AWA 12AX7 from old P.A.

[katopan]

Was given an old P.A. amp yesterday by one of the contractors here that knows I'm into valve amps. Says he used to pick them up for $5 at a local market years ago. It's a AWA (Amalgamated Wireless Australia) PA774 like shown in the link below (although not in as good a shape as that one). 8 Watts output, one 12AX7 and two 6BM8s. 100V line output. Having trouble dating it but other similar looking units are from the 60s.
http://ozvalveamps.elands.com/awa.htm
Not that excited about doing a conversion, and the 6BM8s might be good for something later. But I was keen to test out the 12AX7 in the V1 spot of my 18 Watt. First tube in my collection that's not current production. So I checked it visually and made sure that the heaters were still in tact and there wasn't any obvious shorts with a meter. Swapped it out with the Tung Sol current production that was in there. Turned on the power, heaters glowed nicely. Turned on the standby, strummed a couple of chords, and then the phone rang. There goes the rest of the evening. So I'm looking forward to giving it a good play through tonight.

Anyway, the post is really to ask if anyone else has had experience with old AWA valves and any thoughts on them?

[reubster]

Hi Katopan

I'm a Melbourne boy myself.
I've a few AWA 12Axers hanging around, they are all old and well used but still sound quite good....Strong and warm if that description makes sense.

I have yet to try one in my 18 watter, but I used em in old Australian Goldentone 15 watter [2 x el84 OP] and they worked really well.
In that amp, I settled with a mullard in V1 [more gain] and the AWA's elsewhere

Let me know how you find em.

[leslie]

Hi Katopan

I'm a Melbourne boy myself.
I've a few AWA 12Axers hanging around, they are all old and well used but still sound quite good....Strong and warm if that description makes sense.

I have yet to try one in my 18 watter, but I used em in old Australian Goldentone 15 watter [2 x el84 OP] and they worked really well.
In that amp, I settled with a mullard in V1 [more gain] and the AWA's elsewhere

Rumor goes that ''ecc83 higain twin triodes were made in Sydney at AWA's Ashfield plant who were licenced to manufacture Mullard tubes''....

[greaser_au]

do the AWA valves look anything like the second from left in this photo?




david

edit: oops I forgot the caption,,, Spot-on, leslie!
L-R:
British made Mazda ECC83 (old),
Australian made AWV 12AX7 (nos).
Russian made Sovtek 12AX7LPS (new)
Russian made ElectroHarmonix 12AX7EH (new)

[leslie]

as far as I know two tubes on right side are of russian origin with typical plate shaped getter and the first one is clearly in the philips standard for short plate.

[katopan]

Thanks for the info so far. I attached a photo of the AWA 12AX7 on the left, Electro Harmonix new prod in the middle, and Tung Sol new prod on the right. Greaser - The print is the same as your photo second from the left, but the plate structure is different. No ladder and different holes. Oh, just remembered you can't attach in this area of the forum. Well, here's a link to the photos I was going to attach.
http://chosenaudio.comfypage.com/index. ... tent_id=15

Regretfully the P.A. amp it came out of was pretty dirty and so I wiped the valve with a rag. I think there was some cleaner residue on there as the printing wiped clean off. What's left is the white flecs you can see in the pics and the 12AX7 logo on the other side.

Got to have a bit of a play today. It's made the normal channel of my 18W a bit darker (more balanced?) but definitely has a smoother sound to it. A bit lower gain to it as well, but still plenty when cranked.

Appreciate any more info as I know absolutely nothing about old valve structures.

[greaser_au]

Regretfully the P.A. amp it came out of was pretty dirty and so I wiped the valve with a rag. I think there was some cleaner residue on there as the printing wiped clean off. What's left is the white flecs you can see in the pics and the 12AX7 logo on the other side.

yeah, they do that! ,,,and without any cleaner residue either! Marking paint is the bane of the vintage radio buff!... The old trick is to put the valve in the fridge for a while to cool it down & then breathe on it. Where the paint was shows up in the condensation & you can ID the valve.

david

[katopan]

The old trick is....david

That's a nice one to know. Thanks!

[katopan]

Been doing some more digging.... The only valve I can find pictures of with the same plate shape and hole position are the two hole smooth plate Telefunkens. Then I read up on the company's history and AWA was formed with "exclusive rights throughout Australasia to the patents, present and future, of both Marconi and Telefunken".

But the Ashfield plant made valves under the AWV company name, which was a joint venture between RCA and AWA, and from the little I could find this was under licence from RCA rather than Telefunken. Some of the AWV valves around look like RCAs, but not the one I've got. Also the Ashfield plant supplied valves under the AWV, RCA and Radiola brandnames. But mine was printed as AWA, not AWV. Interesting.....

[leslie]

A small contribution,
I was curious enough about this AWA plant making philips and mullard tubes under licence so this beauty arrived from Sydney this morning...







It seems that these tubes are structurally identical to mullard/philips ecc83.
I will post sound review later...

[zaphod_phil]

Those really do look like real Mullards.

The only valve I can find pictures of with the same plate shape and hole position are the two hole smooth plate Telefunkens. Then I read up on the company's history and AWA was formed with "exclusive rights throughout Australasia to the patents, present and future, of both Marconi and Telefunken".

So you have an AWA-labeled Australian version of a Telefunken.

But the Ashfield plant made valves under the AWV company name, which was a joint venture between RCA and AWA....

So they probably also manufactured AWA as well as AWV. You would logically expect AWV ones to be RCA types.

[leslie]

I got some chance to open the amp a bit and of course, to rasp the neighbours
So here's review. Control group were consisting of Tungsrams, Amperex herleens, and Philips. This tube is very similar to 6o's herleens but with a mellower top.
It has a tad less gain than Tungsrams and not so extended bass.
That's what I heard live, but here is rec. for those who want to hear for themselves... tungsram & mullard respectively http://www.box.net/shared/616gpygx4e

[kleuck]

I got some chance to open the amp a bit and of course, to rasp the neighbours
It has a tad less gain than Tungsrams and not so extended bass.

And beautiful lively and 3 dimensional hi-mids...just as an english Mullard.
I didn't know these australian Mullards, thanks

[katopan]

Thanks for the extra info. Mine certainly isn't the Aust made Mullard, but the Telefunken licencing makes sense and some more photos I've found pretty much confirmed that's what it is.

Thanks for the soundclip Leslie. Clear difference in the sound.

[dotfret]

Er ... that smooth plate design was not exclusive to Telefunken. You also find similar smooth plates from CIFTÉ (France) and MBLÉ (Belgium) in the 50s, and Ei (Yugoslavia), both grey plates and shiny plates.

Many Ei valves were commonly sold in Australia in the 50s as Philips Miniwatt. The plant was set up as a joint venture, partly to cover supply shortfalls into that marketplace.

If the smooth plate in question is one of those Ei valves, relabelled, it should carry a short version "etched" Philips code near the base. Look closely, the code is often faint.

[katopan]

Thanks Dotfret, I'll have a look for the etched code. Thing that led me away from Ei is that the plate vent holes are positioned and sized differently to all the Ei photos I could find.