[00940]

Quote:

Originally posted by Prune 00940, I have read on several places that while capacitors such as the paper in oil or the Audionote copper or silver foils are more euphonic than the rest, that is due to the type of coloration they add to sound, and that polypropylenes such as the MIT Multicaps and the Audience Auricaps (and their solid lead predecessors, the Sidereal caps) are the most neutral and transparent. The latter two are also much cheaper, but still not exactly cheap.

It seems indeed to be a big controversial topic on diyaudio and audioasylum. I just found a place that has paper in oil caps 1uF/200V at 1.2€ a piece. Pretty cheap, I'll take a shot at it and hear for myself.

 

[rickcr42]

Quote:

00940, I have read on several places that while capacitors such as the paper in oil or the Audionote copper or silver foils are more euphonic than the rest, that is due to the type of coloration they add to sound, and that polypropylenes such as the MIT Multicaps and the Audience Auricaps (and their solid lead predecessors, the Sidereal caps) are the most neutral and transparent. The latter two are also much cheaper, but still not exactly cheap.

another example of circuit requirements

use paper in oil in an already soft sounding circuit and you end up with a lifeless sounding device but use the same cap in a bright sounding amp and it may balance out perfectly

same can be said for wire selection

All passive parts can be considered like a tone control and once you decide on a basic circuit topology the real fun begins

the voicing or if you prefer , the "EQing" of the sound

Dull sound ?

use a brighter part .Not a part that smears the details but one that just takes the edge off and tones it down

 

[Prune]

Quote:

Your signal has already seen more capacitors than you will find in the mouser catalog

LOL, that's just beautiful! Can I qote you on that? Hmm, I guess I just did...

On a related note, a lot of people at diyaudio deride chip amplifiers as opposed to discrete constructions, yet conveniently forget about the mutlitudes of opamps that the signal has gone through in the studio's mixing boards. Circlotron tried a dozen opamps set to unity gain in series and it took him extensive listening to hear any difference (see this).

 

[ITZBITZ]

That's the great thing about audio.

You can do everything in the reach of your wallet to improve the perceived quality out of that CD player. However, you have zero control over the mixer/recorder/microphone that recorded. Do you think the recording studio used a $32 AC plug with teflon insulated power cords? Last I looked, those aren't in the Markertek catalog and most recording studios are built to those level of components.

I like the mouser catalog line, that's a good one indeed.

 

[Prune]

Quote:

Last I looked, those aren't in the Markertek catalog and most recording studios are built to those level of components.

Markertek isn't exactly cheap. I bought a bunch of Canare connectors from them once, and it added up to a lot of dough...or perhaps that's because I'm buying with Canadian dollars

 

[rickcr42]

Quote:

Do you think the recording studio used a $32 AC plug with teflon insulated power cords? Last I looked, those aren't in the Markertek catalog and most recording studios are built to those level of components.

And as an add ,all we can try to do is approximate what the original recording engineer heard unless we use the same exact monitor amp and speakers.

I use live music and not recorded music as my benchmark

In my life i have heard systems that make beautiful sounding music ,but music that has almost no relationship to what i personally hear live.

Just good sounding stereo

I have also heard systems that capture the "live' feeling .not perfect ,can't be done,be a hint of what i hear when i attend a preformance

and for me at least it mostly comes down to not tone but dynamics.

Real music has dynamic contrast from leaning forward soft to knock me back loud plus everything in between.

Ever notice how noisy the background is at a live performance ?

And yet it does not bother you

Ever move around in a venue ?

The tone will change according to where you are standing or sitting but yet the essence of the perfromance is there and you do not give it a second thought

But yet when trying to design a piece of audio equipment absolute tonal accuracy and exeedingly low noise are paramount while the loud to soft is forgotten .

Many circuits "self compress" the dynamics and you never even notice because it is making "beautiful recorded music" (music in a can) but not anything resembling a live performance

for that you need low level resolution , an ability to eek out the little things in the background and when a loud note hits the full weight of the note should startle you ,bring goosebumps and make the little hairs on your neck stand up

You look behind you and go "hey man , did you hear THAT ?" but there is no one there !

 

[ron]

My favourite caps are Multicap RTX, I use them for coupling and psu bypasses, I have not tried Auricaps yet

Ron

 

[kwhead]

Hmmm.... If you think capacitor effects in the feedback network are *less* intrusive than those caused by a coupling cap then you don't understand how feedback works very well.

Actually, Douglas Self has demonstrated (as in actually measured) that the cap commonly placed at the bottom of the feedback chain can be one of the most significant contributors of distortion in an otherwise well designed amp.

As for the compensation cap in an op-amp or discrete design, this is the absolutely last one anyone should be worried about. Unless your amp topology and design sucks to begin with. Furthermore any topologies I'm aware of that eliminate it actually make open loop distortion worse - truely throwing the baby out with the bath water.

Pick high quality caps that do the job. If you can elimnate one without doing something stupid then do so. Don't invest in capacitors sprinkled with magic pixie dust. DC coupling maybe nice, but a driver slightly DC biased will most likely have more problems than would be caused by one good capactior removing the bias. Those are my design criteria (not that anyone else cares

).

 

[aos]

Quote:

aos I am shocked thank god you omitted these Caps in your DAC or i would be using something else.

Ppl, since you DO have an all in one system, there is no need for a cap in signal path

. But I do want them in my speaker amp - they'd be dead already had I not have one as occasionally in my experimenting DC can come through. The amp also seems to have an overcurrent protection as a few times relays clicked and disconnected the speakers for few seconds due to inrush of current (e.g. big turn-on thump on a connected source).

 

[JohnFerrier]

Prune,
Circlotron's concatenated IC op-amp test certainly is interesting; however, he will not be someone that claims to have golden ears as he has posted that his hearing rolls off at <10khz…http://www.diyaudio.com/forums/showt...ght=#post85091

Further, the idea that recorded audio has already gone through numerous IC op-amps (if that is in fact bad) is not entirely true either. Forssell Technologies claims to have sold thousands of discrete circuitry into the recording industry, Erno Borbely’s discrete circuits are also probably used in the industry, and there are studios that use tubes during recording/mixing. Good discretes can be as cheap to use (as thus, potentially as prevalent) as op-amps.
http://www.forsselltech.com/

aos,
Anyone breadboarding circuitry can use the cheapest voltmeter to check for DC offset. I’ve tossed any DC offset adjustment in my discrete circuit because with careful selection, I’ve got the output offset to <1mV.

Et al,
As far as capacitors, I’m putting all 18 cubic inches of polypropylene capacitors into the power supply…four 9V alkaline batteries. As far as capacitance in the signal path, I’m living with parasitics and about 200pF of active device capacitance.


JF

 

[aos]

I do check for DC before plugging stuff in, but as I mentioned connections can get loose on an experimental unit as you keep plugging and unplugging and if you do this often, sooner or later you will have an incident. E.g. just keep rolling opamps and you'll have a case where one of your soic to dip adapter pins will fall out or lose contact - that can be all it takes. It may be once every 2 years but I don't plan on re-purchasing my Studio S100's every 2 years.

 

[JohnFerrier]

Quote:

Originally posted by aos E.g. just keep rolling opamps...

hehehe...rolling op-amps...when I'm finished, the only thing I'm rolling is CDs...they roll better than op-amps ; ).


*EDIT* Well, by necessity, guess I'll also be rolling batteries too...


JF

 

[rickcr42]

you are not going to find the forsell discrete opamps in the average board but you WILL see API discretes and if you check the designs for both you will see what ?

capacitor coupling !!!!!!!

and phase compensation caps

and again , all studio mic preamps have capacitor coupling as do digital effects and ADC inputs,all equalizers including digital domain EQs , mixing console ,monitor amps,the monitors themselves unless a single full range driver is used ,etc.

As for feedback path vs. signal path caps-i never said they were equal just that they are there and have an effect regardless of how much.

not that it really matters.the final mix is EQ'ed to obtain the "house sound" anyway so the inherent phase shifts of a frequency modification circuit are there

 

[PinkFloyd]

Hold on guys...... as interesting as this is I was trying to find out which type of cap sounded best to your ears. ie: I think polypropelyne caps sound best overall but they inject a rubbery, bouncy signature into the sound etc etc etc. Polyester sounds more natural though it has a tendancy to reveal a lot more information whether good or bad etc. etc etc.........

That type of thing is what I was looking for. I'd even appreciate comments like " polypropelyne sounds like freshly mown grass with a hint of wild nettles allowing the capacitor to inject an undercurrent of newly laid tarmac which underpins the proceedings and makes the music sound so quintessentially Pimms and lemon.

erm....... I've lost it

 

[JohnFerrier]

hehehe...maybe as an evolution of the idea of being unplugged...artists will come out with CD's without caps in the recording path... i.e. Tori Amos: Directly Coupled...

JF