Final question about completing my 5e3

[ratgon]

As I just posted at the end of the other thread I started about getting trem into my 5e3, all your guys' and particularly Sluckey's help did get the tremolo working in my 5e3 to the point of some tweaking to really make it perfect. It also made me realize I was forcing the issue and the final circuit and the idea of trem in and of itself is better served on a kit I'd made when I first started down this whole road about 6 months ago. The kit was The Ardmore from guytronix.com. A great 8 watt amp that will be amazing with a version of Sluckey's trem in it. Plus the 5e3 is sounding so great in and of itself I want to finalize it in its classic form first.

But I have one more question which I suspect I already know the answer to but it doesn't hurt to ask. I've built a cabinet for the 5e3 and I have a 12" and, if possible a great sounding little MOD 5 " in it. My OT ( Classic Tone 18022) has only an 8 ohm tap. Obviously with two 8 ohm speakers there's a problem. Is there any creative solution two using both of these speakers with that OT or do I need to just get a different OT if I want to go with the two speakers. I've run another project through it that has a 4 ohm tap and they really sound great together. So is there any sorcery I can employ to avoid getting a different OT?

Again, thanks for your help and patience.

[sluckey]

You'll be OK connecting a 4Ω load to the 8Ω output of that 5E3.

[ratgon]

Really?! That's great Sluckey! Thanks a lot. But for my educational purposes, why is that? Interesting. ( another moment of being embarrassed  at actually having an EE degree and not knowing)

[sluckey]

Sorry, you already asked your final question.   















Just kidding. Having a perfect impedance match between output tubes and speaker load means you will transfer maximum power from the tubes to the speaker. For tube amps when you have a mismatch you will not be able to transfer all the power the tubes can make to the speakers. Tube amps are pretty tolerant of 100% impedance mismatch, especially if the mismatch is lower. You do need to avoid very high mismatches or infinity loads.

[PRR]

A 5E3 won't blow-up with 4 on the 8 tap. Just be a bit down on power.

However I don't think you want ALL (even half) your power to a 5-inch, when you have a monster Twelve in the cab. Heavy bass will embarrass the poor Five, make the twelve pointless.

Put 15uFd to 50uFd NON-polar cap in series with the Five. It will pick-up the midrange and extend treble-spread where the twelve gets tight and beamy. By 400Hz-1KHz, both "8 Ohm" speakers will be well up in impedance; the twelve is likely to be over 12 Ohms. Also there's less power up there, so a power-loss mismatch is less important.

You want "loudspeaker crossover caps". Partsexpress.com is a major supplier. Car-audio shops sell the same thing (often overpriced) as "bass blockers" for the same purpose-- tap a small speaker across a heavy-bass speaker to extend the range without small-cone slap. Experimentation is needed. Get a quartet of 25uFd (22-27u) and work them in series and parallel to find a happy blend. 50 Volt is usually the lowest rating sold and way-ample for this power level.

[ratgon]

Thanks again to the whole damn lot of ya. And PRR thanks for that. Truly. I was wondering if there was something to be done about "balancing", so to speak, but figured I'd asked enough for the moment so thanks a lot. I really had no specific reason to add the 5" other than to experiment and it worked to create a slightly differently sided cabinet. I gotta admit that the overall cabinet design is starting to grab almost as much as the circuit itself.

And, so I take it these caps are just wired P2P between the speakers themselves.

Thanks again.

I'll be out of commission for the next two months so hopefully I'll finish this 5e3 and post some pics before I head out.