Tag Archives: Amp

Q&A: Adam Clarkson

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Tube Amplifier Design
Brothers collaborate on a new audio system with a classic look

SHANNON BECKER: Tell us a little about your background. Where are you located? Where and what did you study?

ADAM CLARKSON: I have been working in product development for the past 10 years in Franklin, IN, for my father’s company, Agri-Tronix, where we manufacture agricultural electronics and also professional tournament fishing scales. Yes, tournament fishing is a sport and we provide the scales necessary to decide the winner. I attended Indiana University for two years after high school where I studied graphic design and pre-engineering. After my brief tour of college life, I bounced around from bartending job to bartending job before deciding to come to work for my father. It’s truly been a blessing to work for the man I most admire, I’ve learned more from him than I could ever describe. My brother, Ben, began working with me about two years ago after he graduated from the University of Southern Indiana with a Bachelor’s degree in Fine Arts.

SHANNON: What is your current occupation?

ADAM: Sales, marketing, project manager, graphic designer, technician, and anything else that needs to be done.

SHANNON: How did your interest in audio electronics develop?

ADAM: I’ve always been interested in electronics and always loved good audio. There was an allure to vacuum tubes, so we started experimenting and we really think that we’ve created something special.

Photo 1:Brothers, Adam (left) and Ben Clarkson, are working on BlueTube Audio’s classic wooden speakers designed to match their new vacuum tube amplifier.

SHANNON: How did you and your brother Ben get involved with Kickstarter? What about it appealed to you?

ADAM: The ClockOS was our first kickstarter project. I had a friend who had  decent success on Kickstarter, and I thought, “Hey I could do that.” So we set out to come up with a project to put on Kickstarter and test the waters. We came up with the ClockOS, which had  mild success. We learned so much from doing that project. And, we did some things wrong with that project that really held it back from being great. The idea of Kickstarter is really neat, and I think that a lot of people want to just help out. They want to be involved in something new, get in on the ground floor, so to speak. Even though the backers are not
investing in the company, they still have this desire to be involved. The all-or-nothing funding was the one thing that really convinced us to go with them over the other crowd-funding sites like indiegogo.com.

SHANNON: In what stage of development is the ClockOS?

ADAM: Unfortunately, this project had to be retired as the manufacturing cost was just way too high. The machine shop that originally quoted the aluminum for us came back after the project ended with a price that was three times as high. We then had to scramble to  find a new shop and what we saved in money, we sacrificed in quality. We spent many weekends reworking the machined parts, hand polishing and surface prepping each one to a show quality finish. If you added our time to the cost of the ClockOS project (which any good business owners should) we would have lost money on the ClockOS project. We learned from our first project and took it to the BlueTube amplifier to make sure it was a success. It worked.

Photo 2: BlueTube Audio’s new vacuum tube amplifer comes with two handcrafted wooden speakers.

SHANNON: Share some details about your company, BlueTube Audio. What made you and Ben go into business together?

ADAM: BlueTube Audio’s niche is “functioning art.” We want to design products that are art pieces but have function in modern society. Our new project is the BlueTube Audio vacuum tube amplifier. As for our partnership, we were already working together and, in my opinion, we make a great team. We are brothers so we do have our battles, they are usually small though, and we always work through them.

SHANNON: Describe the BlueTube Audio vacuum tube amplifier and its current status.

Photo 3: The back of the BlueTube Audio amplifier is clearly labeled for easy use.

ADAM: We decide to put the amplifier on Kickstarter as it really is a good platform for raising funds for your initial production run. We needed to have custom sheet metal plates punched, powder coated, and silkscreened for the back panels. The front panels are made of brushed stainless steel and require specialized machinery to punch and cut them. The internal chassis is really a marvel of sheet metal bending that I designed, and I am pretty shocked the sheet metal shop said they could bend them.

We have also three separate PCBs in the unit. The main board is populated with the tube sockets, the capacitors, the resistors, and the other fun components that are required for a vacuum tube amplifier. The secondary PCB has all the inputs and DC voltage circuitry on it. This board also has the USB port attached with smart charger circuitry.

Photo 4: The amplifier’s power button emits a soft blue glow when the device is on.

The circuitry automatically detects the proper voltage and current for your USB device, whether it’s an Samsung Galaxy or an iPad, we can give the device all the power it wants. This secondary PCB also has all the Bluetooth circuitry attached to it. The third board is a small one, but it is connected to the input selector switch and distributes the input signal to the amplifier and then out to your speakers.

All these things require quantity orders that we would not have been able to fund without the Kickstarter program. Now that we have the start-up capital, we can order more parts than we need and actually have inventory on the shelves—about 10 times as much inventory in some cases. Currently, production of the first units is in full swing, and we are constantly ordering parts.

SHANNON: The amplifier’s old-world look camouflages some very modern audio electronics. Why choose this combination?

Photo 5: The amplifier’s vacuum tubes provide the modern-day amplifier with some old-world charm.

ADAM: Because it looks awesome and sounds great! I love the look of the old-time tombstone radios and the handcrafted woodwork. The warm glow of the vacuum tubes. The reflection of the glass and metal. We don’t put plastic on our units because plastic looks cheap. Ben is the woodworker, and he did an amazing job handcrafting these units.

As for the new world technology, well, we don’t really want to sacrifice our convenience either. Why not have both? Great sound and the convenience of Bluetooth.

SHANNON: Do you have any advice for audioXpress readers who are thinking of building their own sound systems?

ADAM: Be careful when working with tube amplifiers. The capacitors can take hours to fully discharge and even when unplugged they can give you quite a jolt.  Also, don’t be afraid to experiment.

SHANNON: Are you planning any other speaker-related projects?

ADAM: Yes, Bluetooth and stereo. That’s all that I can say right now.

SHANNON: Where do you see the audio industry 10 years from now?

ADAM: Much as it is now; however, with the shift to digital in the last few years, there has been some sacrifice of quality. I foresee people crying for better quality. Many people, including myself, love the convenience of having their entire music library in their pocket. But I’ve noticed that I don’t buy albums like I used to. I have the shuffle bug or the skip bug and I don’t listen to a whole album through and through like I used to. I guess this isn’t really a prediction just a complaint of something that I find missing. I miss the collection of a music library. I miss sitting down and listening to an entire album. I miss the sound of good music and the music sounding good. We’re seeing a shift to better things. I just can’t say where we will end. aX

January Products: HiWave Wireless Speaker, Power Amp Kit, Wolfson DAC

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HiWave develops new wireless speaker platform

HiWave offers a Bluetooth wireless speaker demonstrator that runs for 100 hours at normal levels from a single charge cycle.

HiWave Technologies, a provider of innovative audio amplifier ICs, full-frequency range speaker drivers, and next-generation haptic-touch devices, has developed a new product called Endfire. Endfire is an efficient wireless stereo speaker reference platform that delivers 100 hours of high-quality audio playback at typical listening levels.

Endfire uses Bluetooth to pair with tablet PCs, smartphones, and laptops and outputs 30-W audio from its two full-frequency range, wide-dispersion HiBM36S12-8 BMR speakers. These are combined with HiWave’s DyadBA3 module, which supports both AVRCP and A2DP Bluetooth audio profiles and uses the HiAS2002 stereo amplifier. The system is powered by three 2,200-mAh Li-ion batteries and charged via a micro-USB connection.

The reference platform consumes less than 300 mW during typical playback and its onboard HiWave HiAS2002 (Audium) amplifier can switch voltage rails to reproduce peaks without any detectable artefacts. The system automatically enters standby when not in use and waking. Device pairing and battery check are controlled via Endfire’s volume control dial.

The HiAS2002 amplifier IC and BMR speaker drivers are available from HiWave. Visit www.hiwave.com for more information.

 

Akitika’s complete stereo power amplifier kit

Akitika’s GT-101 contains everything you need to build a stereo power amplifier.

Akitika’s GT-101 is a complete stereo power amplifier kit that supplies everything but the solder. It produces greater than 50-W RMS per channel into 8 Ω with low distortion and low noise. The kit includes a toroidal power transformer, film, COG capacitors, metal film resistors, heavy-duty extruded aluminum heatsinks, isolated input jacks, double sided FR-4 PC boards, five-way speaker binding posts, and a fully regulated power supply. It’s contained in a black custom chassis. The component quality is characteristic of high-end equipment, at a cost of a little more than $300. Akitika’s GT-101 stereo power amplifier sounds better because you build it. Visit www.akitika.com for more information.

Caption: Akitika’s GT-101 contains everything you need to build a stereo power amplifier.

 

Wolfson’s newest DAC delivers great sound

Wolfson Microelectronics has introduced its latest stereo digital-to-analog converter (DAC), the WM8533, which provides audio performance in a small package for a wide range of consumer electronic applications.

The WM8533 delivers 106-dB signal-to-noise ratio (SNR) and features an integral charge pump, a software control interface, and offers 2 Vrms line driver outputs where a 3.3-V power supply rail is used. The WM8533 is suitable for a wide range of consumer digital audio applications including set top boxes, digital televisions, DVD players, and games consoles.

The WM8533 also features ground-referenced outputs and a DC servo to eliminate the need for line driving coupling capacitors and effectively eliminate pops and clicks at power on. The device also supports all common audio sampling rates between 8 and 192 kHz. For more information, visit www.wolfsonmicro.com.

November Products: Cush Headphones, Measurement Mics, & More

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The November 2012 issue of audioXpress features product information about a variety of interesting, well-designed audio gear. Headphones, an amp, a mic, and more are detailed.

Cush Headphones Offer Sound Quality, Comfort, & Style

KICKER recently unleashed its 39 years of high-performance audio knowledge to offer KICKER Cush headphones.

KICKER’s Cush (Source: KICKER)

Featuring an ultra-lightweight design and thick over-the-ear cushions, Cush headphones offer 54-mm speakers and a 118-dB maximum output to provide the legendary bass response and tonal accuracy for which KICKER is known.

The headphones feature a smooth, soft-touch finish in black gloss or white with monochromatic graphics for a subtle appearance. The breathable, perforated headband cushions the listener’s head.

Cush headphones utilize a 53”, Kevlar-reinforced, flat cable to provide freedom for movement while listening. The flat cable is smooth and less prone to tangles. The angled “L” plug connects into any iPod, iPhone, MP3 player, or KICKER docking system.

Barix Expands Audio Product Range

Barix markets its Annuncicom IP audio and SIP/VoIP devices around the world, bringing bidirectional audio streaming and control solutions to various markets within the commercial, entertainment, private sector, and residential worlds.

Barix’s Annuncicom 60 (Source: Barix)

Barix now offers two low-cost, reliable VoIP and IP Annuncicom audio devices that optimize features and functionality for universal applications.

The new Annuncicom 50 is built specifically for OEM applications. The device delivers Barix’s trademark reliability, open standards design, and multi-format audio capability at a low cost for OEM customers.

Barix also offers the Annuncicom 60, a universal, programmable, and ultra-compact device that offers reliable IP encoding and decoding. It is roughly 40% the size of existing Annuncicom devices, which are known for offering a compact footprint to systems integrators and end users.

The Annuncicom 60 is a single-zone paging interface device that can decode VoIP codecs as well as MP3, AACplus, and PCM audio. Its built-in speaker amplifier, balanced line output and microphone interfaces, serial and contact closure control interfaces, and Power over Ethernet (PoE) support is unique to the market—delivering universal functionality at a competitive price.

Contact Barix for more information at www.barix.com or www.ip-audio.info.

Sennheiser Offers High-End Amp & Headphones

Sennheiser now offers an amplifier for dynamic headphones. The digital HDVD 800 has a fully symmetrical layout and sampling frequencies of up to 24 bit/192 kHz to ensure an unequalled listening experience. It also harmonizes perfectly with Sennheiser’s HD 800, HD 700, HD 650, and HD 600 high-end headphones.

Sennheiser’s HDVD 800 (Source: Sennheiser)

The HDVD 800’s features include its balanced sound image, maximum precision, and impressive spatiality. The high-end headphone amplifier has a fully symmetrical layout for operation with analog audio sources, ensuring symmetrical signal transmission from the source to the headphones. For use with digital sources, the amplifier is equipped with a high-quality Burr-Brown digital/analog converter that converts digital audio data into analog signals, enabling the HDVD 800 to transmit the entire frequency spectrum of high-end audio sources without any frequency loss.

A rotary gain switch at the rear of the unit provides simple adaptation of the amplifier output to the audio input voltage. This ensures that the dynamic range can be used to its full extent.

The HDVD was developed and designed in Germany, which is where the latest member of Sennheiser’s high-end series is also being manufactured.

Sennheiser also offers the IE 800 in-ear earphones, which the company describes as headphones with “the most innovations per square millimeter.”

Sennheiser’s IE 800 (Source: Sennheiser)

The IE 800 offers innovative technology providing brilliant trebles, precise bass response, and a detailed, lifelike sound image with a 5-to-46,500-Hz frequency response.

The IE 800’s interior conceals many small but effective innovations: the centerpiece is Sennheiser’s specially developed extra wide band (XWB) driver. With a 7-mm diameter, it is the smallest wide-band sound transducer available in dynamic headphones. Its functional principle guarantees distortion-free sound even at high-sound pressure levels. It also features a modern design and high-quality materials (e.g., scratch-resistant ceramic housing).

Pro V-Series Speakers Provide High Sonic Accuracy

Pro Audio Technology (PRO), a leader in professional-grade loudspeaker and digital amplifier technology, announced the new V-Series loudspeakers, designed to deliver the high-impact dynamics for which PRO is known, but at a more affordable price. Both new models, the SCRS-210v full-range loudspeaker and the LFC-12v subwoofer, feature 6” enclosures, placing high-output systems in small rooms.

The SCRS-210v loudspeaker (Source: Pro Audio Technology)

The SCRS-210v’s two 10″ woofers provide a high-sound pressure of 102 dB with 1 W of input and combined, can handle 300 W of continuous power. Offering even higher sensitivity, the 1” annular-diaphragm compression driver produces 110 dB/W and delivers detailed and extended highs. Striking a balance of power and accuracy, the SCRS-210v fills nearly any space with cinema-quality sound and concert-caliber music without industrial-grade pricing or space requirements.

For low-frequency support, the companion LFC-12v subwoofer features a high-output 12″ professional-grade woofer with a 4″ voice coil. With sensitivity rated at 96 dB driven with 1 W, and power handling up to 700 W, the LFC-12v has no problem with today’s high-quality recordings.

When paired with the PMA amplifier/processor, advanced digital EQ can be applied to compensate for speaker positions near boundaries or for the effects of placement behind viewing screens or fabric. The PRO V-Series loudspeakers and PMA amplifiers provide a level of sonic accuracy unparalleled at the price.

Acoustic Measurement Microphones

PCB Piezotronics, a leader in the design and manufacture of microphones, vibration, force, torque, load, strain, and pressure sensors, and the pioneer of ICP technology, now offers a 0.25” prepolarized microphone series to complement its line of acoustic products. Models 378C01 and 378C10 are microphone and pre-amplifier combinations designed to measure high frequencies and high amplitudes. The distinguishing features for this series are the microphone frequency capability, which can accurately measure up to 100 kHz, and the 165-dB amplitude range (i.e., 3% distortion limit).

PCB’s Model 378C01 free-field microphone (Source: PCB Piezotronics)

Model 378C01 is a free-field microphone and pre-amplifier suitable for automotive and aerospace noise source location and array applications. Other common applications include biological and medical acoustic analysis, machine monitoring and defect detection, gunshot analysis, cabin noise, and other applications (e.g., testing in anechoic chambers). Model 378C10 is a pressure response microphone typically used in noise absorption applications within impedance tubes or general noise testing in cavities or small enclosures.

PCB carries a full line of prepolarized condenser microphones and pre-amplifiers. The prepolarized designs can also be used with the same constant current source used for ICP accelerometers, minimizing set-up time. PCB also offers the traditional externally polarized microphones that operate from a 200-V power supply.