#dynaco 416

I am not going to buy anything for a while I promise.

Obviously I cannot spend every free hour at home listening to the steam powered stereo.  I have a life.  I exercise rather a lot for an old man which takes a few hours out of the week. I am not a gym rat so everything shutting down for Covid-19 has had no effect on my fitness program.

I have not sold my old Sony TT yet.  I dropped the price a bit.  Of the three similar units online right now it is the most expensive, but it has a high end tonearm.  If no nibbles by Xmas I will put it back in storage.

I was beginning to pre-spend the money I was getting for it and shopping around.  All my stuff is pretty good.  I saw an opportunity for a new preamp with two in the running.  By 1985 standards my SP-12 is pretty damn good. It is high end, but not the best of the era. There were a couple I liked frankly for the look rather than the sound. I was getting quite serious even making an offer on one.

Now I am stepping back.  I have to calm down and think.

Preamps are a particular problem as they have a hard job to do if you spin Vinyl. The character and all the mystery of LPs are deeply dependent on the phono section.  Preamps have fans and cultist devotees.  Many swear by tubes and mine is a tuber.  With all the argument and conflict it is hard to cut through and find truth.  The real trick is there really isn’t any truth.

A big problem is a lot of people happily spend stupid money.

One central issue is the type of phono cartridge you use. The big schism is moving coil versus moving magnet, iron, or whatever.  Two particularly respected companies think all moving coils are simply not worth it. Those are Soundsmith and Grado. They make really good stuff.  Their opinion is worth considering.  The MC vs MI, MM divide in no small way drives preamp design, performance and reactance.

All types of pickup are tiny machines that convert vibration to electric signals. These machines  behave differently depending on the electrical behavior of the phono circuit.  Most obvious is the capacitor load the pickup sees.  Many moving magnet types hate higher capacitance.  The AT 440Mla case in point. It sounds like shit with harsh treble with anything more than 150 pf total.  The treble kinda resonates and bounces back.  Many moving coils need higher capacitance. The Audio Research SP 14 and many others came from the factory with over 500 pf at the phono input.  It was intended for some MC pickups. MM types will sound bad.

There are so many loops in the chain you cannot help but get tangled up.

Previously I discussed an article in Absolute Sound where the author mused that maybe the rush to moving coils was an error. If you visit the Soundsmith website there is a well written piece on why moving coils cannot be very good. Finally Grado invented moving coil pickups and abandoned them years ago. Both those use moving iron and sell 5 figure phono pickups.

I was investigating if getting a modest MC cartridge was worth the investment.

The gist is that moving coil internals are heavier that alternatives.  That has important effects.  If you have a vibrating rod, like the pickup cantilever, its behavior depends on how heavy its parts are along its length.  A relatively large coil is heavier and more flexible than a tiny magnet or piece of iron.  Specifically moving iron working parts are much lighter than the best moving coils.  The physics says they should move faster than moving coils can.  Physics has an annoying habit of being right.

Soundsmith claims that the vibration from the diamond bounces off the heavy coil structure and runs back to the diamond causing a distortion.   They say that this distortion may be what golden ears claim is the “Aire” and space between instruments.  It is an effect like reverb.  Actually it is a reverb of the treble.  Accuracy it aint, but it sounds nice.  That really is the problem. People who judge just by what they like will prefer things based on other things than accuracy.

If you go through forums and such you see a lot of people sitting on top of heaps of assumptions and other people’s opinions.  This is bad that is good.  I especially enjoy people judging things they never heard because somebody said....  When they comment on something I used to own as this or that it is pretty funny.

The sound we hear in our systems is an illusion.  The less sweet syrup on the signal the more accurate, but it is only an illusion.  I am amazed at how convincing it can be. My system is old but old aint bad.  It is tweaked in critical parts.  If I get a new preamp will is sound different? Almost certainly yes.  Will it be better? Probably not that much.

Hey I am a geek and I like to think about these things.

Bottom line is it really is about the information on those plastic disks.  It is art and effort and skill captured in a physical medium.

If you are an anal retentive nit-picker this is the hobby for you!  How small a change does it take?

I just got 2 more basic headshells to replace the twisted ones.  I had the vessel and the 440 in those.  To get the right angle I had to shim them with these tiny washers on one side.  I know that was not optimal as cartridges need to be firmly attached to work right.  So I got the cheapest headshells that LPGear sells.  I also got some lead weight shims as sometimes you need some mass.

Of course that changed the sound dammit.

I ran through the TOTO album, and Tony Bennett Duets 2 and Paul Simon’s Graceland. Yes better.  I am at the point where I get all the stuff off the album, it is just the balance and the clarity and lets call it the spice.  The differences are real.  I suppose the real question is are they important?

One of the basic principles of solving a complex problem is only change one thing at a time.  More than that and confusion is inevitable.  A new cartridge with a compromised mount what could happen?  So uncompromise the mount.

I am seeing slightly more clarity and distinction between voices.  It is almost annoying when a singer also sings background on a song.  Harmonizing with yourself is not real harmony.  The fact that multi track lets you do this a shame,  When you tease that out of a recording well congratulations.  Does it help the art?

So the headshells made a difference.  Probably suppress vibration better etc.

It is a real shame.  The twisted head shells are a good example of what is wrong with China.  Nice materials, ebony wood and gold plated connectors were used. But assembled badly.  Well what can you expect from slave labor?  They look good and should work very well, but 5 and 10 degrees of twist is bad.  I saw it immediately but the QC guys did not.  Or there are no QC guys. Or they saw it was crap and sold it anyway buried down in the box so the vendor did not see them. Rule of thumb when dealing with China trust only if you can check every single thing.  I will try to fix the least screwed up one.  It will probably break.

I really have to dial back a bit.  I have been in buying mode for too long.  Its been 6 months since I got the HK Rabco turntable which in turn led to my Phaser and the whole SLT worldview .  Being in that mode also made me seriously look at a new preamp and on and on.  I really need to just listen and stop being critical.  I can do that.  Part of this is the plague as Audio is an indoor at home thing.  It is safe to do.

Is my system perfect, hell no!  No audio system is perfect.  Perfect cannot be defined.  The best you can do is an honest system.  One that adds very little of its own color, and pleasant effects.  Most of the really expensive ones add lots of that speakers being the worst offenders.  Sounds nice like the taste of sugar and cream in bad coffee. The best coffee is black no sugar. I have an honest system. Not perfectly honest but damn close.

Current set up:

Phase Linear 8000a Series 2 TT.

AT440 Mla pickup.

Yamaha CD player when digital is OK.

Audio Research SP12 with 5 times JJ 6922 tubes.

Dynaco 416 with 1 farad of supplementary power supply capacitance in dual mono wiring.

Invisible Speakers.

I know enough about electronics to be dangerous.  I also know how to be effective.  I have built stuff from scratch, but to be completely honest I have never actually designed a complex audio circuit.  But I have tweaked the living wee out of them.

I mucked deeply into my tube equipment as parts from 40 or 50 years ago simply were not that good. That was just swapping out for new and better.

I am much more reserved in transistor stuff. My favorite tweak is to the power supply.  If you are in the high end cult you may buy plugs to go from the wall to your precious equipment that cost silly money.  If you do you are silly.  Golden ears will swear they hear an effect, and they actually may, but better or not is not a given.

Power to your machines comes from the wall socket.  The wires in the wall are plain single conductor and unshielded unless you built your house to order. The power to your home comes through high voltage cables and line transformers and is not really very clean.  Perfectly clean power would be a 60hz pure sine wave. (50hz in many places on the globe)

Even with fancy plugs the power coming into your devices is not perfect.  You may buy surge protectors and filters for your computers and TV that is all about noise and poor quality power.

My thing is dealing with this inside the box.  All audio equipment resolves alternating current into direct current.  It takes the noisy sine wave and makes it clean and steady plus + and minus - volts.  The quality of that is how steady.  Tiny variations can be heard.

Electrical power has a wonderful analog, water. Imagine you had a device that runs on water pressure (analog to volts) and is available in large volumes (analog to amps).  Now think of that water coming from a fast moving stream that surges and jumps (analog to the house current).  You want it calm and placid.  You dig a pond or build a dam to hold the water and calm it down.  The calmer the pond the more steady the supply.  If you want it really calm you make as big a pond as you can so the effects of the stream are dissipated.

It is exactly the same in amplifier power supplies.  The pond is a thing called a capacitor.  It charges up and acts as a reservoir of power.  The bigger the capacitors the bigger the pond the calmer the power for the machine.

The first thing you can do is plug the biggest capacitors in that will fit.  The downside is you can overwhelm the rectifier device that separates the plus and minus as a big capacitor that is not charged draws huge currents at start up.  For small devices that is not much of an issue for big ones it is.

Also there is the fact that big capacitors are like batteries using chemicals.  They are very fast high current batteries, but they only respond well to low frequencies.  Noise on the line will get through to your precious circuits. Noise being anything that is not exactly 60 hz pure sine wave.  The fix to that is to ground the capacitors with a smaller film type that respond to high frequencies.

The final big picture thing is each channel needs it’s own power.  If you have stereo you need two power supplies.  see below.

                 A tale of three amplifiers

I have three stereo amplifiers.  Each is considered good for its time and is collectable. They are very different.

Carver Magnetic field  M -200 T.  Roughly mid to late 1980′s vintage. This is a cool device.  The magic part is the power supply.  A standard power supply converts wall current to DC at 60 hz in North America.  That means the capacitors get charged in pulses 60 times per second.  You can hear 60 hz it is that background hum that is so annoying.  As I understand it Mr Carver did the simple and brilliant thing of artificially increasing the AC frequency so the power supply is charged far more often therefore requiring smaller capacitors to filter the current. They can therefore respond much faster.  It sounds very nice and is also one of the beasts tweaked to sound like a cost no object high end amplifier in a blind test.

Harman Kardon Citation 12.  This is a classic design from the early 70′s and is  half the rated power of the Carver.  Its magic is the power supply.  Inside the box it is two completely separate amplifiers.  This means Two power transformers, two full wave rectifiers, 4 power supply capacitors. It is otherwise dead conventional.

The difference between these two is far more than just the power supply, but the Carver shares the power between two channels so a big sound in one channel will draw power from the other.  It is subtle but this hobby is all about subtle.  The Citation sounds better even though it has poorer test scores.  The way it sounds better is the stereo image drawn between the speakers is clearer and more steady.

Even though both are “old” they both have been repaired and tuned up in the last two years so they are fresh.  I credit the superiority of the Citation to the separated power supplies.  One channel is free from the other.

Dynaco 410 / 416.  The beast. Design dated to the 1970′s. I built this thing from mostly prefabricated circuits while adding extra output transistors.  The Amplifier circuit is identical to the Dynaco 416 but in a black box.  I built it with two separate full wave rectifiers into two completely separate capacitor banks each the same size as “stock”.  That avoids the problem with excessive current at turn on.  So it is dual mono just like the Citation, but for sharing the HUGE transformer which is ok cuz its HUGE.

The capacitor banks are bridged with film capacitors to kill the noise from the wall.  All by itself this thing sounds amazing.  It is clear and clean and has huge bass and solid stereo imaging.  I fear no amplifier that may come against it.

Comparing all three the Dynaco is the king.  There is no contest on the clarity and the performance.  Recall that the Carver is reputed to be indistinguishable from very expensive high end amps of the day.

The final bit is my tweak to the tweak.  Just before Dynaco Inc. bit the dust they made an accessory to their top 416 model that was an enormous additional capacitor bank to plug into the 416.  It has a pretty complicated circuit to control the charge at turn on.  If it did not, it could fry the house wires.  I built one with a stupid simple charge circuit.  I found a bunch of big capacitors and built a set of 4 banks with 1 Farad of total capacitance.  That is 50 times the size of the stock design.

My trick here was that the capacitors charge through big resistors to limit current going in.  Those are them back fed through really fat diodes to let the current out very fast.  The effect of plugging it in is profound.  An already quite amp goes silent.  The image of a well recorded orchestra is solid where you can place every instrument and feel the metallic sound of the brass and the woody sound of the woodwinds.  In Rock the bass is solid and deep.  Vocals are just amazing.

Now the car stereo geeks will go meh.  “We use one farad caps all the time.”  Not the same kids.  The power in a capacitor is proportional to the square of the voltage.  A car uses 12 to 14 volts.  My beast uses 74 volts. That is about 30 times more power.  You could weld with it.

The Carver and the Citation have at best factory tweaks to “normal” circuits.  The designers were very good to brilliant.  The Dynaco was designed by a team that included people working on state of the art (1970′s) and included great and brilliant names too.  It was very good, but they were accused of hobbling it to hit a price point.  The 416 was apparently an attempt to un-hobble it.

I have vintage equipment.  I respect the Carver and the Citation and do no more than keep them maintained. The Dynaco is another matter.

Aside from my speakers my audio system represents really good stuff for the late 1970′s to 1980′s.  The stuff of that era was not bad by today's standards, and is much better than consumer grade equipment of any era.  Some of these devices are collectable and that creates an artificial value for them.

Almost all the best stuff from then is now considered not that good now, or at least far surpassed. For several years the Audio Research SP3a1 was the best.  Several reviewers called it a straight wire with gain and it reigned from on high.  Today it is far less than that.  The RIAA phono equalization curve was off significantly which made it sound like many people expected a good thing to sound.

The SP3a1 is valuable as a collectors item.  I am sure the owners enjoy it.

Actually to that point last night I was listening to a Decca London recording from the 60′s and parts of that sounded brilliant other parts were crap.  The RIAA standard phono curve is an equalization put on vinyl records for various good reasons.  It is an extreme cut in the bass and a boost of the highs going into the vinyl and a boost of the bass and cut in the highs coming off.  Thing is up to the 1970′s it was not an actual standard.  I think that the recording I had was from before RIAA was adopted in the UK and that caused the full orchestra to go weird.

It was a London Geshwin’s Rhapsody in Blue.  The Clarinet and Piano were really nice.  The full orchestra strings were shit.  This was a “Phase 4″ recording mixed down from 20 mike channels and that may also have been the problem.

Anyway all of my electronics date from the designs of 1970′s to mid 1980′s.  This was the peak era of tube versus transistor wars and the fundamental questions of what is good, and who should decide.  They were all considered good stuff then.

Stock version of my Dynaco 400 amp was a solid second then third tier machine with real or imagined flaws compared to the top tier.  In that time powerful amplifiers were just becoming possible. 

In the early 1970′s the best transistor amps were 60 watts per channel such as the HK Citation 12.  That is a lovely design with basically two completely separate monophonic amplifiers in one metal case.   I have one.  If you find one in working order it is a nice machine. They are repairable if sick. For a short while it was the best in several rankings.  Transistors were popular as they solved a lot of problems with tube amps specifically a lack of bass in available speakers.

Then tube amps struck back with more power by adding ranks of tubes and the discovery that more power sounds better.  Power is determined by volts times amps.  In tubes it is easy to drive volts by adjusting the output transformers as the circuit already had lots of volts.  Chaining together ranks of output tubes was fairly easy to get amps.

In transistors the output devices are basically attached directly to the speakers and they had not yet made available higher voltage transistors.  When those happened so did 200 and 350 Watts per channel machines.  When you listen to music at orchestral levels you are averaging maybe 2 to 5 Watts, but peaks are many times that.  The peaks are the key advantage with big amps.

A trumpet is capable of 130 db.  A quiet room is say 40 db.  The difference is 90 db which corresponds to a power ratio of 1,000,000,000 times. That is way more than even a huge amplifier.  But if you want the impact of a big drum you need as much power as you can get.  There are limits in that if you actually could get that many Watts it would probably liquefy your brain sometime after you went deaf.

Actually 90 db far exceeds the dynamic range of vinyl but is within the theoretical capability of CD and lossless digital with enough bits.

But more power sounds better.  The more pedestrian advice is buy the biggest amp you speakers are rated for.  I ignore that.  I have the biggest amp I could build and hope that I do not drop anything that makes my speakers smoke.  I do not use fuses even.  Making my electrons march down skinny wires that get warm is a compromise. I have been 40 years lucky to not cook any speakers yet.

Tubes are expensive and fragile so adding more and more is very expensive.  That was the fundamental battle.

I have had good tube amplifiers and enjoyed them, but they do have a voice and there are compromises. It all boils down to compromises.

If you chase numbers and specifications and that is all I feel sorry for you.  For myself I understand the limits of such and you have to restrain yourself.  I like listening to music I have owned for decades and hear new things, or at least things as I remember them.  I am amazed that I can listen to a recording I have not heard for 30 years and remember every song.

Last night I dusted of Ian Thomas’ “Glider” a strange and beautiful record.  The sound was amazing and clear and I truly enjoyed it with my old machines.

The battles are far from over and now include Mosfets and class A Amps in transistors and tube triodes and many other things. Switching amps are interesting and theoretically very capable.  Those are often called Class D with the D taken as digital, though there are not really that.

It is fun that many classic expensive designs can be bought as kits from China as patents and copyrights have expired.  I will troll those places and wonder if I really want one of those.  I like to build things.  Then I put on a record and relax.

Anyway it is interesting but you have to remember that this is all about enjoying the music. 

My current system:

Sony 2251 la turntable with a grace 707 arm and a Signet TK7E and a tweaked mat.

SAE MK 30 (III) preamp ( AR SP12 is sick)

Dynaco 416 black box tweaked as detailed on an earlier post.

Ordinary heavy gauge wires.

AUDIOFILE

I have a nice stereo. I do not have one of those systems that cost more than a car or even a house. Still I think it is pretty damn good. If my house burned down I could probably replace the main parts of it for less than $8000.00. The LPs though, that would take a lot of time and a lot of money.  I have some pretty good ones.

Back Story:  

This will take a while.

Let’s set the wayback machine to a time when everyone knew what a wayback machine was.  I entered the engineering program at a big eastern US university in 1973.  I had some cash and I wanted a stereo in my dorm, as that was a good thing to have. The year before my brother and I travelled to NYC to buy exotic bipolar power transistors that went into an amplifier design out of a magazine.  They were about 60 Watts per channel. We each built one. Frankly I do not remember what kind of preamplifier I had. We probably built that too.  I had built some big ass speakers with a lovely 12” die cast aluminum frame woofer in a two way system.  It got loud. I thought it sounded fine.

The only “factory” components I had was a Dual Turntable and a Shure phono cartridge I think it was an M95. That system lasted two years before I caught the bug or curse as the case may be.  In the second year my amplifier was sick.  Whenever my roommate played Queen it went crazy and demonstrated what I now know as thermal runaway.  Only Queen had this effect for some reason.  I did not like Queen.

Over the next summer I bought and built a Dynaco 400 Amp and a Dynaco Pat 5 preamp kit.  I also made a friend who turned out to be even weirder with more money who bought a Harmon Kardon Citation 11 and 12 with a really nice Sony Turntable with an SME arm.  He had these speakers called Advents that some guy in Boston was selling to raise money to build a big TV.

The two of us got a subscription to a sort of underground magazine called the Absolute Sound.  It eschewed advertising as that was corrupting and yet somehow convinced serious manufacturers to loan them equipment. When they managed to get an issue out we devoured it.  We also managed to visit stores that actually had much of the equipment they listed as good stuff. We heard almost everything on their lists.

My friend got tired of his Sony Turntable and I bought it from him and I sold my Dual.  He kept his SME arm and I do not remember what he did with it.  I bought a Grace 707 tone arm and a Sure V15 cartridge as that was considered really good if you tweaked it a bit.  It was so tweaked.

I remember he went from the Sony to a HK ST7 turntable.  It had pretty lights.  Then he went off the reservation and got a Transcriptor Skeleton Turntable.  I think he managed to get the SME arm on it as the funky transcriptor arm was a recognized PITA.  He had a part time job at a stereo shop and could order stuff wholesale.

He also sold me his old Advents which were wrapped in vinyl phony wood stuff and bought a pair of Advents that were covered in real wood.

He also traded his Citation 11 for an exotic tube thing called an AR SP3.  He later sent it to the factory to have it upgraded to SP3 a1 status.  

At that point I had his old Sony 2251la turntable, Grace 707 arm with a Sure V15, playing into a PAT 5 preamplifier and a Dynaco 400 amplifier feeding into a pair of Advents.

All that should tell you that for a couple of college students we had some pretty good stuff. It should also tell you I have no fear of cracking open a case and messing with things.  When Dynaco upgraded the PAT5 to better OP Amps I got a set and soldered them in.

A very strange Grad-student with an all tube system would visit and offer restrained praise of our systems.  About mine he said it was really good for a transistor system.

As all good things had to come to an end I graduated and had to move far away.  I sold almost my whole system to another guy keeping only my LPs and my turntable.  I still have that turntable that arm but not the Sure V15.

When I arrived at my new home and job in the Frozen North (Edmonton Alberta Canada) I had no tunes. Once paycheques started I got some stuff.  I bought a preamp and I do not remember what kind of amplifier or maybe I did not have one, but I had a project.  I was building electrostatic loudspeakers.  Big ones too.   For those I bought a pair of Dynaco Mk3 tube amps.  I almost killed myself with high voltage building the speaker power supply. The palm of my hand got charred by being too friendly with some capacitors while they were “hot”.

Interestingly these big ass electrostatic speakers 4 ft square per channel worked!  The bass was less than great so I built a 15” subwoofer and some other bits.  I lived with my cousin and this crazy setup took a lot of space up and sounded impressive if not actually good.  For the record I now think electrostatics have more problems than benefits.

I saw an ad for somebody who was selling a Transcriptors Skeleton Turntable and as one of the few people who knew what that was in the Northern Alberta I grabbed it.  You cannot overstate how cool that thing looks. I still have that too, though I may sell it soon.  The Stock arm got broken.  I think alcohol was involved.  I still have the parts.  I modified the Transcriptors to fit another Grace 707 arm which was tricky as the bitch was heavier than the stock one and I had to rebalance the whole thing with ballast.

At this point things get fuzzy.  I tired of the big electrostatic speakers and I think I built some small more wife friendly things as I had acquired a wife.  Powered by the pair of MK3s it was pretty good.  I had tweaked my preamp power supply with bigger caps and it got better.  Then one day in a shop I found an orphan Audio Research SP12 for sale.  All tubes 6DJ8s instead of 12ax7s.  Somewhere along here I had built a copy of the SP3a1 from the circuit diagram on a breadboard and found 12ax7s to be PITAs as well.  So that was my system for a while. All glowing warn lovely tubes.

The next step was newer bigger speakers.  I had a design idea and paid a wood worker to make me some boxes.  They were fairly big towers with a biamped woofer thing and went down to seismic bass and the treble was way past what I could hear as a young man. Those were still fed by the MK3s and a midsize  transistor amp for the woofers.

Thing is the MK3s though really good are tube amps and those tubes were getting bloody expensive. So I went backwards.  Dynaco was out of business.  I found a company that had bought all their stock and I ordered a black box 400 kit and a few extra parts to build something special.

What I built was a black box Dynaco 416 with two power supplies and some really nice film bridging capacitors.  I tweaked the mother while I was building it.  No magic smoke when I turned it on.  It was wonderful.  I did another silly thing by adding an outboard power supply capacitor bank. Actually a pair as each channel was separate. Do you know how big 1 farad is at 74 volts?  Unplug the bugger and it plays loud for a long time.  Not being silly under normal operation it just made the beast remarkably quiet and potent.

I made a diversion to surround sound and 7.1 channel movies for a while.  My black box and tube preamp went in the crawlspace.  I sold the MK3s for a decent price. If you wanted to listen to records you needed the programmable remote.  Life was getting complicated.

The old SP12 came out of the crawlspace with a nasty hum.  I replaced a failed big PS capacitor with larger value but physically smaller caps and it worked fine.   I dragged out the 416.  I needed new speakers.  The big guns were tied up in the surround system.

Actually what got me going was an ad on craigslist.  I found some Advents and thought about going back in time. I also saw an ad for a speaker called Sonabs.  I remembered hearing them 40 years ago and liking them.  They were gone before I got in touch with the guy.  I read up on them and decided to build some like it.  I really liked the theory behind them. Simple and very restrained in a Nordic sort of way.  The drivers you can buy today are really good and the crossover parts are really very very good now.  They have computer programs to lock down optimum millihenries and microfarads based on the impedance curve of the drivers.  So I used those.

The idea behind these things is to put the speaker drivers as close to the wall as possible to minimize reflections.  It is a good idea, the sound I get out of them is very clear and uncluttered. Spooky actually.

So over the last few months that is what I have been playing with. I set up the Sony / Grace table and it has been a lot of fun.  The Black Dynaco lurks in the corner and things are good. You push a few buttons and the thing turns on and music is available.  No remotes required.

One of the really fun things is the cartridge on the Sony.  I have a Signets TK7e and loved it 20 years ago.  I found a replacement stylus and it still works.  The thing responds to 45 khz.  That is insane.  I do not think any current cartridge is comparable. It was designed for 4 channel sound that used an ultrasonic carrier.  Interesting the Grace 707 was also intended for 4 channel sound.  They work very well together.

So take it as reasonable that I do have a serious and good home stereo system.  I have more than a passing technical appreciation of electronics, but I am not a repair technician.

Then the fun really starts.

Set the reference frame to now. I am trying to reason out the basic issue of quality in audio.

Why do things sound different? Why does equipment have a unique voice?

One of the fundamental mathematical ideas behind low distortion is to have a given device respond to frequencies double or better than you want to recreate.  So if a tweeter can go to 40 khz it has no trouble with 20khz. Same thing for that Signet it can do 45 khz so 22khz is easy.  My latest preamp is rated to 100 khz so it really has no problem with audio frequencies. This should mean that normal frequencies are handled with respectably low distortion.

If signals are so accurate and distortion is very low should not all “good” equipment sound the same? The audiophile cohorts at this point lean back and say of course not.  So let’s restate it as “If signals are so accurate and distortion is very low, why does all “good” equipment not sound the same?” It really should you know.

Both of my preamps are both earlier 1980’s vintage.  One is the Venerable AR SP12 the other is an SAE Mk 30.  Both list distortion as a tiny percentage of the signal.  In db terms way down under -70 db. That should be effectively inaudible. Yet they sound very different. Taking it a bit weirder swapping different tubes out makes the SP12 sound different from itself though the distortion should still be low.  That should not be.

People familiar with Audio Research products will know that they built a machine called an SP11 which is still regarded as a wonderful device and much sought after.  The innovation of that design was using 6DJ8 tubes which are radio frequency capable and just much better than the venerable 12AX7 tubes. The SP12 was apparently a less expensive version of the SP11 using a much simpler power supply and I think one fewer tubes in one section.  It still measured impressively so it is not trash. The design came out of the same very capable brains. It was a business decision.

The thing with Audio Research Fans is they think every subsequent model must surpass the previous or it is a failure.  Even so that SP3a1 my friend had was once considered “a straight wire with gain” until it was later proved to be very coloured and muddy.  The SP 12 is probably much better than the SP3 but is not worth near as much.  I saw a recent sale of an SP3 for $3000.00 and for an SP12 for $500.00.

So why do they sound different?  There is no point in picking which is better as it is like saying blue is better than green. A difference in frequency response would be measured and actually the SP 12 has a much more accurate RIAA phono curve than the SP3a1.  In the high level section they both show a damn flat plot.  Distortion is very low.

One of the most informative experiences I had with Audio was many years ago.  I was reading a high end magazine extolling the virtue of a really expensive interconnect wire between a very expensive CD player and a similarly very expensive preamplifier.  The reviewer said that only with this particular interconnect cable could he hear this particular very subtle sound on this particular CD.  I had that CD, and I had heard that sound.

This was years ago.  I am not sure what the full equipment set I had then was, but I had a “cheap” Philips CD deck.  The cost of that deck, and my preamp would have been less than this wire. I could hear the sound he described. First Track Cowboy Junkies Trinity Session, down to the left a metallic rattle. There is also audile air rushing from a vent. So it was not the wire itself it was how this wire interacted with his equipment. (Good album) Most important I could hear it clearly without that stuff.

There I learned that good and better depend on a lot of things.  Later I learned that many high end designers cannot afford extensive testing of certain things. The commercial demands are severe to get stuff out quickly. Some circuits will react badly to inductive and capacitive reactive loads. That can make them freak out. Fancy wires are both capacitive and inductive so get the wrong mix of parameters with a given machine and the reaction to those changes the sound or may even let out the magic smoke.

The best I can come up with is speculation.  There is a famous Bet made by Mr Bob Carver that he could make one of his relatively inexpensive amplifiers sound EXACTLY like any amplifier a group of golden eared critics chose.  He then proceeded to do just that.  What he did was run a music signal through a channel of the target amp and inverted through his amp.  If they were perfect the signal would completely cancel.  At first they did not cancel indicating that there was a difference in how they sounded.  Then he tweaked his machine until it did cancel.  Once that was done, the two machines sounded indistinguishable.  You could say he “voiced” his amplifier. I believe they still measured very low distortion.  Very low distortion combined with a particular sound.  Vellly interesting!

Subsequently he built a mad, cost no object all tube monster amplifier then produced a product line of smaller transistor amps voiced to sound just like it.  This is very clever for business and not supportive of the idea of ultimate sonic goodness.

What must be happening is subtle interference, reactions and resonances inside the circuits. Sometimes there must be reactions between different devices entirely. Given a complex signal complex stuff happens and it comes out different if there are different components arranged differently.  Neither is right or wrong, just different. We are noticing different voicings perhaps deliberate perhaps accidental.  If you like something more than the other it is then better for you. So it ends up a personal choice.

Sometimes I hear something I had not heard before.  I have many albums I have heard many times.  A few nights ago I played a Philips recording of Stravinsky’s Firebird and a particular oboe part jumped out at me.  I have heard that part many times before, but now there was something about it.  I could tell it was made by a wooden instrument. It felt dimensional I could hear the wall behind it.  Why? Some previously interfering sound was gone is the best I can come up with.

The real problem was the turntable was the same, the amplifier was the same the preamp and speakers not the same at all.  Was the preamp clearer and more accurate? Maybe, it’s pretty good.  Are the speakers clearer and more accurate?  Was it an interaction between the two? Probably it was all of those things to some degree.

In this particular case I think the “new” things I am hearing are due to the speakers.  My amplifier is really very clean.  I assume the preamp is.  My speakers are derived from the Sonab design from 40 years ago. The intent is to minimize wall reflections by keeping the drivers close to the wall and away from major reflective surfaces.  I think that idea works very well.  

I think a lot of very respected speakers are not really that good because they react badly with the room surfaces. Sounds get to your ears that are not on the recording based on the design and placement of speakers in the room and furniture for that matter. If sound waves that are not on the recording are audible then that is wrong. Maybe that’s why people like headphones so much. Dipoles are the worst for it. (My Electrostatics were dipoles.) Box speakers set far from a wall are bad too.  If they sound “good” then these interactions must be compensating for a flaw in the voicing. Large panel speakers like electrostatics and Magnepans couple well to the air in a room and that gives the impression of presence and immediacy. That is actually good device-to-room impedance matching as large surfaces couple to the air better.  Yet you will be hearing sounds that are not on the recording. Perhaps it is better to say they were not in the recording in the place and time that you hear them in.

To a certain degree you can get pretty close to honest and true sounds coming out of these machines. A powerful amplifier pumping many Watts into a little box is very persuasive. If it produces linear power, which almost any amplifier will, you can depend on it getting out into the room.  The only limit is the frequency range of the speaker.

According to the charts of the components and the formulas for calculations I used, my speakers should respond from 30ish Hertz to over 40khz.  The bass sounds good and is much dependent on the recording.  My high frequency hearing is gone with the years but I still can appreciate the tiny metallic character of cymbals on a drum kit or bells or a lonely triangle in the back of an orchestra.  I have an FFT analyser on my tablet and it shows some response over 18 khz on some records.  I will not vouch for the frequency response of my tablet, but if something is there it is there.

So with respect to the room my little speakers work well.  I know that they have a voice, but it is subtle. Another visit with the wayback machine is illustrative.  

Does anyone remember the Fulton J Modular speaker? It was a behemoth and for a time at the top of the “good stuff” list. I heard it and was really impressed.  My college friend bought a piece of one.  The Modular moniker referred to it being built up from 3 pieces. There was a refrigerator sized base that had some number of woofer drivers a small box speaker midrange and an electrostatic tweeter array.

The piece in question is the Fulton FMI 80.  In the day it was well thought of.  It was responsible for all the middle frequencies of the unit, and those are where most of the important information is. You can see reviews of it in the archives of Stereophile magazine.  They liked it.  It was small and plain and you know it sounded great with chamber music and acoustic guitar and many instruments that had wood sound boxes.  When he got his he kept the Advents, keeping them in my dorm room to keep my pair company so for a time I ran what were called double Advents. A certain magazine liked that arrangement. My room was the main listening place and we puzzled over the FMI 80s.  They were good and not good depending on the material.  Actually it was all about the material.

So being curious we brought the little guys into my room, and fiddled. String quartets were great, Fleetwood Mac not.  We knew some musicians and invited their opinion.  They liked them for acoustic instruments with strings and some woodwinds. Horns and such not really good at all.

I was sitting between them (it was a small room) and I noticed the sound coming off the side of the box.  Revelation it was. I knocked the side of the box with my knuckle the box was made from thin wood.  When you played certain instruments the box resonated and made the sound more “real” and alive, but that is not right.  You should hit the box of almost any speaker and get a dull thud at most.  These highly respected speakers had a definite voice. If the recording was woody it made it sound more woody.

We also opened one up and found the crossover circuit was a single rather cheap electrolytic capacitor. This was an educational experience. Well that is what college is for is it not?  He sold them for what he paid for them and took his Advents back.  Here is an example of a great respected behemoth speaker with a flawed heart.  Respected reviewers were fooled, or perhaps charmed by the seductive flaws.

I wish there were definitive objective tests we could use.  Then we could depend on getting things that are actually better.  I will continue to play in this field.  I mess with my equipment to keep it in the zone and listen to music.  That is what it is really all about.