[fredgarvin]

You'll often hear people say that although they loved the transparency they missed the 'drive' or 'punch' of an active pre. Usually that's because of impedance mismatch, depending upon their gear. For those folks an autoformer or transformer based passive usually sounds better than just a switcher be it stepped or not. That's when the price starts going up.

[rollo]

OK plugged the sucker in. To my surprise out of box VG sound. If one uses an SET amp with low input sensitivity and a DAC with a 3V output or more this baby is for you. Big open sound. Transparent to source and DEAD quite.
Compared to my Lamm bass MIA, harmonics lacking at extremes, less decay of harmonic and a bit hard and lean. The Lamm gives ya 1 thru 10 the passive 3 thru 8. For $56 a no brainer.


charles

[RDavidson]

Always, always , get a second opinion.

https://parttimeaudiophile.com/2012/12/30/mini-review-luminous-audio-axiom-ii-walker-mod/

And another.

https://positive-feedback.com/reviews/hardware-reviews/luminous-audio-technology-axiom-ii-passive-preamplifier/

I like what The Part Time Audio dude has to say. The only thing incorrect in his review is that he says the Wyred 4 Sound STP SE is passive. It is not. It uses active SS buffers at both its input and output stages as a means of alleviating possible gain and impedance mismatches. So...it is really a unity gain active until one gets into the upper registers of the volume control where it applies a smidge more output gain.

[rollo]

You'll often hear people say that although they loved the transparency they missed the 'drive' or 'punch' of an active pre. Usually that's because of impedance mismatch, depending upon their gear. For those folks an autoformer or transformer based passive usually sounds better than just a switcher be it stepped or not. That's when the price starts going up.

  Agree with that.


charles

[maty]

I have been intrigued for some time with cermet pot, which some recommend but others deny.

What do you think about them? Best company?

https://www.diyaudio.com/forums/analog-line-level/314563-aksas-lender-preamp-40vpp-output-post5652078.html

It was Hugh's FAQ's that originally put me onto the Cermet pots (search the page for "cermet"). I meant to use this model pot from RS, but it was out of stock and then I got a slightly different version - with plastic shaft, but still Bourns.

[fredgarvin]

OK plugged the sucker in. To my surprise out of box VG sound. If one uses an SET amp with low input sensitivity and a DAC with a 3V output or more this baby is for you. Big open sound. Transparent to source and DEAD quite.
Compared to my Lamm bass MIA, harmonics lacking at extremes, less decay of harmonic and a bit hard and lean. The Lamm gives ya 1 thru 10 the passive 3 thru 8. For $56 a no brainer.


charles

I was really surprised myself.

[maplegrovemusic]

Anyone open the nobsound and verify the Alps pot ?

[Letitroll98]

If everyone could hear a CD player direct into their amp, they would be shocked. I will never understand why people buy an expensive DAC with remote volume, and run it through a preamp.

I have a DAC with a very nice volume control that also allows you to run fixed gain into a preamp.  The system sounds great just running the DAC into the amp, but alas I also have a turntable so I need the preamp for phono pre and switching facilities.  It can run active or passive and I generally run it passive, occasionally switching to active for cheap thrills.   But you're right, the most direct path sounds best.

[OzarkTom]

I nominate Rollo as the most honest dealer in the world award. I doubt if you will ever find another that will compare a $20K plus preamp to a $56 passive and give an honest review like he did. I wondered how much it would cost to beat this passive. Now I know.

If Charles sells any equipment you want to buy, buy it from him. You cannot go wrong.

[OzarkTom]

You'll often hear people say that although they loved the transparency they missed the 'drive' or 'punch' of an active pre. Usually that's because of impedance mismatch, depending upon their gear. For those folks an autoformer or transformer based passive usually sounds better than just a switcher be it stepped or not. That's when the price starts going up.

I looked up the transformer based units. 30K for the Vivaldi? 

How does this one look to you?

https://www.ebay.com/itm/AM-Audio-Music-passive-preamp-TVC-Type-transformers-Volume-control/192229314729?hash=item2cc1c290a9:g:A~UAAOSwyZ5UoGzF:rk:1:pf:0

[Letitroll98]

Looks great, but out of pricing guidelines.  That doesn't mean someone can't try it.

I've met Charles (rollo) a couple times at audio shows, everyone instantly likes him. 

[sumoking]

I nominate Rollo as the most honest dealer in the world award. I doubt if you will ever find another that will compare a $20K plus preamp to a $56 passive and give an honest review like he did. I wondered how much it would cost to beat this passive. Now I know.

If Charles sells any equipment you want to buy, buy it from him. You cannot go wrong.

Exactly the purpose of my post. You have to spend significant money
To beat this little baby. $56. FANTASTIC BARGAIN.
To many folks, you should sell your name brand preamp and use
your money on speakers, DAC or a better amp.
Cheers .

[rollo]

   Thanks for the kind words Guys. I am an Audiophile before I'm a dealer. Buying another passive to try a dual mono configuration. The passive is changing as it breaks in. I would suggest 100 hours to burn in path of least resistance and the connectors. Some weight on top helps as well.
   With 50 hours in the hardness is lessened and beginning to open up more sound stage wise and the bass is no longer MIA. If this passive thing catches you search out Stevens and Billington [ copper trannies ] and Slagleformers.



charles
 

[fredgarvin]

I looked up the transformer based units. 30K for the Vivaldi? 

How does this one look to you?

https://www.ebay.com/itm/AM-Audio-Music-passive-preamp-TVC-Type-transformers-Volume-control/192229314729?hash=item2cc1c290a9:g:A~UAAOSwyZ5UoGzF:rk:1:pf:0

I remember Promethius used to have a circle here selling TVC models for about $300. I was thinking then about trying one but he shut down for awhile.

[davidldl]

It seems like the Promitheus web site is still up.    I wonder if they are still taking orders.
http://promitheusaudio.com/




David

[rollo]

  Used to sell Promithius as I was his partner for a short time. Still a fine product  colored warm.



charles

[rollo]

  OK guys it takes 200 hours for this little guy to sound its best. Bought another to try dual mono as my main rig is such all the way. It was a bit hard and bright later on then at 200 stopped changing.
  Set up another system using a Dennis Had Inspire amp [4W], Omega speakers [ Fostex driver], Sony CDP as transport and tubed DAC. Pretty darn good guys.



charles

[OzarkTom]

Also try reversing phase at both speakers. This should give even a bigger soundstage. Anthony Gallo said years ago that most amps inverts phase.

[OzarkTom]

This is what the Nobsoind looks like inside.

[RDavidson]

Also try reversing phase at both speakers. This should give even a bigger soundstage. Anthony Gallo said years ago that most amps inverts phase.

I don't think what Mr. Gallo says is really true (at least not anymore), BUT worth trying. Shouldn't hurt anything. I think older amps, particularly tube amps were somewhat notorious for this. Some preamps invert phase too. I've experienced this myself with a tube preamp.

You'll know your amp (or possibly other upstream components) do not invert phase if the soundstage is diffused and completely lacks focus / image lock when you invert your speaker cables. If the sound stage is focused via "normal" cable setup, then the amp does not invert phase.