Cool 🙂
"All is well that ends well"
I suggest you use 8 ohm speakers (which anyway are easier to find)
A lot of data is missing, and even if Class H (or G, or F 😱 ), to my conservative eyes TO220 devices look skimpy when talking >100W RMS amps, so let´s play it safe.
"All is well that ends well"
I suggest you use 8 ohm speakers (which anyway are easier to find)
A lot of data is missing, and even if Class H (or G, or F 😱 ), to my conservative eyes TO220 devices look skimpy when talking >100W RMS amps, so let´s play it safe.
It seems we were both so tied up in our own explorations that we totally missed comopasta's confirmative post.
But it shows how keen we are to help and, as a bonus, useful information was shared for future reference. 😎
You bet.
FWIW , even if problem is either solved other way (as it was here) or can´t be (sad but often happens), my personal benefit, after semi-retiring, is to keep the old grey matter working out, call it the "Brain Gym" if you wish.
Thanks God quite a few around here doing something similar.
Beats feeding the pigeons or playing Bocce at the nearest public square (LOTS of Italians here) 1000:1
I know, I know, I should also use the real Gym .......
FWIW , even if problem is either solved other way (as it was here) or can´t be (sad but often happens), my personal benefit, after semi-retiring, is to keep the old grey matter working out, call it the "Brain Gym" if you wish.
Thanks God quite a few around here doing something similar.
Beats feeding the pigeons or playing Bocce at the nearest public square (LOTS of Italians here) 1000:1
I know, I know, I should also use the real Gym .......
Thanks.
I didn´t expect it completely out of place in the middle of the "keyboard" diode matrix section.
Oh well.
I didn´t expect it completely out of place in the middle of the "keyboard" diode matrix section.
Oh well.
I think in practice they would be fine in normal domestic use. My own 'marketed as 8 ohm' speakers have an impedance curve that dips to well below 3 ohm but are they classed as 8 ohm by the manufacturer (B&W 703).
I just happened to note it while trying to make it fit my screen and eyeballs.
There's NO way I could make sense of the jumpers across several pages, so I snipped it to a drawing tool, paste and markup.
Wow! I see you are really digging into the schema finding lost pieces 🙂
But yes, now I should find a set of 8 ohm speakers and I guess it should be ok.
I´m planning to disconnect that destroyed battery holder and use an external one with new batteries.
I removed the batteries and it is a complete mess of course.
I guess those batteries take care of internal memory settings, because the radio channels were stable for just a moment and then changed the channel back.
What I´m surprissed is that the capacitors are still alive, after so many years.
Thank you again!
Cheers.
But yes, now I should find a set of 8 ohm speakers and I guess it should be ok.
I´m planning to disconnect that destroyed battery holder and use an external one with new batteries.
I removed the batteries and it is a complete mess of course.
I guess those batteries take care of internal memory settings, because the radio channels were stable for just a moment and then changed the channel back.
What I´m surprissed is that the capacitors are still alive, after so many years.
Thank you again!
Cheers.
Caps don't always give problems despite what you may hear. I have a 17" Philips CRT TV from around 1985, still all working perfectly. Nicad batteries used for backup were always an issue in every product ever made in my experience. They never last beyond a few years before wreaking havoc.
I really wouldn't worry to much on the speakers. Impedance is a variable that depends on frequency, it is not constant.
https://audiojudgement.com/speaker-impedance-curve-explained/
I really wouldn't worry to much on the speakers. Impedance is a variable that depends on frequency, it is not constant.
https://audiojudgement.com/speaker-impedance-curve-explained/
Well I guess that means I could enjoy a bit the ones I have while I get new ones.
Don´t know, I read some post that stated that the amp would get too warm if connecting an 8 ohm amp to 4 ohm speakers.
But if you say so 😊
A lower impedance speaker draws more current for a given voltage applied across it. 8 volts across 8 ohms draws 1 amp. 8 volts across 4 ohms draws 2 amps.
Things aren't that straightforward though, firstly for normal domestic listening you might be surprised to find you only actually listen at around 1 to 2 watts at most. If you run the amp at its maximum output voltage level and use 4 ohm instead of 8 then yes, things will run hotter than they should.
4 ohm speakers can be more efficient acoustically (db output per watt input) and that means you run the amp at a lower volume. Efficiency is really the big unknown. An efficient 4 ohm speaker is much easier on the amp than an inefficient 8 ohm, the first giving lots of output for little driving voltage, the second needing lots of voltage to achieve the same thing.
https://www.diyaudio.com/community/...h-voltage-power-do-your-speakers-need.204857/
Things aren't that straightforward though, firstly for normal domestic listening you might be surprised to find you only actually listen at around 1 to 2 watts at most. If you run the amp at its maximum output voltage level and use 4 ohm instead of 8 then yes, things will run hotter than they should.
4 ohm speakers can be more efficient acoustically (db output per watt input) and that means you run the amp at a lower volume. Efficiency is really the big unknown. An efficient 4 ohm speaker is much easier on the amp than an inefficient 8 ohm, the first giving lots of output for little driving voltage, the second needing lots of voltage to achieve the same thing.
https://www.diyaudio.com/community/...h-voltage-power-do-your-speakers-need.204857/