Stellavox Introduces a New State of the Art Amplifier IDEM Monoblocks

[Mike Lavigne]

ok, i was able to find the quick connect banana plugs, and stick my ground cable spades into the barrel and tighten it and so hook up my Tripoint Troy Sig to the IDEM's. not ideal metal to metal connection, but even so a bit of added air and lowered noise....and mid range textures. just a little. and after a few hours connected the Tripoint does engage a bit more.

later i listened to those vinyl cuts from yesterday, and based on my reference memory we are firmly in the general darTZeel reference territory for body and tone. it's familiar to me now and does not stand out as missing anything. flow, energy, scale and bloom are good. all of which is progress, but not a head to head either. i did play some serious vigorous bass performance cuts and i'd say very good.....but need to do more. and i suspect we are a week from the bass coming most of the way in.

is there more nuance and sparkle here and there in my reference cuts? more musical truth? more action? there could be. or just a little different? does it justify a change....yet? the darts are hard nuts to crack. at least we have a presentation now that is apparently complete and working well. no way you could characterize what i'm hearing NOW as lean solid state. (should i be less definitive without a head to head? ) moving to the 18db gain setting and the additional hours has brought us far. they arrived brand new, unsettled, and cold as ice less than a week ago (last Wednesday noon).

on we go.

 

[Audioarts]

Marty - good eye!

I’m glad you point out the ac/dc switch because it’s a critical feature of the Stellavox amplifier design.

For now, prior to the forthcoming Stellavox preamplifier, the switch should always be on AC.
In DC position the input-caps are off (means bypassed).

The Stellavox preamplifier will have all devices linked in DC - no caps in the signal path, which is why the IDEM and DIADEM will be maximized in the dc mode. I heard it in this (dc) manner in Switzerland and the purity, speed and body, combined with an effortless power range has not been matched yet by my efforts with (ac) preamps. Close in some respects but not quite on the purist (dc) level.

The reason we have the ac/dc switch is that
most preamplifiers have capacitors in the output to block DC flow. So we erred on the side of caution and also to allow flexibility re client choice of preamplifier, as they would with any other ac based amplifier prevalent in high end, despite the recommended dc path with the Stellavox preamplifier.

Gideon

 

[Kvali1]

Marty - good eye!

I’m glad you point out the ac/dc switch because it’s a critical feature of the Stellavox amplifier design.

For now, prior to the forthcoming Stellavox preamplifier, the switch should always be on AC.
In DC position the input-caps are off (means bypassed).

The Stellavox preamplifier will have all devices linked in DC - no caps in the signal path, which is why the IDEM and DIADEM will be maximized in the dc mode. I heard it in this (dc) manner in Switzerland and the purity, speed and body, combined with an effortless power range has not been matched yet by my efforts with (ac) preamps. Close in some respects but not quite on the purist (dc) level.

The reason we have the ac/dc switch is that
most preamplifiers have capacitors in the output to block DC flow. So we erred on the side of caution and also to allow flexibility re client choice of preamplifier, as they would with any other ac based amplifier prevalent in high end, despite the recommended dc path with the Stellavox preamplifier.

Gideon

Gideon could you educate me a bit more on this, Is the actual dc signal amplified ? Or is the dc current just used for the circuitry ? And I assume there is a mechanism in place to block dc current from getting to the speakers ?

And secondly , will the pre amp have a battery , battery powered to fully take advantage of a dc current from the start ?

How about future dac .. will that be looped into same ecosystem?

 

[Ron Resnick]

For now, prior to the forthcoming Stellavox preamplifier, the switch should always be on AC.
In DC position the input-caps are off (means bypassed).

The Stellavox preamplifier will have all devices linked in DC - no caps in the signal path, which is why the IDEM and DIADEM will be maximized in the dc mode.

That's a very cool design!

 

[Audioarts]

Gideon could you educate me a bit more on this, Is the actual dc signal amplified ? Or is the dc current just used for the circuitry ? And I assume there is a mechanism in place to block dc current from getting to the speakers ?

And secondly , will the pre amp have a battery , battery powered to fully take advantage of a dc current from the start ?

How about future dac .. will that be looped into same ecosystem?

What I find interesting (and unique I believe), is that no battery is envisioned for the preamp.

 

[pk_LA]

What I find interesting (and unique I believe), is that no battery is envisioned for the preamp.

"...Envisioned...," implies that they are still very much under design. What is the targeted release date?

 

[marty]

Marty - good eye!

I’m glad you point out the ac/dc switch because it’s a critical feature of the Stellavox amplifier design.

For now, prior to the forthcoming Stellavox preamplifier, the switch should always be on AC.
In DC position the input-caps are off (means bypassed).

The Stellavox preamplifier will have all devices linked in DC - no caps in the signal path, which is why the IDEM and DIADEM will be maximized in the dc mode. I heard it in this (dc) manner in Switzerland and the purity, speed and body, combined with an effortless power range has not been matched yet by my efforts with (ac) preamps. Close in some respects but not quite on the purist (dc) level.

The reason we have the ac/dc switch is that
most preamplifiers have capacitors in the output to block DC flow. So we erred on the side of caution and also to allow flexibility re client choice of preamplifier, as they would with any other ac based amplifier prevalent in high end, despite the recommended dc path with the Stellavox preamplifier.

Gideon

Thanks Gideon, but I'm confused. Tons of amps (and preamps) are direct coupled. To the best of my knowledge, nobody ever heard an amp with a DC blocking cap that sounded better with the cap than without it. (The best sounding cap is always no cap at all). Even good DC output preamps however can get flustered with input switching that may send a transient DC signal to the preamp output (sometimes heard as a pop). The Soulution 727 remedies this by inserting a DC blocking cap in the circuit momentarily when an input is switched that turns off in a second or two so the preamp remains truly direct coupled under listening conditions. Clever approach. One key advantage of SS circuits over tubes is to have a circuit that can be truly capacitor free. So I can't imagine why AC operation would be preferred when you can easily select the DC mode? If you have a preamp that doesn't send DC to its outputs, I wouldn't be able to resist listening to Stella in DC mode. What's the down side? A flip of a switch is all that's required to return to AC operation if it is preferred. Bottom line, color me skeptical that you "need" the companion Stella preamp to benefit from using the amp in DC mode with any other preamp, whether it be tube or SS.

 

[Audioarts]

Thanks Gideon, but I'm confused. Tons of amps (and preamps) are direct coupled. To the best of my knowledge, nobody ever heard an amp with a DC blocking cap that sounded better with the cap than without it. (The best sounding cap is always no cap at all). Even good DC output preamps however can get flustered with input switching that may send a transient DC signal to the preamp output (sometimes heard as a pop). The Soulution 727 remedies this by inserting a DC blocking cap in the circuit momentarily when an input is switched that turns off in a second or two so the preamp remains truly direct coupled under listening conditions. Clever approach. One key advantage of SS circuits over tubes is to have a circuit that can be truly capacitor free. So I can't imagine why AC operation would be preferred when you can easily select the DC mode? If you have a preamp that doesn't send DC to its outputs, I wouldn't be able to resist listening to Stella in DC mode. What's the down side? A flip of a switch is all that's required to return to AC operation if it is preferred. Bottom line, color me skeptical that you "need" the companion Stella preamp to benefit from using the amp in DC mode with any other preamp, whether it be tube or SS.

Marty, thanks for the good questions! Naturally, I consulted with Stellavox because I do know my limits and want to be accurate. I’ll try to relay my understanding of their approach along with their own explanations.

I’m certain the below points will raise even more questions, so I urge all those interested to contact Stephan at schertler@stellavox.swiss for a deeper education and understanding of their methodology.

Obviously the best capacitor is no capacitor but the standard in audio seems to be a capacitor on the input and on the output. An exception would be the speaker outputs of power amps, simply because on all passive speakers connected to an amp, there is no DC conflict.

Perhaps I’m mistaken but there are no active audio devices in direct coupled mode (Exception: those coupled from the same manufacturer). So the question is really about the definition of dc coupled; having capacitors on In and Out (not DC coupled from one device to another), but rather “inside” they are DC coupled from amp state to amp state to buffer state etc. So maybe we’re speaking about two different things which leads to their approach:

“The problem of direct coupling is complex and therefore not applicable from device X to deviceY, in consequence not defined by AES, NAB etc. (apart from some recommendations).
We have to imagine, when direct coupled, to different devices see each other through DC. So there is a DC current flow from one device to the other additionally to the music signal! This has far-reaching consequences and requires all inputs and outputs to be designed according to a common strategy, which all manufacturer offering DC coupled connection must follow . This is however not the reality. There are too many ways to think and build input and output amps.

Just an example of many: The first step would be that all designers refer the DC level to ground. But how could a designer at the output refer to ground, having chosen for justifiable reasons an unbalanced PSU? No signal would be the result, with the possibility of DC coupling only to similar (and rare) devices (maybe referred to 20 Volts or so?). Etc. etc.

Idea No. 1
As mostly seen, two devices X and Y are connected trough two capacitors, one on the output A and one on the input B. There is one capacitor too much, one is already enough to block DC and let just go through the music signal (AC) and to avoid the uncountable conflicts with DC. You know your preamplifier is decoupled with a cap on the output? So you can switch the IDEM input on DC. This will more or less sound better. But it is not DC coupling. It is a AC coupling with only one capacitor.

Idea No. 2
The upcoming source devices from Stellavox will have an incorporated “strategy” to be DC coupled from the pre or DAC to amp with pre output on DC and IDEM or DIADEM input on DC as well.”

Idea No. 2 is what I heard at the factory and it was quite significant in terms of liquidity, purity and effortless power, but the 727 is certainly no slouch!

 

[microstrip]

I’m certain the below points will raise even more questions, (...)

Can you post in normal font, as we (and you) usually do? I find bold extremely tiresome and disagreeable to read.

 

[marty]

Marty, thanks for the good questions! Naturally, I consulted with Stellavox because I do know my limits and want to be accurate. I’ll try to relay my understanding of their approach along with their own explanations.

I’m certain the below points will raise even more questions, so I urge all those interested to contact Stephan at schertler@stellavox.swiss for a deeper education and understanding of their methodology.

Obviously the best capacitor is no capacitor but the standard in audio seems to be a capacitor on the input and on the output. An exception would be the speaker outputs of power amps, simply because on all passive speakers connected to an amp, there is no DC conflict.

Perhaps I’m mistaken but there are no active audio devices in direct coupled mode (Exception: those coupled from the same manufacturer). So the question is really about the definition of dc coupled; having capacitors on In and Out (not DC coupled from one device to another), but rather “inside” they are DC coupled from amp state to amp state to buffer state etc. So maybe we’re speaking about two different things which leads to their approach:

“The problem of direct coupling is complex and therefore not applicable from device X to deviceY, in consequence not defined by AES, NAB etc. (apart from some recommendations).
We have to imagine, when direct coupled, to different devices see each other through DC. So there is a DC current flow from one device to the other additionally to the music signal! This has far-reaching consequences and requires all inputs and outputs to be designed according to a common strategy, which all manufacturer offering DC coupled connection must follow . This is however not the reality. There are too many ways to think and build input and output amps.

Just an example of many: The first step would be that all designers refer the DC level to ground. But how could a designer at the output refer to ground, having chosen for justifiable reasons an unbalanced PSU? No signal would be the result, with the possibility of DC coupling only to similar (and rare) devices (maybe referred to 20 Volts or so?). Etc. etc.

Idea No. 1
As mostly seen, two devices X and Y are connected trough two capacitors, one on the output A and one on the input B. There is one capacitor too much, one is already enough to block DC and let just go through the music signal (AC) and to avoid the uncountable conflicts with DC. You know your preamplifier is decoupled with a cap on the output? So you can switch the IDEM input on DC. This will more or less sound better. But it is not DC coupling. It is a AC coupling with only one capacitor.

Idea No. 2
The upcoming source devices from Stellavox will have an incorporated “strategy” to be DC coupled from the pre or DAC to amp with pre output on DC and IDEM or DIADEM input on DC as well.”

Idea No. 2 is what I heard at the factory and it was quite significant in terms of liquidity, purity and effortless power, but the 727 is certainly no slouch!

I appreciate the reply but either the explanation or my understanding of it lacks some clarity. With respect to the Soulution 727 preamp, the DC–20 MHz bandwidth strongly indicate a fully DC-coupled path from input to output in normal operation, with no fixed series coupling capacitor in that path. But that's not material to my query and is furthermore both OT and of little interest to anyone. (I would also add that the darTZeel NHB-18NS mk2 preamp is also a DC coupled design).

Rather, I asked why you would intentionally choose to put a DC blocking cap in the input of the Stella if you had the option not to do so? By your own admission, you preferred the sound of the amps at the factory when used in the direct-coupled mode. I'm not sure what preamp was used, but I suggest it is irrelevant as the sound of the amp when run DC is probably independent of the preamp used. Simply put, why add a coupling cap at the amp input (any amp!) if you don't need it? To answer my own question, the obvious answer is that you would add it if it sounded better in the AC mode than the DC mode. Since Stella conveniently provides a selector switch to allow for either mode to be used, it seems the experiment is both doable and easy to perform. I'm inclined to believe the DC mode will sound best (particularly in the bass) but I may be wrong.

 

[pk_LA]

When is the pre-amplifier supposed to launch?

Based on the words from Autoart it seems that they are still conceptual.

 

[Al M.]

Can you post in normal font, as we (and you) usually do? I find bold extremely tiresome and disagreeable to read.

Yes, I can't read the bolded post, my eyes are burning. So I won't.

 

[Audioarts]

When is the pre-amplifier supposed to launch?

Based on the words from Autoart it seems that they are still conceptual.

Pat - this Spring. The pre is completed but production is slated, along with the new StellaDac, for Spring. The Diadem stereo this January. Assuming we are on schedule, hoping to have the official launch in Vienna. I’m planning on launching stateside at SWAf and PAF. Any other questions?

 

[Audioarts]

I appreciate the reply but either the explanation or my understanding of it lacks some clarity. With respect to the Soulution 727 preamp, the DC–20 MHz bandwidth strongly indicate a fully DC-coupled path from input to output in normal operation, with no fixed series coupling capacitor in that path. But that's not material to my query and is furthermore both OT and of little interest to anyone. (I would also add that the darTZeel NHB-18NS mk2 preamp is also a DC coupled design).

Rather, I asked why you would intentionally choose to put a DC blocking cap in the input of the Stella if you had the option not to do so? By your own admission, you preferred the sound of the amps at the factory when used in the direct-coupled mode. I'm not sure what preamp was used, but I suggest it is irrelevant as the sound of the amp when run DC is probably independent of the preamp used. Simply put, why add a coupling cap at the amp input (any amp!) if you don't need it? To answer my own question, the obvious answer is that you would add it if it sounded better in the AC mode than the DC mode. Since Stella conveniently provides a selector switch to allow for either mode to be used, it seems the experiment is both doable and easy to perform. I'm inclined to believe the DC mode will sound best (particularly in the bass) but I may be wrong.

Marty - you raise excellent points and in the absolutist sense…, you’re correct - just maintain a purist dc chain, I’m with you… But as you know better then most, many audiophiles like to have the choice and flexibility to use a preamp of their liking. It’s no surprise that the hybrid school of combining an ss amp with tube preamp is well rooted in our community. Further, my clients have begun using various preamps to excellent effect. Cognizant of audiophile subjective tastes, Stellavox desires to accommodate with the ac/dc option.

Interestingly, the upcoming StellaDac will have an analog variable volume control option in digital only systems (in place of a pre/phono) and will also be dc into a Stellavox amp.

 

[pk_LA]

Pat - this Spring. The pre is completed but production is slated, along with the new StellaDac, for Spring. The Diadem stereo this January. Assuming we are on schedule, hoping to have the official launch in Vienna. I’m planning on launching stateside at SWAf and PAF. Any other questions?

Thank you for asking if there are 'any other questions!' There are! Many. So kind of you

What is the planned retail?
Is it one box, two, three?
What is the output impedance?
Are these products being manufactured in entirety in Switzerland by Stellavox?

 

[Audioarts]

Retail tbd but we should know in Spring prior to introducing to market. Once determined I will revert. Swiss tariffs are going from 39% to 15% to take effect soon which is certainly encouraging.

Two boxes with separate power supply, fully symmetrical class A DC amplifier open loop no feedback design. Stellavox has spent years researching and studying time distortions which imho evidences in the listening experience with this preamplifier.

I don’t know the output impedance but will forward to Stellavox.

Yes, Swiss Made in Mendrisio by Stellavox. In addition, many proprietary parts are designed AND made in house which is quite rare. The Stellavox high end division benefits from their pro audio division tremendously as that is in house as well with machinery and tooling. After visiting the factory this Summer, I was stunned at the extensive facility and obvious pride in keeping production Swiss Made. The engineers are musicians as well and Stephan Schertler toured as a double bassist; I’m mentioning this because you really hear (and feel) this musical authenticity in their equipment.

 

[Kingsrule]

If Swiss tariffs are coming down 25% does that mean the amps are coming down 25% ?

 

[Kvali1]

If Swiss tariffs are coming down 25% does that mean the amps are coming down 25% ?

I fear it’ll be more complicated , I suspect manufacturers and importers worked together during super high rate; and I suspect tariff is mainly applied to import price versus msrp ; but I’m no expert . But looking forward to seeing what solution , ch precision , goldmund and darTZeel do … oh wait , not darTZeel .

 

[Kingsrule]

Its all linear...cost goes down , retail goes down the same percentage. Profit margin stays the same %.
And do u really think any of the Swiss importers/ manufacturers here are "working together" (leaving money on the table on their end??) I really doubt that......
But of course you served up the perfect reason/excuse for them not to reduce pricing..

 

[Kvali1]

Its all linear...cost goes down , retail goes down the same percentage. Profit margin stays the same %.
And do u really think any of the Swiss importers/ manufacturers here are "working together" (leaving money on the table on their end??) I really doubt that......
But of course you served up the perfect reason/excuse for them not to reduce pricing..

I think it’s safer to rely on demand/supply rule. As long as there customers paying 100-300k for amps, nothing comes down. Once demand slows , maybe there will be a correction or more discounts …