View Full Version : Modding Class 5 for attenuator
12-10-2010, 08:45 PM
I will admit to being a complete idiot when it comes to wiring. I want to get my Marshall Class 5 modded to where I can use an attenuator with it. Can anybody give me step-by-step instructions on how to do this given that it doesn't have a traditional 1/4" plug that I can just plug and go? Any help is greatly appreciated.
12-10-2010, 09:28 PM
I do this mod to amps when needed also. Since it doesn't have a traditional 1/4 jack we will add one.This way you can use an attenuator and also use an extension cab like a 2x12 assuming you match the impedences.
1)Go buy yourself a 1/4 mono jack and (2) speaker cables
2)Unsolder or pull the clips off the speaker terminals, noting positive and negative polarity.
3)Solder the positive wire to the "tip" of the mono jack. The "tip" is most often the shortest lug.
4)Solder the negative to the other lug. Finished
1) Cut one side of the speaker cable off and strip.
2)Designate the inner wire as the "positive" wire and the outer wire as "negative."
3) Solder the inner wire to "+" speaker terminal and the outer wire to - terminal. Finished
4) Since this cable is hanging loose it might benefit you to clamp it down inside the amp cabinet at any convinient spot
There are a couple different ways you can go about this issue, however.
Instead of snipping a speaker cable you could .....
Step 2 - opt. 2
1)buy another mono jack
2)solder a black wire to positive. The solder a white wire to negative.
3)Solder the black wire to the "tip" lug(shortest)
4)Solder the white to the other lug. Finished
Either way works the same and either way you need two speaker cables. Step 1 is the same either way. You decide - election 2010.:rotflmao
12-10-2010, 09:48 PM
Okay very detailed. Couple of questions. Is there a way to do this with out soldering? As in easy, I know soldering isn't hard but if there's another way...Second, as I read that it looks like I'm creating a mono jack speaker out but wouldn't I need a jack at the end of the speaker wire in step 2 for the in from the attenuator? Yes I'm an idiot so bear with me and thank you for your help.
12-10-2010, 10:15 PM
Your last question first....Yes, purchase a speaker cable with the 1/4 plugs on both ends, and snip then strip one end. I know it sounds like an absurd thing to do but honestly is the easiest. You can absolutely do this without soldering . Use speaker slide connector clips, the same thing that is on the existing speaker wire now I assume. You can buy different sizes so that you can use them on the mono jacks as well. This is very risky tho.......
Soldering is the best way to go, If you use clips and one of them comes undone from the jack,speaker ect., then you put your tube amp at severe risk. If you use clips I would strongly suggest doing a protection mod that would involve soldering. Looks like either way you get the solder gun out. If your tube amp is on it needs to have a speaker plugged in at all times even with an attenuator. Unless your add a protection mod.
Pretty loud for five watts, eh?
12-11-2010, 04:10 PM
I think I'm with you now. The 1/4" jack coming from the amp will connect a speaker cable to the input of the attenuator, then the speaker cable I solder to the speaker will plug into the out of the attenuator right? Thanks for the help, I've also been pointed by another forum member to the fact that Weber makes a wiring harness to do this, I overlooked it because it was labeled as a wiring harness for Peavy amps, I guess they too use the hardwired speaker instead of a jack.
12-12-2010, 12:06 PM
You know about the headphone trick.. right?
12-12-2010, 01:58 PM
Never assume anything, please used dumbed down lingo for those that might not be hip, thanks for sharing
12-12-2010, 06:21 PM
Ok.. I assumed people know how to google.. .
The poster on this forum (Steve D) designed the Class 5 so I will take his word that this is safe :)
12-12-2010, 07:44 PM
-buy a speaker cable (10ft or so 2 1/4 in PLUGS)
-cut in half
-strip all 4 open ends
-Cut current speaker connection in half
-Strip all 4 open ends
-connect new leads to both halves of old wiring use MARR connectors..no soldering
Plug amp side into att'r input and plug speaker side into att'r output
To use normally you will have to reconnect the speaker directly to the amp by redoing the connection at the Marr connectors. Not hard.
12-12-2010, 08:04 PM
SamBooka answered your question, thats way too easy.
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