Vinnie Rossi LIO modular integrated amplifier Associated Equipment

Sidebar 2: Associated Equipment

Analog Sources: Acoustic Signature Wow XL turntable + TA-1000 tonearm, Thorens TD-124 turntable with Abis SA 1.2 tonearm; Ortofon 2M Black & CG 25 DI II, Shure SC35C, Soundsmith Carmen, Zu Audio DL-103 phono cartridges.
Digital Source: Onkyo Integra DPS 7.2 universal player; Puresound A-8000 CD player; Halide Design DAC HD and Line Magnetics LM-502CA D/A processors.
Preamplification: Intact Audio step-up transformer; April Sound GB-1, LFD LE, Schiit Audio Mani phono stages; April Sound BB1, Simaudio Moon Neo 350P preamplifiers.
Power Amplifier: Simaudio Moon Neo 330A.
Integrated Amplifiers: Hegel Music Systems H160, Line Magnetic LM-518IA.
Headphone Amplifier: Schiit Audio Asgard.
Headphones: Audeze LCD-2, Audio-Technica ATH-M50x, Bowers & Wilkins P5, Sony MDR-7520.
Loudspeakers: DeVore Fidelity Orangutan O/93, Falcon Acoustics LS3/5a, KEF LS50, Magnepan .7, Morel Octave 6, Technics SB C700.
Cables: Interconnect: AudioQuest Big Sur & Cinnamon & Golden Gate, Auditorium 23. Speaker: AudioQuest Type 4, Auditorium 23, Kimber Kable 8TC. AC: manufacturers; own.
Accessories: Sound Anchor stands, Dr. Feickert Analogue cartridge-alignment protractor.—Herb Reichert

Vinnie Rossi
800 Main Street, Suite 125
Holden, MA 01520
(774) 234-0800

music or sound's picture

I hoped for an explanation of the main feature of the LIO. Each Ultra (or super) capacitor has apparently 350F with a max voltage of 2.7V and 9 of them have to be connected in series for each bank to reach 24V with 34F. So the statement of "6300F at 2.7V of total charge under the hood if they all were connected in parallel" is completely misleading because there are not connected in parallel. One bank is charging during the other supplies voltage separated from the charging circuit. As capacitors do not supply a constant voltage when discharging how is that voltage regulated? How often is a switch between banks necessary and does that switching have any influence on sound?

Vinnie Rossi's picture

Hi Music or Sound,

Correct - and Herb asked me about the total capacitance under the hood, which is 6300F worth of ultracapacitors. In use, each bank is approx. 38F (equivalent to 38,000,000uF) as 9 caps, each 350F, are connected in series.

You are also correct about the ultracapacitors not supplying a constant voltage (as they discharge). Over the course of approx. 10 minutes, they slowly discharge by about 4V. All modules downstream are linear voltage regulated, and the ultracapacitor bank in use always feeds them with a higher voltage than what we are regulating to.

Cap banks switching approx. every 10 minutes. It cannot be heard in the speakers or headphones. It happens very quickly (a couple of milliseconds) via relays switching the + and - terminals. Switching has no influence on the sound whatsoever, and at NO time is any of the audio circuitry connected to the capacitor bank that is charging, which is connected to the grid via an external AC to DC power adapter. So only DC enters the LIO. No internal power supply transformers. And the audio circuitry is ALWAYS 100% disconnected from the power adapter (which gets power from the mains). No matter how clean or dirty your power is, it has no influence on any of the audio circuitry because they always run isolated from it.

Feel free to contact me if you have any other questions. I'll be happy to clear things up for you. You can learn a lot from our website.

All the best,

Vinnie Rossi

Venere 2's picture

Are you related to Walter Rossi the guitarist? Ever build him a guitar amp :-)

dreite's picture

According to JA, the unit switches capacitor banks every three minutes with a 1WPC load and there IS an audible click. And the power amplifier performance is considerably short of the published specifications.
I also don't understand 60Hz (and components) making their way into the measured performance if the circuitry is "ALWAYS 100% disconnected" from the power adapter.

If your objective testing indicated better performance than JA measured, you should have noted that in your reply on the "Manufacturers' Comment" section of the print Stereophile. If he made a mistake in his testing, I'm sure JA would be more than willing to entertain an explanation(s).

John Atkinson's picture
dreite wrote:
According to JA, the unit switches capacitor banks every three minutes with a 1WPC load and there IS an audible click.

Audible in the quiet of my test lab with me sitting next to the amplifier. But with music playing on speakers, the click will be masked.

And forgive my impatience with the original poster, but he should have read the entire review before commenting.

dreite wrote:
I also don't understand 60Hz (and components) making their way into the measured performance if the circuitry is "ALWAYS 100% disconnected" from the power adapter.

Spuriae at the wall AC frequency and its odd harmonics are primarily due to magnetic interference, so as the LIO does not have a hefty power transformer and has that hefty ultracap supply, I was puzzled by this. I did check the possibility that my test equipment had some ferrous content, like the switches in the load resistor bank, but this did not appear to affect the LIO's measurements.

The noise and distortion performance of some amplifiers is approaching the point where factors like this can be seen. But the LIO's power amplifier module doesn't get close to equaling those amplifiers.

John Atkinson
Editor, Stereophile

CG's picture

AC remnants are really hard to get rid of in most test set-ups. The transformers in most - but not all - power supplies are close to saturation at some part of the incoming AC waveform, especially if there's junk on the ac power. This comes with the territory, especially with capacitor input power supplies. When the transformers reach that non-linear point of their magnetic properties, they tend to radiate a lot. This can very easily couple into the equipment under test as well as the test set-up itself.

There's thousands of references on this topic to be found in a Google search.

Vinnie Rossi's picture

Hi Venere2,

I am not related to Walter Rossi (or Carlo Rossi, or Martini and Rossi) - lol!

Hi dreite,

Since the review unit was made, we started applying damping material on the internal relays for the ultracap bank switching. If no music is playing and you are right next to the LIO, you probably will still here a slight 'click' when the banks switch. With music playing, I doubt you will hear anything from LIO (and certainly not in the speakers, headphone output, or preamp outputs).

Hi JA,

I was also puzzled why you measured some 60Hz components, especially since the LIO's power adapter is external (so only 24Vdc is fed into the LIO to charge the capacitor banks). Even using very sensitive IEMs (headphone jack), we could not hear the slightest bit of 60Hz noise or harmonics. I'm wondering if they were getting into the LIO via the external connections during the test process (maybe via the signal grounds)?

Best regards,

Vinnie Rossi

jmsent's picture

regarding the linear regulators in the power supply? Does that include regulating the supply rails for the output transistors? And, regarding the switching time between banks, I am assuming that the 10 minute figure you gave was with the amplifier in idle with no signal at the speaker terminals? JA got a much shorter switching time of 3 minutes with just 1 watt output, and I assume that would be shorter still at full output?

Vinnie Rossi's picture

Hi jmsent,

Yes, the circuity for every active module (e.g. dac, phonostage, power amp, etc) features linear voltage regulation. In some cases, multiple linear voltage regulators. For example, the dac has separate regulators for the clocks, the XMOS chip, the d/a chips, the analog output stage, etc. And no switching regulators are used for any module (no DC-DC converters).

Regarding switching between banks, the timing does vary based on how you have your LIO configured. Configured just as a dac, phonostage, or linestage w/o tubes runs longer than with the speaker output module, as there is typically less avg. current draw. If you have your LIO configured with the speaker output module, there is some quiescent current always being drawn when the speaker output module is ON, and there is also current draw that depends on the impedance of your speakers and how loud you play.

Running a constant 1W per channel via a test tone into an 8-ohm resistor will likely draw more average current than listening to music (except maybe when playing at loud levels and/or into lower impedance speakers). It is unlikely that the banks will be switching in less than 3 minute intervals, but it is still possible and it makes no difference if they switch every 3, 5, 7 or >10 minutes. The listener does not need to be concerned about this as the process is automatic and seamless. To the listener, the LIO is either turned ON or OFF like any other component.

Please let me know if you have any additional questions, and also feel free to contact me via email and/or phone call.

Best regards,

Vinnie Rossi

otaku's picture

Does John or Vinni or anyone else here have any knowledge or ideas about the similarities and differences between the LIO's Ultra DC supply and Bel Canto's Virtual Battery Supply (VBS), particularly in the C7r?

Vinnie Rossi's picture

Hi otaku,

They are quite different. From reading the VBS white paper, they are using a switch mode power supply (SMPS) that is always connected to the audio circuitry (not disconnected from it like a battery, or ultracapacitor banks as in the LIO).

Somebody please correct me if I misinterpreted this.

Best regards,

Vinnie Rossi

corrective_unconscious's picture

I don't understand the market for products like this: Apparently sophisticated and certainly expensive...but with so few watts. Bluetooth "capable" speakers strike me the same way, whatever their price level - they just don't seem to make sense as values. (Although I can understand people don't like cables.)

aslee's picture

Wonder if it can be powered by good quality SLA or LiFePO4 batteries?
If so, any further improvements in sound?