Set the quiescent current to the manufacturer's specs. They knew what they were doing when they spec'd it. Usually.
The audible difference between .01% and .001% distortion is nil. It's just numbers for geeks to get all hot and bothered over.
An interesting read.
Personally I enjoy collecting gear from the mid to late 70's - this might be akin to those folks who collect / enjoy muscle cars. Many modern "pedestrian" sedans will embarrass those muscle cars, but that doesn't diminish the enjoyment of them - and some of them will still hold their own.
And yes, nostilgia is a significant factor here.
Amongst my collection of 20 (or so, I lose count) restored monster receivers are Pioneers (SX-1980 and down) and Sansuis (G-22000 and down) plus Yamaha, Marantz, and so on.
While I greatly enjoy the sound and build quality of these it must be remembered that these were mainstream consumer products (albeit some were loss leaders to create a halo effect for the lesser models).
Should we expect these to compete with high end / botique products from then and now? In that regard some of these do hold their own.
As far as SMDs go - they are certainly a PITA to build with and repair without the proper tools (and often with the proper tools). But keep in mind that without them the products we enjoy today would cost many, many times more then we are now paying. Imagine a discrete flat screen TV, computer ipod, CD player (and so forth).
I'm sure many of you have seen a modern SMD assembly line. The speed, reliability and cost reduction compared to hand assembly for large scale production is enormous.
As mentioned, when it comes down to it a robust power supply may just be the deciding factor.
Again, just some thoughts to ponder - there are enough aspects to this hobby for everyone.
Personally I enjoy collecting gear from the mid to late 70's - this might be akin to those folks who collect / enjoy muscle cars. Many modern "pedestrian" sedans will embarrass those muscle cars, but that doesn't diminish the enjoyment of them - and some of them will still hold their own.
And yes, nostilgia is a significant factor here.
Amongst my collection of 20 (or so, I lose count) restored monster receivers are Pioneers (SX-1980 and down) and Sansuis (G-22000 and down) plus Yamaha, Marantz, and so on.
While I greatly enjoy the sound and build quality of these it must be remembered that these were mainstream consumer products (albeit some were loss leaders to create a halo effect for the lesser models).
Should we expect these to compete with high end / botique products from then and now? In that regard some of these do hold their own.
As far as SMDs go - they are certainly a PITA to build with and repair without the proper tools (and often with the proper tools). But keep in mind that without them the products we enjoy today would cost many, many times more then we are now paying. Imagine a discrete flat screen TV, computer ipod, CD player (and so forth).
I'm sure many of you have seen a modern SMD assembly line. The speed, reliability and cost reduction compared to hand assembly for large scale production is enormous.
As mentioned, when it comes down to it a robust power supply may just be the deciding factor.
Again, just some thoughts to ponder - there are enough aspects to this hobby for everyone.
To convince yourself, try this. Get a hold of some consumer grade equipment and measure the power supply droop with ordinary program material playing loud. On cheap stuff, the voltage will fluctuate a lot and drop as much as 20% or more during the cycle. Now do the same thing with an "old school" reciever. You will observe the power supply exhibiting much less droop.
Think about the dynamic compression and IM distortion that can be introduced by this phenomenon. Now imagine a marginal design that introduces some of this voltage droop to the voltage gain stages. (On some chip amps this is unaviodable.)
When even a "respectable" manufacturer claims 100 watts a channel times seven or whatever, the reality is that the amp might produce 35 to 50 watts a channel continuous with all channels driven; maybe less. It will probably have enough headroom to produce 100 watts into two or four channels on a transient; but no way 100 watts into 7 channels. Of course, the nature of "surround" program works very well with these limitations; typically only the subwoofer amp has to crank out big watts. But it's still snake oil and in no way compares to how they rated gear back in the day. A 25 watt/channel Marantz can easily blow a new school "100 watts/channel
" Sony or similar ilk clear out of the room.Yup, (TO3) 2N3055 is unique in Lin topology. It gives the best soundstage, and tubelike sound. But remember that when there is no change to bias circuit, the 3055 is biased higher than new sanken for example. But when the newer transistor is biased higher, the 3055 still sound "better"
But my preference go with Toshiba 2SC5200. Less fatigue, and delicious bass
2N3055 in second place. And I have compared many transistors with about 10 schematics at the same time (exactly for contest purpose). Strange that the famous old Toshiba (20-30MHz Green-Black device) perform so badly.
The Great Classic amps had clever analog tone controls and a loudness button that provided an early FletcherMunson contour curve. Twisting a few knobs and pushing a few buttons often compensated for listening room problems, poor recordings, poor speakers, low listening levels, and personal taste.
I think digital equalizers with just a few bands can generate painful sound. A few super equalizers with 20,000 bands solve the problem. Add a measurement mic and built in FletcherMunson functions, and major sonic miracles are possible.
Amplifier design has greatly improved, but great sounding amps are still heavy from power supply and heat sinks. Clever hi-tech digital equalization and digital crossovers make this the best days of audio.... as long as you know which recordings to buy.
I like the line.... The stereo illusion is just a cheap Jedi mind trick.
I think digital equalizers with just a few bands can generate painful sound. A few super equalizers with 20,000 bands solve the problem. Add a measurement mic and built in FletcherMunson functions, and major sonic miracles are possible.
Amplifier design has greatly improved, but great sounding amps are still heavy from power supply and heat sinks. Clever hi-tech digital equalization and digital crossovers make this the best days of audio.... as long as you know which recordings to buy.
I like the line.... The stereo illusion is just a cheap Jedi mind trick.
I worked for a CBS affiliate in the '70s when network audio was over phone lines limited to around 5KHz. When the local news ran the audio had no such limitation. The network distribution changed to a second carrier on the video microwave link and suddenly network had 15 KHz audio and initially I didn't like it - not because ir was bad but because it was different. I can't imagine going back to those conditions.
G²
Our ears plus brain adjust any sound to something pleasant in a matter of 2 seconds
Brain processing.
Brain is a computer that can process at 400 hertz (clock) but has more pr less 650.000 cores..... a little bit more than core 5... also the software is not from microsoft... it is from God.
regards,
Carlos
Brain processing.
Brain is a computer that can process at 400 hertz (clock) but has more pr less 650.000 cores..... a little bit more than core 5... also the software is not from microsoft... it is from God.
regards,
Carlos
Or maybe you just didn't like having to process that additional 10kHz in your brain inorder to just understand voice, which mostly fit into 5kHz before the change, but is now muddled with other sound sources and needs additional brain processing inorder to understand.
Its perfectly reasonable to assume that our brains train themselves to one audio source and then need retraining inorder to 'like' the newer source, the million dollar question is, is the new change a good thing or a bad thing overall.
I for example was at one time content with a simple boombox, I thought it was the best thing in the world, especially with stereo, but now I couldn't live with anything less than a set of 3-ways.
Try explaining these little less known tidbits to any 'modern' person, they will simply laugh you out of the room as being too "old fashioned", and their boomy Sony 7.1 surround sound system makes a noise, so to them its kosher. *shakes head*
I think they can go and get lost, if you cotton on, them and their precious noisy SMPS! which does nothing but lay the shortwave band to waste anyway, haha!
I would love to build a linear power supply for every device in my home, merely for the fact that they would last a great deal longer than SMPS units, but as we all know that is not practical, though the last thing that needs replacing is my brand new microwave, which I'm expecting to die at any time, so it can be replaced by a 30 year old Toshiba unit that has been handed down from generation to generation, and is now showing magnetron ageing (longer cooking times).
What IS practical though is replacing newer equipment with older equipment that still uses linear/transformer based power supplies.
Vintage Oscilloscopes come to mind, but you need to be super careful with these, I would avoid the ones without transformers (live chassis) for one thing, and ones with tubes would be best avoided but if they work let them be until such times as a rare and hard to get tube dies, then replace it with an IC.
And who here is going to say that vintage oscilloscopes aren't useful for audio diagnosis/repair.
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Jcx, latter part of your post #51 (my pc skills will not affect direct text transfer):
I am referring to the part where you say that the output series cap is 'fully' in the signal path and the power supply cap(s) not, and that there thus is a vast difference in the influence on sound ......
Then I should go get my varsity fees back. There I was taught certain laws, a.o. laid down by a gentleman named Kirchoff. If one draws out the basic circuit of a normal amp, one finds load, series capacitor, output stage impedance and power supply (caps) in series - through which other path does the output signal current complete its route? Yes, at l.f. the power supply's own internal impedance by way of rectifier and transformer winding(s) are in parallel with the power supply output capacitor. But with rising frequency that odd 50 - 100 ohms soon looses effect when looking at an 8 ohm load (apart from the fact that in any half-decent amplifier the rectifier keeps that out of contention for most of the frequency band anyway, compared to the filter capacitor's impedance).
Not to start an OT argument here, but somewhere I am not reading you correctly?
I am referring to the part where you say that the output series cap is 'fully' in the signal path and the power supply cap(s) not, and that there thus is a vast difference in the influence on sound ......
Then I should go get my varsity fees back. There I was taught certain laws, a.o. laid down by a gentleman named Kirchoff. If one draws out the basic circuit of a normal amp, one finds load, series capacitor, output stage impedance and power supply (caps) in series - through which other path does the output signal current complete its route? Yes, at l.f. the power supply's own internal impedance by way of rectifier and transformer winding(s) are in parallel with the power supply output capacitor. But with rising frequency that odd 50 - 100 ohms soon looses effect when looking at an 8 ohm load (apart from the fact that in any half-decent amplifier the rectifier keeps that out of contention for most of the frequency band anyway, compared to the filter capacitor's impedance).
Not to start an OT argument here, but somewhere I am not reading you correctly?
They are like anything vintage, cars..clocks...lawnmowers...whatever there is always an interest in days of past. I for one love and own some pretty old gear. Many of them are cool and have their own beauty even if they are passed by, by new design and technology. They often can't be compared to their newer counterparts yet they still hold attention....it's a matter of preference.
You've hit te nail on the head. Those 70s amps, for all their faults had tone controls and occasionally a good loudness control. I am going back to this as well with a new pre in te works that incorporates good tone controls.
Doug Self never waive red from supporting the use of them. He is absolutely right.
Lol.... Get out much ...
Ahhh , another ole bastard like mi self ...
don't forget the manual , vintage equipment had many knobs and function to kill , yet never needed a ferking manual....
Perhaps it comes down to how some design engineers assess the performance of their designs. It is certainly convenient for them to assert that an amplifier with THD vs freq and level below a certain figure and SNR better than whatever must be audibly perfect and that anyone who claims to hear differences is a lunatic/elitist golden ear/hippy etc etc. It is seemingly beneath them to open their mind/ears and listen, besides which to listen properly requires exposure to real acoustic music to have a referrence as to how real insturments sound.
No doubt psychology plays a role in what we hear, but if a loony audiophile only hears differences because they believe they will hear it, so equally well might a blinkered engineer NOT hear a difference because they "know" (ie believe) there is no difference.
Now we have AP2 and other test gear that can measure distortion down to such low levels, perhaps the problem with modern gear is that it has been optimised for THD so well that other factors that have a greater influence on SQ are neglected. The two camps are at extreme positions and as long as the arrogant position of the hard-line objectivists remains dominant the art of engineering suffers as we end up with equipment that is optimised for a spec sheet instead of what it is intended for - enjoying music. Maybe the focus was to some extent more in the right area when some of this classic gear was designed?
No doubt psychology plays a role in what we hear, but if a loony audiophile only hears differences because they believe they will hear it, so equally well might a blinkered engineer NOT hear a difference because they "know" (ie believe) there is no difference.
Now we have AP2 and other test gear that can measure distortion down to such low levels, perhaps the problem with modern gear is that it has been optimised for THD so well that other factors that have a greater influence on SQ are neglected. The two camps are at extreme positions and as long as the arrogant position of the hard-line objectivists remains dominant the art of engineering suffers as we end up with equipment that is optimised for a spec sheet instead of what it is intended for - enjoying music. Maybe the focus was to some extent more in the right area when some of this classic gear was designed?
Yes. And if it does need some work, it most likely can be fixed/adjusted and parts can usually be subbed if needed. It is much easier, for example, to change a capacitor in a 35 year old Marantz than a new <anything> that uses surface mount devices, etc. This stuff was, in general, built to last and sound great doing it.
Speakers are probably the only area where I give serious consideration to a new design, although that is a generalization.
Speakers are probably the only area where I give serious consideration to a new design, although that is a generalization.
Yep, SQ is not the only reason, or maybe not even a reason at all. I like the front panel design of that period amp. And the style. They weren't perfect, but a lot more fun to use and look at than the drab black boxes of the following decades. They didn't have no stinkin' video connectors, either!
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