Hi. I'm gonna need some guidance here. I'm trying to find the preferred resistors used by the man himself and PASS LABS.
I have tracked down the 3W part which sits on the output stage, this is the Panasonic ERG MOX resistor, but when it comes to the others, I am a bit lost, but I have have an alternative. I am thinking of Amtrans AMRT Carbon Film Resistors. Vishay mrs25 can also be an alternative.
Can someone jump in an comment ?
I have tracked down the 3W part which sits on the output stage, this is the Panasonic ERG MOX resistor, but when it comes to the others, I am a bit lost, but I have have an alternative. I am thinking of Amtrans AMRT Carbon Film Resistors. Vishay mrs25 can also be an alternative.
Can someone jump in an comment ?
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Pa is more concerned with active components. But what he regularly uses can be seen in 6Moons pics of First Watt amps. Sometimes he uses Vishay RN’s, and for delicate stuff 1% tolerances. Other than that, I bet his main reason for running those Pans is that they are reliable, dead cheap, poisonous and in huge stock with him.
https://www.diyaudio.com/community/threads/resistor-type-used-by-pass-labs.102572/#post-1219676
I like the RN series myself, if I had to choose one
I like the RN series myself, if I had to choose one
I'm throwing down the gauntlet here – a challenge to anyone daring enough to step up for a blind test. Picture this: on one hand, we've got the grandeur of a carbon fiber resistor from the much-hyped XYZ brand, purportedly the epitome of quality. On the other hand, we're pitting it against the likes of metal film resistors hailing from the stalwart manufacturers Vishay, Koa, or Yageo. Now, let's dive into the realm of Mr. Nelson Pass, a man with an undeniable reputation in the realm of Audio Amplifier design.
Here's where my skepticism kicks in. The idea that a resistor, no matter how exalted its pedigree, costing ten bucks, could somehow transcend and outshine its competition, the humble ten or even ten-cent resistor, in a blind test scenario, just doesn't sit well with me. It reeks of that infamous elixir – snake oil.
You see, ladies and gentlemen, when it comes to the world of audio amplifiers, the factors that I believe hold the potential for a true difference reside elsewhere. It's in the intricacies of the design itself, the architecture that's been meticulously crafted. In my humble opinion, this is where the magic happens – the interplay of circuits, components, and the way they harmonize to create an audible symphony.
To give credit where it's due, let's talk about Mr. Nelson Pass. He's essentially shown the world how to conjure an audio amplifier that gleams with unparalleled perfection and an almost minimalist component count. This is the real deal, where the artistry lies in understanding the nuances of audio reproduction and sculpting amplification with a master's touch.
So, let's not be swayed by the allure of extravagant resistor price tags. In the grand scheme of audio excellence, the real melody is orchestrated through the symphony of design intricacies and the craftsmanship of pioneers like Mr. Nelson Pass.
Absolutely, no trolling intended here. Just stating the obvious – the heart of audio amplifiers isn't necessarily found in high-priced resistors, but rather in thoughtful design and meticulous craftsmanship. It's all about appreciating what genuinely matters in the pursuit of audio excellence.
Here's where my skepticism kicks in. The idea that a resistor, no matter how exalted its pedigree, costing ten bucks, could somehow transcend and outshine its competition, the humble ten or even ten-cent resistor, in a blind test scenario, just doesn't sit well with me. It reeks of that infamous elixir – snake oil.
You see, ladies and gentlemen, when it comes to the world of audio amplifiers, the factors that I believe hold the potential for a true difference reside elsewhere. It's in the intricacies of the design itself, the architecture that's been meticulously crafted. In my humble opinion, this is where the magic happens – the interplay of circuits, components, and the way they harmonize to create an audible symphony.
To give credit where it's due, let's talk about Mr. Nelson Pass. He's essentially shown the world how to conjure an audio amplifier that gleams with unparalleled perfection and an almost minimalist component count. This is the real deal, where the artistry lies in understanding the nuances of audio reproduction and sculpting amplification with a master's touch.
So, let's not be swayed by the allure of extravagant resistor price tags. In the grand scheme of audio excellence, the real melody is orchestrated through the symphony of design intricacies and the craftsmanship of pioneers like Mr. Nelson Pass.
Absolutely, no trolling intended here. Just stating the obvious – the heart of audio amplifiers isn't necessarily found in high-priced resistors, but rather in thoughtful design and meticulous craftsmanship. It's all about appreciating what genuinely matters in the pursuit of audio excellence.
Yep. Pop in a metal film type and you'll be fine. In some locations - like the feedback resistor in a power amp - you'll want a resistor with low temperature coefficient and low voltage coefficient. You'll notice that these parameters tend to be specified for plain Jane metal film resistors whereas they're almost never specified for the boutique brand resistors. This should tell you something...
Tom
Tom
I have built with no-name made in China metal film resistors that I purchased at the local electronics store and have had no issues with the sound or measured performance. I buy local when I need only a few resistors - no need for a Mouser or Digikey order and have to pay shipping for a few cents worth of parts.
Local is always the way to go - support the business so it doesn't go away
Pa is using supersymmetric resistors
and, whenever he parallel them, orientation of readout is opposite, that increases supersymmetry
one day, when I grow up, maybe he'll tell why he's using same ones in non-supersymmetric circuits
and, whenever he parallel them, orientation of readout is opposite, that increases supersymmetry
one day, when I grow up, maybe he'll tell why he's using same ones in non-supersymmetric circuits
Of course because he is symmetralizing the asymmetry!!Pa is using supersymmetric resistors
and, whenever he parallel them, orientation of readout is opposite, that increases supersymmetry
one day, when I grow up, maybe he'll tell why he's using same ones in non-supersymmetric circuits
I’m down for that…when, where, whose building the two amps, and most importantly whose bringing the beer.
I think he uses SFR25 for a lot of his stuff. I would suspect MRS25 as well.
For those looking for low-hanging fruit within the realm of resistors, take a look in the Pass Labs XS preamp. I believe it has just your plain Jane metal film cheapies ...
For those looking for low-hanging fruit within the realm of resistors, take a look in the Pass Labs XS preamp. I believe it has just your plain Jane metal film cheapies ...
It you get a good industrial resistor you are fine. That is my approach.
From RS components I often get the "RS-branded" metalfilm resistors which I found out are cheaper and better spec'ed than e.g. the KOA types like MRS25.
From RS components I often get the "RS-branded" metalfilm resistors which I found out are cheaper and better spec'ed than e.g. the KOA types like MRS25.
I thought a good way to test something like this properly is as follows:
0. Determine a good listening level and measure the resistance on both sides of the wiper of a normal pot in the preamp. Let's call them Rsrc and Rgnd.
1. Buy a 24 position switch.
2. Solder any decent resistor (resistance Rgnd) from the switch to GND
3. Next time you order something from Mouser, add 24 different resistors (carbon, metal film, wirewound, whatever, as long as they are all the same resistance, Rsrc). For single ended stereo you only need 2 of each and as long as you don't buy anything exotic they will all be far below $1 each.
4. Solder a different resistor to each of the 24 positions of the switch. This will be the resistor between the source and the preamp. Don't forget to make a list which position is which resistor.
5. Ask someone to put the switch at a random position and start your blind listening test, making notes of what you hear.
6. Only after listening extensively get out the list and compare your results with the list.
I was daft enough to buy a load of 24k resistors to actually do this. Just haven't got around to actually building the switch and doing the test 😎
0. Determine a good listening level and measure the resistance on both sides of the wiper of a normal pot in the preamp. Let's call them Rsrc and Rgnd.
1. Buy a 24 position switch.
2. Solder any decent resistor (resistance Rgnd) from the switch to GND
3. Next time you order something from Mouser, add 24 different resistors (carbon, metal film, wirewound, whatever, as long as they are all the same resistance, Rsrc). For single ended stereo you only need 2 of each and as long as you don't buy anything exotic they will all be far below $1 each.
4. Solder a different resistor to each of the 24 positions of the switch. This will be the resistor between the source and the preamp. Don't forget to make a list which position is which resistor.
5. Ask someone to put the switch at a random position and start your blind listening test, making notes of what you hear.
6. Only after listening extensively get out the list and compare your results with the list.
I was daft enough to buy a load of 24k resistors to actually do this. Just haven't got around to actually building the switch and doing the test 😎
The types I usually buy are those:
https://docs.rs-online.com/5800/0900766b81657433.pdf
0.25%, 25ppm/C, 0.4W types.
For 100 pcs it is about 10 USD. For 1000 much cheaper pr. unit. I only buy 100 at a time.
For 100 ohm, 1k etc. it would probably make sense to buy a 1000 unit package to have those until "End Of Life" 🙂
KOA, Acrol etc. are more expensive but they will not "sound" better 🙂
https://docs.rs-online.com/5800/0900766b81657433.pdf
0.25%, 25ppm/C, 0.4W types.
For 100 pcs it is about 10 USD. For 1000 much cheaper pr. unit. I only buy 100 at a time.
For 100 ohm, 1k etc. it would probably make sense to buy a 1000 unit package to have those until "End Of Life" 🙂
KOA, Acrol etc. are more expensive but they will not "sound" better 🙂
Those where also on my list.
In my limited mind, ALL components are subtractive. A components that approaches its ideal - aka a resistor with low LC and a capacitor with low RC etc - is going to be the good choice, as long as its made properly and doesn't contain too much noise. So if you find that RS resistor work great, by all means use them.
Measure each resistors RCL values and its inherent noise. This could be interesting in comparison to its "flavour" profile in the system.