Question:
So I'm going to be getting a Peavey Classic 30 within the next few weeks, and I want an attenuator for it. I've been reading the threads on attenuators, and I think I've got an understanding of what to do now. So... here's what I'm looking at on partsexpress.com (quantity is 1 each)
260-261 L-PAD 16 OHM 100W MONO 3/8" SHAFT
260-268 L-PAD FACE PLATE FOR "HIGH"
095-810 GOLD 12 GA. 1/4" FEMALE DISCONNECT 5 PAIR
100-482 DAYTON S213 13 GA 2 COND SPEAKER CABLE
Is that all I need to make it? I'm not sure exactly when I'll have the amp, so I'm planning on not being able to do this until I move back into my dorm room in January. That said, I'm not planning on soldering anything and won't have access to many tools or supplies. So besides a few screws (I was planning on using the face plate to mount it), a screwdriver, and plyers, would I need anything else?
Also, when I'm connecting the wires, how do I tell which side is grounded and which is not from the amp's speaker output?
And... the dial will allow me to adjust how much volume I'm cutting, right? If I were to, say, dime the amp, and put the dial so that the volume was as low as the attenuator would allow, would I overload it? I'm not actually planning on doing that, just wondering what limitations the attenuator has.
Answer:
You'll also need some male disconnects to connect to the wires coming out of the amp, the females will go onto the speaker. I think you will find that the C30 has a smaller size than the 1/4" in your link, I believe they are 3/16". That's what I have supplied on the ones I made for those amps, apparently they work. You could use the 1/4" females for the speaker, but the males need to be the right size to fit into the existing lugs.
The 12 gauge wire is major overkill, and will be harder to work with. Believe me, 18 gauge is more than big enough for a 2 foot length in a 30 watt amp, that's what mfr's commonly use for guitar amp speaker wiring. My Fender HR DeVille is a perfect example.
Faceplate - not sure how that thing works, if you can actually mount the LPad to it, it might be worthwhile. If its just a faceplate, I don't think it will do you any good.
Also, when I'm connecting the wires, how do I tell which side is grounded and which is not from the amp's speaker output?
And... the dial will allow me to adjust how much volume I'm cutting, right? If I were to, say, dime the amp, and put the dial so that the volume was as low as the attenuator would allow, would I overload it? I'm not actually planning on doing that, just wondering what limitations the attenuator has.
The speaker output polarity doesn't matter unless you are going to use an extension speaker with it, in which case you would need to maintain the proper phase. I would just look at the color of the wires - the one that's black or maybe green would be the "ground" side. Otherwise, check for continuity with a multimeter to the ground side of the extension speaker jack.
The Lpad is like a very large pot - like the volume control on your guitar. It will work in a similar fashion, although since the Lpad is linear by nature of its design, it will be non-linear when controlling volume. Most of the adjustment will be in the first 1/4 turn.
If you dime the amp with a heavy distortion tone, you may overheat the LPad - if so, you'll know it, as it will start to emit some smoke....turn the amp down some. With a moderate OD type tone, you should be fine. I never had a C30 to test 'em. My HR DeVille will smoke them when cranked with distortion, but not with moderate OD or clean. A little bit of smell when they are new is normal, after a while that should stop.
BTW, the way those Lpads are made, when you turn it all the way up (CW), it passes the signal thru with no attenuation; its essentially bypassed.
Caution, they do get quite hot, that is normal. You do need to mount it in the cab, it will need open-air ventilation. Not as hot as a tube, but too hot to hold on to, about like a 40 watt light bulb. No mounting in a box, or laying it on top of the amp.
Answer:
So, the disconnects just attach to the wire and then slide onto the terminals? I would assume that they are like the things that already attach the wires to the speaker. Is it fine to just solder the wires to the terminals?
Answer:
Originally Posted by sabertooth181 So, the disconnects just attach to the wire and then slide onto the terminals? I would assume that they are like the things that already attach the wires to the speaker. Is it fine to just solder the wires to the terminals?
Those slide-on lugs are usually made to crimp onto the wire, you stick the stripped end of the wire in and squeeze it hard enough to hold the wire in place. Sometimes I will solder it after crimping. You could just solder the wires to the terminals of the speaker, it does make it a bit more work to undo later - like if you go to sell the amp and want to restore it to original, or if the Lpad were to fail and you needed to re-connect like it came from the factory. I would definitely solder the wires onto the Lpad, its terminals are very thin, and have a concave shape; they may bend and/or break if you try to put the slide on connectors on them. I would also use the male and female disconnects.
Answer:
Ok, thank you so much. I think I've got it all figured out. If I have any trouble when the time comes for me to actually put it all together, then I may resurrect this thread.
Answer:
I made myself a Major-Tom-style attenuator with parts from partsexpress.com for my Peavey Classic 30. I will try to get some pictures of mine and then I'll post them for you.
Answer:
I bought an attenuator from Major Tom for my C30 - I'll try to post some pics soon, too.
Answer:
So on the wire, 12 gauge is bigger than 18 gauge?
Answer:
Originally Posted by sabertooth181 So on the wire, 12 gauge is bigger than 18 gauge? yes...just like shotgun shells and earlobe plugs
Answer:
Originally Posted by thesteve yes...just like shotgun shells and earlobe plugs Haha, I'm not too familiar with those either.
Answer:
FYI, I'd not waste time with a face plate. My L-pad actually came with a face plate I believe...and that's when I bought one similar to what you linked to with it, so I had an extra with no use for it.
Answer:
Originally Posted by Brent FYI, I'd not waste time with a face plate. My L-pad actually came with a face plate I believe...and that's when I bought one similar to what you linked to with it, so I had an extra with no use for it.
I noticed that the description of the L-pad said it came with mounting hardware, but I wasn't sure what that would be. So thanks for the heads up.
I ordered the parts a few days ago to get sent to my school address. I got 16 gauge wire, because I couldn't find any 18 gauge wire that I didn't have to buy in a large quantity. I'm going to be picking up some 3/16" disconnects at Radioshack today, too.
For you guys that have made attenuators for a C30, where did you end up mounting it? If you could get the pictures up as well, that would be helpful. I should be able to put this all together within a week.
Answer:
I mounted mine under where the power wires come out of the amp chassis. In retrospect it might not have been the best place as that's also close to the power cable that likes to move around now and then and if it touches the L-pad when it's too hot it can potentially smoke a bit. I don't have any pics of mine, but I'll see what I can do. Rigged a little L-bracket to mount mine to. It does the job, but not that great. Attenuator is just great, though.
Answer:
What I am doing so far is just letting it rest on a small cardboard box I had. It is working pretty well I think.