Building amp with vintage speakers - Newb Needs Help

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flat1ine

New member
Hi all -

I'll try and make this short and sweet. My wife and bought an older house, in it were 6 of these badboys (they're Altecs from before they became Altec-Lansing). The guy who owned the house kept everything in immaculate shape, and I kinda like the idea of giving some new life to these awesome, old speakers.

I want to make an amp with 4 of 'em.






Just for kicks, I swapped one of them into my beat to crap Peavy Blazer 158, and it sounds pretty cool.

Now, for some background, I'm a hobbyist musician at best - I'm never gonna be famous, I'm never gonna be all that great, but playing's fun as hell.

I figure there's probably a fairly difference between these suckers and speakers specifically tuned for amps -- I just want to build it 'cause i think it'll be a cool project, and I want to do something unique. I've had the same 15-watt amp for about 12 years (again, the Peavy), so anything louder or different is going to be a massive step up for me.

I've check out many of the amp kits online, but it's been almost 10 years (damn!) since I took electronics classes in college, and I'm clueless as to if any of those kits can power multiple speakers -- basically, I don't remember crap about how any of this works. I can solder decently enough, and I've been building PCs for decades, so I'm hoping to be technical enough ...

Preferably, I'd like to build my own cabinets (woodworking i can handle), I don't want to spend a ton of cash, and I have no idea where to start.

I don't care if it's solid state or tube, but in a perfect world, reverb would be nice.

Other than that, I'm clueless beyond belief.

Thanks!
-Erik
 
So, if it fit in that Peavey 158 (15 watts, 8" speaker) they are 8" speakers, right?

They seem to be selling for $20-25 each, these days. I can't get a bead on when they were made, but it seems the company, later called Altec-Lansing, pretty much went under in about 1974 (extrapolating from what I read, I could be way off on this.)

I'd build a cabinet for 4 of them (no chassis, just speakers) and maybe another cab, with room for a head, for the other two. My guess is a tube amp in the 15-20 watt range would sound the best with them. Go to this website
Series Parallel Speaker Impedance
to figure out how to wire them for the proper impedence.

I'd make the cabs to look like scaled-down versions of Fender 410 cab, and a scaled-down Fender Vibro-Lux combo. But that's just me, and my aesthetic preferences- I love the look of narrow-panel Fender amps (I think the "TV-front" amps are ugly.)
 
stevieb said:
they are 8" speakers, right?

They seem to be selling for $20-25 each, these days. I can't get a bead on when they were made, but it seems the company, later called Altec-Lansing, pretty much went under in about 1974 (extrapolating from what I read, I could be way off on this.)

I'd build a cabinet for 4 of them (no chassis, just speakers) and maybe another cab, with room for a head, for the other two. My guess is a tube amp in the 15-20 watt range would sound the best with them.
Click to expand...

stevie --

thanks for the reply :)

they ARE 8" speakers. [as a side note, altec-lansing is still around, though they're more in the computer speakers/accessory market these days.]

i'm definately intending on a 4x4 cab -- i've got an older cheap celestion and might want to build another cab for that, maybe have a nice lookin' mini practice stack :)

i did a bit of looking, and found this: GuitarCenter -- could i just build my cab, wire my speakers, and hook it up to this head? could it be that simple?
it's spec'd at: "4-, 8-, 16-ohm outputs for speaker flexibility", which seems promising, even though it's low output.

this: GuitarCenter looks like a sweet sumbitch, too ...
it's rated at, "Output Power: 20W into 16 ohm or 2x 8 ohm speaker outputs', but i'm not sure if it would be switchable between my 4x4 or the single 12" -- that's much less of a concern for now.

thanks again,
-Erik
 
My guess is a tube amp in the 15-20 watt range would sound the best with them. stevieb
Click to expand...

this would be plenty loud with 4 speakers.

could i just build my cab, wire my speakers, and hook it up to this head? could it be that simple? Erik
Click to expand...

Yes. the Epiphone head unit comes with a multitap output transformer. ex: set the dial to 8 ohms and plug an 8 ohm speaker into it.

If you decide to build a kit then read up on the dangers of high voltage or have someone build it for you that has experience working on tube amps. Tube amps produce high voltages that can KILL! GC, once in a while has some really nice used tube amps as well as the occasional garage sale.

I have heard some good things about the Jet City amps.

i'm not sure if it would be switchable between my 4x4 or the single 12. Erik
Click to expand...

it calls for 16 ohms only. a 16 ohm cab or 2 x 8 ohm speakers summed to 16 ohms.
 
drumslinger & stevie - thank you both very much for the help!

I'm in the middle of building a cabinet for my speakers, and so far, it's wicked fun. I've tweaked the original plan, and now the cab is going to house 2 of the 8" Mustangs (8-16 ohm), and the Celestion V12-60 (8ohm).

After loads of research, and confusion galore (i do NOT have a head for math), I think i'm getting close to nailing down some of technical details.

The Mustangs are rated at 8-16ohms - so if I wire them in parallel what will happen?
2x @ 8 ohm = 4 ohm total
2x @ 16 ohm = 8 ohm total -- i don't know what to make of this, i know impedance is a curve ...


I would be EXCELLENT to be able to wire this thing so I can:
1. Use just the 2x 8"
2. Use just the 12"
3. Be able to use both simultaneously (it'd be really cool to compare/contrast)

Let's assume that I get myself the Jet City JCA20H; it's rated at "Output Power: 20 watts into 16 ohm or 2x 8 ohm speaker outputs."

So, if I'm right, i'd be able to just use the 2x 8ohm outputs ->two cables, one into the 1/4" jack for the 2x Mustangs, one into the 1/4" for the Celestion; and i'd be able to just swap cables to change the speakers, right?

One more broad question (sorry, this is getting convoluted) -- if a head has a 4 ohm, 8 ohm and 16 ohm out, you can only use one at a time, right?

Thanks again,
-Erik

(more pictures of the build as it happens...)
 
The impedence switch- 4, 8 or 16 ohms- will change the impedence the amp "wants" to "see." It primarily keeps your amp from over heating- a 4-ohm load is BAD for a 16-ohm amp. Yes, you must choose one. Oh, wait, that amp's got three jacks. I dunno, I'd use only one, unless the maker tells you otherwise. There must be a way to use more than one, but I have no idea what that way would be.

I don't know what to make of speakers that are rated at "8-16 ohms." Either they are one, or they are the other. Put a ohmmeter on them- DC resistance will be a bit lower than the actual impedence- an 8 ohm speaker will check out around 6 to 7 ohms, for instance. Round up to the nearest 8, and go with that.

IMO, you would do better building one cab with 2 8's, and another cab with the 1 12. Install dual jacks on each cab. Run the 2 8's in series. When you run a speaker cable from the head to one cab, and another speaker cable from one cab to the other, you will have a resistance of 5.33 ohms- use the 4 ohm jack on the amp.

You could use all 4 8's in one cab, and run three different wiring in the cab, and have three jacks- marked 4, 8 and 16 ohms- on the back of the cab... Now, THAT would be wild.
 
ok, so i'm back at it again, and even more confused than before.

in hopes of finding out what these "8-16ohm" speakers actually ARE, i've hooked them up to a multimeter, along with the 12" celestion v12-60 8ohm. i'm going to assume DC resistance is about 80% of ohm impedance - i've read 75-80%, so i'll round up.

celestion: 6.8ohms (on the meter) = roughly 8.16 ohms

university m-8 #1: 5.4omhs = roughly 6.48 ohms
university m-8 #2: 5.4omhs = roughly 6.24 ohms

so, in parallel that's 3.15 - won't work for the JCA20H i just bought :confused:

in series that's 12.8 -- can i plug this into the 8ohm out? that'll only underload the amp, right?

thanks again all,
-erik
 
stevieb said:
Yeah, you should be able to run 2 of 'em in series, no worries.
Click to expand...

you sir, are a scholar and a gentleman - and an freakin' lifesaver.

thank you very much for all the help - it's sincerely appreciated.

also, i've got a buddy that used to live in Marietta -- nice place :) i REALLY miss bojangles ...CANNOT find a decent biscuits and gravy, chicken biscuits, bo rounds or anything of the sort up here in CT. :(

EDIT - UPDATE: build log here: Guitar Amp Build*: An Album on Flickr
If you prefer the photostream view, it be here: Flickr: Gallery by erikbetti

I have a few more things to do, then it's wiring, wrapping, final assembly and testing. BOOYAH.

I also ordered Jet City's JCA20H their a 20W tube amp to go along with my to-be-done-soon cab. I've never had a tube amp before, and i'm crazily excited to see how this combo works. :D
 
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If the sides of the cab are wood (not MDF,) I highly recommend tung oil to finish the cab. Using it on a Hammond organ I am rehabb'ing, and it looks BEAUTIFUL.
 
stevieb said:
If the sides of the cab are wood (not MDF,) I highly recommend tung oil to finish the cab. Using it on a Hammond organ I am rehabb'ing, and it looks BEAUTIFUL.
Click to expand...

i LOVE a tung oil finish - sadly, this whole box is MDF. i picked up some thick black canvas-like stuff to wrap it in, though and i think it'll look alright.

i've never built anything like this before (first project now that i've got an actual workbench), so i wanted to stick with something simple, and i don't think i have the chops to make anything beautiful out of wood yet.

thanks :)
 
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