Telos

Amplifiers


Pre-amplifiers


Alluxity: PRE ONE

Alluxity PRE ONE fully featured balanced preamplifier

Alluxity PRE ONE is fully featured balanced preamplifier hewn from a solid block of aircraft grade aluminium, with advanced touch screen technology to take ease of use to a new level.

Stunning award winning sonics and deep Danish design heritage

The PRE ONE has two gain stages per Channel driven by a custom built ultra-high quality relay volume control. It appears elegantly simple.

The topologies of the amplifier modules are balanced with zero global feedback. This prevents even minor phase errors and low noise levels. As the modules are easy to exchange, futur

The topologies of the amplifier modules are balanced with zero global feedback. This prevents even minor phase errors and low noise levels. As the modules are easy to exchange, future upgrades are not only easy, but also cheap compared to exchanging to a new preamp.

The Pre One features a total of 5 inputs with 2 RCA and 3 in XLR. There is 2 outputs one for both RCA and XLR but also a dedicated bypass output.

The volume is adjustable from -66dB to +6dB.

Pre - amp One
Inputs: 3 x XLR, 2 x RCA, 1 HT Bypass
Outputs: 1 x XLR, 1 RCA
Dimensions: 110 H x 435 W x 300 D mm
Weight: 14 kg.

HiFi Review Magazine “2013 Product of the Year” Award!! Well done to Alexander Vitus Morgenson the designer.

As the son of the globally respected Hans-Ole Vitus ot Vitus Amplifier fame, Alexander has studied under the tutelage of a master. Qualified in his own right to design and build these wonderful pieces for the modern age of interconnected appliances, he has stepped out into the limelight and wowed everyone with his first class effort. Designed and built entirely in Denmark in a purpose built factory with the most up to date surface mount machines and laboratory conditions the build quality is that of the upper echelon.

Smart applications design and integration with Apple remote make this an elegantly simple preamplifier to operate.

Sonically we hear the musicality and freedom from grain expected of a top flight design. Extended responses mean no detail is obscured but you wont get fatigued from long listening sessions. Deep and powerful bass is also a hallmark of the design. Worth a serious audition!



Ypsilon: PST100 TA

PASSIVE Transformer Attenuator Preamplifier

PST 100 is also available without the valve stage for systems that don’t require additional gain. This version is equipped with the transformer attenuators and is called PST 100 TA. Notice that it is fully upgradeable to the full version at any time by returning to factory

PST 100 TA

PST 100 is also available without the valve stage for systems that don’t require additional gain. This version is equipped with the transformer attenuators and is called PST 100 TA. Notice that it is fully upgradeable to the full version at any time by returning to factory

Your PST-100 has six inputs on the back panel. With input 4 being input/rec for both input signal and recording output signal. In input 6 an XLR connector is used which is unbalanced.

The volume is controlled by an output transformer. The transformer has 26 steps of 3db, 2 db, 1,5 db and the final four steps are of one db attenuation.

SPECIFICATIONS PST-100 TA

BANDWIDTH 9Hz-100KHz  –3db
OUTPUT IMPEDANCE 150 ohm
INPUT IMPEDANCE 50 Kohm
GAIN(in active mode) x 7(16,9db)
POWER CONSUMPTION 100 VA maximum
DIMENSIONS 400x180x410  (WxHxD)mm
WEIGHT 25 Kgr

This preamplifier has all the sonic attroibutes of the more expensive PST100 Preamplifier with out the active gain stage. Horn Loudspeaker lovers will find this a perfect solution. Owners can upgrade at anytime to the Active Gain Stage by a factory upgrade.

Sonically sublime purity in every aspect. A masterpiece.



Ypsilon: PST100 MKII

Vacuum Tube Preamplifier with Transformer Volume Control

Preamplifier with volume control output transformer custom-wound at Ypsilon on an amorphous double-C core. The impedance of the output stage, which is hardwired with fine, custom-drawn silver wire, is around 600 ohms. The active stage is a small, single-ended amplifier using Siemens C3M Tubes with 10000 Hour life.

Most manufacturers develop a circuit for their power amplifier and then use the design for their preamplifier. The raison d’etre of a power amplifier is to amplify the signal and drive the loudspeakers. That of a line preamplifier is to draw together the various source components; to attenuate the signal in order to achieve "volume control"; to have low enough output impedance in order to drive the cables; and finally, to provide gain if it is required. It performs totally different duties to those of a power amplifier and needs to be designed in a totally different manner.

Conventional wisdom suggests that the most critical part of a preamplifier is the active circuit design. Ypsilon, however, believe that the means of signal attenuation (the volume control) is the most critical to the overall sound of a preamplifier. Most designers use resistor attenuators for volume control. Ypsilon themselves have used resistor attenuators with high quality resistors (Vishay, Holco, tantalum types etc.) in the past, but that was before they developed a very special transformer as the means of attenuation. It was immediately apparent just how grainy and discontinuous resistors sound, even the best of them. The short explanation of this observation is that the series resistor transforms the constant voltage into current and the parallel resistor the constant current into voltage. The materials used in resistors are far from ideal as conductors- they sound much worse than pure copper or silver- and they do a lot of harm to the signal.

In a transformer, however, the magnetic circuit can be ultra linear when the very best core materials are used. The sound of such materials is much more musical and detailed compared with the best resistors. So Ypsilon produced, in-house, a special transformer attenuator with 31 taps.

The active gain stage is a no - feedback s.e. ,C3m triode, transformer coupled. The power supply uses valve rectification(using the 6CA4) and choke filter. Wiring is point to point with custom made pure silver wire. The transformer attenuator is placed after the valve stage, preserving the purity and micro details of the signal.

The maximum attenuation is 52db and maximum gain is 16db. Output impedance is 150 Ω max. PST is the pinnacle in preamplification. It is a must have component for building a "no holds barred" system.

Ypsilon's co-owner and chief designer, electrical engineer Demetris Backlavas, believes that the key to a preamplifier's sound is the means by which it attenuates the signal it's fed. Instead of the more commonly used resistor attenuation, Backlavas uses a very linear, 31-tap transformer that Ypsilon winds in-house. By comparison, he says, attenuators that use even the finest-quality resistors tend to sound grainy and discontinuous because the in-series resistor converts voltage into current, while the parallel resistor turns current back into voltage.

The problem, according to Backlavas, is that, in order to resist, a resistor must be made from a bad conductor of electricity. Copper and silver are good conductors and small-value resistors can be made from these metals that, not surprisingly, can sound very good. Unfortunately, it's impossible to use copper and silver to make high-value, wideband resistors because of the parasitic inductance that goes along with the need to use coils of very many turns. In addition, resistor-based attenuators waste signal energy by turning the attenuated energy into heat.

In fact, transformer-attenuated preamplifiers—or, more precisely in this case, autoformer-attenuated preamps, in which the primary and multi-tap secondary overlap—aren't new. The advantage of such an attenuator over one that uses resistors is that energy is transformed and not lost as heat. Backlavas gave an example: starting with a source impedance of 1200 ohms, attenuating the signal 10dB (or 3.16 times), produces an output with lower voltage and higher current and an impedance of 120 ohms (1200/3.162), which has an easier time driving loads, unlike the less amplifier-friendly results produced by a passive-resistor attenuator.

The core material must have low hysteresis (hysteresis being like unwanted "magnetic memory") at both low and high frequencies, and linear magnetic permeability with flux and frequency.

However, there is more to know about this microprocessor-controlled circuit, which features both active and passive modes of operation. In active mode, high-quality silver-contact relays route the input directly to the transformer volume control, up to step 6. The controller then routes steps 7–37 through the active stage, to produce a maximum gain of 17dB.

When the PST-100 is set to passive mode, its active stage never kicks in. (The PST-100 is available in a less-expensive TA version that only operates in passive mode.) Instead, the signal is routed only to the transformer volume attenuator, bypassing the active stage altogether, with step 31 producing 0dB (unity) gain. In order to drive the transformer efficiently, the manual suggests not running the system in passive mode with sources whose output impedance exceeds 3k ohms.

Regardless of mode, attenuation is 3dB per step up to step 5. Between steps 5 and 10, each step is 2dB, and steps 10–28 are 1.5dB each. The final three steps (35–37) offer 1dB of attenuation each.

In addition to transformer-based attenuation, the PST-100 features 6CA4 tube rectification, choke supply filtering, and a zero-feedback active stage based on a carefully selected Siemens C3m pentode tube configured as a true triode and transformer-coupled to the output. The power supply uses Mundorf and Jensen four-pole electrolytic caps, chosen based on listening tests.



Thrax: Dionysios

Tube Line level PreAmplifier – remote controlled

Dionysios is a single ended, single triode stage transformer coupled remote controlled line level amplifier with Balanced and Single Ended Output

The line level pre-amplifier or control amplifier, is still the centrepiece of a High-End audio system. It is responsible for source selection, signal conditioning and volume control. It has to match the output of your source to the input of your power amp. Its output stage must be able to drive any power amplifier through any length of cable with optimal quality-via balanced and unbalanced lines.

The Dionysios is fundamentally different and as simple as it can get. It uses a custom wound transformer with various winding ratios and by means of computer controlled switches between the output taps allows for precise volume control without using resistors in the signal path. This methodology is also used by several well respected designers including Ypsilon Electronics, Wavac and Kondo.

The Input of a pre-amplifier has to provide optimal loading for the source component to develop its full potential allowing it to extract the maximum amount of information while keeping all noise picked up on the way out of the signal chain. Thrax designer Rumen Artarski hails from the Pro-Audio and Studio world and through research and evaluation of the various approaches settled for the most obviously “perfect” method - a transformer!

Some of the advantages are:

Inductive loads are very well received by almost all output topologies It provides complete isolation from the rest of the system It stops EMI/RFI and provides truly balanced differential input. To be fair transformers have disadvantages - they are expensive and few know how to make them properly.

The volume control of a pre-amplifier has to adjust the level of the input signal to the value required by the power amp without burying in noise to the low level information and transferring enough power to properly drive the amplification stage without affecting it’s operation.

Potentiometer and resistor ladders as sophisticated as they might be have a fundamental flaw. They operate by dumping the unnecessary signal across a resistor. It is like driving a car with fixed engine power (signal) and adjusting the speed with the brakes (resistor)!

The Output has to provide absolute optimum driving signal for the following power amplifier’s input stage. This would include: Low impedance, DC free, truly balanced, isolated from noise sources and the other components in the system. The solution yet again is a transformer. As a bonus it is the perfect load for vacuum tubes.

To reduce power supply noise further, instead of the normal arrangement of bridge rectifier and electrolytic capacitor bank, we use a choke input full wave tube rectifier arrangement. This practically eliminates switching noise and anything that comes before the choke stays there. The other beauty of this topology is that the choke keeps the voltage on the capacitor bank pretty constant. In our case this allows for a considerably small capacitor bank to open the possibility of using vibration resistant military paper in oil capacitors for the job that would last a lifetime.

The chassis to house all of the above had to be a masterpiece itself. Milled from solid plates of different thickness 6061T651 grade aircraft certified aluminum are interlocked together to form a ring like structure. The power supply mounted on the left sidewall of this structure and the signal transformers on the right side. Two semi flexible bars on which the motherboard and its heat sink are attached then support this ring. The top and bottom plates link all sides of the ring with the flexible bars and the feet made from carbon doped plastic on flexible screws. There are no screws visible anywhere on the chassis. And the chassis feels like a solid block.

The power supply of Dionysos uses a very well known but extremely rarely used arrangement. Thrax use a C core transformer with a gap in the core to prevent any saturation of the core from distorted mains or a DC component in the mains.

As the power transformer is in the same case Thrax chose a design that has two identical sets of windings (essentially two transformers) on the same core.

This way all the nasty magnetic and electrostatic leaks cancel each other and it does not influence any of the other components in the chassis.

The ergonomics. It doesn’t matter how advanced a technology is if it is not useful. Thrax anticipated the possible needs of our clients. The Dionysos has 4 inputs on RCA connectors and 2 inputs on XLR connectors. All inputs are balanced differential unless the grounding option is engaged on the RCA inputs. As we switch the ground plane when switching inputs there are no hum loops and induced ground noises, allowing for large setups with multiple sources powered from different mains outlets in the house. It applies for the outputs as well.

For those that use bi-amping Thrax have accommodated 2 simultaneously active sets of outputs.

It might be considered legacy but for Open Reel afficianados Thrax have implemented a buffered tape output that could be disengaged when not in use. They also have a level set function programmable on any input allowing the preamplifier to be in the loop of home cinema processors when the music and cinema systems share amps and front speakers. Controls are as simple as possible and self-explanatory including an absolute phase switch with memory for each input. All functions are available on the supplied remote.

Specifications:

• Inputs
- 4 pair unbalanced RCA connectors
- 2 pair balanced XLR connectors
• Output
- 2 pair unbalanced RCA connectors
- 2 pair balanced XLR connectors
- 1 pair unbalanced RCA connectors – tape out
• Attenuation steps ………………..............................................................…….. 32
• Volume Control Range
- Minimum gain …………….......................................................…….. -46dB
- Maximum gain …………........................................................…….. +18db
• Power supply ………………......................................................…….. 115 or 230 V
• Power consumption ………..……........................................................…….. 45W
• Dimensions ………………....................................…….. 432W x 400D x 120H mm
• Weight ………………............................................................................…….. 15Kg
• Finish ………………...............................….. Black or Silver anodized aluminum
• Tube compliment :
- 1 x 6H6П amplification
- 1 х 6Ц4П rectifier

One of the best preamplifiers you will ever hear! Bar none!



Sutherland: Line Block - Destination Series

Reference Solid State Line Level Preamplifier - Dual Mono

The Line Blocks are mono line-level preamps --- two of them for stereo. You can carry the advantages of true mono construction all thru every element of your system (that is, everything but the cartridge !). Ron Sutherland, known for his well-regarded phonostages, has recently brought his engineering skills to building preamplifiers and a power amp.

Sutherland Engineering offers a brand new line called the Destination Series whose models can be characterized by “channel-separated construction”; everything is housed in separate L and R<

The Line Blocks linestage adds a third chassis just for the control electronics: input selection, volume control, and the display—which gets a bit of retro chic in the form of a pair of 1950s-style Nixie tubes whose elements display numbers depending on which elements (within the tubes) get voltage fed to them.

The two other Line Blocks' chassis have all the input and output connections, and are where the signals are actually buffered and amplified, thereby keeping the control electronics well away from the audio signals.

 

Kansas City Missouri is home to a few secrets. Secret sauce recipes for BBQ that can't be copied, home of Western Electric tubes which to this day are unrivalled and a few local wizards like Ron Sutherland who produce truly outstanding electronics.

Ask Ron Sutherland about beauty and his mind travels to the tall grass prairie in the flint hills of Kansas. In those flowing waves of tall grass, Ron sees the elegant patterns of life. The purity of simplicity and the essence of design.

Line Blocks are his Destination Series Reference grade Preamplifier solution.

We are glad he is free to pursue his passion and pure approach to making music come alive in your home.

 

 

 



Sutherland: N1 Preamp and Phono

Solid State Preamp and Phono with Nixie Tube Display

Preamp and phono stage in one box. The N1 also includes what we would expect from a modern design. It has remote control of volume, input and mute. Each component is carefully selected to bring you closer to your music. AND it uniquely incorporates Sutherland circuitry derived from the cost-no-object Destination series.

To fully appreciate the heart-felt passion that went into every detail of the N1, you also need to study the thoughtful, meticulous layout inside the case. Every detail makes for ‘pride of ownership’. The machined aluminum front panel, the tempered glas

To fully appreciate the heart-felt passion that went into every detail of the N1, you also need to study the thoughtful, meticulous layout inside the case. Every detail makes for ‘pride of ownership’. The machined aluminum front panel, the tempered glass display window, the understated minimalism --- all speak of old fashioned pride of craftsmanship.

That’s the N1 story. But the true appreciation and enjoyment of the N1 is really based on direct experience.

As we surge ahead, focused on the latest break through, it is easy to loose sight of prior art. The N1 design reaches back to incorporate the latest technology of 1955. That would be the Nixie tube, the first numeric display.

The design then moves forward to mine other historical treasures.

In the 60s, 70s and 80s, all preamps were full-featured. That is, they included a phono stage, a line stage and a power supply all in one box. There are significant advantages in going that way. The installation is simpler, the cabling requirements are simpler – it has a feeling of concentrated purpose.

All preamps of that era had single-ended circuit topology. That was the standard and had the very significant advantage of simplicity of the signal path. More recent marketing efforts promote balanced connectivity. Balanced topology imposes twice the circuitry into the signal path. Abandoning single-ended is not an advancement.AND playing vinyl (or should I say records?) was how we accessed our music. The advantages and enjoyment of vinyl are more treasured now than ever before.

The N1 also includes what we would expect from a modern design. It has remote control of volume, input and mute. Each component is carefully selected to bring you closer to your music. AND it uniquely incorporates Sutherland circuitry derived from the cost-no-object Destination series.

To fully appreciate the heart-felt passion that went into every detail of the N1, you also need to study the thoughtful, meticulous layout inside the case.

Every detail makes for ‘pride of ownership’. The machined aluminum front panel, the tempered glass display window, the understated minimalism --- all speak of old fashioned pride of craftsmanship.

That’s the N1 story. But the true appreciation and enjoyment of the N1 is really based on direct experience.

Installation is straight forward. The N1 will automatically accept incoming AC line voltages between 90 volts and 260 volts. No adjustments are necessary. It is designed to be powered up all the time. There is no on/off switch.

The N1 dissipates very little heat. It has no special ventilation needs. However, do not place it on top of heat generating components – like power amplifiers.

All right channel connections are on the upper row of connectors.

All left channel connections are on the lower row of connectors.

There are two sets of output jacks per channel. One output would go to your power amplifier. The second could be used for a subwoofer, a recording device or other accessory. Output impedance is a low 200 Ohms and can drive long runs of interconnecting cable, if necessary.

Line level inputs use connectors 2 thru 5.

Input 5 is a unity gain pass through for integrating into your home theater system.

Phono uses input 1. Attach your turntable’s grounding wire to the thumbscrew near the phono inputs.

 

When AC power is first applied to the N1, software begins a power up sequence.

The digital display will count down from 60 seconds. When 00 is reached, the initial selected input will be 1 and the initial selected volume will be 00.

To select a different input, press the control knob. The two digits of volume indication will go off. That leaves only the input display illuminated. The outputs are now muted and the knob is used for selecting an input. The N1 is unmuted by pressing the front panel knob again. The volume numeric indication comes back on and the volume level will then ramp up to the value last used with that particular input.

The N1 has a timer feature that will automatically turn off the Nixie displays.

If the N1 controls (knob or remote) are not used for a certain time period, the Nixie displays will go off and a yellow LED will go on. There is no change is audio settings. The Nixie display simply turns off. You can select the time period (in hours). To do so, press and hold the control knob in for 5 seconds. When it is released, the yellow LED will blink and you can select the time period with the control knob. When set to 0, the timer is disabled and the Nixie display will stay on continuously. After selecting the time period, press the knob again to return to normal preamp operation.

CONFIGURATION OF THE PHONO STAGE

The phono stage is configurable for many gain and loading options. It is shipped with 200 Ohms for loading and 60 dB for gain.

You can easily choose other values. Remove the top cover. On the left side of the audio board are connectors for the loading and gain cards. Simply plug in the value of your choice. Each card carries two values. With no card in the loading socket, you will have a loading of 47.5 k Ohms. Each card will connect to both the left and right audio boards – thus both channels will be set to the same value.

THE REMOTE CONTROL

If you’ve been frustrated by complex remote controls, you will appreciate the N1’s remote. It is so simple there was no need to even label the buttons. And yet it still does more than you might expect.

Basically there is the volume up button, the volume down button and the mute button.

Beyond those basic functions, are more thoughtful and useful aspects. When the N1 is muted (by either pressing the front panel knob or the orange mute button on the remote), the volume level quickly goes to zero and the two digits of volume indication go off. That leaves only the input display illuminated.

The remote up/down buttons then function to make changes to the selected input. When the N1 is then unmuted, the volume numeric indication comes back on and the volume level will then ramp up to the value last used with that particular input.

The orange LED on the remote shows how rapidly commands are being sent. One command for each flash. A quick push of the volume up or down buttons will send only one command. Volume can be easily raised or lowered by one value. Holding the button down for longer will send more commands and at a faster rate.

DISCUSSION OF DESIGN

The N1 uses a stack of two identical mono boards. Each board contains a mono phono preamp, a mono input selector, a mono volume control, a mono line stage, multiple stages of power supply filtering / regulation and a processor for control.

Each channel of music will see exactly the same circuit and physical layout. The most subtle details between the two channels will be preserved as they travel thru precisely identical signal paths.

Construction details contribute not only to the N1’s performance but also to pride in owning a well-crafted instrument. The neat and orderly internal layout reflect the attention to every design detail.

THE PHONO STAGE

The phono stage is the same circuitry as used in the Destination level PhonoBlocks. Only the power supply is down sized a bit. It is assumed that vinyl is the primary listening source. This phono stage compares to the finest available separates.

One half of each audio board’s area is dedicated to the phono stage.

THE LINE STAGE

The line stage is the same circuitry as used in the Destination level LineBlocks. Only the power supply is down-sized. The line stage circuit and layout of the N1 was literally lifted from the LineBlock’s CAD files using copy and paste.

THE CONTROL SECTION

The N1 uses exactly the same control board as the LineBlocks.

The Nixie displays are not only an aesthetic retro touch, they are bright, large and easy to read from a distance.

Control couldn’t be simpler. One knob for input selection, volume control and muting. The N1 will also conveniently remember and restore the volume level last used for any particular input.

Muting is fast, but volume is more slowly ramped up when unmuting.

THE WHITE NOISE GENERATOR

It can take quite a long listening time before a high resolution component reaches its full performance potential. The N1 is no exception.

However, the N1 has a built in white noise generator that can be used as a break-in signal. Simply select input number 6 and the white noise generator will be enabled. When an input other than 6 is selected, the noise generator is completely disabled and out of the listening path. You can use the white noise generator with your power amplifier either on or off. If it is on, you will hear white noise from your speakers. Thus all of your system will be subjected to a break-in signal.

 

SPECIFICATIONS

GAIN LINE STAGE: 12 dB (max, display at 99)

0 dB (display at 76)

GAIN PHONO STAGE: 45 dB, 50 dB, 55 dB, 60 dB

LOADING PHONO STAGE: 100, 200, 475, 1K, 10K, 47K

INPUTS: Input 1 is phono, Inputs 2, 3 and 4 are line level with adjustable volume

Input 5 is unity gain pass thru for Home Theater

Input 6 enables a built in white noise generator

OUTPUTS: Two paralleled per channel.

SIZE: 3.5” high X 17” wide X 18” deep

 

As we surge ahead, focused on the latest break through, it is easy to loose sight of prior art. The N1 design reaches back to incorporate the latest technology of 1955. That would be the Nixie tube, the first numeric display.

The design then moves forward to mine other historical treasures.

In the 60s, 70s and 80s, all preamps were full-featured. That is, they included a phono stage, a line stage and a power supply all in one box. There are significant advantages in going that way. The installation is simpler, the cabling requirements are simpler – it has a feeling of concentrated purpose.

All preamps of that era had single-ended circuit topology. That was the standard and had the very significant advantage of simplicity of the signal path. More recent marketing efforts promote balanced connectivity. Balanced topology imposes twice the circuitry into the signal path. Abandoning single-ended is not an advancement.

AND playing vinyl (or should I say records?) was how we accessed our music. The advantages and enjoyment of vinyl are more treasured now than ever before.

The N1 also includes what we would expect from a modern design. It has remote control of volume, input and mute. Each component is carefully selected to bring you closer to your music. AND it uniquely incorporates Sutherland circuitry derived from the cost-no-object Destination series.