Does that mean you were talking in the context of a correct load match? Or that the situation with a correct load doesn't need explaining and so you were talking about mismatches?
Will do, thanks.
Help with cab and ohms question
- Thread starter romanianreaper
- Start date
glpg80
Well-known member
Ideal scenario - so correct bias, correct intended tubes for the OT primary, correct impedance setting on the secondary that matches the cabinet impedance correctly. No funny business and nothing mismatched or substituted.
Yeah totally not trying to be an ass but the search feature will give lots of info on this topic that goes back many years. If you find something that I’ve said which needs clarification I’m always open to answer Q’s.
Ah got it, that explains why I was so confused.
I've already started poking around, and will probably have more questions at some point. Thanks for being open to them. For now, any good books on magnetics? My background is a bachelor of science in physics (as of next month), so nitty gritty physics and EE books are welcome, no need for sugarcoating.
Also thanks for engaging in my questions over in that other thread regarding standbys, I appreciate it. I haven't had time to sit down and write well thought out responses to your replies yet, but will eventually™.
glpg80
Well-known member
311splawndude
Well-known member
Mismatching power to cab. You said:
So I said: "I believe it is in the middle somewhere, say 13.6 ohms for example. Somewhere. Not exactly, like 12." Which is not right anyway I believe, so just listen to the smart people here and not me
I actually think the ohms would drop down to 5.3 ish something but that is not a hard and fast rule.But as we know, Solid State amp output is different than Tube amp output. I found this from a reputable dude at MLP forum:
In a SS amp, the speaker is directly coupled to the power transistors (kind of like the power tubes), but there is no output transformer doing impedance matching. Lowering the speaker impedance increases the watts, roughly 2X.
So for the most part, you can use any speaker load on a SS amp without damaging the amp. However, you have to watch for overheating the power transistors when using a low impedance speaker load. The amp will be louder, but the power transistors can cook if they don't have adequate heat sinking.
I think I'm confused because you're talking about ohms (impedance) and not watts (power). When I said that bit you quoted, I meant I'm not sure how many watts of output power you lose. I'd guess that you halve it, but I don't have the in-depth knowledge about tube circuits yet to say for sure.So I said: "I believe it is in the middle somewhere, say 13.6 ohms for example. Somewhere. Not exactly, like 12." Which is not right anyway I believe, so just listen to the smart people here and not me
Racerxrated
Well-known member
..and to throw another curveball, you can run a 16 ohm cab with an 8 ohm cab, as long as you set the amp to 4 ohms. The amp sees 5.33 ohms.
Of course, the two cabs will seem to not match each other’s volume though.
Of course, the two cabs will seem to not match each other’s volume though.
311splawndude
Well-known member
Ah. I see now. My bad. I'm far from being any kind of engineer or electronics/physics expert. I'm just a semi retired non practicing industrial/organization psychologist who pretends to play guitar
But yeah, I'm def not the expert so I'm going to bow out of this thread now
@romanianreaper - did you get your answer?
I take it a cab further, three 8 ohm cabs for 2.66 ohms total. But I use a z-matcher to step it up to 4 ohms.