This thread isn't a total waste. For instance, I now know what "recalcitrant" means, heh.
Ay!
Question. For a given analog amplifier, the maximum output voltage is always Vcc minus some losses in the circuitry.
Yes or no?
I'm working on some equations on a perfect parallel amplifier and this is a fundamental assumption.
Oh, please don't flame me for asking the question... just wait until I post my power and current equations... then you can go at it.
In the meantime, take a look at the POWER relationships and think what happens as load impedance drops. Will a perfect parallel amplifier work under such circumstances? Will the voltage be kept from sagging as the current and power increase?
https://diyaudioprojects.com/Technical/Ohms-Law/
Question. For a given analog amplifier, the maximum output voltage is always Vcc minus some losses in the circuitry.
Yes or no?
I'm working on some equations on a perfect parallel amplifier and this is a fundamental assumption.
Oh, please don't flame me for asking the question... just wait until I post my power and current equations... then you can go at it.
In the meantime, take a look at the POWER relationships and think what happens as load impedance drops. Will a perfect parallel amplifier work under such circumstances? Will the voltage be kept from sagging as the current and power increase?
https://diyaudioprojects.com/Technical/Ohms-Law/
Last edited:
I sincerely hope I wasn't. ;-)
I'm supposed to be recalcitrant, remember? >:-(
Whatever happened to humor? It's not like I was discussing running two Tice clocks in parallel to make time go faster!
Note... I think a number of people are posting based upon early posts. Oh well... I got thick enough skin and, as a matter of fact, I got pretty thick skin. Otherwise I would have been skinned alive on certain peer reviews... I used to have this boss over at a very well known research lab... she was the nicest lady but during a peer review, with a white board, in a conference room, she'd become the Miss Manners of she-devils! She would make us sweat with her questions.
Last edited:
Well, at some point in parties when I meet new people they ask what I do for a living.
When I tell them... there will be a slight pause and then they will start talking about the weather.... in my profession we have almost no connection to the majority of civilization. 😕
Maybe I ought to tell them I'm a politician... or a Vegas pimp... or someone trying to figure if a parallel amplifier configuration has any value...
OTOH, the fact I always keep a fully stocked bar helps to ease the situation.
"Will that be shaken or stirred? "
Resistors all 0.1% or 1%, and the capacitors from the shelve +/- 20-50%. Did they ever build it?
Third harmonics are the result of non-linear transfer characteristics, not the amount of involved (nfb-) amplifiers.
I was joking... OK?
I'm trying to get over the antagonism and hope to discuss the subject at hand, not my putative shortcomings and personality disorders.
Why is everyone so serious nowadays?
Do you all wear white anti static smocks in the lab? I borrowed a blue one once and the union steward wrote me up.... yikes. No humor, that guy.
I know why we get distortion and non-linear transfer characteristics... did you notice I correlated a triple driver with 3rd order? Which, of course, means a double driver would incur 2nd order... did you catch that? Naturally, 3, 5, 7 would incur odd order... Ay! Did you miss that?
I just want to know if I can put together a parallel amp... OK?
It's a simple question.
And it looks like from a theoretical point of view it makes sense (current into low impedance loads), but from a practical point of view it's sort of insane (matching the amplifiers).
Can we agree now? Peace?
I sure wish the Argentine could make peace too.
BTW- I've noticed people hook up on the humor bombs but very few actually answer the technical questions. Please look at my question above on Vmax for an analog amplifier. It's obvious to me, but I want to make absolutely sure... otherwise the guy from the Pampas and his buddies will jump on me again. I want to use the exact wording and equations on the proof this time.
Last edited:
I know a few people outhere making fun of those who really wanna help them sort their bussiness out...They usually have some not so funny adjectives attached to their personality all the time . In the end they like that tag and behave accordingly even during their sleep... A friend of mine sais that an internal study among Continental staff found that the misconceptions around the covid epidemic, vaccines and such was equally spread at all organisational levels drawing a the conclusion that the IQ distribution was also equally spread among all employees no matter how high the organisational role was...and they litterally have rocket scientists and people who never finished gimnazium...
I find these specs baffling ... to put it mildly:
"45 watts per channel into 8 Ω"
lead straight to:
"90 watts bridged into 16 ohm"
and NOT to
"90 watts bridged into 8 Ω mono"
By the same token, I would expect:
"60 watts per channel into 4 Ω"
lead straight to:
"120 watts bridged into 8 Ω mono"
and NOT to
"90 watts bridged into 8 Ω mono"
Weird specs is an understatement, that´s not what bridging does to amplifiers.
One trivial explanation might be that those specs don´t come from measurement or even simulation but were simply made up.
To boot, by some none too skilled in the trade.
I´m open to other (plausible) explanations, if somebody can offer one that is.
"45 watts per channel into 8 Ω"
lead straight to:
"90 watts bridged into 16 ohm"
and NOT to
"90 watts bridged into 8 Ω mono"
By the same token, I would expect:
"60 watts per channel into 4 Ω"
lead straight to:
"120 watts bridged into 8 Ω mono"
and NOT to
"90 watts bridged into 8 Ω mono"
Weird specs is an understatement, that´s not what bridging does to amplifiers.
One trivial explanation might be that those specs don´t come from measurement or even simulation but were simply made up.
To boot, by some none too skilled in the trade.
I´m open to other (plausible) explanations, if somebody can offer one that is.
BTW, I posted that a while back... it was late at night, I forgot that the power increases into lower loads... subject to the limitations of the power supply voltage and current delivery.
They're not really...it means you can't drive past 90 watts due to final stage limitation while 16 ohms load is irrelevant.
Actually the mains power reserve does increase during the night so you had no excuses 🙂
I've seen many such situations like that where the power supply is simply not up to it. Like they say, power ratings are made up, specmanship.
I got this used Conrad Johnson MF2100... 100 watts into 8 ohms, 200 watts into 4 ohms.. it weights a ton and it has a huge power supply.
Then I got these DIY A2s, again 100 wpc into 8ohms, 200 wpc into 4 ohms... if you peer inside, the power supply dwarfs everything. The things are heavy.
Indeed, I figure both of those amps can drive a 2 ohm load with ease.
Both of those amps drive Maggies with ease and there is more than enough power, because their "rated power" is conservative.
I believe they do measure, but the "rating" is anywhere on the curve they so choose. It becomes a marketing decision. Heck, have you taken a look at how multichannel AVRs are rated nowadays?
BTW, compare the A5/A60.... rated at 60wpc at 8ohms and 90wpc at 4ohms... so there's a case of a very good sounding amp that won't double its power into half the load. Why? Hmm... well, the power supplies are not as big as the A2.
Or a lot of those classic receivers, for example the Marantz 2325 and Sansui G-7500. They don't double their power into 4 ohms either. Indeed, don't even try them into 4 ohm loads, as big and heavy as they are they simply can not drive the necessary current. But they sure work great as voltage amplifiers into 8 and 16 ohms.
Last edited:
Why not?
For the power supply it´s exactly the same to feed 2 x 60W into individual 4 ohm loads than to feed single 120W into a single 8 ohm load.
That´s what bridging does.
Maybe somewhere else but here if it can feed 2 x 45W@8 ohm then it can feed single 90W@16 ohm
Not sure why 16 ohm would be irrelevant, first because there are 16 ohm speakers and even more because that´s what Math adds up to.
By the same token if the power supply can feed 2 x 60W@4 ohms (they say so in the specs), then it can feed single 120W into 8 ohms.
But they contradict themselves, not exactly making their brochure believable. .
I'm not in marketing.
If you look at the curves, you can choose any point and use it as such.
Personally I prefer to look at the graphs... and you just have to hope the marketing team was honest. First clue is to compare the rated output into different loads. If they don't double as expect then you know they have played with the numbers somewhat.
Or, more food for thought, perhaps the circuit topologies are the culprits.... maybe the components can not dissipate the additional heat?
Yes, 16 ohms is very useful. I got two pairs of english minimonitors that present a 16 ohm load and they are driven most excellent by 60 watts a pair of 6550s in a push/pull configuration. IMHO, tube designs work quite well with 16 ohms.
No, I didn't notice. I presume you are serious about your topic. I respond with sincere arguments. We don't share the same coffee corner.
Life is too short to be taken seriously at all times.
I am serious about the parallel amps, I am not serious about Tice Clocks and strange arrangement between amplifier blocks and distortion components.
I mean, the first is a serious, if quixotic endeavor, the second, well, honestly, I'd have to be nuts to be serious about the Tice Clock and cables made from pure silver mined in the Andes by Orthodox Jesuit nuns.
I thought that was, ahem... obvious.
Good night.
- Status
- Not open for further replies.