sanyofreak
Active Member
Out of respect for the author of the thread on 4 ohm published specs for monster receivers, I decided to start this thread since I have no data to add, and that is all that was requested.
We've beat the 4 ohm thing to death, but here goes -
I dont recall ever seeing FTC ratings at 4 ohm loads in any manuals, I'm not sure they did this in the vintage era at all, therefore it appears all receivers with any 4 ohm number comes from the manufacturer. We know what that means.
If the FTC rating pre-conditioning period was or is the same when rating 4 ohms than it is for 8 ohms,(If it was even done) then it should be obvious that most receivers would not survive, or if they were protected (thermally), they would have been shut down before the pre-condition period expired, and therefore would have failed the test or measured 0 WPC at that load rating. Fire up most vintage receivers cold, measure their max output before clipping, and I'm sure many of them (although not some monsters) will yield impressive results into a 4 ohm load.
My guess is this was not tested much at all, reported even less, and was not an issue when these units were being built as almost all speaker sytems were rated at 8 ohms (nominal imp.)
The SX 1280/1980 will not have a 4 ohm rating because (at least an official FTC one) they could(would) not survive the pre-condition. Very few will. Very few seperates from that era would survive either. Those two units pushed the limits of the technology they employed to yield the tremendous power they can deliver into 8 ohms, and I dont believe should be pushed near clipping into a 4 ohm load, which of course asks the amplifier to double its 8 ohm output. No receiver was designed with that kind of overkill and as we see, the very best top their 8 ohm rating by about 50%. In fact, I would bet that as a percentage of the 8 ohm load rating (as its being calculated in NN's recent thread), MOTL units would actually top many if not all of the monsters above 100 WPC. Much easier for me to believe that a well built vintage 50WPC receiver could deliver 80WPC into 4 ohms, than I would believe a 200WPC receiver (no matter how well built) could deliver 320WPC into 4 ohms. Follow my thinking ???
Any of You, go take your monster unit, drive it with a sine wave at 66% of its output before clipping, connected to a four ohm dummy load, for an hour. Tell me how it works out ????? Do I smell something burning ???
As another aside ---- Can someone please replace any capacitor in any receiver I have and then show me how many more watts it puts out because we installed black-gate's or Nichi-con caps (or whatever, for that matter)........(C'mon!!!)
Tell me how that one works out as well...
If You want more watts out of your receiver, than someone else got it right, which is to connect its pre-amp outputs to a more powerful outboard or stand alone amp. There are no stock parts that You're gonna replace and make any kind of increase, argue with me all You want about how resistors and capacitors are so much better today than they were 30 years ago. And no, replacing your receivers 10000uF 50V capacitors with 12000uF 80V capacitors isnt going to buy You a watt per channel - power output is a function of the design, not the type or quality of parts used, sorry. Yeah, I know, the new ones have 80V in them, the old had 50.....um hmmm...
If its official manufactures published specs your looking for, well, heck I've got a SPARKOMATIC auto power booster from the late 70's thats rated at 200 watts per channel, and it fits in the palm of your hand. Oh yeah, thats at 4 ohms too. From what I see that actually puts me in the league with many of the units that have been listed in another thread so far. We know that is totally bogus, and not an FTC rating, but makes the point of manufactures claim - thats why the FTC spec was devised in the first place. Maybe wrong though, The FTC may have rated at 4 ohms, I just have never seen such a rating on any vintage equipment.
The thread has been explained, and I understand, but I dont think we'll be able to draw many meaningful conclusions when the data is compiled. I've got a collection of over 25 receivers from Sanyo, Pioneer, Sansui, Philips - I have manuals for most- and 4 ohms are mentioned in none of them. I believe this will be the general rule, and there will be more gaps in the data than there are entries.
There's gonna be bottleheads here as well that chime in about output transformers and the fact that great amplifiers put out their rated power identically into any load from 2-16 ohms. There will perhaps be some valid points there as well, along with the usual flaming.
Also, why do the old receivers seem to be rated so conservatively,(?) part of it may have to do with the fact that when we do bench test them today, as said many other places, line voltage is typically higher in the US than it was 30 years ago and more. Many may have been FTC tested at 115V line input,(or 117) and today so many of us run something more like 123V, may be a factor, not the whole reason, but a factor. Remember also, FTC wording says "Minimum, continuous RMS WPC", so being conservative with the rating seems kind of built-in. So, when manufactures stated a number, they may have overshot it in design on purpose to allow for normal tolerances, etc. I dont think there were many complaints when units exceeded their published spec. -- How much they exceeded them by may have been a factor of how conservative the design team was, or what they expected their tolerences to be, but actually got better parts than they planned on getting, or parts that bent toward the high end of tolerance, and not the low. Sorry though, not capacitors !!!
Not really expecting much response since this issue has been discussed from so many angles here, but wanted to express these thoughts without intruding on the thread "monster receivers:How much WPC into 4 ohms" -as directed by the author.
We've beat the 4 ohm thing to death, but here goes -
I dont recall ever seeing FTC ratings at 4 ohm loads in any manuals, I'm not sure they did this in the vintage era at all, therefore it appears all receivers with any 4 ohm number comes from the manufacturer. We know what that means.
If the FTC rating pre-conditioning period was or is the same when rating 4 ohms than it is for 8 ohms,(If it was even done) then it should be obvious that most receivers would not survive, or if they were protected (thermally), they would have been shut down before the pre-condition period expired, and therefore would have failed the test or measured 0 WPC at that load rating. Fire up most vintage receivers cold, measure their max output before clipping, and I'm sure many of them (although not some monsters) will yield impressive results into a 4 ohm load.
My guess is this was not tested much at all, reported even less, and was not an issue when these units were being built as almost all speaker sytems were rated at 8 ohms (nominal imp.)
The SX 1280/1980 will not have a 4 ohm rating because (at least an official FTC one) they could(would) not survive the pre-condition. Very few will. Very few seperates from that era would survive either. Those two units pushed the limits of the technology they employed to yield the tremendous power they can deliver into 8 ohms, and I dont believe should be pushed near clipping into a 4 ohm load, which of course asks the amplifier to double its 8 ohm output. No receiver was designed with that kind of overkill and as we see, the very best top their 8 ohm rating by about 50%. In fact, I would bet that as a percentage of the 8 ohm load rating (as its being calculated in NN's recent thread), MOTL units would actually top many if not all of the monsters above 100 WPC. Much easier for me to believe that a well built vintage 50WPC receiver could deliver 80WPC into 4 ohms, than I would believe a 200WPC receiver (no matter how well built) could deliver 320WPC into 4 ohms. Follow my thinking ???
Any of You, go take your monster unit, drive it with a sine wave at 66% of its output before clipping, connected to a four ohm dummy load, for an hour. Tell me how it works out ????? Do I smell something burning ???
As another aside ---- Can someone please replace any capacitor in any receiver I have and then show me how many more watts it puts out because we installed black-gate's or Nichi-con caps (or whatever, for that matter)........(C'mon!!!)
Tell me how that one works out as well...
If You want more watts out of your receiver, than someone else got it right, which is to connect its pre-amp outputs to a more powerful outboard or stand alone amp. There are no stock parts that You're gonna replace and make any kind of increase, argue with me all You want about how resistors and capacitors are so much better today than they were 30 years ago. And no, replacing your receivers 10000uF 50V capacitors with 12000uF 80V capacitors isnt going to buy You a watt per channel - power output is a function of the design, not the type or quality of parts used, sorry. Yeah, I know, the new ones have 80V in them, the old had 50.....um hmmm...
If its official manufactures published specs your looking for, well, heck I've got a SPARKOMATIC auto power booster from the late 70's thats rated at 200 watts per channel, and it fits in the palm of your hand. Oh yeah, thats at 4 ohms too. From what I see that actually puts me in the league with many of the units that have been listed in another thread so far. We know that is totally bogus, and not an FTC rating, but makes the point of manufactures claim - thats why the FTC spec was devised in the first place. Maybe wrong though, The FTC may have rated at 4 ohms, I just have never seen such a rating on any vintage equipment.
The thread has been explained, and I understand, but I dont think we'll be able to draw many meaningful conclusions when the data is compiled. I've got a collection of over 25 receivers from Sanyo, Pioneer, Sansui, Philips - I have manuals for most- and 4 ohms are mentioned in none of them. I believe this will be the general rule, and there will be more gaps in the data than there are entries.
There's gonna be bottleheads here as well that chime in about output transformers and the fact that great amplifiers put out their rated power identically into any load from 2-16 ohms. There will perhaps be some valid points there as well, along with the usual flaming.
Also, why do the old receivers seem to be rated so conservatively,(?) part of it may have to do with the fact that when we do bench test them today, as said many other places, line voltage is typically higher in the US than it was 30 years ago and more. Many may have been FTC tested at 115V line input,(or 117) and today so many of us run something more like 123V, may be a factor, not the whole reason, but a factor. Remember also, FTC wording says "Minimum, continuous RMS WPC", so being conservative with the rating seems kind of built-in. So, when manufactures stated a number, they may have overshot it in design on purpose to allow for normal tolerances, etc. I dont think there were many complaints when units exceeded their published spec. -- How much they exceeded them by may have been a factor of how conservative the design team was, or what they expected their tolerences to be, but actually got better parts than they planned on getting, or parts that bent toward the high end of tolerance, and not the low. Sorry though, not capacitors !!!
Not really expecting much response since this issue has been discussed from so many angles here, but wanted to express these thoughts without intruding on the thread "monster receivers:How much WPC into 4 ohms" -as directed by the author.
Some amps will survive this without a hitch.