dsavitsk

It's impossible to get a good cup of tea in a hotel. You have to use the coffee maker to boil water which is a) never hot enough, and tastes like coffee, and the tea itself is terrible. Even in the restaurants, people don't seem to understand that tea needs water at a boil, and that the cup needs to be preheated. I've taken to traveling with a paired down tea ritual: + + +

Fritz Sennheiser, 98, Electronics Executive, Dies - Obituary (Obit) - NYTimes.com

Indeed -- don't try to sneak out on Saturday for a quick lunch there. Last time I went it was ~15F out and I waited on line (outside) for about 2 hours. When it is warm, there is often a guy with an ice cream truck there to serenade the line. And, there is nothing else worth seeing around - it is totally out of the way so it isn't like you can even have an enjoyable walk around the neighborhood. They close at 4:00pm. With all that, it is still worth going, and waiting.

For any guitar players, a trip to the Chicago Music Exchange is worth the time and effort, and the snotty attitude you'll get. Vintage Guitars | Chicago Music Exchange | Electric Guitars | Fender Gibson Marshall Rickenbacker | Vintage Guitar Dealer Other neat Chicago things you should see that aren't on the tourist maps http://www.garfield-conservatory.org/ http://www.hotdougs.com/ Nowhere else are you likely to find "Pear-Infused Elk Sausage with Foie Gras Dijonnaise and Mustard-Seed Gouda Cheese"

There are quite a few little record shops spread around Chicago. Off the top of my head, Laurie's Planet of Sound in my neighborhood, Hard Boiled Records in Roscoe Village (~a mile or 2 south of LPoS), Vintage Vinyl up in Evanston (which is right across the street from Audio Consultants if you need some Ayre power amps and Wilson Speakers while you're in town), 2nd Hand Tunes (also in Evanston), Dusty Groove which I've never been to, and the venerable Jazz Record Mart which is downtown. There also used to be a few more near Reckless, but I haven't been to them in years, and I don't know if they are still around.

Well, the initial 3 to 4 week estimate for winding the transformers turned into 2 months. They finally arrived last week, and the pinout was wrong. New ones are being wound, and should ship soon ... I hope. They told me it would be this week. We'll let you know. Sorry again for the delay.

Where does Rane say that pin 1 is only connected at one end? Pin 1 is connected to the chassis at both ends. You would only need to disconnect one end if one side is improperly grounded. Here is what they say is the "The Absolute Best Right Way To Do It" http://www.rane.com/note110.html

Pin 1 Revisited

CadSoft Online: Non-Profit-Lizenz

Indeed I can. The DAC is pretty simple. It is a CS8416 receiver connected to a SRC4192 upsampling to 96K connected to a Wolfson WM8741 DAC chip. The output is straight off the chip. Generally, people put a buffer, or an opamp, or at least some caps there since the output is biased up ~2.5V and can't drive a difficult load. Here, however, because the amp it was connected to (with short low capacitance cables) has an input transformer, the bias is effectively nullified. The amp thus acts as the output stage for the DAC. The amp is one of my prototypes that Tom has been listening to. It is basically a differential mosfet follower using an input transformer for a little voltage gain, and an output transformer to block offset. The fets are CCS loaded, and there is a servo that measures offset and adjusts one of the current sources to keep them in balance. The arrangement, which is fully differential (not balanced bridged) makes sure that there are no caps in the signal path, no power supply caps in the signal current loops (the "rail" caps are 0.1u per side), and no attempting to match inherently unmatchable P and N channel devices. Here is a simplified schematic: The amp is pretty much designed around, and voiced for Grados. It works OK with a few other phones, but really seems to excel with Grados. There will be a couple of prototypes at CanJam (TomB and I have a table) in nice wood and anodized cases. There will also, I should add, be a new tube amp and maybe a DAC next to it -- more on that in a few days. The long tube amp is one of our prototypes. We had been hoping that prototypers would build them, we'd make changes, and we'd have at least a semblance of the kits at CJ. Alas, the prototype transformers that I thought would take ~3 weeks took two months to get wound. They should be here tomorrow, so more on this very soon. But, we'll have the first version at CJ anyhow with kits sometime later this summer.

Digikey is carrying these now, in case that's interesting: E-Switch - PV6 Series 16mm Anti-Vandal Pushbutton Switch | DigiKey

Guys -- sorry for the long delay. We have the cases. We are just waiting on the transformers which have been promised and delayed a number of times. They are winding them as I type this, so they say, and should ship to me early next week. Also, one person backed out so if anyone wants to jump in for the last one send me a PM. -d

Does anybody (in Chicago?) have a pair of pcb mount octal sockets to share?

What do these (T50rp's) sound like out of the box? Worth playing with for cheap closed phones, or are the mods transforming?

I am going to have to befriend one. But, off the shelf for these would be a lot easier ...

Unfortunately, I haven't found anything like it in the local hardware stores. Sorry, I didn't mean to be that specific. One side will go into aluminum using a small machine screw, the other into wood using a small wood screw. It needs to fit in a space less than 50mm. But, whether those screws are M2.5, 4-40, #4, whatever -- doesn't really matter. I just need something that is overall small. 50, 100? Not sure yet, but more than 3.

Anybody know a good source for angle brackets like the one pictured? Basically, this one would be about perfect if the measurements were in cm, not inches. Overall, I am looking for aluminum or stainless, 20mm to 40mm in length, and holes for 4x 4-40 screws.

Balanced != Bridged. Balanced has no signal ground. The benefits to a balanced topology are many, while the benefit to bridged, at least in headphone use, is that the manufacturer can sell twice as much stuff. http://www.jensen-transformers.com/as/as032.pdf http://www.jensen-transformers.com/an/an004.pdf

Yes No. Sound System Interconnection

More assistance/advice than sourcing ... Anybody tried tapping the mounting holes on the Neutrik PCB mount XLR connectors? Does it work? And, what size tap did you try? The panel mounting holes are very difficult to reach, and when they are packed in on a PCB, the bottom one is, so far as I can tell, completely useless.

With one big difference in that speaker amps are rarely quiet enough.

You got the last one ... I thought you hated output transformers?

Yup, I'll include you on the list. You can probably use whatever you want in terms of size. There can be an issue with a large cap charging across a parafeed transformer and magnetizing the core, but probably not an issue here.

Tom used 3.9u, I used 4u. I think from 3.9u to 4.7u is probably a good spot. Pins are 45mm, so a 41mm long cap is about right. 300V min as unloaded B+ is ~275V or so.

Probably depends on how many people are interested in doing the prototype build. Assuming all goes well, kits should be along before too long Update: Cases will be in the $25 to $30 range.