Cab Ready with Speaker, Now What

[KYChucky]

So I pulled together some pine and a Jensen ceramic 12" C12Q, looking good. Now what to build to drive it with? I was thinking something like 6 watt +/-. I have a Vox AC15, 5E3 and a '68 Champ.

[stratcat55]

A Supro Model 24. I'm looking at a kit from Watts Audio for my next project.

[mike inwis]

Gee, you just about can't go wrong with anything 6V6 in the 5 to 15 watt range. I think you need to be a little careful with that ceramic speaker though, unless that's what you're going for. Between those tubes and lower wattage speaker there's not much headroom. I just went through hell with a c10r that just couldn't handle bass at all. The 12 should help a lot, but still a factor.

[phantomman]

The C12Q is rated for thirty watts.

It should remain healthy if not driven to excess.

[mike inwis]

The c10r was something like that too, and I couldn't believe how that just quit when hitting bass strings. Looking back I would have keep the amp that had that speaker had I known I should have just got the alnico version of the same speaker. That mistake cost me a cool Princeton but it's water under the bridge. At least I learned something, not that it will ever do me any good now.

[yankeerob]

The C12Q is rated for thirty watts.

It should remain healthy if not driven to excess.

I agree with Rog... Jensens are made by Sica and I have NEVER had one of their products let me down.

What you then have to realise is that there are 30W amps and there are 30W amps.

To explain: Mine produce a specific voltage into a given load and we then derive an output rating. No point in talking about or saying 'RMS' because I do not have the time or equipment to quote an honest RMS rating. I am open and honest about this...

OTOH - most much bigger manufacturers just decide to bludgeon straight through to the sales/marketing end of the deal (because actually finding out and then telling the truth is far too laborious a process) and say to the engineers can we say this is a 30W amp? The answer - based on the voltage/load scenario - may be 'yes' because you can measure 15.5V@1kHz into an 8 ohm load but what we don't know is how much CURRENT is being pumped into the load and therein lies the problem. My power supplies are very healthy, over specified beasts and my output stages are NEVER robbed of available current (apart from those that are so by design; primarily custom built tube/valve rectified affairs...

So - the answer - really... is you have to use your ears and your beenie... a C12Q will be happy with most reasonably pokey 15W tube amps. I wouldn't put one on the end of one of mine. That is not a brag... I have just serviced a 2x6V6 12W tube rectified amp custom made for Mike Walker and it really does require something like a 50W rated loudspeaker so... We found a one of a kind solution - a Rola 15" that came out of an organ. That'll never happen again in my lifetime...

Best wishes with your project Chucky,

YR