Vintage SVT Cab Wiring Question

nitram · #1 08-13-2010, 10:04 PM

Hello everybody !

Let me just start off by saying that this is my first post !

I joined about two years ago and I somehow forgot that I had !

And it's only recently when I tried to sign up and was informed that I was already a member that I realised that I could have joined in on all them posts I've been reading for years now !

I would have a question for the SVT cabs experts around here... I know close to nothing in electronics so please be nice to me !

I recently bought a very nice 1974-1975 SVT 810 cab and I am ready to change the speakers, as the dust caps are farting like crazy... I will keep my CTS' and have the dust caps reglued by a pro or something eventually...

In the meantime, I got 8 speakers from a USA made SVT 810AV from 2001 that I will put right in ...

I just removed one speaker from my cab and noticed that the CTS squareback is not marked to specify which wire attachement is the positive (+) and which is the negative (-).

I looked all around the speaker housing and can't find the + or the - signs anywhere...

My first question would be as follows... Now if I was to put the CTS back in, I wouldn't know which speaker connector is the positive and which is the negative. Can somebody help me ?

My last question would be as follows...Now that I want to put my SVT810AV speakers in my vintage cab, I looked inside the cab where I pulled a speaker from, and I see two sets of wires... A first set is all black and ends with a connector... I guess this is the negative, right ? The other set has got a green wire attached to a light blue wire ending to another connector... So I guess this is positive, right ?

I hope someone can help me with this, as I'm sure this is really simple for someone who knows these cabs... I know there are a lot of real Ampeg savies here...

Thanks in advance !

Nitram

sedan_dad · #2 08-14-2010, 11:40 AM

First things first.
Lets determine the hot side of the speaker. Take a AA, D,C what ever battery. (1.5 volt )Run a wire from the + on the battery to the right terminal on the speaker . Now run a wire from the negitive post on the batter to the other terminal on the speaker. At the moment of contact, which way does the speaker cone jump? Make note whether it jumped in or out. Mark the speaker terminal that went to the + post of the battery as +. Do the next speaker,and the next. We want to make sure they are all moveing in the sam direction. This is also known as being in phaze.

On to the cab. The easiest thing to do is just to rewir the whole thing. The 2 wires comming from the input goes to the firest speaker. Then leads are taken off that one to the next speaker.Attachment 177463

JimmyM · #3 08-14-2010, 02:38 PM

dude, come on...you've got cts's. get them fixed up and you won't recognize how great your cabinet sounds. i've played all the 810 models except the new heritage many times over and it's not even close. the cts speakers are by far the best. do it right, bro...do it for the children.

nitram · #4 08-15-2010, 11:27 AM

Quote:

Originally Posted by sedan_dad

First things first.
Lets determine the hot side of the speaker. Take a AA, D,C what ever battery. (1.5 volt )Run a wire from the + on the battery to the right terminal on the speaker . Now run a wire from the negitive post on the batter to the other terminal on the speaker. At the moment of contact, which way does the speaker cone jump? Make note whether it jumped in or out. Mark the speaker terminal that went to the + post of the battery as +. Do the next speaker,and the next. We want to make sure they are all moveing in the sam direction. This is also known as being in phaze.

On to the cab. The easiest thing to do is just to rewir the whole thing. The 2 wires comming from the input goes to the firest speaker. Then leads are taken off that one to the next speaker.Attachment 177463

Hey Sedan Dad !!!

Thanks a lot for this !!!

Thanks to you, I was able to determine which is the + and - on the CTS...

When the speakers pop out, this is the correct phase I assume...

So then the + is on the righ side of the CTS and the - on the left, when looking at the speaker's squareback side.

Thanks for the wiring diagram ! But I don't think I'll rewire, 'cause everything is fine with the cab's wires.

I also tried that little battery test on the cab itself by the wires of the speaker that I removed... And when I plug the + of the battery to the green-blue wires and the - to the black wires, all of the cab's speakers pop outwards... So everything there is in phase !

Thanks mate ! You rock !!!

Nitram

nitram · #5 08-15-2010, 11:36 AM

Quote:

Originally Posted by JimmyM

dude, come on...you've got cts's. get them fixed up and you won't recognize how great your cabinet sounds. i've played all the 810 models except the new heritage many times over and it's not even close. the cts speakers are by far the best. do it right, bro...do it for the children.

HI JimmyM !

Thanks for your advice... I will contemplate the option of having the CTS's fixed sooner than I previously planed...

I'm in the process of finding a good place to have the dust caps glued back, or even replacing them 'cause it seems like they're really filled with crap.

I just need to know now what would be a decent price for fixing the CTS's would be... as I have no idea how much it could cost to replace 8 dust caps on my CTS's...

Hey man, I know you're really into Ampegs 'cause, like I said, I have read the forum actively without participating for about 2 years now... I was wondering if you knew about this one: I have a touring cab (that SVT 810AV I was talking about) that I use for live stage performances and it's now loaded with the new Eminence Legend B810 speakers... I heard about a rumor that these speakers could very well be the ones loaded in the new 810 Heritage series...

Thanks a lot Jimmy !!!

Nitram

JimmyM · #6 08-15-2010, 12:45 PM

it seems like the timing for when the b810 and heritage cabs came out is pretty coincidental. but i can't prove it, and one of the guys on here who has one pulled a speaker and couldn't find any evidence that they're the same speaker. so that's still a rumor at this point, though i think there's something to it.

nitram · #7 08-15-2010, 01:43 PM

Quote:

Originally Posted by JimmyM

it seems like the timing for when the b810 and heritage cabs came out is pretty coincidental. but i can't prove it, and one of the guys on here who has one pulled a speaker and couldn't find any evidence that they're the same speaker. so that's still a rumor at this point, though i think there's something to it.

Thanks man !

Would you happen to know now what would be a decent price for fixing my CTS's dust caps ?

So you preffer the old CTS's over anything you tried before ? Why mate ? I guess it has to do with the tone...

How many watts are they by the way ? I don't think they're that powerful but I don't know how many watts RMS they are... They are stamped by the year 1974.

Thanks mate !!!

Nitram

JimmyM · #8 08-15-2010, 01:49 PM

you could fix the dust caps yourself if you have the paper for them, which is pretty easy to get at speaker stores. just cut the old dust caps off, leave a little bit of paper around the edges to glue the new ones on, and viola!

and yes, the cts speakers sound fantastic. true, they don't handle power like the newer ones (i think they're rated at 50w real world power handling...ampeg used to say 250w but i think they do a little better than that) but the tone is oh so sweet! having said that, i haven't tried the heritages or the b810's.

nitram · #9 08-19-2010, 11:13 PM

Just removed my speakers from the cab yesterday night !

Damn, it was such a pain !!!

JimmyM... Have you ever had to fight to get them stupid speaker holding bolt screws out of a 70's vintage cab ? Did you have to struggle to get your ratchet around them wood screws ?

The speaker's baskets were soooooo in the way !!! Man, I'm not putting them bolt screws in again that's for sure... I'll keep them for the sake of authenticity, but I'm not half dumb enough to put them back in there !!! The hell with that !!!

Nitram

nitram · #10 08-26-2010, 09:14 PM

All right !!!!!!!

I finally managed to have my CTS's fixed !!!!!!!!!

IT SOUNDS AWESOME !!!

The guy I brought them to for repair glued the dust caps with Weldbond. When I saw him do this at first I was really unimpressed...

I was like, what the hell is he doing with that kind of all purpose glue on my CTS's... I was really feeling like I was gonna puke... I didn't know what to think really... Does he really know what he's doing or what...

Anyways, I thought ... ok... "he's a repair guy that specialises in vintage stereo systems so I he must have repaired old speakers before..." so I let him complete the job...

When I got home I searched the Internet and I saw a lot of high end speakers forums and sites praising Weldbond as a real wonder for speaker repairs... I felt kinda relieved.

Tried them a lot today, and it seems like it's gonna be all right !!!

I got my 1974 SVT cab back to life !!! This is a great day for rock & roll !!! haha !

Thanks to all of you who helped me here.

Nitram

JimmyM · #11 08-26-2010, 09:22 PM

do you have the clutch head screws in yours? i made a msitake and threw all mine out because they were so frustrating. wish i'd have kept them now because it's a cool look

anyway, what'd i say?

those cts's beat all!

nitram · #12 08-26-2010, 10:25 PM

Quote:

Originally Posted by JimmyM

do you have the clutch head screws in yours? i made a msitake and threw all mine out because they were so frustrating. wish i'd have kept them now because it's a cool look

anyway, what'd i say?

those cts's beat all!

Here's what resembles the kind of screws that I didn't want to put back in...

http://french.alibaba.com/product-fr...239521805.html

Look at the second one from the right... It looks a little bit like this but in black... looks good on the cab, but what a pain to remove them that I didn't dare put them back in...

My digicam is dead so I can't post an actual picture right now...

I love them CTS's !!!

Nitram

JimmyM · #13 08-26-2010, 10:28 PM

ya, those are a bit of a pita...although i have them in mine

mine have flathead slots too. they're replacements, but the clutch head screws are a bigger pita since you have to have a special driver for them.

nitram · #14 08-26-2010, 10:34 PM

Quote:

Originally Posted by JimmyM

ya, those are a bit of a pita...although i have them in mine

mine have flathead slots too. they're replacements, but the clutch head screws are a bigger pita since you have to have a special driver for them.

It's the speaker metal frame that's always in the way...

The sockets can't fit at all sometimes and you don't want to strip the screws...

Real PITA all right !