Starving Student II Headphone Amplifier
UPDATE OCT 16th 2019: Tube rolling kit
now available sold out
- The tube rolling kit consists of a random selection of 4 pairs of 18FX6 and/or 18FX6A tubes
- The brands shown in the photo are typical, but not guaranteed
- Maximum 2 per SSII customer
The Starving Student II is a hybrid tube/solid state headphone amplifier and pre-amplifier. 48VDC is fed via in from a high quality universal-voltage Meanwell power adapter. It has dual RCA inputs, with a 1/4” jack for headphones and another pair of RCA outputs for use as a pre-amplifier.
BOM and schematics are inside Pete's excellent SSII assembly instructions. 6L6 has prepared a beautiful SSII step-by-step build guide. The SSII information directory contains links to every SSII resource.
Both the parts kit and chassis will ship immediately from our US warehouse at the same time. You can ask questions and discuss your build in the SSII discussion thread on diyAudio.
- New and improved redesign of the classic Starving Student by tube guru Pete Millett
- Detailed step-by-step SSII build guide from 6L6
- Can be used as a headphone amplifier or pre-amplifier
- Includes two 18FX6 vacuum tubes, functioning as triodes
- Choice of resistor or CCS plate loading for preferentially lower distortion or softer clipping, using a blue LED to bias CCS and light the tubes
- Time delay muting circuit to allow the tubes to warm up
- Just $119 each for either the parts kit or chassis, and $229 as a bundle
|Spec||Plate load||150 ohm load||30 ohm load|
|Gain (at max volme setting)||CCS||20 dB||18 dB|
|Resistor||17 dB||16 dB|
|Frequency response +/-3dB||CCS||11Hz - 40kHz||18Hz - 40kHz|
|Resistor||12Hz - 50kHz||20Hz - 50kHz|
|Frequency response 20Hz-20kHz||CCS||+/- 0.8dB||+/- 1dB|
|Resistor||+/- 0.8dB||+/- 1dB|
|THD+N 1V 1kHz||CCS||0.47 %||0.15 %|
|Resistor||1.8 %||1.3 %|
|Maximum output @ 5% THD||CCS||9.9 V RMS||2.5 V RMS|
|Resistor||3.1 V RMS||2.4 V RMS|
We also have available a zip archive containing 12 different SSII graphs.
Since I rarely listen to headphones, this one is being used primarily as a preamp. I Have really enjoyed the project, and the results. Haven't welded it yet but this is where I am going with the chassis.
Excellent kit. Instructions very clear and kit very simple to build. This is my second DIY audio project (the first one was an AudioNoteKits DAC for my room sound system five years ago -I love valves sound, as you can see-). I needed an alternative for my little moments working in my desk with my computer, so I found out your SS-II and said myself "this is it, this is what I need".
No doubt for me to choose the resistor option for the plate load, not the CCS. I use a pair of Final Sonorous III headphones and they work excellent with the SS-II. They move well and the sound is sweet and clear; the bass is enough and well controlled. Maybe I would like a little bit more power and punch in this part, but I insist: enough for price and for what I expected.
From the picture you'll be abble to see my provisional idea for the chasis. I expect to get your finer chasis next year. But for the moment, this is what I have.
I had real problems soldering the mass parts of all the components. Because all the PCB mass is a big surface of copper, my 25 W solder was not abble to compensate de heat dissipation, so after desperating tryings I had to use a pair of solders for each and every single mass pad! After 35 years soldering, this is the first time I've had to do something like this. But never mind: I could do it and... the result was good. Another experience for my soldering skills.
The only thing that really concerns me is that there are unnatural sounds in my left channel. They dissapear after some minutes of listening, but I have the impression that with the pass of the weeks, they need more time to dissapear, they remain longer. I know valves can do this things, but I wonder if this can affect some parts of the circuitry and if I will have to fix it.
To finish: I'm very very sorry for being the first to give the SS-II a four stars review. In fact, I'd prefer "four and al half", but there is no option for this.
This was my first DIY Audio kit and I am really glad I started with this one. The excellent build guide from 6L6 makes assembly easy. Having all needed parts and the chassis in one kit guarantees success in completing the project. The case was a little bit finicky to assemble, but all parts came together nicely and the amp looks and sounds great.
As many folks during COVID-19 lockdown, I was looking for projects and this one fitted the bill nicely--even though I wasn't in need of another headphone amp. The kit is very relaxing to build, even without the well-written and well-ilustrated instructions. Basically, the markings on the PCB provide sufficient information for putting it all together. Even though I have considerable experience with electronics, I would say that with patience and care, this kit could be assembled successfully by a complete beginner. I took my time to do it over two evenings, going from lowest height (diodes), to resistors, to highest parts (heatsinks). For those, my vintage 1985 Weller gun came in handy. The only little gripe is that in my opinion the headphone jack should be soldered AFTER the whole thing is assembled, as soldering it with the plastic in contact with the PCB resulted in my case in a slight vertical misalignment with respect to the front panel hole. The switch and volume knob were perfectly aligned however, so it's definitely a phone jack issue. I decided to solder the current source LED on the component side of the PCB. I might be old-fashioned, but tubes usually don't glow blue... At such low heater current, these don't glow much anyway.
I feed it from the Tape Out of a Rotel RC-995 preamp via 25' of RCA interconnect (yes!) and the sound is sweet. So far I have only used the constant current source mode. The tubes are very microphonic, but since the heater current is very low and the tubes remain cool, any tube damper would likely fix this. I haven't bothered with that yet, since the amp is on a small IKEA bed table and I don't touch it. I have used it with Grado SR225e, B&O H6, Audio Technica ATH-M50x and... a pair of Koss Porta Pro. Great kit that is easy to assemble, sounds very good and looks completely professional. Makes a perfect gift--assembled or not!
This is a great place to start for diy audio!
It was my first PCB soldering attempt, and i did struggle a little bit at first, but the clear instructions and easy layout and labeling helped me through. I did struggle a bit with some of the larger joints with my 25W Weller (especially the heat sinks), but overall very straightforward.
Also I decided to put the LEDs all on the bottom of the board, as long as you pay attention to orientation and shift the order you attach the parts a bit (do the second set of LEDs before the sockets) I haven't had any issues.
This was the first time I built an electronics kit since I was maybe 10 or so. Went together very smoothly. The available documentation for this kit is great. I nearly bought a cheap "tube amp" of dubious origins on Amazon, but decided to build the starving student after reading lots of great things about it. I am glad I did. This amp adds real presence to both my headphones and to my newer Sony HiFi amp when used as a preamp.
this is a really good unit considering the price, i am replacing my Massdrop CTH with this. this is a really dynamic amp and a really neat kit
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