Low-power vintage gear.

[Semanon]

is rated at 45 WPC at .02% THD. I have a new Yamaha receiver rated at 100 WPC

And let’s be clear, the SPL difference between a 45 and a 100 watt amp is a smidge over 3dB...not a whole lot. If the speakers are 93dB efficient, the 45 watt amp full out will produce about 105dB at 8' while the 100 watt will give you a little over 108dB. Those are both REALLY loud! I would never listen at that level for any length of time. There is headroom and other considerations, but even at a loud 95 and 98dB both amps, will have 10dB of headroom.

 

[spark1]

Just a curiosity but for example a Pioneer SX-820 (SX-3700) is rated at 45 WPC at .02% THD. I have a new Yamaha receiver rated at 100 WPC at .2% THD. My thought on this is that the old Pioneer if cranked could make more power than 45 watts but the THD would exceed the rating, but there was more power (Scotty!). How much more I do not know but the unit never seems strained to shake the house. And conversely though the new Yamaha unit has awful by comparison THD at rated power, if played at normal listening levels the THD would be much improved, perhaps comparable to the Pioneer when it (Yamaha) is at 40 to 50 watts output?

I think the FTC rules specify that the power rating be measured at

Yes, someone with a good understanding of the meaning of the measurements could reasonably compare if an amp had sufficient power to drive a set of speakers to a specific level. But how about THD and other measures? That can be driven down with NFB or servos to extraordinarily low levels, but adds its own coloration. Crappy amps are sold at the audition sites with phenomenal specs and abysmal sound. Is everyone being honest, or are they pulling the best one off the line to test?

Specs are just a starting point, like going to the car dealer and knowing that you want a car that seats 5. That weeds out a lot of vehicles, but does not give any real information about the car you will eventually buy. It’s just one of the boxes to tick.

Oh. I see. Thanks for sharing.

 

[3-Crows]

I was just watching a You Tube video for recapping and they were using a SX-3700 (SX-820) and when he was finished he ran the output and it showed over 55 watts. So, what I was thinking, that at least some of the old units were capable of greater than rated output but the THD rating for each,.02 and .2, that is a big increase in THD. Sorry to kind of go too far off topic. Thanks for the discussion, appreciated.

 

[birchoak]

[QUOTE="birchoak, post: 14284156, member: 17416"... much better build quality than my massive, late 70's Scott 380R with 80 watts. .

Birchoak,
How do you like your Scott 380R? I do not see it offten.
Vito[/QUOTE]
First, I let me confess that I've gotten very spoiled working on things like the Sansui AU-555A and the Hitachi SR-1100, which were designed to be worked on at a later date and pretty much go forever with a little love and knowledge.

I loved the 380R at first as it had all the bells and whistles: power meters, triple tone controls, IEC power cord, massive aluminum face.

But...the power switch is a nightmare and goes open. You have to dissect it to clean it, then you've got a few years before it needs it again. The last time I had to do this, I accidentally broke one of the discs (it's an OFF/ON/SPKR A/SPKR B cluster-intercourse that's jammed into a very tight spot) and that was the end of the proprietary switch. Inside, the quality is just not there, with some parts crammed into tight spaces and others dangling in the breeze. The insides show cost-cutting and haste: the 380R was built in an attempt to save Scott's skin during the Spec-Watt Wars. The sound is excellent, however, so I left the dead switch in place and rigged an HK 630 ON/OFF switch into the rear panel--DC offset, if I recall, cannot be adjusted and it's on the high side--so there's that aspect, too. FM started to fail but I was able to coax it back to life by wiggling a few screws on top of the tuning head and cleaning the contacts with D5.

So, a mixed bag. If you can find one for $100 or less, I'd say jump on it. If you fall in love with it's looks and want big, impressive sound (though not necessarily accurate), then the price is up to you. It's got a special look that departs from the blue lights-on-black theme and that appealed to me. Working on that switch got very tiresome, and even leaving it in the ON position and using a power strip didn't alleviate the problem. I was impatient the last time I wrestled with the switch; now that you know about this you won't make the same mistake! It does sound fantastic--as good as it looks--I just wish it was built better. The earlier Scott R74S I also own is much better built, much easier to work on, but not as dramatic or impressive looking.

 

[Semanon]

I think the FTC rules specify that the power rating be measured at

The FTC rule requires stereo amps to report, for both channels driven, the %THD, load impedance and wattage. It is not a test against any standard, only a reporting of the conditions used to obtain the wattage. As far as I’m concerned (and back to the car analogy) it’s no better that saying ‘Gets 25 MPG, highway.’ That says almost nothing about the car or allow any real comparison. It just stops inflated claims.

This probably needs to be its own thread...

 

[spark1]

The FTC rule requires stereo amps to report, for both channels driven, the %THD, load impedance and wattage. It is not a test against any standard, only a reporting of the conditions used to obtain the wattage. As far as I’m concerned (and back to the car analogy) it’s no better that saying ‘Gets 25 MPG, highway.’ That says almost nothing about the car or allow any real comparison. It just stops inflated claims.

This probably needs to be its own thread...

Go for it. Share your knowledge.

 

[_tk]

And let’s be clear, the SPL difference between a 45 and a 100 watt amp is a smidge over 3dB...not a whole lot. If the speakers are 93dB efficient, the 45 watt amp full out will produce about 105dB at 8' while the 100 watt will give you a little over 108dB. Those are both REALLY loud! I would never listen at that level for any length of time. There is headroom and other considerations, but even at a loud 95 and 98dB both amps, will have 10dB of headroom.

As you mentioned, the 100watt amp provides a lot more headroom and reserves for demanding speakers or bass notes. So while what you said may be true, it certainly doesn't tell the entire story.

It takes a lot more "oomph" to produce a 50Hz note than it does a 1kHz note at said db levels.

 

[spark1]

My headroom "target" is 12-15dB. I consider this to be an important variable in maintaining good sound quality.

 

[_tk]

I agree.

The 80 wpc in stereo my new Yamaha AVR is rated is the same way as the 45 wpc that my 1976 Realistic STA 90 was I believe.

One difference is most vintage stereo recievers are stable into a 4 ohm load. That is they will happily power 2 pair of 8 ohm speakers in parallel all day without complaining. Where as Yamaha wants me to switch the amp into the low impedance setting which I'm guessing cuts power to perhaps 50 - 60 wpc.

That's in stereo, my guess is with all 5 channels operating simultaneously we're looking at about 30 wpc. While that may sound pathetic, considering how often all 5 channels will be called upon at the time, and the use of a sub for the heavy lifting, Even this entry level network AVR with 4+ star reviews seldom gets complaints about a lack of power.

I'd put a quality "vintage" 45WPC up against any newer budget Yamaha any day of the week. They might be able to eek out 80x2 WPC @ 1Khz, but with any challenging loads they'll start to sound quite strained.

 

[vito1]

Birchoak,
How do you like your Scott 380R? I do not see it offten.
Vito

First, I let me confess that I've gotten very spoiled working on things like the Sansui AU-555A and the Hitachi SR-1100, which were designed to be worked on at a later date and pretty much go forever with a little love and knowledge.

I loved the 380R at first as it had all the bells and whistles: power meters, triple tone controls, IEC power cord, massive aluminum face.

But...the power switch is a nightmare and goes open. You have to dissect it to clean it, then you've got a few years before it needs it again. The last time I had to do this, I accidentally broke one of the discs (it's an OFF/ON/SPKR A/SPKR B cluster-intercourse that's jammed into a very tight spot) and that was the end of the proprietary switch. Inside, the quality is just not there, with some parts crammed into tight spaces and others dangling in the breeze. The insides show cost-cutting and haste: the 380R was built in an attempt to save Scott's skin during the Spec-Watt Wars. The sound is excellent, however, so I left the dead switch in place and rigged an HK 630 ON/OFF switch into the rear panel--DC offset, if I recall, cannot be adjusted and it's on the high side--so there's that aspect, too. FM started to fail but I was able to coax it back to life by wiggling a few screws on top of the tuning head and cleaning the contacts with D5.

So, a mixed bag. If you can find one for $100 or less, I'd say jump on it. If you fall in love with it's looks and want big, impressive sound (though not necessarily accurate), then the price is up to you. It's got a special look that departs from the blue lights-on-black theme and that appealed to me. Working on that switch got very tiresome, and even leaving it in the ON position and using a power strip didn't alleviate the problem. I was impatient the last time I wrestled with the switch; now that you know about this you won't make the same mistake! It does sound fantastic--as good as it looks--I just wish it was built better. The earlier Scott R74S I also own is much better built, much easier to work on, but not as dramatic or impressive looking.[/QUOTE]

Birchoak,
Thank you for taking the time to write a comprehensive summary. That's all I wanted to know.
Vito

 

[jd3rdcoast]

First, I let me confess that I've gotten very spoiled working on things like the Sansui AU-555A and the Hitachi SR-1100, which were designed to be worked on at a later date and pretty much go forever with a little love and knowledge.

I loved the 380R at first as it had all the bells and whistles: power meters, triple tone controls, IEC power cord, massive aluminum face.

But...the power switch is a nightmare and goes open. You have to dissect it to clean it, then you've got a few years before it needs it again. The last time I had to do this, I accidentally broke one of the discs (it's an OFF/ON/SPKR A/SPKR B cluster-intercourse that's jammed into a very tight spot) and that was the end of the proprietary switch. Inside, the quality is just not there, with some parts crammed into tight spaces and others dangling in the breeze. The insides show cost-cutting and haste: the 380R was built in an attempt to save Scott's skin during the Spec-Watt Wars. The sound is excellent, however, so I left the dead switch in place and rigged an HK 630 ON/OFF switch into the rear panel--DC offset, if I recall, cannot be adjusted and it's on the high side--so there's that aspect, too. FM started to fail but I was able to coax it back to life by wiggling a few screws on top of the tuning head and cleaning the contacts with D5.

So, a mixed bag. If you can find one for $100 or less, I'd say jump on it. If you fall in love with it's looks and want big, impressive sound (though not necessarily accurate), then the price is up to you. It's got a special look that departs from the blue lights-on-black theme and that appealed to me. Working on that switch got very tiresome, and even leaving it in the ON position and using a power strip didn't alleviate the problem. I was impatient the last time I wrestled with the switch; now that you know about this you won't make the same mistake! It does sound fantastic--as good as it looks--I just wish it was built better. The earlier Scott R74S I also own is much better built, much easier to work on, but not as dramatic or impressive looking.

Birchoak,
Thank you for taking the time to write a comprehensive summary. That's all I wanted to know.
Vito[/QUOTE]

Vito and Birchoak; this thread discussing utilizing a Triac to operate On/Off and remove that load from the power switch might be a good option for the 380R and it's power switch issues. I have one on my bench now that had same issue. I am considering doing the triac mod. If I do, I will post a thread.

 

[vito1]

Birchoak,
Thank you for taking the time to write a comprehensive summary. That's all I wanted to know.
Vito

Vito and Birchoak; this thread discussing utilizing a Triac to operate On/Off and remove that load from the power switch might be a good option for the 380R and it's power switch issues. I have one on my bench now that had same issue. I am considering doing the triac mod. If I do, I will post a thread.[/QUOTE]

jd3rdcoast,
That would be great!
Vito

 

[taineasy]

I know that pretty much everyone here would love to own a nice assortment of the totl vintage receivers & integrated amps from folks like Pioneer, Marantz, Sansui, etc. But, I thought I would start this thread, to share my love of my low-powered vintage gear & How musical it is!

I am not really a "collector" per se, of vintage gear, but seem to be more of an accumulator. I still own my first receiver a Pioneer SX-626 (27w/ch.), but over the years I seem to have accumulated a few more pieces of low-powered vintage gear as well: a Marantz 2220b receiver (20w/ch.), a Yamaha CA-410II (25w/ch.) integrated amp, a Technics SA-80 receiver (15w/ch.), etc.

What I have learned over the years is that when this gear is matched up with good quality 2-way speakers they perform wonderfully well. But I have also stepped on a few landmines soundwise. I have tried all of these components on my 1971 era Pioneer CS-R500 speakers & for the most part they have all performed reasonably well, with the exception of the Yamaha. The Yamaha was a terrible match to the old West Coast Sound Pioneer CS-R500's, but especially the metal diaphragmed mini-horn tweeter & midrange. The result was much much too bright! But, the 3-way CS-R500 & also my 3-way Klipsch Heresy's was a little too much speaker for the little 15-20w/ch. amplifiers. But those little amps always performed well on some of the older 2-way speaker systems I have.

So, what has been your experience with your vintage low-powered gear? I would love to hear about your setup: what gear you are using, what source components you use, what speakers you've tried, what worked the best, & most of all, what kinda music you listen to.

The best sounding vintage low wattage integrated I've ever heard is the Kenwood KA-4002. It was designed by Nakaichi and Jiro Kasuga who left Kenwood shortly thereafter to form Accuphase. Seldom seen in these parts and when they do get scooped up quickly. An amplifier this small should not sound this good. Amazingly good sound.