Project Starlight - Tube Headphone Amplifier:
What the heck is Project Starlight? Well in short and to the point, she was designed to kick sand in the face of the affordable overseas offerings and other affordable tube amplifiers. Having to purchase an amplifier and then replace the majority of the parts to work properly should not sit well with anyone (we know the popular cheap designs well as we used to modify and fix them on a regular basis). So we went to the drawing board to see what we could do to not just make a quality affordable hybrid, but to make a damn fine hybrid that was ready to sing out of the box. Starlight is a Tube / Opamp hybrid capable of rolling opamps as well as countless 6 & 12V dual triode tubes. Stock output stage features quad 4562's and she sings like an angel. We even gave her Easy Set LED bias and a fully dedicated tube heater power supply supporting up to 1A! That means power hungry tubes such as the 12bh7, 6n6p and 6n30p are no problem. In fact Starlight outclasses and outfeatures EVERY SINGLE hybrid on the market in this price range and even well above its price point giving you the ability to tweak and tune to your desire. Best of all, no need to frankenstein her with modifications. The parts you may want to play with later on such as opamps and tubes are easy to change without soldering!
I really hate to come across as ranting but I just feel people should be better informed. Cheap tube hybrids are just that - CHEAP. From poor quality parts, PCB and power supply to absolute flaws in the design such as no bias adjustment and crosstalk so bad the signal might as well be mono. Not to mention all other measurements that are simply terrible. So many of them are designed just to the point they work and nothing more. Just plug a tube in and it falls within a range that makes sound. Not a dig - but FACTS.
Some claim you should purchase one of these cheapies, throw parts at it and you are getting a deal! Really? NO. Do the math and the research. After you buy the amplifier, then buy the parts to modify the amplifier RIGHT (not partially) you literally could have had a built Starlight or kit. And you would not have to de-solder most everything on the cheap PCB in order to replace all of the parts. After having modified / repaired so many cheapies, it really does make me do a face palm in frustration. Actually a double face palm (yes it is that bad) as I know what people are getting with a cheapy and what they could be getting. Am I biased? (no pun intended) clearly yes, but it is more because I know what you can get for the money vs. a headache and loads of time spent on band-aid efforts that end up just barely tolerable. Ok ok [/endrant]
Features of Starlight:
- Easy Set bias via LED indicators. No need to use a multimeter anymore when rolling tubes! Access from the side of the amp, no removal of top cover
- Easy access to bias trimmers. You can use a jewelers screwdriver to dial in the bias through the top cover, no need to remove the cover to set
- Three output impedance settings to dial in your Starlight
- Revised protection circuit protects your headphones and audio gear
- 1A dedicated heater power supply for current hungry tubes
- Ability to run a pair (one per channel) or quad opamps (two per channel) for increased output
- Ability to roll several opamps to see what you like better
- Designed in the U.S. & Netherlands. Kitted or Built in the U.S. depending on how you order / 5 YEAR WARRANTY ON G1217 BUILT AMPS!
- All parts sourced in the U.S. From reputable distributors, NO FAKE COUNTERFEIT PARTS, CAPACITORS OR RESISTORS!
- Only top quality components used, such as Bourns pro audio potentiometer, Bourns trimmers, Low noise Vishay/Dale RN, CMF and CPF 1% resistors, Nichicon & Wima capacitors, Neutric phono jack. Ruggedized PCB RCA jacks, Rugged 5a power switch ETC…
- Beautiful piano gloss black .096 thick double sided PCB with gold wash - top and bottom ground planes. Will not bend or flex while inserting a tube
- Turn on / off protection for your headphones and audio gear
- Fused with reverse polarity protection
- Chassis hardware features all stainless steel allen bolts, washers and nuts. Stand-offs are aluminum
- Each factory built amplifier is meticulously hand built and tested prior to shipping. Solder work is outstanding and clean with no flux or fingerprints left on the board. Pride in workmanship is evident from every angle of this amp. What you see in photos is the quality of build you will get!
For Advanced Tuners:
- Input capacitor section is drilled for multiple capacitor footprints. 2, 2.5, 3.5, 5 or 7.5mm spacing available
- Output capacitor section is drilled for 7.5mm
- Power supply capacitor section is drilled for 7.5mm
- Variable output resistance, selectable from 2.5 to 70ohm
Actual Project Starlight measurements:
- Opamp output stage / quad LM4562
- Power consumption: 7.2W peak.
- Power supply: 24VDC (0.3A peak)
- Input Resistance: 40k
- Input Sensitivity (6N23): 270mV (dependent on tube)
- Gain: 20dB (dependent on tube) Changed from the original higher 26dB specification
- Max Output voltage (no load): 7Vrms at 120ohm
- Output Resistance: Selectable 2.5, 34 and 72ohm
- Frequency Response: 15Hz – 80 KHz (-0.5dB) with 32ohm load
- Frequency Response: 4Hz – 230 KHz (-3dB) with 32ohm load
- Signal to Noise ratio: 91dBA (dependent on tube)
- Crosstalk: -87dB (dependent on tube and in most all cases, better!)
- THD: > 0.015% (dependent on tube)
- Suitable for: 16-300ohm Headphones
- 5.75L X 5W X 2.75H in inches
- Acrylic Chassis .65lb (without power supply)
- Aluminum Chassis 1lb (without powers supply)
Optimized for Headphones 16 - 300ohm | Shown with both aluminum and acrylic chassis options
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