Impressions from the SF Head-Fi meet

[sl-15]

I went to the Head-Fi meet last Saturday in San Francisco to see  the Bottelhead family and check out some gear. It was very nice to meet Dan again and finally meet Eileen who I had not met before. Really nice people indeed. I am pretty unexperienced with headphone-amps or audiophile headphones and I brought my trusted Sennheisers SL 25-1 which I would consider Dj or Broadcast headphones. Those are the only headphones I have and I was curious to see how they hold up against the 'serious' stuff. I started with the Crack and moved my way up to the Smack and Sex amps. I cycled through different headphones. It was rather difficult to do very critical listening as the room was pretty loud which Dan also pointed out. But after more back and forth between different amps and songs and headphones the conclusion was pretty clear. First these amps are amazing. Second my Sennnheisers are not that far behind other audio cans and third I want a Crack now. I always went back to it and the difference to the Smack and Sex are noticeable but it is not a night and day difference. What really stood out that all amps were dead quiet, no hum or hiss or anything that would distract from the music. The whole setup was quite amusing to me. I was sitting at this table just full of little Bottlehead boxes and I started to follow the cables to figure out the pathway. It was  kind of like a maze. Dan brought some prototypes as it turned out which explained all the extra stuff that was sitting around. There was some  preamplifier prototype to give the setup more drive, and a prototype of the DAC. Mac mini with Amara was the music source and there were to many headphones that I can recall. Not to mention all the fancy power cords and headphone-cables.  In the other room was Ironbut which I also never met before. He brought a rather amazing sounding setup too. Technics Reel to Reel with the Bottlehead Tube Repro but I forgot what  head-amp he had, but it was not a Bottlehead one. The music here just sounded absolutely sweet. Maybe I prefer the analogue sound or maybe the music itself was more up my alley, but to me it was like that this setup had something that the digital files were missing. In any case I had a great time and wanted to say thank you again for bringing down all the gear and music!

[Doc B.]

Hey Stefan, it was great to get a chance to chat with you. Thanks for the kind words. Regarding the analog tape vs. digital, I agree. That's why we started the Tape Project ;^)>

[ironbut]

Thanks Stefan,

It was cool to meet you too!
While I realize that having a nice reel to reel rig isn't in the cards for everyone, I'm more than happy to give folks a chance to listen to the offering from The Tape Project and hear what the guys in the studios get to hear.
I'm always happy to take credit for the wonderful, textured sound that these tapes bring to the table but of course, it's Doc and the other principles (not to mention the guys that made the original recordings and masters) that really deserve the credit.

See you at the next one.

[lextek]

Saw this on Head-Fi.  Is the DAC the one to the right of the Crack.  What is a 300b stage gain?  The box in the back with nothing sticking out of the top?  Power supply of some sort?

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi44.photobucket.com%2Falbums%2Ff21%2Flextek%2F15232f91.jpg&hash=37380d5e2a88bb268ee726d97ace7c29663dadaf)

[keto]

Its cool to see pics of all that yet-unobtanium gear: high-current Crack, 300B pre and the DAC! Woohoo!

[Grainger49]

I'm pretty sure that the two items on the right are the DAC.  My guess is that the back one, with the card in front of it saying "DAC", is the digital stuff, the front one is the tubed buffer stage.  Maybe the digital is in the front.  Doc will tell.

But you need both chassis for the complete DAC.

The 300Bs are the next generation, high end, line stage, right?

[lextek]

Makes sense.  Looks like an umbilical between the front and back box to the right of the Crack.  Looks like a thin optical going into the DAC.  So what doses the 300b thingy do?

[kgoss]

I believe the box in back of the DAC is an outboard power supply for it.  The DAC itself appears to be in front with a digital cable, RCA cables, and the power supply umbilical attached.

And I suspect the 300B gain stage is the new 300B preamp prototype Doc and the team are experimenting with.  I'm hoping both will make it to production before too long.

Ken

[Doc B.]

You guys are doing pretty good with your deductions. Back box is power supply, front box houses DAC board and tube output stage. DAC was connected to the 300B gain stage monoblocks (hey, they're prototypes) for a little extra boost, and that ran into the distribution box we use to fed the three amps - Crack, Smack and S.E.X. I ran balanced HD800s on the Smack, K1000s on the S.E.X. and HD650s on the Crack.

[porcupunctis]

Doc, if you don't mind, what brand/type of distribution box were you using? 

[Doc B.]

Just something we made, one of those black Hammond boxes with one set of input jacks and four sets of output jacks, one of which has a pot to control the level so it can be hooked directly to a power amp.

[porcupunctis]

So the preamp "sees" the impedance of the potentiometer and is not affected by the number of devices that it distributes to?  I'm asking because I currently use a CELabs distribution amp to extend the outputs of my FPIII.  Ever since I set this up, I've wondered if there wasn't a better way to do it.

[Grainger49]

The pot is also in parallel with the input impedances of all the attached amps.  The preamp should see that total impedance.

[porcupunctis]

I don't want to steer this thread off its original mark so if it takes me too much longer to wrap my head around this, we can move it to its own.

Am I correct in thinking this is basically wired up like a passive preamp?  A pot on the input and multiple outs?