Guitar amp/speaker configuration question

[ack1961]

Hello all,
Trying to salvage my son's Vox VT120+ combo amp - the PCB blew for the 2nd time, and we're done soaking any money into fixing it.
I'd love to re-use the speakers (2x12) as an external cab, but I am confused about my options.

The cabinet has two 8 Ohm speakers.  The VT120+ specs show 150W RMS @ 4 Ohms. 
A Pair of black & white leads run from one speaker to the Input jack (of the now removed head).
That speaker is then wired (to the other speaker) with two B/W leads.

Here's what I did:  I connected the speaker leads that were going to the head to a mono input jack, giving me:
Input Jack -> 8 Ohm Speaker -> 8 Ohm Speaker

Just as a test, I then plugged in a unamplified keyboard just to ensure that I get sound out of both speakers, which worked fine.
I then plugged that keyboard into Peavey Mark VIII amp and ran the output to the new input of the speaker cabinet.
Both speakers work fine.

My son found a Vox NightTrain NT50H head, but I'm not so certain about whether or not it's going to work with the cabinet with 2 x 8 Ohm speakers.
The NT50H has 3 outputs:  1x8 Ohms or 2x16 Ohms & 16 Ohms.

To me (a complete novice), those NT50H head outputs should work with:
1. a single 8 Ohm speaker
2. a single 16 Ohm speaker
3. two 16 Ohm speakers

Am I correct in assuming that I can't use this 2x12 with that head?
Is the best I can do is wire 1 of the 8 Ohm cab speakers to an output jack and then to "1x8 Ohm" output of the NT50H head?

Hit me with any options or suggestions.

Thanks
-Steve

[amptech]

If I understand correct, the amp you´re going to use has a 16 ohm out? And you have two 8 ohm speakers? Wire them in series and plug in

[ack1961]

If I understand correct, the amp you´re going to use has a 16 ohm out? And you have two 8 ohm speakers? Wire them in series and plug in

Thanks - I was unsure how to wire these two up in Series, but my meter tells me I've got 16 Ohms if I do:

S1 (pos) ------------------------> Output Jack (pos - Tip)
S1 (neg) -----> S2 (pos)
S2 (neg) ------------------------> Output Jack (neg - Ring)

I think I'm all set now - I appreciate your response.

Steve

[amptech]

Your meter, measuring DC resistance, might give a reading wich is not spot on, but wired as you did you have the correct impedance.

[ack1961]

Yup - got ~15.1 Ohms on the meter.
Works like a champ!