Audiophile quality for transistors...

Started by Gainmonger, July 31, 2018, 11:13:48 AM

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Gainmonger

Hey friends!
I was wondering if any of you guys had go-to brands for clearly above average silicon transistor sounds.
Generic 2n5088/89... do their job, no doubt but are there any models with a real audiophile quality (like a JRC's has an edge over standard TL's) without sacrificing output of course.
Thanks!
GM
Ekil Erif, Ekam Erif, Erif Erif, Di Maggio.

bloxstompboxes


Floor-mat at the front entrance to my former place of employment. Oh... the irony.

diffeq

Hello. Welcome to the forum.

Honestly, I lack experience with Hi-Fi transistor circuitry, but according to TAoE, lowest noise bipolar transistor is ZTX851/ZTX951, supposedly because the die inside them is larger (collector current up to 5A), but the best performance is achieved at low source impedance (less than 1k) and low collector current (around 0.1mA). At higher source impedance (100k), high Beta 2N5962 outperforms ZTX851 at any collector current. I suppose it's a matter of particular application, so the choice depends on whether you use it in a gain stage, or output stage, or as buffer, or a mixer...
Both of these are not officially endorsed as "low noise"/audiophile parts, by the way. It was a research done by the book authors.
I've read elsewhere that BC337 is also a fine low-noise transistor.

Gainmonger

Indeed. Low noise is great but "texture" is greater as for audiophile quality in stompboxes.
My main focus is for transistors used in gain stages (fuzzes etc).
Are tere any 2N type NPN trans/brands around which could sound more "open" than regular ones?
Ekil Erif, Ekam Erif, Erif Erif, Di Maggio.

wavley

#4
The openess of a pedal is probably more circuit based than transistor based, particularly when you're clipping that transistor on purpose.  Good news is, transistors are pretty cheap, buy a bunch, throw them in a breadboard, and find the ones you like!


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stringsthings

For your average fuzz pedal, noise performance from a silicon transistor would be really hard to hear.
Coupled with the noise floor of a typical guitar amp?  Even harder to hear. 

My ears aren't the greatest, but I've never been able to hear the difference between 2 brands of NPN's.
OTOH, I've never set up a formal test.  I'm more of a "build it, hear it, apply it" pedal builder.
As opposed to designing/building towards a specific end goal.  That's too complex for me.

Gainmonger

Yes, sili NPN's are pretty hard to differentiate soundwise, hence my question.
I've built tons of mosfet projects and so far I've been able to single out the type of mosfet trans I really like to work with, as those have very different character and behave differently in a gain stage(s) configuration (ex: J201 are very meaty, 2N7000 are much tighter etc...)
But when it comes to silicon trans, apart from the output there's not much difference.
I know that the general circuit design does the heavy lifting in terms of texture but still, I wonder is there's a brand/nos type trans that adds something to the sound, just like a JRC is better than a TL opamp...
Ekil Erif, Ekam Erif, Erif Erif, Di Maggio.


ElectricDruid

Quote from: thermionix on July 31, 2018, 07:26:34 PM
Quote from: Gainmonger on July 31, 2018, 05:34:04 PM
JRC is better than a TL opamp...

Says who?

I was wondering that too. TLxxx ain't great, but JRC are cheap and old just the same.

<dons tin hat and jumps into trench>


Gainmonger

Quote from: ElectricDruid on July 31, 2018, 08:02:33 PM
Quote from: thermionix on July 31, 2018, 07:26:34 PM
Quote from: Gainmonger on July 31, 2018, 05:34:04 PM
JRC is better than a TL opamp...

Says who?

I was wondering that too. TLxxx ain't great, but JRC are cheap and old just the same.

<dons tin hat and jumps into trench>

says me.
I can't be the only one to notice a difference between JRC and TL opamps, am I? It might be subjective but still.
I've made a lot of circuits with cheap generic TL's and they sounded pretty good but circuits with JRC 4558 or 4580 just sound a lot better, tighter with more definition (and less prone to hiss)
Ekil Erif, Ekam Erif, Erif Erif, Di Maggio.

MaxPower

Socket them and use an oscilloscope I guess.


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antiuser

I don't f%#@ with op amps so this is kinda outside my wheelhouse, but I remember seeing a video a couple years ago of a lecture in a studio where they basically did a double blind test with several ICs, including vintage and current JRC, TI and even a video op amp. There was no discernible difference.

I reckon if you try hard enough, you could find a specific situation where a small detail will be different between same spec chips from different manufacturers, but I am highly skeptical of that difference being enough of a factor that one would advocate for one chip in detriment of the other. Probably easier to hear the difference between film/foil and silver mica capacitors. It just smacks of cork-sniffing audiophile snake oil to be quite honest.

R.G.

I'm only going to say this once. Well, I'll try.

@Gainmonger: you're on the slippery path to hifi tweako hell. Today, it is quite difficult to know if the brand stamped on the transistor is actually the brand that it was supposed to be, due to counterfeiting. Then there's the fact that transistors are now a "jellybean" item, too inexpensive and too low a profit margin item for many companies to waste their MBAs' time on, and the dillema that wafer fabs to make transistors are too expensive to be owned by one company. You see the problem - the brand imprinted on a transistor may not mean much from lot to lot.

So hunting for ever-tinier, subtler differences between transistor brands may well be fooling yourself.

Squinting subtle "texture" differences between parts is a good way to get hooked on Cork Sniffer's Disease, the malady that searches for hyper refinement in changing out one part for another. It's a common misapprehension that by taking a circuit and changing out parts for "better" brands recommended by other self-proclaimed experts is a good way to get lost. Humans are famous in psychology circles for self deception on many levels. For instance, how do you know that the PCB material and quality of the copper on it are not a bigger factor than the transistors? Can you hear the difference in tin-lead solder and tin-lead with a percent or two of silver in it? Does the circuit sound better when oriented to magnetic north under a pyramid?

I know it's tempting to believe that the magic is in getting magic brands of parts. Don't get sucked in.,
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

Phoenix

Quote from: Gainmonger on July 31, 2018, 05:34:04 PM
Yes, sili NPN's are pretty hard to differentiate soundwise, hence my question.
I've built tons of mosfet projects and so far I've been able to single out the type of mosfet trans I really like to work with, as those have very different character and behave differently in a gain stage(s) configuration (ex: J201 are very meaty, 2N7000 are much tighter etc...)

J201 isn't even a mosfet, it's a Jfet. J201 and 2N7000 won't normally even operate in the same circuit (DC source follower being an exception), J201 is depletion mode (normally on), 2N7000 is enhancement mode (normally off), so they have entirely different biasing requirements.

Similarly, when you reference "JRC" and "TL" op amps, I assume you mean the common RC4558 and TL072? JRC is a brand, they make hundreds of different op amps, and Texas Instruments make thousands. You could mean JRC1458 and TLE2074 for all we know.

Anyway, they're both quite different op amps. The 4558 is a general purpose bipolar op amp, most at home dealing with medium to low impedances, and has relatively poor noise performance if used as a front end input for a guitar effect due to this. Quite at home after the guitar has been buffered though. The TL07x series is BiFet, with fet inputs and bipolar output, it is designed for high impedances, and has much better noise performance than the 4558 when dealing with guitar impedances.

So one does not sound "better" than another, at least not universally. It's entirely dependent on the circuit it resides in whether one will have better performance or "sound" better than the other.

thermionix

Something I've been wondering since I revisited Analogman's tube screamer page the other day, what's the difference between a Texas Instruments RC4558P and a Texas Instruments TL4558P?

diffeq

Quote from: Gainmonger on July 31, 2018, 03:07:45 PM
Indeed. Low noise is great but "texture" is greater as for audiophile quality in stompboxes.
My main focus is for transistors used in gain stages (fuzzes etc).
Are tere any 2N type NPN trans/brands around which could sound more "open" than regular ones?

Well, I think the only instrument to measure "openness" is human ears, but unlike noise measuring, readings from ears vary greatly from unit to unit.  :icon_biggrin: You'll have to use your own to find out.

Quote from: thermionix on July 31, 2018, 07:26:34 PM
Quote from: Gainmonger on July 31, 2018, 05:34:04 PM
JRC is better than a TL opamp...

Says who?

Datasheet for NJM4558 (made by JRC) shows a slightly lower noise, around 11nv/√Hz. TL072 is 18nv/√Hz. Perceptible? Doubt it.
TL072 has faster slew rate - 13V/uS, versus 1V/uS of NJM4558. Maybe for some "worse is better" applies here?

Phoenix

Quote from: diffeq on August 01, 2018, 02:48:57 AM
Datasheet for NJM4558 (made by JRC) shows a slightly lower noise, around 11nv/√Hz. TL072 is 18nv/√Hz. Perceptible? Doubt it.
TL072 has faster slew rate - 13V/uS, versus 1V/uS of NJM4558. Maybe for some "worse is better" applies here?

Not the whole story. 4558 has lower VOLTAGE noise than '07x, but higher current noise (though you have to really dig through the datasheets to find that parameter for the 4558). With high source impedance, current noise becomes dominant.
So, as I mentioned above, it depends on the circuit. You CANNOT make blanket statements like "a is lower noise than b", because it depends.

Here's a link to a datasheet with some info, you want figure 2. LINK

merlinb

Step 1) Go to any vendor's website.
Step 2) Hit the 'sort by most expensive first'.
Step 3) Congrats you've found the audiophile parts.

thermionix

Of course real audiophiles will only accept single-ended triode monoblock tube gear, so there is no such thing as an audiophile transistor.

Ice-9

If you want to get into the Audiophile game then buy a few of these op amps at £42 each
to play with, or have a go at building some discrete op amps yourself to try.

https://orangeamps.com/product/op-amp/#specs




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