• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

A little digression= read on

I recently attended an tube amp audio design meeting (no not a HiFi magazine) and this question was thrown from the audience;
“ Those of us who are tube addicts; Of all the HiFi amplifiers one has built in spare time, was there one design that sounded and stood out from the pack ? Nirvana. This certainly applies.

A bit of a wild question but a reasonable one in raising the point. I felt the person hadn’t really researched the foundations that staple audio designers had laid nearly ¾ of a century ago.
Later on, a questionaire showed that a third of the audience (some outsiders) and not so deep technically minded had actually risked life and limb and built a HiFi tube amp during their sparetime hours. I thought that was quite a high percentage, considering financial misery annum 2009. Some like myself came from abroard, so it was a mixed bag.

Ha!...Now my turn...The person who stood up knew my presence, exposed the fact that I had designed and assembled 45 HiFi push-pull Tube amps over a 40 yr evening sparetime period. Yes, that’s me all right but sure, I’m not the only one beavering some evenings behind the soldering iron. I like to play my card Bridge as well. So as the conversation digressed; that person also exposed that (some decades ago) I worked for the famed Rupert Neve. Audio engineering, by gosh, it’s mighty addictive stuff with a never ending kudos. One gets into it and mighty hard to get out.
Now the debate can really start.
Question: Does that sparetime number over a 40 yr period seem alot or not ?
There must be others out there who have also burnt wicks of midnight oil on exotic designs and risked their marriages and the warm bed of loved ones ?
The thing about all these amps, they weren’t copies of existing designs although the circuits often resembled others with modifications. All the amps had something unique about them, beit the sound quality or the punch they provided. The mains & output transformers in all my designs were bespoked as was the circuitry, which to some appeared to eschew convention..but never botched up.
Looking at this backwards and a bit commercial, a tidy number of people have profitted out of my lot. Transformer winders, yes; tube suppliers, yes; component suppliers, yes; and 30 tube amps which I sold privately around the world are still working. 2 of them, the most powerful (200W+200W) and the best sounding ended up in a recording studio. Influence yes.

The British Carboot sales has also seen some of my reject power amps which had a bit of a streak in them, i.e transformer errors. Sold an outright bargain, still fine.

So, I’ve ended up up with 10 custom amplifiers which audibly are the closest to recreating the absolute sonic fidelity which I set out to do. Out of this lot, I cannot decide which amp sounds the hottest.. So when I’m in the listening mood, each evening I connect a different amp from the previous and end up unable to compare. There is alot more to all this analysis, a bottle of vino is the quickest way to destroy it.

Back to the bench; “If one builds a custom amp design would one commend it to others as a build” ? As a designer, this is in the "ingrain" back of ones mind. Does one feel psycho’ confident about the design ? Not only the standpoint of a technical specification coupled with good aesthestic looks, but also more importantly the sound quality. Lets hope the ethos continues.

Keep up the good work you lot out there.

richy
 
richy,
You are not alone in asking that question. From my perspective it is quite normal.

I am not at your level of understanding and am probably incapable of obtaining that level.

While most of these are copies of a design the *** indicate that I was at least being creative.

Bride of Zen
Zen v4
Aleph 3
Aleph 5
Son of Bride of Zen
*** Aleph X 100 Watt
A chip amp (I had to put it in sorry)
3x 12b4 Preamps
2x Simple SE
Tubelab SE
*** The OPUS 5.0 monoblocks
Salas Simplistic RIAA
*** Have version 4 of the 12b4 on my bench
*** Have various parts of a new SE amp on the bench
*** Parts of a revisit to the Opus 5.0(beta) on the bench
*** My turntable is on the bench (and dining room table, and a few other places as well)

Too many speakers to count.

Yes it gets commented on by my wife, kids and others as some sort of OCD. And no, my wifes kitchen cabinets are still not done.
 

Cassiel

Disabled Account
2004-09-30 3:53 pm
Madrid
Back to the bench; “If one builds a custom amp design would one commend it to others as a build” ? As a designer, this is in the "ingrain" back of ones mind. Does one feel psycho’ confident about the design ? Not only the standpoint of a technical specification coupled with good aesthestic looks, but also more importantly the sound quality.

It's always difficult to judge your own work. You never know for sure. 40 years of experience should help but the fact is that you are constantly changing; your perceptions are not the same, audio memory is short and so on.
Does your amp sound great to you? Good, that is a first. Now you must find out if it sounds great to others.

One thing is to be a good audio engineer and another to be a discernable listener. Maybe you're both or maybe not. Isn’t the affect of music on the soul really what we are after here? And isn't it true that audio engineers have sold their souls to the Devil in exchange for "nice sounding" distortion numbers? :D
 

kevinkr

Administrator
Paid Member
A couple here and there stand out in my mind, others not so much, and the occasional grand failure that no one knows about, maybe.. (That would be rare since I usually that figure someone somewhere might learn something useful from my most egregious mistakes.)

Did audio design professionally for more than 15yrs, not doing it now, and find it ever so much more fun.. Doing it as a day to day seems to sap my enthusiasm for diy..

I too have spent a disproportionate amount of time slaving away with a hot soldering iron, evenings and week-ends, some vacations, and the inevitable bane of modern life when redundancy (layoff) strikes as it so often does in the engineering career path.. In my case probably 45+ yrs, although I started in my pre-teens, got my first solder iron at the age of 7..

I got started with the audio hobby specifically because I could not afford the gear I dreamed of owning. (Audiophile going way back, back to a time when that label was not pejorative.) Initially I felt this was second best, but the best I could do - when I did finally get my hands on some of this stuff to compare I found in a lot of cases my designs suited my goals better, and fortunately those of a lot of other people too.

Now it is mostly for fun.. (I tell myself) :D
 
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One thing is to be a good audio engineer and another to be a discernable listener. Maybe you're both or maybe not. Isn’t the affect of music on the soul really what we are after here? And isn't it true that audio engineers have sold their souls to the Devil in exchange for "nice sounding" distortion numbers? :D

Quite right. Das problem. I've become two animals. One of my early mistakes was to build amps to a rigid spec. Being of Germanic trait encourages this. So, yes there's a historical element too.
How very wrong can one be ! An amp with a shocking thd can sound beautiful. In one example I was in concert playing with an amp that had a duff output tube. Fortunately in parallel push pull, the question of redundancy crops up, but neverless I remembered it sounded "quite good" for a trumpet. One can get away with it.

My connection with MI is via trumpet, However in years to come I shall probably end up into Cello or Bass end. On replay one hears all the wind noises and it's mighty putting off as is a wind organ keyboard.

However, I consider myself as extremely lucky having the career I did.

richy
 

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Many of my creations are built on a piece of plywood and do not last a day. All just for fun!

I never went through the "plywood" build botch phase allthough a collegue successfully used plywood and assembled a SW transmitter using an 807. In the late 1950's my electronics pick up was the massive electronic surplus WW2 available & schooling that steered a career toward the merchant fleet and Cold War service. So it was the miL metal and electronic workshops that got me started and REME. This training was the superlative anyone could have had, far better than todays stuff. I was later to regret by doing the foolish thing by selling my Fender 58. Had the guitar stayed with me, perhaps things would have turned out different. As it was I did play in local Country & Western groups. Rather feral stuff. We all were farmers son's !
The remaining evidence of my 1950's electronics past is sharing with others on this forum and the boxes of junk that permeate the chalet loft. After the war games ended I emigrated to the ALps to persue studio electronics design proper.
The circle is complete, MI has returned and just as loud as it used to be. The 1960's sound did resonate the guts more. The over-dimensioned loudspeakers did sound alot better than alot of the modern stuff.

On the bench, My helmet is close too. Anyone nervous of electrolytics and plastic MOS blowing up ? In some evening classes I did a decade ago, I found more enthusiasts are more frightened than I thought..... High voltage confidence and proficiency problem. Takes time.

richy
 

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Mr_Zenith

Member
Paid Member
2009-08-20 3:16 pm
KC Metro
Hello all,

It's a rather refreshing change to see posts of a philosophical bent on this forum, aside from those of the "SE vs. P-P" or "$5,000 interconnect" varieties. Nice to see what makes some of us tick...

There must be others out there who have also burnt wicks of midnight oil on exotic designs and risked their marriages and the warm bed of loved ones?
Burnt the midnight oil, yes. Risked my marriage, no! I'm very blessed to have a spouse that actively supports my various eccentricities (and I have many!). To her credit, she thinks nothing of traveling 5 hours to go to a hamfest or swap meet. We should all be that lucky; I know not all of us are.

Engineering is an iterative process; it is not complete until the client runs out of time or money sometimes both. Many of my creations are built on a piece of plywood and do not last a day. Is there the pride of authorship? You bet!
Especially when the client is yourself (I normally run out of both)! My garage is full of pieces of plywood and sheet aluminum with thousands of holes, remnants of prior "breadboarded" projects. I learned to do this after spending a boatload of time and money building a big SE amp from a popular magazine, only to discover it sounded like a steep heap o' hippo dung.

As it was I did play in local Country & Western groups. Rather feral stuff. We all were farmers son's !
So now comes the big question: did your group ever play the theme from Rawhide from behind chicken wire? ;) Love the helmet, BTW; I myself use an outdated hard-hat. It wards off flying electrolytics quite well, but I'll admit it's definitely not as robust as a "tin hat"!

I've attached pics of the RH84 I just completed. My watchword for this build was craftsmanship. It's not my first scratch DIY build, but it is the first one that hasn't ended up as yet another unfinished project (i.e. one with unfinished metal or woodwork, etc).

So I guess DIY with tubes is all an issue of personal growth, for me at least. By completing this project I learned to listen better, do my homework more thoroughly, and keep a more open mind (as a P-P man, I finally found out what all the SE fellows were raving about!). I have immense respect for those folks who share their expertise and wisdom on this forum. I'll probably never achieve the level of knowledge required to design a "nirvana" audio circuit (I am, after all, a Civil Engineer - not an EE), so I'll just have to be content with expressing any creativity I may possess through "crapsmanship" and "crapentry". :D
 

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Some time ago I tried to initiate a similar discussion, but it did not work. Very happy to see this.

I think building things (including audio gears) is a bit like hiking: it is not the same to get to the peak by helicopter, the walking is part of the fun. And in the specific case is also always a learning process.

I got often the question: why do you build so many ? Yes, from one point of view I am still looking for something that sound really mind blowing, but mostly I just have fun in doing it.

Living in Japan, it's kind of hard to get in touch with the local DIY community (don't speak Japanese) and having the possibility to show things to other people, exchange ideas and have feedback. I think is what I am missing to evaluate the quality of my work. We say in Italy "Every bug is beautiful for his mom". Very difficult to judge your own work.

Thanks,

Davide
 

M Gregg

Disabled Account
2010-06-28 11:04 pm
UK
LOL,

Yes I have burnt the midnight oil, just to change that capacitor that will make the system sound so good. But then again did the other one sound better? Ah yes must be that resistor that made "dark side of the moon sound so good!" Then my wife saying, " it sounded better before the mod". The femail vocals on Avalon and the obsession of the driver tube that sounds good, however the other sounded good in a different way. "I want both at the same time".

When I was 14 I took 2 amps out of old record players each was a single ended N78. When one N78 failed I tried to get another with no success and every ham fest look for one just so I can kick myself and say well you can get one now. Why not then.LOL

Then there is the box or was it 3 of old parts and piles of magazines with the circuits I never had time to build!

The trips to HIFI conventions to see if my system sounded "any good".:p
Then dragging my wife arround 60+ rooms in a London Hotel listening to different systems, so in the end I can't remember what sounded good and what didn't.

The Quad amps I saw for sale at £150 and thought shall I buy them or have a new set of tubes. So I had the tubes and regretted it ever since:rain::mad:

The speakers you had a while ago that seemed so good! And you sold for the latest hype!

What fickle creatures we are. Do we crave "better" or is it that we need change to inspire us. Think I'll keep the partener who puts up with it all.:hug:

Regards
M. Gregg
 

M Gregg

Disabled Account
2010-06-28 11:04 pm
UK
Philosophy,

I find it interesting that we have moved on! LP-CD-Digital down load.

Are we a group that appears to find “old technology” more inspiring than new?
Or is it a comfort blanket. IE we found valves interesting when we were younger and want to recreate “youth”.

Or does it look better, sound better?

Is it the pleasure we gain from making something that is individual that we can put “our” mark on? Is it the HV and feel of the equipment, the simplicity of circuitry, or are we practising Zen.

I find that I escape when building a project, however I could do this in the garden!

Have you noticed how we time travel into the early hours in the blink of an eye!

Regards
M. Gregg

 
So now comes the big question: did your group ever play the theme from Rawhide from behind chicken wire? ;) Love the helmet, BTW; I myself use an outdated hard-hat. D

Well done youv'e got'it..Well, this is now a total thread distraction, I started it, so be it. The heritage secrets of my upbringing revealed. . Eastern England, in the 1950's to 60's; A sat night, a heavin' village hall, not a copper in sight (policeman); stuck in the countryside miles from nowhere, so full of smoke that one can't make out the door from the wall (and of course the dart board behind it). There wasn't any drink-drive restriction then, so cider (scrumpy) and homemade beer was liberal. Between stage and audience there was something a bit thicker than chicken wire but often removed. It took only a whisker or girly problem to start things flying. canteen eggs, tomatoes, ashtrays, beermugs,chairs and the lot. The strange thing was of all the times no-one got really hurt, and the same scene must have occurred up and down the country (nowadays it's all gotton a bit placid and straight laced).
And of course outside there was strawbales for natures obvious.

Got the jist ? The pic says it all. A community effort.

Then was Good old Suffolk.


richy
 

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Does that sparetime number over a 40 yr period seem alot or not ?
There must be others out there who have also burnt wicks of midnight oil on exotic designs and risked their marriages and the warm bed of loved ones ?

Are we talking about a hobby that borders on obsessive? Well does a normal 17 year old kid go dumpster diving behind electronics manufacturing plants to find IC chips? Does he spend all of his spare time soldering more than 350 of those RTL logic chips together to make a fully polyphonic digital music synthesizer...in 1970. (first picture) Audio amplifiers. I started making them at a very young age. The ones that actually worked started appearing around age 13. All of these early designs used tubes because they were essentially free at the local trash dump. So were some rather large germanium transistors (50's car radios) but they blew up too easilly. I discovered silicon in high school and made some rather high powered audio amps. My biggest used 24 2N3773 transistors to make at least 1200 watts. Thats where it tripped the line breaker! The second picture shows a smaller one that used 6 transistors to make 300 watts. Does a normal person save this stuff for 40 years?

Normal? I had decided long ago that I was different. I can't say exactly when I started building stuff, since I don't remember not building stuff. Not just audio stuff, computers? I made my first one in 1975 and I still make them. Hot rod cars, yes I have built a few of them too. Did this obsession have any affect on my marriage? Probably. My first marriage failed, and my hobby was mentioned, but the main reason had to do with two immature people who hadn't found themselves yet. Sherri understands my quirks, and dutifully attended hamfests for the first 20 years, but doesn't anymore. I'm down to 2 or 3 a year myself.

Do I have a favorite amp? Do you have a favorite child? Some have matured and left the nest, and some still live at home. Unlike real life none of my mature amplifiers have returned to the nest! I made more guitar amps than HiFi amps, but I still don't have one. Guess it's time to make some more.

What if, instead, you had dedicated that time spent building amplifiers and speakers, to learning to play a musical instrument ?

What happens when you do both? The neighbors call the cops, that's what! My parents got me a cheap guitar at a young age, not knowing what terror they would unleash. I thought I was a decent player, and played in a garage band using a homemade amp at age 13. We played the surf music of the 60's. In the late 60's I went to a Hendrix concert. That was the moment when I realized that I was NOT a guitar player! So, if you can't be good, be loud!

Check out the disco era speakers too. Naugahyde and crushed velvet were cool in 1976. I built a van with velvet, shag carpet, and 8 channel sound. 400 horsepower, and 400 watts, loud times two!
 

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Mr_Zenith

Member
Paid Member
2009-08-20 3:16 pm
KC Metro
Hmmm... In the center photo, do I see the word "ZAPPA" etched in the grunge-infused remains of Dymo label residue? So fitting!

("He was a very nice boy... He used to cut the grass... I'm calling the police!") :D

Never built electronic stuff as a teenager in the early '80's, but I did have a friend who was heavily into this stuff. I spent many hours helping him dumpster-dive for old electronic parts, and I still cringe when I think of how many vacuum tubes we used to use for target practice (thankfully most were compactrons, but still...)! :ashamed:

Digital electronics were just then becoming a real off-the-shelf commodity, and one time he built a speech synthesizer using an early IC he, uh, "appropriated" from the local community college. Later that year he entered it in the local science fair, and told a group of us to be present during judging. Those of us who were there will never forget the moment the judges pushed a button to hear a computer utter the immortal words:

"Mrs. T________ is a fat b____..."

He only avoided being disqualified by the narrowest of margins after convincing the judges that the statement regarding the "Mrs. T_______" in question (a teacher in our school who was much feared and loathed by students and teachers alike) was indeed true, and therefore neither slanderous nor libelous. I was flummoxed further when I heard him state that use of the "b-word" in this context wasn't an obscenity per se, since it was an apt description of the person's reprehensible behavior. In the end, he won his division. What a guy!!

As years went on, I lost track of my pioneering friend, but I was able to quench my undying electronics curiosity by restoring antique radios. The illustrious "Mrs. T_______", meanwhile, went on to become an undistinguished alum of the "NC License Plate Academy"!
 
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do I see the word "ZAPPA" etched in the grunge-infused remains of Dymo label residue? So fitting!

I earned that name in high school electronics class (where that amp was built) for antics similar to what I do now, but with a typical teenagers approach to safety. I had a thing for playing with electricity, usually wall outlets, neon sign transformers, the Tesla coil, and the arc welder in the HS auto shop. There were also a few incidents with kite string, aluminum foil and power lines, but we won't discuss that here.

I think of how many vacuum tubes we used to use for target practice

My shooting ability was never good enough to hit the little tubes that I took from dead TV's. The mid sized ones I kept, but I used to shoot the BIG ones (CRT's). A 21 inch CRT is a good sized bomb in its own right, but shoot it with a 12 gauge deer slug and it makes a real mess! Be at least 100 yards away. On second thought.....don't even do it.