Starving Student II Headphone Amplifier

[Alan4411]

Originally Posted by DualTriode

The install instructions call for R13 and R21 to be 1.4 watts.

Is this correct?

In the photos they look the same as all the 1/4 watt resistors.

Thanks DT

Just a 'typo'. It should read 1/4 watt.
If you scroll down to the Appendix 1, R13 and R21 are correctly listed as 1/4 watt types there.

[patkhan1]

Shared album - Patricio Ri - Google Photos

Got it in the morning, completed in the afternoon. I do not use headphones that much, I paired to "The DCPP engineer's Amp" as a Pre. I does sound really good, it gives a very organic sound. I'm using the CCS load option, I'll probably try the resistive load later.

My gratitude to Pete Millett and the DIYAudio store for providing this kit, it was easy to build and, again, it sounds great.

[starkeyg]

Hello,

Quick question for you guys.

Does this unit used as a preamp put out enough to drive the Amp Camp amp well? I know not all preamps seem to do so and am asking if anyone has tried this one.

Regards,
Greg

[mpeg2]

Originally Posted by starkeyg

Hello,

Quick question for you guys.

Does this unit used as a preamp put out enough to drive the Amp Camp amp well? I know not all preamps seem to do so and am asking if anyone has tried this one.

Regards,
Greg

Completed my build this morn - 1st tried it out with some HD650 phones - more than adequate drive, very nice sound. Curiosity then arose, so I swapped it in for a BottleHead Smash preamp & drove an ACA - plenty of drive & combo worked very well. I'll have to do more careful listening when I get a chance to see if all the subtleties that the Smash did so well are still present. I'm using the CCS option - when I did the first test (outside of the case, I noticed a bit of static noise at high volume settings with the resistor option (and less gain).

The build went well & quickly - some of the solder pads are quite small, so it took a bit more care to get them right (especially if they led to the ground plane, lots to heat).

I've got a Whammy kit waiting to be assembled (I put it off, since I wasn't looking forward to chassis work) - when I get that together, I'll try to compare.

Rich

[RafaPolit]

Looking forward to the comparison with the Whammy.

Thanks.

[RafaPolit]

Well... as usual, those that prefer to think it over and those undecided DIYers please refrain from purchasing in the store!

Congrats on selling out on the first 5 days of availability and only couple of days after the email invite. Incredible community! Looking forward to the builder's opinions (hope they mostly went to actual builders and not hoarders that would later on resell them on eBay at a profit )

Best regards,
Rafa.

[starkeyg]

Hi MPEG2,

Thanks for the feedback. Will try to get in on the next buy.

[pmillett]

Originally Posted by RafaPolit

Thanks for the info. Indeed, there are now interesting specs, and I... as Meeper, was wondering what the 10K figures would look like.

Great seeing folks already getting their kits, please let us know how they turn out!

So Pete, you would suggest to use the Resistor plate load if it suffices, and only go CSS if you need more gain? What about 300ohm Sennheizer HD600? Where would this fall regarding plate?

Thanks!
Rafa.

10k load won't be a lot different than 150 ohms. You can see at 30 ohms the output is current limited - the follower cannot deliver more than ~100mA.

300 ohm Sennheisers could be good either way, but if you listen very loud you probably want to use the CCS plate load. Best to try both and see which you like best...

Pete

[pmillett]

Originally Posted by mpeg2

The build went well & quickly - some of the solder pads are quite small, so it took a bit more care to get them right (especially if they led to the ground plane, lots to heat).

Rich

That was pointed out to me by 6L6... on the next batch I made the pads bigger. Sorry about that!

Pete

[pmillett]

Originally Posted by John ALSR

After more than 50 years of DIY audio, and upon receipt of the invitation email to purchase the SSII kit, I realized that it is most likely now-or-never to dip my aged toe into the 'sea' of tubes. I purchased the full kit!

I'll be using the SSII with my Hifiman HE400S headphones (22 ohm impedance, 98dB sensitivity).

So questions (in ignorance):

1. How long are the tubes expected to last?

2. Will different tube brands sound different?

3. Would there be any benefit to channel matching to have a matched pair of tubes?

4. Will the tube model become 'unobtanium' like the original SSI tube model has become? That is, should one 'stock up' on a favored tube brand?

5. Would there be any benefit to increasing the size power supply input reservoir capacitor? If so, how much?

Thanks,
John

1. Should be the same as any small signal tube... I would expect 5-10,000 hours.

2. There may be subtle differences from one type of tube to another. I would not expect anything drastic.

3. I doubt that any difference would be audible. Of the units I've tested the gain was matched to about +/-0.2dB.

4. The risk with any project that uses an unusual tube - it's possible that somebody will buy up the world supply. I've learned that lesson. There are quite a few out there (they were used in the last generation of the "all american 5" tube radio), and I proactively bought a lot of them (thousands). So hopefully this won't be a problem. If they disappear, there are other tubes that can be used with a resistor change.

5.. I think there would be no benefit.

Pete