Vintage amps (70s)

[Mikado463]

Saw a new NAD amp that's rated at 30wpc. Why would you use this with modern speakers with high wattage? I don't see any modern speakers that are rated as low as 30watts.

not exactly sure what you're implying, but with any speaker, start with looking at it's sensitivity and nominal impedance

 

[TLS Guy]

Can you expand on the "as good as tube amps" comment?

Well, the 303 had better specs than the tube amps of the day and more power. Peter Walker set up a double blind test for the "golden ear brigade". They could not tell the difference between a Quad II tube and the 303. Then he naughtily added 2% THD to one of the set ups, and the "golden ears" could not tell the difference. They were furious at having been called out.

 

[mtrycrafts]

Well, the 303 had better specs than the tube amps of the day and more power. Peter Walker set up a double blind test for the "golden ear brigade". They could not tell the difference between a Quad II tube and the 303. Then he naughtily added 2% THD to one of the set ups, and the "golden ears" could not tell the difference. They were furious at having been called out.

It's almost as good as when just switching the same tested component back and forth without the listener knowing nothing was changed, yet they hear a difference.

 

[lovinthehd]

Well, the 303 had better specs than the tube amps of the day and more power. Peter Walker set up a double blind test for the "golden ear brigade". They could not tell the difference between a Quad II tube and the 303. Then he naughtily added 2% THD to one of the set ups, and the "golden ears" could not tell the difference. They were furious at having been called out.

Sounds like the old Carver challenge....

 

[lovinthehd]

Saw a new NAD amp that's rated at 30wpc. Why would you use this with modern speakers with high wattage? I don't see any modern speakers that are rated as low as 30watts.

If you wanted high spl you probably wouldn't use such an amp. If you have a small room or don't listen loudly 30wpc can be fine with many speakers, tho. A speaker wattage rating isn't very useful, it's just more an indication of it's limits before damage might occur. Sensitivity and impedance specifics are far more useful. Try this tool http://www.hometheaterengineering.com/splcalculator.html

 

[Verdinut]

In the 1970's, there was a very little percentage of high power amps, because most loudspeakers then had a higher sensitivity than currently designed and produced drivers. But with the advent of rock & roll, heavy metal, drum& bass, high dynamics movie soundtracks and high definition opera recordings, more amplifier power became necessary.

With respect to opera as a music source, the real fact is that at least one such recording has a dynamic range of 35 dB.

 

[highfigh]

You can bet it is an AM/FM receiver then. I think those were the only offerings from Sansui at that time. But as you know, I have never been a receiver guy. I did buy a used one for one of my teenagers. Most were 20 to 30 watts per channel. The later G series cranked out160 watts per channel. For some reason they had a poor reputation which I think was totally undeserved.

Pretty easy to find out what SAnsui offered around 1970- from the link:

Pre Amplifiers
1968 TC-505 (pre amplifier w/tuner: pre-ceiver) (JDM)
1970 CA-606 (JDM)

Power Amplifiers
1968 BA-60 20 watts
1968 BA-90 28 watts
1971 BA-100 30 watts (JDM)
1970 BA-150 45 watts (JDM)

Sansui Product History: Amplifiers 1967-2000

The list below is complete for solid state integrated amplifiers 1967 - 2000. And solid state separates 1968 - 1979. V. 06/27/23 Organized chronologically, separate blocks of JDM and International, power low to high Dates based on actual production dates JDM = Japanese Domestic Market AAFES =...

audiokarma.org

 

[highfigh]

Saw a new NAD amp that's rated at 30wpc. Why would you use this with modern speakers with high wattage? I don't see any modern speakers that are rated as low as 30watts.

Speakers don't have Watts. Amplifiers don't have Watts. Testing and ratings changed during the 1970s.

Speakers are rated differently from the way the seds were shown in the 1970s- at that time, sensitivity was rated by showing '8 Ohms, XX db @1W, 1 Meter distance" but the change came when more speakers became available and '1W' was seen as too arbitrary, so they used 2.83V. That's due to the Ohm's Law formula P=E²/R, where the resistance is the value that determines what makes 1 Watt. Sensitivity using that voltage with a 4 Ohm speaker is actually not 1 Watt, it's 2 Watts. In order to show 1 Watt with a 4 Ohm speaker using that formula, the voltage needs to be 2V AC.

 

[Mikado463]

Speakers don't have Watts. Amplifiers don't have Watts. Testing and ratings changed during the 1970s.

Speakers are rated differently from the way the seds were shown in the 1970s- at that time, sensitivity was rated by showing '8 Ohms, XX db @1W, 1 Meter distance" but the change came when more speakers became available and '1W' was seen as too arbitrary, so they used 2.83V. That's due to the Ohm's Law formula P=E²/R, where the resistance is the value that determines what makes 1 Watt. Sensitivity using that voltage with a 4 Ohm speaker is actually not 1 Watt, it's 2 Watts. In order to show 1 Watt with a 4 Ohm speaker using that formula, the voltage needs to be 2V AC.

LOL, now you've got him really confused

 

[Eppie]

Saw a new NAD amp that's rated at 30wpc. Why would you use this with modern speakers with high wattage? I don't see any modern speakers that are rated as low as 30watts.

Well, pretty much what the others have said.

Speaker sensitivity determines how loud a speaker will play for a given wattage going in. Early amps did not have a lot of power so speakers were designed to be very sensitive and not require a lot of power. There are still some high sensitivity designs out there where 30W per channel would be enough but the majority of speakers these days are closer to the 87db - 90db range that requires more power to reach reference levels.

As lovin mentioned, speaker power ratings are not about how much power they need. Those ratings state the maximum power the speaker can handle before damage will occur. You need to look at impedance and sensitivity to know how much power is required to reach a target volume and there are on-line calculators for that.

My father had a tube amp setup that only had about 28W per channel. That would not run a modern speaker very well but he had high sensitivity horns from Electrovoice that did not require a lot of power and I know from personal experience that those speakers could get very loud even with only 28W of amplification.

 

[PENG]

There's a thread here about a Sansui vintage amp. Guy said he inherited it from family member and he said he couldn't believe how it sounded.
I'm an engineer but know little about electronics. Barely passed EE101.

I can tell you the same about my Marantz vintage amp, or Kenwood amp but there will tons of others telling you the same about their vintage amps. IMO, especially as an EE, you would be better off just look at the specs, and try to find lab bench measurements and see how they perform on the test bench. Or, if you really "trust your ears" then unfortunately you won't know the answer until you have auditioned tons of those amps at your place lol......

 

[PENG]

Well, the 303 had better specs than the tube amps of the day and more power. Peter Walker set up a double blind test for the "golden ear brigade". They could not tell the difference between a Quad II tube and the 303. Then he naughtily added 2% THD to one of the set ups, and the "golden ears" could not tell the difference. They were furious at having been called out.

He is one of the few, or many amplifier designers who is actually an EE, and he's confident enough to not use listening tests to help "fine tuning" his designs/build but only use it in the end just to see if there might be anything wrong with the product. That's very different than Marantz's use of their so called "Sound masters".

To the OP, @ifsixwasnin9 , if interested in vintage amps, Quad's, as TLSGuy mentioned, are probably a better choice than Marantz. Marantz will sound great too, and I have a pair, but they are very good in marketing and know how to bias audiophiles with their marketing info, so do your research on them but don't pay much attention to their owners subjective reviews found on audio forums.

 

[highfigh]

He is one of the few, or many amplifier designers who is actually an EE, and he's confident enough to not use listening tests to help "fine tuning" his designs/build but only use it in the end just to see if there might be anything wrong with the product. That's very different than Marantz's use of their so called "Sound masters".

WRT "He is one of the few, or many amplifier designers who is actually an EE"? Huh? Did you mean "one of the few, out of many amp designers who are EEs, who doesn't use listening tests"?

I can't imagine marketing any electronics designed by someone who isn't intensively trained in electronics and EEs would have a definitely edge over someone who came along as a hobbyist and built a reputation for building life-enhancing equipment.

TBH, I don't remember hearing or reading about Marantz sound masters- they may have, but I didn't work for a Marantz dealer. I do remember that their equipment was usually better than average and didn't see much of that brand coming in for service- our store did A LOT of repairs, too. What model are your amps?

 

[highfigh]

Well, pretty much what the others have said.

Speaker sensitivity determines how loud a speaker will play for a given wattage going in. Early amps did not have a lot of power so speakers were designed to be very sensitive and not require a lot of power. There are still some high sensitivity designs out there where 30W per channel would be enough but the majority of speakers these days are closer to the 87db - 90db range that requires more power to reach reference levels.

As lovin mentioned, speaker power ratings are not about how much power they need. Those ratings state the maximum power the speaker can handle before damage will occur. You need to look at impedance and sensitivity to know how much power is required to reach a target volume and there are on-line calculators for that.

My father had a tube amp setup that only had about 28W per channel. That would not run a modern speaker very well but he had high sensitivity horns from Electrovoice that did not require a lot of power and I know from personal experience that those speakers could get very loud even with only 28W of amplification.

Technically, it's Voltage input- power is a calculated value and that's the reason the current sensitivity spec uses 2.83V@8 Ohms. Using 1 Watt isn't specific when the speaker impedance ISN'T 8 Ohms and it removes the variable- a 4 Ohm speaker needs 2V for 1 Watt input.

I went to a McIntosh-sponsored amplifier clinic with my Pioneer SX-525 and the output was a blistering 13W/Channel at 1% THD- it wasn't a lot of power, but it was enough to pi$$ off my dad when I cranked it.

 

[lovinthehd]

It seems OP has gone a different slant in this thread https://forums.audioholics.com/forums/threads/jbl-75w-continuous-power.143849/

 

[dlaloum]

Thank you for the explanation regarding models and there corresponding model numbers. It's all very confusing for the new buyer,
As I said before Quad are virtually unknown in OZ, The same as Cyrus are unknown in America.

The same thing has happened with the entry level Cyrus 1 Which carries the same model number as the early and possibly first
Cyrus model produced way back when.

I used to work for a Quad retailer in Oz in the 1980's - they have been around consistently, but with limited distribution.

They were always upmarket/relatively expensive, in the 80's you could get similar performance Pioneer, Yamaha or Sansui for less $$... But the Quad amps I purchased then, are still running today, and they are readily serviceable when needed.

So always a fringe/boutique brand here in Oz, but always available...

 

[lovinthehd]

I used to work for a Quad retailer in Oz in the 1980's - they have been around consistently, but with limited distribution.

They were always upmarket/relatively expensive, in the 80's you could get similar performance Pioneer, Yamaha or Sansui for less $$... But the Quad amps I purchased then, are still running today, and they are readily serviceable when needed.

So always a fringe/boutique brand here in Oz, but always available...

Interesting. What were the other than fringe/boutique brands available to you??

 

[dlaloum]

Interesting. What were the other than fringe/boutique brands available to you??

Well, we also stocked Marantz, Pioneer, nearby competitors stocked Yamaha, Sony, Harman Kardon, as well as more boutique brands from the US and the UK (we also stocked Revox) - Dual, Monitor Audio, VTL, Musical Fidelity, Cyrus, Naim, Lynn, Martin Logan, etc...
Most brands were represented at the time, but some were represented in only a handful of stores in the country, or by a single store/importer...

 

[Mikado463]

Well, we also stocked Marantz, Pioneer, nearby competitors stocked Yamaha, Sony, Harman Kardon, as well as more boutique brands from the US and the UK (we also stocked Revox) - Dual, Monitor Audio, VTL, Musical Fidelity, Cyrus, Naim, Lynn, Martin Logan, etc...
Most brands were represented at the time, but some were represented in only a handful of stores in the country, or by a single store/importer...

what , no Krell or Threshold ? how bout 'Ampzilla' ?

 

[lovinthehd]

Or Carver, Phase Linear, Fosgate, Peavey, etc?