Need advice for powering retro speakers(warning, complete noob)

[BiscuitAbuse]

Hey guys and gals.

I'm going to come right out and say it I have no idea where to go from here. 

I have just purchased a set of 2 Kriesler speakers circa 60's - early 70's.

They aren't powered so I'm in need of an amplifier, but as I go along I would like to learn

a little about the audio world. I've popped them open and all the wiring seems to be 

in good nick but I have a question. The positive and negative wires from the woofer and tweeter

are connected to a little black cylinder labelled MICROCAP. This then feeds out the back

to what looks like standard beige speaker wire. My question is what is that thing? and what do I

call it? Also I am weary of overpowering such old speakers and was wondering what a safe

bet would be. I've attached a couple of pics but I haven't been able to find any power ratings

for them anywhere. I plan on replacing the drivers in the future but for now I'm curious as to

whether or not the original gear will actually play. Oh and my budget is minimal, seems a bit

embarrassing considering some of the amazing stuff going on elsewhere in the forum.

So #1 What is the thingy changing the positive and negative signals to one wire labelled MICROCAP?

     #2 What kind of amp am I looking at to get these two guys going?

     #3 What would be a safe wattage to use so I don't ruin anything?

 

Thanks guys, sorry if this is silly stuff, like I said. complete noob.

[k-k-k-kenny]

You've come to the madhouse - the longer you hang around the worse it's going to get, so don't say you haven't been warned.

 

Others more knowledgable than I will be able to tell you more but sounds to me as though ye microcap is a crossover which limits signal to the tweeter so it doesn't get blown up, for want of a better explanation.

 

So - your interconnects from whatever amplifier you use connect to that (via some sort of terminals on the back of the speakers which I hope are there)

 

Chances are that the speakers can only take limited continuous power - maybe 15-20 watts, maybe less. So, whatever amp you can beg borrow or steal, keep the volume low for a start. Try borrowing something before you commit. Others will have plenny of suggestions as to what might suit.

 

Bit hard to tell from the pic, but it looks as if the surrounds (where the edge of the cone of the speaker joins the suspension) might be o.k. If they have decayed or detached from cone/suspension it's going to sound a bit, ah, soggy and you'll probably hurt the cones.

 

I'd be doubting that replacement of the drivers would be financially worthwhile - there's plennyo good second hand near new speakers available in the classifieds here which are likely to outperform them, but YMMV.

Edited June 4, 2013 by k-k-k-kenny

[daemon d]

Hi Biscuit,

 

They will probably be 40 watt.  Kriesler were a badge on a home goods shop targeted range of low to mid range Japanese gear. Very common in Norman Ross type shops in the late 70s before they took on Marantz and Kenwood. They never got to be classic vintage hi fi, but you find their stuff around a bit still. Used to make nice timber cabinet work and sell fully matched component systems in a design matched cabinet. Can't remember who's guts they used to use in the electronics: I have a vague memory nagging AWA, but I also suspect that they weren't actually in that class of quality, so I'd only be guessing I guess.

 

As Kenny says, if the cone surrounds aren't breaking down they'll be OK, but sound wise they're sort of warm and woolly with loose bass and a rolled off top end, and distort if you try to run anything like their rated power into them. I recall running some up back in the 80s and getting full welly out of them at around 15 or 20 watts.

 

Any amp of more than 15 watts should drive them as hard as they want to go. If the amp you have is way overpowered, it won't hurt em if you don't turn it up. I wouldn't buy anything special for them. If you push them the cone surround will almost certainly begin to breakup, cause they're just old.

[BiscuitAbuse]

Thanks for the info guys. The cone surrounds are in surprisingly good nick all things considered. Glad to know that I shouldn't be pushing too much power into them.

With these I'm not after amazing clarity or kidney mashing loudness, just would be a step up from computer speakers that came with my laptop.

Kenny I'm not sure what you mean about terminals on the back, from the crossover comes a single wire which just exits through a little hole in the back not a negative

and positive, but of all of the amps I've looked at the outputs for wires are 2 sets of negative and positive. Would there be any way of splitting the single wires that comes

out the back? Anywho I'll get a couple more pictures of it's innards tomorrow as I guess there's not a whole lot of info available from the pics I've already posted.

[k-k-k-kenny]

Yer single wire sounds like it's your speaker lead. I'm guessing that it is of two strands - sorta figure 8 in cross-section? So one will be positive, one negative - to terminate eventually at corresponding amp terminals (whether or not you need to splice some extra length onto it).

[daemon d]

Oh yeah, sorry. Forgot to mention that. Originally the leads were soldered on internally and were a fine gauge figure 8 that terminated on the amp end in a split and a pare of RCA sockets to plug into the matching Kriesler amp (like allot of the cheap mini systems or computer speakers).  By now most of these would be cut off so they can plug into normal amps.

 

You have to bare the wires back carefully biscuit so as not to cut the insulation between the strands, as if they touch bad things happen, and the insulation is very thin. Then you just run one wire to each amp terminal for left and again on the other speaker for right. You may need to play something with a single clear singer to see if the way you plugged them in matches. If the singer voice comes from between the speakers from a clear centre, you've got it, otherwise swap the leads between +ve and -ve on one side only.  Connecting them to the amp crossed over wont hurt them, it'll just make them out of phase and sound bad.

[BiscuitAbuse]

Awesome, so I'm to split the single wire down the middle(now that I have a look it does look like 2 wires that have been insulated into a single strand) so that there is a separate

positive and negative being careful to re insulate so the don't touch when in operation. And which wire is which is a case of trial and error.

[daemon d]

That's it Biscuit; which is which doesn't really matter. Not like battery leads or something.  What matter is that they're the same on both speakers to both amp terminals. If you get it wrong, the only thing that happens is they sound crap with poor bass and no centre, because they're out of phase. If that happens, nothing goes wrong, nothing gets hurt, You just swap wire on one set of amp terminals, which will make them both match, and it's fixed.

[Markonthecoast]

Couldn't find any information on Kriesler speakers when I searched on here or the rest of the net. Bought these little beauties from a charity shop and they sound sweet for their age, very warm, crisp and no subwoofer needed here. Haven't turned the sound too high, so as not to damage them, but there's no need they sound great at mid volume.

Any info, on Kriesler LS10 speakers would be welcome.

[audiofeline]

The speakers look in visually good condition. 

 

However, to be able to help you the experts will want to know the model of the speakers - it should be noted on the back where the wires are inserted.  Or maybe behind the front grille.  Some pix would probably be appreciated.