Jump to content

B.M.C - Tysk brutal-hifi!


Recommended Posts

Årets klart mest intressanta nyhet på Munchen-mässan finns nu representerat i Sverige av Transient Design: B.M.C Audio

bmc_web.jpg

http://www.bmc-audio.de/

I augusti så kommer även deras superläckra förstärkare med 2000 VA trafos!

4315764-origpic-1e6e57.jpg

Listan på all kul och innovativ teknik är lite för lång för att lägga ut här i ett svep så jag lägger ut en bit i taget här i tråden. Den som är otålig kan givetvis själv gå in på deras hemsida och studera allt direkt.

Mer info och priser kommer inom kort!

Mvh Lasse

Link to comment
Share on other sites

Vi börjar väl med signalkällan DAC1

4315768-origpic-0b1ca1-1.jpg

Pris: 27500kr

Lite info:

For receiving digital audio signals besides the established SPDIF-compatible interfaces (AES/EBU 110 Ohm, coaxial 75 Ohm and optical Toslink) there is the exceptional and consequent “Superlink”. Unlike SPDIF transmission the different digital audio signals are not merged into one single signal stream and decoded to separate signals again after being received by the DAC. SPDIF surely makes sense from the commercial point of view, but Superlink is the solution without compromise, which requires 4 times the amount of interconnection cables but skips any coding process. Left/right-clock, bit-clock, digital audio music data are transmistted from the CD-transport to the DAC while the master-clock is generated inside the DAC and sent to the CD-transport. The transmission is done with 4 x 75-Ohm BNC cables with impedance matching.

Superlink results in a more intense link to the music, wider and more realistic sound-stage, more details and beautiful sound colours. Due to the consequent approach of Superlink just the shortest signal path is available and thus the sample-rate-converter (alias SRC, or up-sampler) is not available.

For standard SPDIF inputs the SRC may deliver a better result whenever the source signal includes a noticeable amount of jitter. But due to its digital signal proceeding an SRC adds a certain note to the music signal.

All other options are available for any digital input. Two different digital filters are available with either “Flat” frequency response optimisation or “Pulse” for best dynamic response and with minimised pre- and post ringing. The pulse filter has a soft treble roll off, but avoids specifically the unnatural pre-ringing. In spite of its filter's soft treble roll off, it is generally considered as more transparent sounding.

Furthermore there is a “Low” ( 32fs) and a “High” (128fs) oversampling rate available. Both options have their individual character and are suitable for decent sound tuning. “Low” has a more dynamic and detailed expression, while “High” is softer and smoother.

The digital signal performance is further optimised by a clock synchronisation circuit right in front of the DAC-Chips. All digital signals are re-timed to the local master clock and thus the point of lowest jitter is at the DAC-Chip where the analogue music signal is made.

The conversion is made by two 24-Bit / 192kHz TI/Burr-Brown PCM1792 chips with current output.

The output current is filtered and converted to an output voltage by discrete, fully balanced I/V converters, which operate feedback free. Thanks to the special “Current Injection” circuitry a maximum of sound quality is preserved, which is stabilised with the unmatched “LEF” driver circuit keeping all sonic details.

Originally those circuits were designed to put focus on the sound quality and leave the measurement specifications second, but the present standard is on a level that leaves no need for such a choice: Both are on top level and the sound in a class of its own. Eine Klasse für sich.

Edited by Transient Design
Link to comment
Share on other sites

Som en option på DAC1 så går försteg att välja till och då heter produkten DAC-PRE och får ett pris på 31000kr

Om man även använder förstärkare från BMC så sker det nåt mycket spännande. Volymen kommer inte att regleras (strypas) i själva försteget utan sker istället i slutsteget! Detta fungerar även med DAC1.

Link to comment
Share on other sites

BMC MCCI

4275111-origpic-b3422a.jpg

Pris 21500kr

Detta Riaa-steg är en fantastisk produkt! Första testerna på det visar att BMC verkligen lyckats då uteslutande toppbetyg har utdelats. 100% gavs som kritik i en ledande tysk tidning.

info:

B.M.C. applies exceptional concepts to their components to make technical innovation and perfection serve music reproduction.

B.M.C.'s Phono MCCI is a truly balanced, global feedback free, passively equalised moving coil phono pre-amplifier with the exceptional Current Injection input and LEF single ended class-A output stages.

Amplifier features

1. Balanced Current Injection input

2. Common base circuit for highest bandwidth

3. Widely automatic gain adjustment

4. Feedback free circuit with very short signal path

5. Full balanced circuit

6. Balanced LEF single ended class-A output

EQ and Other Options

1. Passive equalisation with the I/V converter

2. Neumann corrected RIAA, or traditional RIAA

3. RIAA options for low end extension and warmth

4. 3 selectable gains

5. Subsonic filter selectable

High End Parts and Exteriors

1. Special ultra-low-noise transistors with very high Hfe, 10 in parallel

2. “Balanced Current” capacitors for precise and colourful sound

3. Induction-free Polystyrene capacitors

4. Metal-thin-film resistors with 0,5% tolerance

5. Fully gold plated 4-layer printed board

6. Copper plated iron shield cover

4275111-origpic-2c61b6.jpg

Amplifier circuit

“Current Injection” (CI) means a current input, in which the pickup cartridge itself becomes part of the amplifier. The MC-cartridge is a generator injecting its current into a system of balanced DC-currents, directly creating an amplified output voltage. CI uses the original current of the cartridge and therefore the amplified voltage has a very precise analogy to the source signal. Actually this CI is rather an I/V converter than an amplifier in the traditional sense. Dynamic losses and distortions are remarkably lower compared to common voltage amplifiers.

The Current Injection input circuit is an unusual application of the common base circuit, which is known for widest bandwidth, lowest distortion, best dynamics and musical performance. In common applications the disadvantage would be a low input impedance, but fortunately this matches perfectly to our most important audiophile sources: MC-cartridges and current output digital/analogue converter. Already, for decades some, of the best phono MC amplifiers use common base circuitry, but just with the balanced CI input circuit such an idea can be applied without compromise.

The current for the CI-operation is determined by the cartridge's impedance and the phono amplifier's input impedance. This way the resulting gain in a wide range adjusts automatically to different MC-cartridges as a high-output MC may generate a higher voltage, but due to the higher impedance it reduces the current.

The whole signal proceeding is done in two short gain stages. Due to the fact of no feedback there is also no need for excess gain.

Generally there are many ways of designing low-distortion voltage amplifiers, but at lastly there is always a current driver required. Dynamically there are no alternatives to single-ended (opposite: push pull) designs, but those require a mandatory full class-A operation and also deliver higher grades of even-order distortions. LEF (Load Effect Free) applied to a single-ended class-A design avoids distortions by not moving the transistor through it's un-linear characteristic curve. Additionally the fully balanced design widely rejects even-order distortions.

A truly class-A balanced design is a constant non-moving load to the power supply. However much energy one signal requires, the balanced mirror signal requires less. In theory this way there would be no modulation of the power supply by the music signal at all any more and in our existing applications the power supply modulation is decades smaller compared to an un-balanced circuit.

Furthermore balanced designs have a natural rejection of common-mode power supply disturbances. This results in a remarkably improved “inner quietness” of the music reproduction. In consequence there is more space left for sound details, colours and 3-dimensional sound-stage.

RIAA and Other Options

Due to the absence of global feedback, the RIAA equalisation can not be an “active-type”, which usually would be inside the feedback loop. The precisely made RIAA filters are applied in two decoupled stages in a “quasi-passive” manner, which means a frequency dependent passive I/V converter. Excess gain, which is a traditional disadvantage of common passive RIAA solutions, is not required. B.M.C.'s Phono MCCI combines the dynamic neutrality of a passive equalisation while avoiding excess gain.

The common RIAA rolls off with endless damping for high frequencies. Logically a perfectly matched LP was cut with an infinitive gain before, which is obviously impossible. Consequently the common RIAA is never truly accurate. For the treble emphasis limitation in recording for decades there is a quasi-standard defined by the leading record-cutting-machine manufacturer Neumann. Applying a correction according to Neumann makes a small but very well audible difference in voltage. The correction of the phase shift is even more obvious. Optionally the Neumann-correction can be disabled so it is easy to check out the difference. There is simply more breath and transparency within the music.

4275111-origpic-a93e9d.jpg

For matching cartridges with low-level-extension problems or too less “body” it is possible to extend the lower bass or adding “body” plus lower bass.

Although the gain between different cartridges differs less than usual, according to the construction of the MC there might be level differences. Phono-MCCI allows the setting of 3 different gain levels.

Ideally the cartridge should match to the tonearm and the system is well damped. In other cases a subsonic-filter can be selected.

High End Parts

Phono-MCCI's very special transistors feature a super high Hfe and a super low typical noise figure of 0,3dB which is at the limit of today's possibilities. Each functional group uses 10 in parallel which reduces the statistical noise by 10dB. There should hardly be any more quiet solution for a phono amplifier.

The “Balanced Current” electrolytic capacitors have a balanced characteristic for charge and discharge. The important ESR-bandwidth is far beyond common electrolytic capacitors. This results in an improved musical performance, precision, detail and beauty, starting from the very low frequency, covering the whole spectrum.

Induction-free Polystyrene capacitors feature the lowest losses of all film capacitors and show no resonances. Used in audio circuits they deliver very open and pleasant treble.

Metal-thin-film resistors with 0,5% tolerance represent the highest part level within this group. SMD types do not have clamped contact wires and show lowest inductance.

The core part is build on a fully gold plated 4-layer PCB. The solder is lead-free and includes silver. The sensitive core module hat its own copper plated shielding box.

New Standards

The digital music reproduction over the years challenged the analogue technology to deliver better phono components. This improvement process should not be limited by old standards. In this sense an un-balanced phono input and circuitry is no longer state-of-the-art. With all the limits in noise and the related detail resolution it limits in-depth listening. All aspects of the circuitry should serve dynamic fine resolution all-over the whole frequency range for really unveiling the advantages of Vinyl-reproduction. Part of this philosophy is the abandonment of global feedback also for RIAA amplifiers and the related own dynamic actions. Then music can blossom and catch emotionally while being relaxing; leading us into a different world, touches and may seduce us...

Link to comment
Share on other sites

BMC CD Player

4275076-origpic-1ee049.jpg

Pris 31 000kr

B.M.C. applies exceptional concepts to their components to make technical innovation and perfection serve music reproduction.

One truly uncommon concept is a CD transport with belt drive. Why should a belt drive be applied although almost all other CD player work with direct drive?

Just measurement results don't really serve as a decision maker, but this was already true in analogue ages: In measurement the direct drive turntables outperformed the belt drive, just in terms of sound within the higher grade class of turntables belt drive types outperformed their direct driven counterpart clearly.

In the case of CD players the situation seems to be quite similar, but there is one major difference: While turntables rotate with a constant velocity a CD player constantly adjusts the speed depending on the play time position for a constant data stream. Sometimes this fact is regarded as an argument against belt driven CD players, but the speed changes are slow and continuous and thus a belt drive can technically manage this challenge. Rapid changes in speed just happen during title skip. Naturally a belt driven, flywheel-type CD player reacts somewhat slower here. But sacrificing a higher level of musical enjoyment for faster track access times? This might be too disadvantageous a sacrifice.

1. Belt drive decouples the motor vibration from the CD

2. The CD turns on a precision bearing, analogue to a turntable bearing also regarding size.

3. A CD stabiliser removes vibrations and resonances from the CD and due to the inertia any rotation is quiet and smooth.

4. Quiet operation of the servo circuit instead of plenty small and harsh speed changes.

According to this short description it should be understandable that most mid and high frequency jitter won't ever happen.

Superlink & SPDIF Interfaces

For transmitting digital audio signals besides the established SPDIF-compatible interfaces (AES/EBU 110 Ohm, coaxial 75 Ohm and optical Toslink) there is the exceptional and consequent “Superlink”. Unlike SPDIF transmission the different digital audio signals are not merged to one single signal stream and decoded to separate signals again after being received by the DAC.

SPDIF surely makes sense from the commercial point of view, but Superlink is the solution without compromise, which requires 4 times of interconnection cables but skips any coding process. Left/right-clock, bit-clock, digital audio music data are transmistted from the CD-transport to the DAC while the master-clock is generated inside the DAC and sent to the CD-transport. The transmission is done with 4 x 75-Ohm BNC cables with impedance matching. Superlink results in a more intense link to the music, wider and more realistic sound-stage, more details and beautiful sound colours.

Any digital or analogue circuit has a sonic dependency on the power supply. Due to the fact that different power supplies have different influence on the music reproduction B.M.C.'s CD transport uses an advanced switching power supply, with active primary voltage filtering and separate transformers for display, motor, logic and audio circuitry on digital and analogue domain. Additionally there is complex voltage stabilisation separately in front of each functional group.

By adding the digital-to-analogue converter module the belt drive CD transport can turn into a complete CD player with analogue output.

The digital signal performance is optimised by a clock synchronisation circuit right in front of the DAC-Chips. All digital signals are re-timed to the local master clock and thus the point of lowest jitter is at the DAC-Chip where the analogue music signal is made. The conversion is made by two 24-Bit / 192kHz TI/Burr-Brown PCM1792 chips with current output.

The output current is filtered and converted in to an output voltage by discrete, fully balanced I/V converters, which operate feedback free. Thanks to the special “Current Injection” circuitry a maximum of sound quality is preserved, which is stabilised with the unmatched “LEF” driver circuit keeping all sonic details.

Originally those circuits were designed to put focus on the sound quality and leave the measurement specifications second, but the present standard is on a level that leaves no need for such choice: Both are on top level and the sound is class of their own.

The combination of a belt driven CD transport (belt-drive, precision bearing, CD stabiliser with flywheel effect) and consequent digital signal interconnection, as well as an optional DAC with advantageous technology concludes in a musical performance never revealing its digital origin.

Link to comment
Share on other sites

  • 3 weeks later...

Första B.M.C leveransen har kommit till Akkelisbutiken och grejerna motsvara mer än väl förväntningarna. Både RIAA oh DAC1 Pre har redan hittat sina första ägare i Sverige.

Mycket mer information om produkterna finns på hemsidan www.akkelisaudio.com

Välkommen in också för att se och höra B.M.C live.

/Stefan

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...