Passive preamps

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Jonathon Janusz

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Re: Passive preamps
« Reply #20 on: 22 Feb 2018, 12:59 am »
You're right most DAC's don't meet these specs. This is why very few have experienced the best from Slagleformer's. If John was to recommend DAC's with the specs I recommend to use with his Slagleformer's, Slagleformer sales would have also been thin!

Okay, fair enough.  So, bringing my question back around more directly, could you point me to any DACs available for purchase today that meet your suggested specifications?  I have been unsuccessful in finding an assortment of DACs to look in to that meet these criteria, and am presuming that you used such comparable DACs when developing/testing yours.  I would look in to your offerings as well, but none of those are currently available.

Thank you for any help!  Anyone else with any links to such unique DACs would also be gladly appreciated.  All I could find in my searches were DACs that were part of an integrated headphone amp solution.  I don't use headphones, so I would prefer to be looking at components that are just a DAC and nothing more.

I hope I'm not pulling the conversation too far off track.  I hope this is closely enough related as I'm window shopping around for a DAC to pair with my new to me balanced Tap-X passive pre.

RDavidson

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Re: Passive preamps
« Reply #21 on: 22 Feb 2018, 01:04 am »
There’s that, but I also just found out I must love the sound of noise and distortion. :duh: 

To anyone reading this thread, seriously try a Tortuga and send it back if you don’t like it.  30-day return and cheap to ship back IF you’d want.

And that's exactly it. I'm not dismissing scientific measurements, BUT how the distortion manifests itself (or not) during real world testing (ie listening to music) is the other half of the story that cannot be dismissed.

bavmike

Re: Passive preamps
« Reply #22 on: 22 Feb 2018, 01:07 am »
Okay, fair enough.  So, bringing my question back around more directly, could you point me to any DACs available for purchase today that meet your suggested specifications?  I have been unsuccessful in finding an assortment of DACs to look in to that meet these criteria, and am presuming that you used such comparable DACs when developing/testing yours.  I would look in to your offerings as well, but none of those are currently available.

Thank you for any help!  Anyone else with any links to such unique DACs would also be gladly appreciated.  All I could find in my searches were DACs that were part of an integrated headphone amp solution.  I don't use headphones, so I would prefer to be looking at components that are just a DAC and nothing more.

I hope I'm not pulling the conversation too far off track.  I hope this is closely enough related as I'm window shopping around for a DAC to pair with my new to me balanced Tap-X passive pre.

A great DAC for Slagleformer’s would be the Weiss DAC 1.  0.2 ohm output impedance, and can output up to 27dB of gain. Same discrete opamps I use:

http://www.weiss.ch/products/dac1


ssglx

Re: Passive preamps
« Reply #23 on: 22 Feb 2018, 01:54 am »
I love my Tortuga LDR preamp.

djbnh

Re: Passive preamps
« Reply #24 on: 26 Feb 2018, 02:07 pm »
I like my Allen Flores Warpspeed CE V4x3 (cost including shipping less than $800) feeding my tube amp. The Warpspeed is battery fed and the combo works synergistically with my Zu Omen Defs. 6moons writes in detail about one of the Warpspeed iterations. To quote Srajan's take, "Particularly owners of valve amps should consider this. They might already have all the tone and body necessary to now focus on maximizing the complementary qualities of transparency, speed and energetic immediacy."

tortugaranger

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Re: Passive preamps
« Reply #25 on: 26 Feb 2018, 03:18 pm »
Ummm...really?

https://www.neurochrome.com/tortuga-audio-ldr3/

Don't shoot the messenger...

Best,
Anand.

I debated responding to this thread and specificically the referenced article since I've mostly sworn off online debates of any kind these days as nothing good usually comes of it. But I thought I'd share my thoughts on this particular item.

I was made aware of the review article referenced in this thread a few weeks ago and read it with great interest. I was impressed. The author really put in a considerable amount of work and is obviously quite adept with audio, analyzers and such. Aside from a few minor points where I think he's factually off a bit (and a generation behind on our hardware), not much in the article surprises me. The most interesting aspect of the article isn't what it says but what it doesn't say...which is basically that the weight given to the topic of distoration in audio as the gold standard metric for audio quality is largely irrelevant provided the distortion is sufficiently low.

LDRs have always been known as having higher distortion specs than any other attenuation device. Yet they sound great despite all of that as many of you know. If you dive into the topic of audio distortion and the testing of the ability of humans to detect distortion in music you will find that overall full spectrum distortion has to get upwards of 10% or higher before listeners notice. At very low frequencies you almost need 100% distortion. At upper end frequencies people will begin to notice distortion at levels less than 10%. At say 1% or less no test that I know of has shown human beings capable of detecting this level of distortion under any conditions let alone discerning the differnces at say 0.1% or 0.01%. Engineers rightfully use objective measurement as a useful analytical tool in the design process.... I know I do. Of course measurements also make for great marketing material to wave around and share liberally. But it's a mistake to equate such measurements as definitive determinants of overall sound quality.  If objective measurements were the final word we'd look up published spec sheets and all buy the equipment with the best specs (i.e. lowest distortion) that we can afford knowing that nothing could possibly sound better. That's simply not reality.

One of my favorite quotes from the audio industry comes from none other than Nelson Pass.....

Quote
“The ear is not a microphone, the brain is not a tape recorder, and measurements are limited in describing subjective quality. I like to have low distortion and so on, but these things take a back seat to what I experience when I listen. There are plenty of products which have great specs – I will not be offended if you buy those.” - Nelson Pass