Starving Student II Headphone Amplifier
Batch 2 is now available, this revision includes larger solder pads for easier soldering.
We're happy to announce the immediate availability of this new collaboration between Pete Millett and diyAudio, an updated version of the classic Starving Student.
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.
I bought two of them and have only assembled one at this point. They are from batch one so yes the solder pads for some of the components required me to put on my strong glasses and inspect with a magnifier. I have only used it as a pre-amp driving a pair of ACA running as monoblocks. The sound is very clean and neutral in this combination. As noted in the online build guide getting the board to fit into the front plate of the chassis can be a bit tricky but with some patience and gentle persuasion it will all fit. Build time was about four hours for me start to finish. When building the second one I may try fitting film capacitors in place of the provided capacitors 1 & 2 if space permits even if I need to go with a lower value as I am not a headphones guy. Overall I give it high marks and am interested to here if anyone has tried it with a linear power supply.
The quality of the kit is great and the sound is surprisingly good. I am more than happy with a successful build.
This is a potentially very satisfying project to undertake. The amp kit came with all the needed parts neatly packed in labeled bags. There was a parts lists, with pictures, and a schematic included. The PCB is of very high quality and it has labels for all the parts to be mounted.
With due attention, the assembly is not difficult, and the end result is very satisfying. The sound is somehow tubey, very clear and authoritative throughout the range. I’m using it as a preamp for another of P. Millett’s creations, the engineer’s amp, it’s a very nice match and it plays great all different kinds of music and sounds (I have synths attached to the system). I will recommend the project to all who feel they can do it. If you set yourself up to it, and you are careful and methodic, you certainly can do it!
I got one of the 1st batch of kits - pretty easy assembly (with one caveat - see below) - which means that it was very well thought out & designed. Fits perfectly into the enclosure, which was also very well designed. Coupled with the ACA (which is then driving a pair of Klipsch Cornwall speakers) results in excellent sound - really shows off what the ACA can do.
I recommend this kit hightly for anyone considering it.
The assembly caveat - the 1st run of PCBs had some very small pads for soldering & my soldering iron had an old, beat up tip. Apparently, I didn't get all of the connections right (had to take it back to the bench a few times). The solder pads on the ground plane were the most problematic. After updating the soldering station to something newer than 30 years old, I reflowed all the solder joints and have had no issues since. I've heard that the 2nd release of the kit has a redesigned PCB, with larger pads, which would take care of this problem.
Soldered up the whole board in a few hours, detailed instructions, couldn't be easier. High quality board as always from diy audio. This time I didn't have to de-solder anything, but past experience has proved that the boards from DIYaudio can withstand desoldering without damage.
Sounds great from first second used for headphones and as a preamp. I'm powering my ACA with it and it sounds great right away. I've not had any tube equipment before, but I'm really liking it, it sounds distinctly different from my solid state pre-amps. I didn't know it but I guess I like tube amps.
This was a quick and easy build, easier than the ACA, as all the components are through hole. there is no wiring at all.
Only suggestion I have is to mill holes on the bottom so that you can access the jumpers for changing between constant current and resistive load. It would just need to be big enough to slip a needle nose plier into.
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