AMPRO: Vintage Projector Extension Speaker Cabinet

This is an extension speaker from a vintage projection system, and I wanted to jot down a few notes since information on this particular version seems scarce.

Most examples I’ve seen online are housed in brown cases from the USA (Ampro, based in Chicago). Those typically feature Jensen or Ampro-branded speakers, and some even include a built-in valve amplifier.

This particular unit, however, contains a Goodmans Audiom 60 speaker—12", 15 watts, 15 ohms, with an alnico magnet—made in England. These speakers were popular in the 1950s and very early 1960s, even appearing in guitar amps like the Vox AC30.

Unfortunately, I couldn’t locate a date code on this speaker, so pinpointing its exact age is tricky. That said, I tested it with my alnico blue-loaded AC15, and the sound is incredible—so I’ll leave it at that!

Dimensions:

• Width: 45 cm
• Height: 50 cm
• Depth: 27 cm

Cast aluminium speaker grill cover, looks to have a light coat of hammered paint.

The colour pallette of the tolex on the box reminds me of an old typewriter that my mother used to have.  It's quite well put together, the handle is metal, not plastic and it's spring loaded, so it folds down when not in use.

Nice touch using a film spool to hold the speaker cable

The spool also looks to have a light coat of hammered paint.  The jack is closer to the older telephone style than the modern 1/4" jack.

Apart from the jack on the spool, there's a parallel speaker in / out

There's also some insulation inside, which I hope is a natural fibre.  

MSP: Vintage Alnico Speakers

MSP speakers are often found in Australian made amplifiers, such as Goldentone, Moody, Vase etc.  It seems at the time, local manufacturers had a choice of either MSP or Rola / Plessey Rola speakers.  This is likely because of the high import tariffs and shipping costs at the time.

MSP were made in Sydney, Australia by Manufacturers Special Products.  MSP was a component manufacturer for AWA, which was a huge electronics and broadcasting company up until the mid-seventies in Australia.  MSP made a wide range of products, apparently so they could sell to competitors without using the AWA brand (side note: AWA also made some great germanium transistors and valve PA heads). 

I'm jotting down any information I can find, as there doesn't seem to be much info out there, and these are great speakers; they compare very well to their more expensive vintage counterparts from the U.S.A. or U.K.

I recently picked up one of these speakers in an old projector speaker cabinet and there was also one in a Goldentone amplifier I used to have.  They're sometimes referred to as Hi-Flux speakers.

M.S.P.  VINTAGE ALNICO GUITAR AMP SPEAKERS

12PQ - 21567

12" Alnico speaker,  20 / 25w RMS, 16 Ohms.   Made between 1954 - 1966

Same model, different production run, possible many years apart

12PQCB-21188

Appears to be a variant of the regular PQ - I have no idea what the function of the little attachments to the speaker cone are supposed to do.  They appear to be stock, as I have seen one other photo showing this on the cone.

This

These are a concentric design, with a tweeter mounted above the 12" cone on the rim.  I'm guessing the 12 is very similar to the regular 12Pq, but who knows... 

12PS - 21011

12" Alnico speaker, 16 Ohms - this was in a 4 or 5 watt amp, so I'm guessing it's also a low wattage speaker.  Unlikely a high wattage speaker would be wasted in a little amp like this.

12UA

12" Alnico speaker, 15w RMS

MSP SPEAKER DATE CODES

Look for a two letters and a number ink stamped on the speaker.   In some cases the first character is also a number - there's some question about what the first character is, but it's not that important, as really most people just want to know what year the speaker was made.

AB1 as an example,   A - not sure, B month, 1 year

A = January

B = February

C = March

D = April

E = May

F = June

G = July

H = August

I = September

J = October

K = November

L or O= December

DL9 = December 1959

Information on date codes care of P Fields, Aussie Guitar Gear Heads forum