Nothing measures better than 1cm of copper PCB traces
Not really. A 1 cm copper trace from my DAC to my speaker measures pretty poorly in the loudness and damping factor measurements
When I asked Hypex if there was a way to bypass the buffer on the MP series, they said "no, you don't need to because the opamps and regulators are of the highest standard already"
I guess that means they think the NE5532 is better than the discrete buffer in the Mola Mola Kaluga
The new HSR discrete regulators look pretty fancy though. Wish I could give this thing a listen.
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Those are SOTA remote controllable AVC volume controls. "Slagleformer's". Widely known as the best AVC volume controls on the planet. Nobody makes a better AVC than Dave Slagle.
You'll find Slagleformer's in budget preamp builds like this:
6moons audioreviews: Aurorasound Preda TBSP
For fully balanced you need 4 of them. They charge double for their balanced version. Our NC-500 buffer is similar to the balanced Preda, only they use through-hole gain stages with the Slagleformer's, and we use the Weiss OP2-BP SMT based gain stages together with the Slagleformers.
6moons audioreviews: Aurorasound Preda TBSP
For fully balanced you need 4 of them. They charge double for their balanced version. Our NC-500 buffer is similar to the balanced Preda, only they use through-hole gain stages with the Slagleformer's, and we use the Weiss OP2-BP SMT based gain stages together with the Slagleformers.
Dynamic range is better than 120dB. As long as you don't feed them any DC, they measure great. The way they increase current and lower output impedance as they attenuate, seems to be the biggest advantage. I've yet to hear anything close. Which is why I'm willing to spend several times more compared to the next best option for them.
Rough layout of my big custom Purepower
Attachments
Not sure I see the advantage - don't you need the lower output impedance at higher signal levels?
The Slagleformer's used to be. But John stopped selling to anyone buy OEM's. But Dave Slagle just released some very nice manual "Elma 47" unit's with all the same quality and several steps. Available to anyone. Beautiful units as well!!
intact audio
Rather than ******* the current away as heat, they increase current and lower output impedance as you attenuate. If anything more current and lower output impedance is more desirable at lower levels. However at unity gain our gain stage has a 10 ohm output impedance, and can sink/source 60mA running in pure class A, while meeting the specs on the Weiss OP2-BP datasheet.
http://www.weiss.ch/files/downloads/op1-bp/OP1-BP-Datasheet-R1.pdf
Why would that matter? We are talking fractions of milliwatts here, and you "burn the current" (no, you don't - you dissipate power) in all the resistors and transistors in your circuit anyway.
That as what I was questioning. Why is more current desirable at lower levels?
Nice, but what has that got to do with the autotransformer?
The reason it's more desirable is because you can take all of the noisy active gear out of the path, and not lose anything as you attenuate. All other passives sound thin as you lower the volume. They can even provide up to 7dB gain as well if needed.
Best thing to do is listen to them. People don't spend $2000 on volume control parts alone, just because they suck. And it's not "euphoric coloration's" that make them good. It's the extreme transparency.
Keep in mind you need a 4 deck unit for balanced operation. And they cost $1800 in 47 step!
Even a normal resistive attenuator doesn't attenuate at all at full volume, and even your autotransformer attenuates at lower volume settings - that is what a volume adjustment does.
And why is that? Can you explain what is causing that effect?
All nice, but you didn't actually answer my questions.
So, why is more current desirable at lower levels? And what has "However at unity gain our gain stage has a 10 ohm output impedance, and can sink/source 60mA running in pure class A, while meeting the specs on the Weiss OP2-BP datasheet" to do with the autotransformers?
Even a normal resistive attenuator doesn't attenuate at all at full volume, and even your autotransformer attenuates at lower volume settings - that is what a volume adjustment does.
And why is that? Can you explain what is causing that effect?
All nice, but you didn't actually answer my questions.
So, why is more current desirable at lower levels? And what has "However at unity gain our gain stage has a 10 ohm output impedance, and can sink/source 60mA running in pure class A, while meeting the specs on the Weiss OP2-BP datasheet" to do with the autotransformers?
I try not to wrap my head around the technicalities too much. These are proven units with 1000's of them out in the field already. I've listened to every type of attenuator on the planet. Nothing has sounded better to my ears than these unit's. And I'm not alone.
Better guy to talk to is Dave Slagle if you want all the fine details. He has a great forum as well. Massive resource of information on there:
:: Index
I've kind of noticed that.
So those autotransformers are great because <technical mumbo jumbo that sounds good>, and they are Really Expensive. Fair enough.
I've kind of noticed that.
So those autotransformers are great because <technical mumbo jumbo that sounds good>, and they are Really Expensive. Fair enough.
Listen to my Puregain gain stage equipped with the Weiss OP2-BP's, followed by a balanced set of slagleformers', then quality headphones driven direct, and you won't need to ask any questions anymore. Everything that matters will be answered within seconds
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