Cool. I've been looking at these with some interest as their design intent (SMPS) means they should have very low ESR/inductance and they've got great heat ratings. I was wondering about their microphonics but the construction looks pretty tight. And the prices are pretty good.
I've been ****d over once or thrice by non-ideal capacitor behaviour (particularly ESR, DA and microphonics - and don't get me started on MOSFET gates) back when I was doing low level electronics design as a day job (vale Bob Pease). These days I can't keep track of what's out there. Fortunately, guitar amps don't care about -90db artifacts.
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Bloody capacitors
The science, as used, is a first order approximation, as any EE should tell you.
There are a bundle of papers out there on better models for real world capacitors. However, each type of dielectric, insulator, chemistry and construction (both type and quality) results in a different applicable model. And they remain incomplete approximations at best: no-one tries to model microphonics.
As Gnobuddy points out, no-one's done any serious work for audio applications for decades. There's no money in it and human hearing is far too tricky (and too easily tricked).
Stick to known-good mappings of cap types to applications with decent quality caps and your cap problems will be down in the noise (literally).
As you've discovered, swapping out to something other (high-DA PIO caps or electros/tants with 0v on them) can bring those problems back into the audible range.
Presuming you want to look any further, Bob Pease wrote a whole pile of stuff on capacitor behaviour but it seems to have disappeared from the WWW. I used to have all of them on file but stupidly ditched them when the WWW arrived.
Instead here's some old links to various attempts at adding some scientific method to the mix. Some may 404. In no particular order
Measured Differences Between Capacitors for Audio Applications
Bob Pease: What's all this soakage stuff
Humble Homemade Hifi cap test
Bateman,C. "Capacitor sound" Electronics World July 2002 p12-18, september p16-22, October, p12-, November -47, December, Jan 2003
OR Pro Audio Design Forum
"If the Cap fits" Jung, Walter., Curl, J.
1980: 'Picking Capacitors, Part 1', co-authored with Dick Marsh
1985: 'A Real-Time Signal Test for Capacitor Quality', authored by John Curl and Walt Jung,
was published in The Audio Amateur, in issue 4 of 1985
"Capacitor Sound" by Cyril Bateman, published in the Electronics World in July 2002 - January 2003,
Menno van der Veen & Hans van Maanen:
"Non-linear distortions in capacitors"
124-th AES Convention 2008, Amsterdam; paper 7500.
Capacitor Distortion Mechanisms CO-BW
Capacitor Distortion Reyndardson
The science, as used, is a first order approximation, as any EE should tell you.
There are a bundle of papers out there on better models for real world capacitors. However, each type of dielectric, insulator, chemistry and construction (both type and quality) results in a different applicable model. And they remain incomplete approximations at best: no-one tries to model microphonics.
As Gnobuddy points out, no-one's done any serious work for audio applications for decades. There's no money in it and human hearing is far too tricky (and too easily tricked).
Stick to known-good mappings of cap types to applications with decent quality caps and your cap problems will be down in the noise (literally).
As you've discovered, swapping out to something other (high-DA PIO caps or electros/tants with 0v on them) can bring those problems back into the audible range.
Presuming you want to look any further, Bob Pease wrote a whole pile of stuff on capacitor behaviour but it seems to have disappeared from the WWW. I used to have all of them on file but stupidly ditched them when the WWW arrived.
Instead here's some old links to various attempts at adding some scientific method to the mix. Some may 404. In no particular order
Measured Differences Between Capacitors for Audio Applications
Bob Pease: What's all this soakage stuff
Humble Homemade Hifi cap test
Bateman,C. "Capacitor sound" Electronics World July 2002 p12-18, september p16-22, October, p12-, November -47, December, Jan 2003
OR Pro Audio Design Forum
"If the Cap fits" Jung, Walter., Curl, J.
1980: 'Picking Capacitors, Part 1', co-authored with Dick Marsh
1985: 'A Real-Time Signal Test for Capacitor Quality', authored by John Curl and Walt Jung,
was published in The Audio Amateur, in issue 4 of 1985
"Capacitor Sound" by Cyril Bateman, published in the Electronics World in July 2002 - January 2003,
Menno van der Veen & Hans van Maanen:
"Non-linear distortions in capacitors"
124-th AES Convention 2008, Amsterdam; paper 7500.
Capacitor Distortion Mechanisms CO-BW
Capacitor Distortion Reyndardson
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Ran out of edit time
Kemet modelling capacitors
Modeling Dielectric Absorption in Capacitors Ken Kundert 2008
Kemet modelling capacitors
Modeling Dielectric Absorption in Capacitors Ken Kundert 2008
No, not at all. In principle all capacitors leak a little bit, but there is only one type that leaks enough to (sometimes) matter: that type is electrolytics.
By "leak", I mean that in a mathematically perfect world, a perfect capacitor should be a perfect electrical insulator once it's fully charged. On this earth nothing is perfect, and electrolytic caps are less perfect than other types of commonly used capacitors. A tiny little bit of DC current will flow (leak) through them whenever you apply voltage.
99.99% of the time, this will not matter at all. But if you don't know what you are doing, it might matter that last 0.01% of the time.
For example, if you try to charge a 10000 uF electrolytic capacitor up through a 10 megohm resistor using a 9V battery, you may find that the capacitor will never charge to 9 volts - it may leak enough current to keep it from charging beyond a volt or two.
So is this leakage going to be a problem in our guitar amps? No, not at all, not in any of the places where electrolytics have been used for the last eighty or ninety years.
But now we have cheap multi-layer ceramic caps that are smaller than electrolytics, don't dry up, and don't leak...so why not use them instead? No reason, so I use them.
That's certainly one way to look at it!
Let's me put it this way, many knights wasted their entire adult lives searching for the Holy Grail, and they never found it, because it doesn't actually exist. Perhaps those knights felt that this it was a worthwhile way to spend their lives, who knows. But to me, those were tragically wasted lives. If I could have, I would have whispered to those knights "The thing you are looking for doesn't exist. Go home, love your wife and children, live a good life. Don't waste it on a wild goose chase."
Realistically, I would probably have ended up with a sword through my stomach for daring to say such a thing to a knight, and the knight would then have gone away to seach for the Holy Grail for the rest of his life anyway.
Before I go on, I should add that of course it's your amplifier, your money, your life, so I fully expect that you, and only you, will decide whether or not you want to re-cap your amp, and if so, what sort of cap(s) to use. Also, historically I've had a very poor success rate at converting anybody to my point of view, and I don't expect it will be any different this time around. At least I'm pretty confident you won't stab me with a sword for suggesting that you leave the electrolytics alone.
That said, as long as I'm not offending you, perhaps we can continue the discussion a little more?
Let's say this is true (it probably is, since all capacitors have some self-inductance.)
Now, it is also true that one single centimetre of wire also acts as an inductor, as any engineer working with today's computers, or high frequency RF, can tell you.
We can't eliminate every centimeter of wire in our guitar amps, and it seems we don't have to, because millions of amps have been built containing long runs of wire, often not just a few centimeters long, but maybe even tens of centimeters long.
But if you take a modern computer chip - say a new AMD processor running at 3.6 GHz - and somehow wire it up to make a point-to-point desktop computer, using ten or twenty centimetre long wires connected to each pin, it will not work at all. The wires are too long.
So why is ten centimetres of wire okay in a guitar amp, but not okay in a PC? The answer is simple: the effect an inductance has in a circuit depends on the frequency at which the circuit operates. Guitar amps work at low frequencies under 10 kHz, and wires many inches long are not usually a problem. But our AMD CPU runs at 3.6 GHz, which is more than three hundred thousand times faster than the signals in the guitar amp. At such a high frequency, the inductance of even a couple of centimeters of wire in the wrong place would be intolerable.
So we don't use point-to-point wiring in today's PCs, in fact we can't: the PCB traces on computer motherboards are very carefully designed, and those motherboards themselves are a technological miracle, never mind the chips mounted on them.
Okay, now we understand that inductance is not only in a PIO capacitor, but in every wire. We also understand that the effect of this inductance only shows up if the frequency is sufficiently high. The next question is: is the inductance of a PIO cap large enough to show up in the frequencies at which a guitar amplifier operates? Or is it so small that it has no effect?
There is a simple way to find out. Measure the frequency response of the guitar amp. Replace one capacitor with an identical-value PIO capacitor. Measure the frequency response again. Is it different by more than 0.3 dB? No? In that case, you cannot hear any difference between the two capacitors. Thousands of carefully conducted tests have found that 0.3 dB is about the smallest change in frequency response that people can detect.
If I lived near you, I would bet a nice dinner that if you do this experiment, you will find the PIO cap cannot possibly have any effect on the guitar sound, no matter what any "expert" tells you.
Let's apply the same reasoning. Let's say this is true, mica caps have lower internal series resistance. Let's say we are told that replacing a coupling capacitor that runs from the anode of one 12AX7 triode to the grid of another with a mica cap of the same value will make the amp "better" in some way.
One question we might immediately ask ourselves: how much resistance is already in this circuit? Well, assuming the first triode has a typical 100k anode load, it has an output resistance of about 40000 ohms. This enormous resistance will show up in series with the internal resistance of our coupling capacitor, and mathematically, you cannot tell the two apart. This means our capacitor will only have an effect on the sound if it has an internal resistance that is at least a few percent of 40000 ohms (the same 0.3 dB we mentioned earlier requires about a 3.5% change in resistance.)
Okay, 3.5% of 40000 is 1400 ohms. Is there any type of coupling capacitor so bad that it has 1400 ohms of series resistance? No, there isn't. Logical conclusion: using a mica cap here is a complete waste of money, as it has no effect whatsoever.
Logic is nice, but sometimes we can fool ourselves with false logic. What's better than logic? An accurately done experiment. Once again, measure the frequency response of the guitar amp twice, first with the non-mica cap, second with the mica cap. Is there a difference of more than 0.3 dB? No? Then there is no audible difference.
If the capacitors have different values (capacitance is not the same value because of tolerance), yes, there can be audible differences. But once again, I will bet you a nice dinner that if you replace 20 electrolytic caps in a guitar amp with 20 IDENTICAL VALUED (let's say within 0.1%) exotic capacitors - polyester, Mylar, PIO, mica, mermaid-oil, whatever - you will find less than a 0.3 dB difference in the measured frequency responses, and therefore, no difference in sound.
So have I converted you to my viewpoint? Probably not, I would bet.
If you made all those frequency response measurements, and they showed less than 0.3 dB differences, would you believe the magic capacitors had no sound? Probably not then, either. That's just the way we humans are, we are not at all a logical species, and that will never change, nor do I expect it to.
As an aside: I know from your profile that you feel (or at least, felt) that your life is hard and your surroundings difficult. I just want to say, your wife is not only your partner in life, but also your partner in music? She played drums in the clip you posted? That makes both of you very lucky people. It's a wonderful thing, and I am happy for both of you!
My wife is a good singer, and I play guitar and sing (not as well as her.) It took fifteen years of marriage before my wife felt comfortable and safe enough in our relationship to join me in making music together. When it finally happened, it was such a wonderful thing for me - and since then, it's become a continuing source of joy for both of us.
The real joy in music isn't in the guitar amp or the capacitor types, it's in the people - the person with hands on the guitar, the people playing the other instruments, the people singing, the people listening, the people who wrote the songs...all the people who have a hand in making live music the wonderful experience that it can be.
I just got back home from an outdoor jam with friends at a beautiful local farm. This time of year, British Columbia is so beautiful - bursting with green plants and wildflowers. What a wonderful way to spend an afternoon!
-Gnobuddy
Cool. I've been looking at these with some interest as their design intent (SMPS) means they should have very low ESR/inductance and they've got great heat ratings. I was wondering about their microphonics but the construction looks pretty tight. And the prices are pretty good.
I've been ****d over once or thrice by non-ideal capacitor behaviour (particularly ESR, DA and microphonics - and don't get me started on MOSFET gates) back when I was doing low level electronics design as a day job (vale Bob Pease). These days I can't keep track of what's out there. Fortunately, guitar amps don't care about -90db artifacts.
thats a good idea, i've found some that are similar for around $1,50 BRL each... pretty cheap and seem to be a better choice over the big motor run caps, of which cost +- 5x more;
question: between the motor run and these caps in the attachment below (metallized polyester) will there be any real difference if installed properly on the bypass and power supply stages?
very thankful for the articles;
But now we have cheap multi-layer ceramic caps that are smaller than electrolytics, don't dry up, and don't leak...so why not use them instead? No reason, so I use them.
That's certainly one way to look at it!
Let's me put it this way, many knights wasted their entire adult lives searching for the Holy Grail, and they never found it, because it doesn't actually exist. Perhaps those knights felt that this it was a worthwhile way to spend their lives, who knows. But to me, those were tragically wasted lives. If I could have, I would have whispered to those knights "The thing you are looking for doesn't exist. Go home, love your wife and children, live a good life. Don't waste it on a wild goose chase."
That said, as long as I'm not offending you, perhaps we can continue the discussion a little more?
Let's say this is true (it probably is, since all capacitors have some self-inductance.)
There is a simple way to find out. Measure the frequency response of the guitar amp. Replace one capacitor with an identical-value PIO capacitor. Measure the frequency response again. Is it different by more than 0.3 dB? No? In that case, you cannot hear any difference between the two capacitors. Thousands of carefully conducted tests have found that 0.3 dB is about the smallest change in frequency response that people can detect.
If I lived near you, I would bet a nice dinner that if you do this experiment, you will find the PIO cap cannot possibly have any effect on the guitar sound, no matter what any "expert" tells you.
Let's apply the same reasoning. Let's say this is true, mica caps have lower internal series resistance. Let's say we are told that replacing a coupling capacitor that runs from the anode of one 12AX7 triode to the grid of another with a mica cap of the same value will make the amp "better" in some way.
Logic is nice, but sometimes we can fool ourselves with false logic. What's better than logic? An accurately done experiment. Once again, measure the frequency response of the guitar amp twice, first with the non-mica cap, second with the mica cap. Is there a difference of more than 0.3 dB? No? Then there is no audible difference.
If the capacitors have different values (capacitance is not the same value because of tolerance), yes, there can be audible differences. But once again, I will bet you a nice dinner that if you replace 20 electrolytic caps in a guitar amp with 20 IDENTICAL VALUED (let's say within 0.1%) exotic capacitors - polyester, Mylar, PIO, mica, mermaid-oil, whatever - you will find less than a 0.3 dB difference in the measured frequency responses, and therefore, no difference in sound.
As an aside: I know from your profile that you feel (or at least, felt) that your life is hard and your surroundings difficult. I just want to say, your wife is not only your partner in life, but also your partner in music? She played drums in the clip you posted? That makes both of you very lucky people. It's a wonderful thing, and I am happy for both of you!
My wife is a good singer, and I play guitar and sing (not as well as her.) It took fifteen years of marriage before my wife felt comfortable and safe enough in our relationship to join me in making music together. When it finally happened, it was such a wonderful thing for me - and since then, it's become a continuing source of joy for both of us.
The real joy in music isn't in the guitar amp or the capacitor types, it's in the people - the person with hands on the guitar, the people playing the other instruments, the people singing, the people listening, the people who wrote the songs...all the people who have a hand in making live music the wonderful experience that it can be.
I just got back home from an outdoor jam with friends at a beautiful local farm. This time of year, British Columbia is so beautiful - bursting with green plants and wildflowers. What a wonderful way to spend an afternoon!
-Gnobuddy
thx for the new cap advice, joke ahead: it better be filled with mermaid-whale oil, so it won't freeze in space and will sing on his own... layered with a rare star alloy, that won't dissipate heat such as gold, faster than silver!
the knights who pursuit an one-piece, monolithic 'holy grail' are nothing but empty or mistaken inside, mindless soldiers, seeking something unworthy like their own guts...
...i agree with you, such a monolithic holy grail doesn't exist...
...but theres a holy grail to be seen: it's the whole world itself: the universe within our hearts and our minds, the planet we live with its crust, the deepst of the oceans and the whole inner earth too...
...wise knights engage the road to get closer to this holy grail, each new place they visit in peace, different cultures that they learn and friendships they construct, is a piece of the holy grail that is conquered...
...shame on the knight who leave his home, wife and family behind to seek such wonders, because those things are the holy grail too: choosing between one or another will result in nothing, and nothing is monolithic, literally...
...the void of empty darkness is monolithic, and nothing else besides it 'cause even a massive block of gold or pure silver is composed by many little atoms that ain't mono structurally and in energy...
...some see these blocks as one piece... i see it as a monolithic block, dammit! if i hammer it down i still wont be able to see the tiny atoms!! if i melt it down, it will remain looking like its one-whole-thing...
...even the darkness of the universe is filled by stuff, such a bowel, that is not monolythic because its hollow and can be filled with water, and this deep mystery is known as the biggest paradox, because if the darkness is monolithic, how could it be filled?
of course, knights usually don't think about it, so in darkness they wander... such a pity isn't it?
this PIO and other cap types doesnt affect sound explanation can be something to be considered, since when i swapped caps and there was a major change, it could be due to different capacitances, since the 20nf pios i have gave reading of 28-30nf on my friend's capacimeter...
...but... when i swapped in the 1nf ceramic disk on my bottle rocket pedal's baxandall for 2 pio 1n8 in series, a side effect popped in, literally: now the pedal pops when switched on/off... it seems that these pios charge slower and maybe this speed have effects on tone;
look, i don't wanna defend gimmicks and it can be a relieve to save money buying cheap stuff, so whats the deal that on some stuff such as silver mica x ceramic disk of same value on treble sectors of amplifier resulting in a more pleasant highs' peak when using mica?
in defense of the ceramics, i've seen many amateurs complaining about ceramic disk been unpleasant/shrill on highs (and i noticed it too, but i havent dueled vs mica, but modern phillips orange chiclets polyester with tight, reliable tolerances vs ceramic disks and in fact the disks sounded sharper, edgy)
they complain about microphonics, but it seems that they don't install the disks properly, resulting in cracks that open the coating and this can introduce moisture to the dielectrics, could be it?
of course my life is hard and my surroundings swallowing... this is Brasil, for most its usually hardcore, concrete jungle, neglected to the bone by the government... worse for people like me, that want to do things correctly and refused to be a part in the brotherhoods... but don't mind this, i've been through it all my life... i've been pushing through;
someday show us your sounds with your wife, it always work well this kind of association;
BC seems to be wonderful... a long term friend of mine lives there, she always said good things about it... i promised her to visit when i get to tour worldwide or at least make a decent sum of cash to afford going there or even settling, since i don't agree with my country's politics, climate and mostly everything. i love mountains and can't stand heat... well dreaming is free... yet *lol*
someday show us pictures of the landscape there... i'm curious now... Julia took a great photo of the sky last week, i'll put my sdcard on her phone and upload later... i've never had seen such a beautiful sky, colorful in the dusk with stars... not even when i used to go alone in the night to MT. Anhangava, a 1500m peak in the atlantic rainforest close to my town... i used to go there to see the skies and make songs... on my youtube ch theres a video of me playing there in the day after;
good question, the original i dunno really... but i can measure mine by august when i get able to purchase a multimeter that won't fail on me, lol;
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Have you found a through-hole version or are you using metal frame/SMD ones?But now we have cheap multi-layer ceramic caps that are smaller than electrolytics, don't dry up, and don't leak...so why not use them instead? No reason, so I use them.
I use through-hole ones. The link I posted earlier (repeated here) should take you directly to one of them, a 22uF, 25V, leaded part: FG28X5R1E225KRT00 TDK | Mouser Canada
These are physically very small. Some of the smaller values (2.2 uF, 4.7 uF, etc) are not much bigger than the head of a match, and the wire leads are only a few millimetres long. They are a bit awkward to use with traditional point-to-point or tagstrip wiring, unless you solder some lead extensions on to them.
-Gnobuddy
There is an extraordinary amount of natural beauty here - mountains, forests, lakes, streams, rivers, wild flowers, meadows. And as a group, people in Canada are nicer here than anywhere else I've lived.
There are problems here too, of course. The really big one is the cost of housing, and the lack of enough freeways, both of which have really become serious in the last five years because of explosive population growth. Between those two, millions of people end up stuck in traffic every day for hours.
They are building houses as fast as they can, destroying huge amounts of completely irreplaceable natural beauty in the process. There is no money in a beautiful meadow full of wild flowers where the deer come out to graze every evening, but if you destroy the meadow and build 500 identically ugly condominiums, you can generate millions and millions of dollars.
I'll post a few if nobody objects. I have to go through my collection and resize a few good ones first (they are too big direct from the camera.)
-Gnobuddy
When I moved to BC, I interviewed for a job and was offered the position, but the start date was a couple of months later. So I had time to drive around a little, and with fresh eyes seeing the area for the first time, I took a lot of photos.
Once I started work, life returned to the usual dreary daily routine - wake up, get stuck in traffic, work all day, get stuck in traffic, do chores at home, do paperwork until too exhausted to stay awake, go to sleep, repeat the next day. Not too many photos got taken after that.
So, as requested, here are some photos from my first few months in BC. They were taken variously in areas around Kelowna, Kamloops, Hope, Harrison Hot Springs, Langley, Richmond, and maybe a couple of other cities I've forgotten.
-Gnobuddy
Once I started work, life returned to the usual dreary daily routine - wake up, get stuck in traffic, work all day, get stuck in traffic, do chores at home, do paperwork until too exhausted to stay awake, go to sleep, repeat the next day. Not too many photos got taken after that.
So, as requested, here are some photos from my first few months in BC. They were taken variously in areas around Kelowna, Kamloops, Hope, Harrison Hot Springs, Langley, Richmond, and maybe a couple of other cities I've forgotten.
-Gnobuddy
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Thanks - missed the link last time
I have very fond memories of my time in BC around the turn of the century but even then building was going non-stop (post '98 HK hand over) and the roads & public transport were overloaded.
But I shudder at the thought of someone building a "Katy Freeway" in BC.
As I write this, they are widening the formerly four-lane highway (Hwy 1) from Langley to Chilliwack, adding one more lane in each direction, for a total of six lanes. (A long way short of the 26 lane Katy Freeway
)I can virtually guarantee there will be gridlock on the newly widened six-lane highway the very first day it opens - for several hours every day, there is easily enough traffic to fill four or five lanes in each direction, never mind three. Of course there is neither money, nor land, nor political will, to widen the highway to that extent.
The soaring cost of housing around Vancouver has forced a lot of people to move far away from work, and as a result, it is now starting to be routine to spend four or five hours a day in your car, stuck in traffic, commuting to and from home to work.
It's one of those "Surely something has to give?" situations, and I sometimes wonder how it will end.I've dreamed about visiting Australia ever since I first saw black-and-white drawings of kangaroos and platypuses as a child. The cards never fell the right way, though, and it never happened.
On the plus side, I am now in a beautiful country that I've hardly even begun to see, so I could easily spend the rest of my life finding beauty right here in Canada.
-Gnobuddy
...commuting to and from home to work.
Visit LA.
Places I knew outside LA in 1959 as a diner and gas stop (see Victorville) in the desert are now very large towns (now 122K head). The narrow winding pass (El Cajon) over the hill to them is now multiple ribbons of floating highway (I-15).
OTOH, where I live now, population peaked in 1860 and did not recover for most of the 20th century. Several old roads were essentially lost, though the one I now live on grew-back from a mule-trail to a 2-lane paved speedway.
I lived in LA-LA-land for over two decades. Agree on the traffic, by 2014, top speed on several freeways (405, 5, 10) was about 5 mph between the hours of 7 AM and 7 PM every weekday.
Back in the late 1990s it used to take me 90 minutes each way to travel 18 miles to work near Santa Monica, no matter what route I tried. Average speed 12 miles per hour.
The traffic in some regions around here (lower mainland, BC) is now fully as bad as it was in L.A. On the plus side, the air isn't brown and hazy to the same degree yet. But if you take a ferry and look back at Vancouver once you're a little way out to sea, you can see the pall of brown haze hanging over the city.
I would happily move to a smaller city if I could, but there's the usual problem. The jobs are located where lots of people are, and so is the traffic and expensive housing.
-Gnobuddy
The soaring cost of housing around Vancouver has forced a lot of people to move far away from work, and as a result, it is now starting to be routine to spend four or five hours a day in your car, stuck in traffic, commuting to and from home to work.
Unfortunately you're too close to the US'oA and too far from Japan (or Northern Europe) and so you can't possibly see the blindingly obvious solution.
Where I am, while still quite blinkered (by being in the Anglosphere), we re-opened our "uneconomic" passenger rail lines in the eighties and have since built about a hundred miles of rail with two dozen stations. Most of it up the middle of the existing freeways, freeways which are still carparks twice a day. Importantly the trains run nearly 24/7, at 5 minute intervals at rush hour, and have integrated bus services (for the last 5 miles).
I know BC has been extending the SkyTrain but it barely goes past Burnaby (IIRC) - and at 45kph (our trains do 130kph)
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North America isn't the only place I've lived, and I had no alternative to public transit for a lot of impoverished student years. So yeah, it's been on my radar.so you can't possibly see the blindingly obvious solution.
And, guess what, I always loathed it - slow, expensive, inconvenient, leaves you stranded a kilometre or two from your destination at both ends of your journey, and takes twice as long as driving, awful traffic and all. That 90 minute commute to work in Santa Monica took about three hours one way by rail + bus.
Somewhere there is a solution less ridiculous than two tons of car per person, and less unpleasant that being stuffed into a large tin box with fifty strangers, including the fellow who spent last night in the gutter vomiting over himself. Perhaps powered bicycles and small self-contained towns?
-Gnobuddy
Certainly. But I should stop derailing the thread before the moderators have to remind me that this is about DIY audio and not urban design.
*reminds me of a recent packed flight (in economy) next to someone who'd come straight from a bridal shower
highly entertaining, before until she dozed off.
such beautiful landscapes to see there, thanks!
i don't think its a bad thing when we chill a bit to keep in good mood and later continue on the discussion... its healthy and better than fighting and arguing in such unpleasant way... if all forums/threads follow this example, it gets better for everyone
getting back 'on the rails' i have an important question in the point of view of the engineering:
since the caps question are done and stuff... i've found challenged in one thing... take a look at the presence potentiometer (vr-6) right after the phase inverter and the 22nf caps
its a vox style presence cut
since i plan to remove the 100k tone slope and bypass the tone stack and the master volume (vr-2) to fill with ampeg specs baxandall/james tone stack, then the question:
-the post phase inverter master volume (wired matchless spitfite style with wiper in one side of the phase inverter out, then lug 3 on another) should be placed before or after the vr-6 presence control?
(or for better results should i remove the presence control?)
i was gonna test by ear anyway, but its always better to be based on reasonable engineering point of view;
about the multilayer ceramic caps... i've never seen those in Brazil;
attached below the pics i've mentioned about the dusk view in my home... its the same sky in this video below where i was playing some improvisation with acoustic and we've got surprised by a huge double rainbow in the sky
YouTube
i don't think its a bad thing when we chill a bit to keep in good mood and later continue on the discussion... its healthy and better than fighting and arguing in such unpleasant way... if all forums/threads follow this example, it gets better for everyone
getting back 'on the rails' i have an important question in the point of view of the engineering:
since the caps question are done and stuff... i've found challenged in one thing... take a look at the presence potentiometer (vr-6) right after the phase inverter and the 22nf caps
its a vox style presence cut
since i plan to remove the 100k tone slope and bypass the tone stack and the master volume (vr-2) to fill with ampeg specs baxandall/james tone stack, then the question:
-the post phase inverter master volume (wired matchless spitfite style with wiper in one side of the phase inverter out, then lug 3 on another) should be placed before or after the vr-6 presence control?
(or for better results should i remove the presence control?)
i was gonna test by ear anyway, but its always better to be based on reasonable engineering point of view;
about the multilayer ceramic caps... i've never seen those in Brazil;
attached below the pics i've mentioned about the dusk view in my home... its the same sky in this video below where i was playing some improvisation with acoustic and we've got surprised by a huge double rainbow in the sky
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From what I see in the schematics (both Spitfire and the Handsome Devil), this pot will lower gain, and simultaneously reduce bass response, as you turn down its resistance. In the Spitfire, it's labelled "Master", so it is being used as a gain control rather than a presence control.
Again, from what I see in the schematics, they are both exactly the same thing - the circuits are identical. So you definitely do not need two of them (and they would interfere with each others functioning if you did have two of them, so do not wire two of them up!)
Those are some amazing colours! I've never seen a sunset quite like that.
-Gnobuddy
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