running at 8 ohms. Therefore when he runs both the combo amp and ext. cab at the same time everything should be set at 8 ohms. I've been running my setup that way for almost 5 years now and I have never had a problem. My Marshall runs at 16 ohms with just internal speakers and 8 ohms when I add the ext. cab with the internal speakers. Tbone I thought you had a Marshall Tsl combo amp? Marshalls are setup to run that way. Peace brothers and sisters!

Rewd

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Tbone I always consider your opinion to be one of experience and expertise but reread what he wrote particularly toward the end. I believe all the speakers in question are 16 ohm and he is hooked up correctly. It is the same with my Marshall TSL and my B-52 ext. cab. If the cab runs at 16 ohms in stereo which is one speaker per input then the speakers are 16 ohms. When he runs both speakers at the same time he is running at 8 ohms. Therefore when he runs both the combo amp and ext. cab at the same time everything should be set at 8 ohms. I've been running my setup that way for almost 5 years now and I have never had a problem. My Marshall runs at 16 ohms with just internal speakers and 8 ohms when I add the ext. cab with the internal speakers. Tbone I thought you had a Marshall Tsl combo amp? Marshalls are setup to run that way. Peace brothers and sisters!

Rewd

 

The external cabinet in question has two 16 ohm speakers in it. This is why it runs at 8 ohms mono and 16 ohms stereo. When run mono it is running the two 16 ohm speakers in parallel to give an impedance of 8 ohms. My TSL has 2 8 ohm speakers in it that are wired in series to give an impedance of 16 ohms' date=' so it's a different setup.

 

The way the DSL401 is setup is that it has two speaker outputs in parallel, and a switch to change taps on the output transformer. The total impedance of the speaker system attached has to be either 16 ohms or 8 ohms, and the wiring attached to each speaker has to be the same impedance. This is different from some other marshall amplifiers which have different outputs for the different output taps on the OT.

 

[img']http://www.tbonesullivan.com/amps/MarshallTSL122c.jpg[/img]

 

That is a picture on the back of my TSL122. The DSL401 does not have a dedicated 16 ohm output like the TSL does. It just has the two parallel jacks, and the 16/8 ohm impedance switch. As the two outputs are wired in parallel, you would have to have 1 16 ohm speaker connected at 16 ohms or two 16 ohm speakers connected at 8ohms total. You could also hook up one speaker at 8 ohms with it in 8 ohm mode. I checked the official manual at the marshall site, and that is exactly what it says there.

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Or you could do some simple electronics to give the cabs the same impedance but it would end up quieter..
uhhh... what simple electronics? You'd have to recone the speakers to change the impedance of the cabinet. It has two 16 ohm speakers in it, so your only options for having both running would be 8 ohms in parallel... or 32 ohms in series, which I have never seen.
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Hey your setup is different than ours. My speakers are 8 ohm in the combo but run at 16ohm and when I add the ext. cab I have to switch it to 8 ohm and use the 8 ohm mono jack on the ext. cab. I talked to a local techie about this and he says Sellen is running his system right. He also said if one was getting more of the load in one or the other you would be able to hear it. I dunno I just playem I don't make em or work that much on them other than changing tubes. My ext cab also runs at 16 ohms in stereo.

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hmmm... well I'd defer to the tech, but I've had or owned about 7 tube amps now, and they are not as forgiving of impedance issues as solid state amps are. Recent make Marshalls also tend to not have overspec'd transformers. It doesn't help that Marshall has about 10 different ways to hook up the speakers. From what I read in the manual, the options are:

 

1 16 ohm speaker with the switch set at 16 ohms

2 16 ohm speakers with switch set at 8 ohms

1 8 ohm speaker with the switch set at 8 ohms

 

Those would be the only "valid" ways of having it hooked up.

 

My TSL122 on the other hand has the following choices

1 16 ohm speaker system hooked into the 16 ohm jack

2 16 ohm speaker systems connected into the parallel jacks and the switch set to 8 ohms

1 8 ohm speaker system connected to the parallel jacks with the switch set to 8 ohms

2 8 ohm speaker systems connected to the parallel jacks with the switch set to 4 ohms

1 4 ohm speaker system connected to the parallel jacks with the switch set to 4 ohms.

 

As for me, I prefer the Carvin way of doing it: two parallel jacks with a 4/8/16 impedance switch, so you can hook up virtually anything, as long as the impedance of the speaker systems match.

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According to page 6 in this manual he is doing it right. http://www.marshallamps.com/downloads/files/DSL201_401%20hbk.pdf Tbone I'm not trying to argue with you but Sellen is just a kid and I want to make sure he gets it right that's all.

Rewd

 

If Sellen had a 16 ohm extension cabinet, it would be correct. However Sellen said that the cabinet is 8 ohms mono and 16 ohm per side stereo. The way it is hooked up now there is the 16 ohm internal speaker and the 8 ohm external cabinet (in mono mode). That is not one of the three valid combinations that can be used. the switch does not indicate the impedance of the external cabinet being used, but the total impedance of the system.
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Here's a pic of the page in question all you guys hash it out maybe I am misinterpreting something. It says the switch is parallel wired to make 8 ohms from the internal speakers and then can use it in combination of an external cab rated at 8 ohms unless I don't understand it right. I took an electricity class 35 years ago and bygolly I hardly remember any of it!
I think what it says is that keep it on 16 ohms if you are using the internal speaker, and set it to 8 ohms if you combined the internal speaker with a marshall 4x12, which almost always have an impedance of 16 ohms. This would be correct. Since the external cabinet is 8 ohms mono (as opposed to 16 ohms) it won't work.
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I think what it says is that keep it on 16 ohms if you are using the internal speaker' date=' and set it to 8 ohms if you combined the internal speaker with a marshall 4x12, which almost always have an impedance of 16 ohms. This would be correct. Since the external cabinet is 8 ohms mono (as opposed to 16 ohms) it won't work.

[/quote']

Tbone you are correct he needs to get a cab with a 16 ohm rating mono and run it on the 8 ohm selection switch if using the internal speaker also. I just found out in my manual a paragraph I apparently overlooked and even my setup is wrong. S!@T I need a new 2 x 12 cab. Thanks for the help man your expertise shines thru again Bro. Peace man.

Rewd.

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You have an impedance mismatch to begin with. In other words' date=' you can't use that cabinet with the internal speakers.

 

The internal speaker is a 16 ohm speaker. If you want to mix it with another speaker system, BOTH must be the SAME impedance. Hooking it up to an 8 ohm speaker cabinet and the 16 ohm internal speaker results in a 5.333 ohm impedance, which is not correct and could conceivably damage the amplifier. Also, due to the decreased resistance, more power will flow to the cabinet than flows to the internal speaker.

 

If you put the cabinet in "stereo mode" you could hook up the internal speaker from the combo with ONE of the speakers from the cabinet, but not both.

 

Also please make sure you are using SPEAKER CABLE to hook up the external cabinet. and also do NOT put a splitter in a speaker cable.

 

Your best option is probably to disconnect the internal speaker, set the impedance to 8 ohms, and hook the combo up to the cabinet.[/quote']

Thanks man, i will run it without the internal speaker. Hope i haven't ruined my beloved dsl combo. Have played maybe 5 hours in the wrong mode

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doubtful that you've caused any harm. I would just use the amp as a head and connect it to only the external cabinet at 16 ohms. It's a closed back cabinet and has more air space inside, so you will get a bigger chunkier sound out of it than from the combo speaker.

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If Sellen had a 16 ohm extension cabinet, it would be correct. However Sellen said that the cabinet is 8 ohms mono and 16 ohm per side stereo. The way it is hooked up now there is the 16 ohm internal speaker and the 8 ohm external cabinet (in mono mode). That is not one of the three valid combinations that can be used. the switch does not indicate the impedance of the external cabinet being used, but the total impedance of the system.

Sellen this how you need to hook up your set up. If you get an ext. cab with a 16 ohm mono impedence you can run it alone set at 16 ohms on your amp or run it with your internal speaker set at 8 ohms on your amp. This is the only way you should run your setup. The only way you can use your 2 x 12 ext. cab is to plug into the 16 ohm stereo input this operates only one speaker. If you use the internal speaker with it you have to use the 8 ohm setting on your amp. There is no way to use all the speakers in your 2 x 12 cab. It would be better to take it back to the store if you can and swap for a 2 x 12 cab with a 16 ohm mono impedence rating. Sorry Bro that's the way it is. Good luck I hope it works out for you. Don't feel bad I just found out that my B-52 ext. cab was wrong for my amp too. I had to trade it in and buy a new one with the right impedence ( 16 ohms mono). Peace man!

Rewd

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uhhh... what simple electronics? You'd have to recone the speakers to change the impedance of the cabinet. It has two 16 ohm speakers in it' date=' so your only options for having both running would be 8 ohms in parallel... or 32 ohms in series, which I have never seen.

[/quote']

 

Just put a high voltage resistor in paralell with the speakers.. I cba to do the maths though

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