Ray Samuels Audio is proud to announce its latest state of the art component:
The Emmeline II, “B-52” fully balanced Headphone amplifier and full functioning preamplifier.
It has been a long time since we have displayed the prototype B-52 in its silver non-anodized chassis at the 1st annual Head-Fi National meet. Since then we have re-worked the entire chassis over again to give it a better, more professional and functional look. In the process, both of the internal PC boards were redesigned in order to accomplish a higher quality of workmanship and to implement a newer custom built toroidal transformer which was designed exclusively to our specs, for the necessary voltage, current output and physical size, that we needed to attain our goals by one of the most respected manufacturers of power transformers in the world, Plitron.
The power supply boards were redesigned to accommodate these heavy transformers by modifying a big opening in the PC boards and letting the 2 toroidal transformers rest on the bottom plate properly, fastened with ¼” bolts. This method helps the power supply to stay in one piece when shipped all over the world.
The B-52 has dual mono power supplies. Each dedicated to one channel. It is highly rectified using high quality Panasonic power caps, and state-of-the-art 10 watt ceramic resistors. This process ensures that the proper voltage is passed to the high voltage regulators that hold the voltage steady consistently without peaking or dropping as the input AC voltage fluctuates.
Every component is hand selected and matched between the left power supply and the right power supply. Each resistor has its value written on it before being matched with an identical one. The two power supplies have a tolerance within 1-2 VDC.
The two low voltage power supplies are UNIVERSAL “switching” regulated power supplies, rated much higher than necessary, creating 10 amps of current, between the two units, to feed the heater “filament” of the tubes.
The power supply is capable of running 3 amp sections of the B-52 without a problem. The umbilical cord, a DC cable that supplies the voltages between the power supply and the amp chassis, consists of a five conductor wire. The B-52 uses 16 AWG, 600 volts shielded cable. This keeps any noise or RF signals away from the amp. The power supply chassis is shielded by the AC ground, while the amp chassis is shielded by the DC ground.
The power supply runs cold to touch and you can leave it on as long as your heart desires with out any concerns.
There are two LED’s on the face plate of the power supply each indicating that the power supply is outputting the correct voltage required. The chassis of the power supply is designed in a way to secure the PC board in four locations to make sure it will stay firmly locked in place. Also there is a center stand off that secures the pc board well to the bottom chassis. The other two sides of the pc board slide in a long groove channeled in each side of the extrusion, thus ensuring that the power supply is well secured to it’s chassis, which enables the unit to travel long distances and get to it’s destination without damage or loose parts..
When the power switch is activated, the plate voltage/high voltage, is ramped up slowly before applying the tube full operating power, which allows the filament voltage, which is +12.6VDC to arrive to the tube first before the full plate voltage achieves it’s maximum value to help prolong the life of the tubes. The power supply is completely free of any mechanical noise generated from any conventional transformers and has the lowest possible emission of electro-mechanical noise.
The technology involved in the pre-amp/headphone amp chassis of the B-52 is so advanced and intuitive it is dazzling. The only effort you are required to do is turning the selector switch to the desired input. Next, you select balanced or single ended input and the B-52 will do the rest. For example, If you choose input #1 which is a balanced XLR input, left & right channels, the B-52 will short out all the other four, unused inputs, left and right channels, whether being balanced or single ended, to the ground, not allowing any of them to introduce any cross talk or unwanted signal to the selected input.
The B-52 has a tape loop/record out feature, both in the balanced and single ended mode. If the balanced XLR input option has been chosen, the chosen signal path will appear as fully balanced on the balanced XLR tape loop and also will appear as a single ended on the single ended tape loop in RCA. This gives you two tape loops in both balanced & single ended mode.
If single ended, RCA, input has been selected, the “tape loop out” will have identical signal present at the RCA tape loop and the same signal will appear on the balanced XLR tape loop but in a single mode, as only pin #2 will be active, pins #1 and #3 will be shorted to the ground. This could be still used to copy a signal or activate another external amp even though it is using XLR connectors.
The same applies on the Headphone Amp Outputs. Both are active, balanced XLR & the ¼” headphone output when any input has been selected whether balanced or single ended.
For example, if you select balanced XLR input, the balanced headphone XLR is fully active as balanced output to drive any balanced headphones with XLR connectors. At the same time the ¼” connector is active as a regular non-balanced output. This will give you the option to use your balanced cable between your source and the pre-amp yet the simplicity of plugging your 1/4” into your B-52 without disconnecting anything else, thus making B-52 a very versatile amp/pre-amp.
The same applies if you happened to own a single ended source & the selected input is a single ended, you can still hear your music even though your headphones with balanced cable/XLR are plugged in the B-52 balanced XLR headphone output. This is permitted as the amp/pre-amp will allow the positive signal to get to pin #2 & it shorts pin #3 to ground allowing you to listen to your non balanced source with ease without flipping switches or changing cables or grounding pins. All this is done internally with just one click of the selector input dial.
The same is true with using the B-52 as a pre-amp. It is a great sounding pre-amp, truly high-end by all means. The parts selected in the B-52 are some of the best audiophile parts available. All are hand selected & matched between all four channels. Hovland pure polypropylene, Dale Vishay .1% military film resistors, Holco .5% film resistors Panasonic caps and a great, FR-4, 2 oz oxygen free copper PC board conforming to military specs. Also military spec solder has been used through out the construction of the B-52.
To minimize noise floor, power and signal lanes have been separated by ground lanes & all the surfaces that has not been used is covered with ground patches.
The volume control is DAC, CT-2. It has four independent sections; each section is assigned to one amplifier. The volume shaft is connected to custom manufactured anodized knob.
Two switches are located between the input selector & volume control. The one closer is the volume control knob, which allows you to put the amp/pre-amp into the play mode or it mutes the signal in case there is a need to answer the phone with out lowering the volume control. This will operate in both modes as pre-amp & as the headphone amp.
The second switch, which is closed to the input selector switch, will allow you to operate the B-52 as either fully balanced or non-balanced headphone amp or fully balanced or non-balanced pre-map to control mono blocks. You don’t have to turn your mono blocks off if you want to go into a headphone amp mode, the switch automatically shorts the inputs signals of the non selected mode to the ground allowing the selected mode to operate fully with out any noise. Your mono block will sit very quiet without emitting noise due to the fact that their inputs have been directed to ground.
The same is true, if you select the pre-amp mode the input to your headphones is shorted to the ground and you have dead quite headphones with no noise at all.
The selection of tubes is made very simple, the back tubes, left to right while facing the front of the amp. The tubes numbered 1-4, the first and second being input tubes controlling the gain, the third and forth are the pre-amp drivers. You can use 1-4 12AU7 tube or any substitute that compliments that tube. Make sure tubes #1 and 2 are perfectly matched set, also tubes # three & four are perfectly matched set, in the third and forth location you can use 12AX7 matched set tubes also.
The front four tubes, from left to right starting from the back, tube # five, six, seven & eighth are fully matched 5687. They are the drivers or buffers that power the headphones.
They are not used during pre-amplification.
The active pre-amp outputs, balanced & single ended, are always active regardless of what input you have selected, balanced or non-balanced, enabling you to control two stereo amps or mono blocks from your B-52 preamp, one stereo amp could very possible be in the next room using balanced or single ended output of the B-52.
The chassis is very costly. They are custom manufactured for the B-52, and we have them in black anodized with Gold silk screen. The next batch not far from now will be in clear “silver” anodized with black silk screen. The time that takes to built the B-52 is almost 7 days as a lot of time is spend in matching components, which makes the B-52 more expensive but worth it for the Head-Fier’s who wish to obtain the finest sound that a combination headphone amp/preamp has to offer. I will say this and you can verify this: call any high end outlet anywhere and request a balanced pre-amp, dual mono EXTERNAL power supply with NOS tubes, without even mentioning balanced headphone jacks at all, you will find that you have to pay between $8-12K for pre-amp alone.
The B-52 offers the best of the 2 worlds available to you and has the power to drive any headphones with impedances between 32-600 ohms with a warm, soothing detailed sound that will put a big smile on your face. It just might be the very last pre-amp/headphone amp that you will ever need to purchase.
Specifications (Pre-Amp Section)
- Fully balanced, input to output.
- Input impedance 50k.
- Frequency response 10-100K.
- THD less than .008
- Output impedance around 300.
- Signal to noise -90dB
- Tube compliment, two 12AU7, in the gain section two 12AU7 or 12AX7 in the driver section.
- Two fully balanced inputs and three RCA inputs.
- Balanced and non-balanced tape loop.
- Fully balanced and non-balanced active pre-amp outputs.
- Balanced Attenuator.
- External power supply.
Specifications (Headphone Amp Section)
- Fully balanced input to output.
- Input impedance 50K.
- output impedance 20-2K
- frequency response 20-20K
- THD less that .08
- Fully balanced headphone output, XLR, and 1/4” jacks on the front panel.
- Tube compliment for the buffer section, four 5687.