Help identifying Hughes & Kettner CM3 Vacuum tube

[DrGonz78]

Well I got this great stash of tubes recently and came across a couple of Hughes & Kettner tubes. The one I can identify says on the tube CM1 91G09 and according to the link I found it is a 12ax7. Funny thing is that that one link is from Helmut Weigl's personal tube collection on the Radio Museum website. I have not found anything else about the CM1 tube other than his link.
CM 1, Tube CM1; Röhre CM 1 ID39565, Double Triode

However, the other tube is marked CM3 91A09 and I cannot figure this one out. I am sure the 91A09 is house or date code etc. The CM3 must correspond to something more commonly named, but I just can't seem to find anything on it. Anybody else here come across this type of tube? It does have a 9 pin layout and my gut is that it might be 6BQ5/EL84.

[J M Fahey]

The CM1 is a plain Jane 12AX7 , and as "collectable" as one labelled saying "Marshall" , "Fender" or any other current commercial brand, meaning: not much / not at all (pick one) .

Don't overthink it

And if CM3 looks like 6BQ5 .... now you know

Look at it closely under a good light, use your best reading glasses or a jeweller's loupe and follow each pin connection, some are very easy and obvious such as plate or filaments, cathode slightly less, others somewhat obscure (they are all grids after all), if 4 or 5 out of 9 match 6BQ5, assume the remaining ones also do.

I seem to have the faint idea that those killer hybrid H&K pedals (Blues/Metal/Cream Machine) used CM-something labelled tubes, they definitely used 12AX7 for gain and 6BQ5 for power tube distortion.

They could even straight drive a cabinet with a couple Watts output with killer sound.

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Update: yup, there you have them, CM1 and CM3 in all their glory:



As a side note of the harsh reality of production:
a few years ago (maybe 5) , members asked Mr H&K (who posted there) to resume production, that "sales were guaranteed and me and all my buddies want one, so many others will also want them, so the market is out there".

Mr H&K answer: "thanks, you say so, unfortunately our own accounting books say otherwise. To be fair: if you or anybody else can guarantee that we will sell 50000 of them (in any combination of "flavours") within a year , proof enough is an initial order of 10000 units ..... "

I almost spit my coffee, asked if it was a typo, they answered: not a typo.

To be fair, Factory price was a very low ~100 bucks per unit, that shows how much different Distributors and Shops, plus Tax and Freight increase price.

They didn't even ask for cash in advance, but a signed contract by somebody who had the muscle to stand behind it, say, GC or some large Distributor.

Last week I reread the sad Pearce/Lab story , where Mr Pearce said that Norlin (the company behind Gibson and Lab) had "only" sold 10000 Lab L5 in the first couple years so they pulled it out of the line for being a poor bread earner, go figure.

Oh well.

[Enzo]

Not really a new story. A lot of people in this game have an inflated idea of the market, and at the same time no idea of scale. They think rock and roll is a major user of vacuum tubes and it ought to be profitable for some new company to start making them again. But our tube amps are a tiny part of the music industry, let alone of electronics in general. And while someone constructing them in a basement might think 100 amplifiers is a lot, as the example shows, 100,000 would be more like it for a commercial venture.

[DrGonz78]

Very insightful information thank you. I will look at the pin connections inside the tube to double check it out. However, it is obviously a pentode and most probable that it is EL84. As far as collectable stuff, I find it strange to never use or play old guitars/amps. I mean if you gave me an authentic 1969 Fender Stratocaster played by Jimi at Woodstock, well I would be playing it and not locking it away just to look at.

[g1]

It's definitely 6BQ5/EL84. Their 6BQ5 stereo power amps also had them labelled as CM3.
And the Cream Machine also used a 12AU7, which if I recall correctly was a "CM2".

[Pedro Vecino]

That CM1 (Radiomuseum photo) is a ECC83 Ei (former Yugoslavia). The EL84 used in that series (Crunch master and others) were equally Ei.