Further to my previous post, I've just been checking the Rola Loudspeaker Data guide (1961).

It has the Rola 8 MX voice coil as having an impeadance of 15 ohms.

The Rola 8 M, which has the same physical dimensions as the above - voice coil impeadance 2 & 15 ohms.

Just don't touch the printing on the valves.
You can hug them at the base with your fingers.

Studying the schematic of 11-97 and 11-77 it seems the later model upped the voltage from 260 to 275 do you think this would matter?

Yes I have looked up the specs of the 8mx and thats why i'm confused because they are meant to be 15ohm but mine is clearly marked 2. Can I upload photo's on here or do I have to upload elsewhere and link? I have a pic of the speaker for interest sake clearly marking 8mx and 2 ohm!

Send photos to Brad and he'll upload them to your post.

Going though all my Rola loadspeaker guides from the 1950's through to the early 1970's and cant find anything to suggest the 8 MX coming in a 2 ohm version.

Running the power transformer unloaded you should barely feel anything at all. Loaded, it should be warm, but not too hot to burn you.

With the speaker disconnected from the output transformer,
measuring the DC resistance with a multimeter will be close to the labelled impedance,
definitely a distinct difference between 2 and 15 Ohms (with regard to pm speakers).
A 15 Ohm speaker might measure 13 or so Ohms.

I just sent through the picture to Brad so hopefully it will be up soon! I've always been led to believe you can up the ohms safely with speakers because it will draw less current. Therefore can anyone see a problem if for the time being I used some 4ohm speakers? ps. I'll send a pic of the actual stereo too seems my post seems to be lacking without one

I just used some resistors in series to match impedance
to use 8 Ohm speakers with transformers that expect 15 Ohm impedance.
I used 4.7 Ohm, at least 5 Watt.
Since speaker and output impedance is related to AC characteristics,
I believe DC measurements will be a little off,
but mine hasn't blown up yet, and it is getting daily use.

But if you could get hold of four 8 Ohm speakers,
two 8 Ohm speakers in series for each channel,
that's a pretty close match.

Yes I have seen that done - apparently they can generate heat and reduce output but protects the trans. I would be going the other way around which I believe is ok but I'm not definative about it.....?

I would measure across the speaker you say is 2 Ohm first,
I suspect that your output transformers expect 15 Ohm load.
ROLA output transformers, are they model K53-2 ?
When one speaker was replaced, was it's output transformer also replaced?

I have the schematic and it lists the output transformers as K9 7k/2Ohm Rola.

However I did not check the markings on the actual transformers - they look identical to yours though.

The markings I quoted are off the transformers.
The schematic for mine was missing from the back of the cabinet,
which is why I don't know what model it is, but parts are dated 1962.

I take it your original schematic is missing too,
if you had to chase one down elsewhere.

You can parallel connect a pair of 4 Ohm speakers to each channel if you have four x 4 Ohm speakers.

I will send you mine in time,
It would be easier to start with them if you chase some vintage 15 Ohm speakers.

If you want to spend some money to use whatever speakers you want,
a pair of new Hammond 125C are very suitable.
Their footprint is a little wider than originals which means drilling one new hole to accommodate them.

Funnily enough I do have the chassis layout etc on the back which has model no etc so I could get a detailed schematic from kevin chant (who was very helpful).

Interesting about the Hammond although I don't know if I want to go down that track.......will see!

I think i'll keep an eye out for speakers and see whats out there!

Not cheap for a pair!
http://evatco.com.au/product-list/transformeroutput/tr-125c/

and also, yeah, depends on your intention.. vintage restoration,
or allowances for modernisation...
Not to mention budget.
I understand both sides of the coin.

Art,

I think your Kriesler might be an 11-88, chassis no. 89-1, dating from 1961.