Help me pre-game my Crack

[williaty]

This week, I'll be ordering a Crack+Speedball. Just have to wait for the check from my last client to clear. One thing I learned from my first Foreplay build is that it's a better idea to have a clear plan of attack for the mods you know you're going to do (or at least strongly suspect you'll do) before you do the initial build. To that end, I have some questions:

1) With the parts layout, is it better to build the Crack, test it, then install the Speedball, or just build it with the Speedball installed to begin with? I've done the listen to this, change it, listen to that thing before and I'm sold on the Speedball-type circuit upgrades. I have no interest in a before/after comparison, the question is solely about the ease of construction.

2) If the answer to #1 is "build it stock first", is there anything I can do during the initial stock build to make the Speedball install easier?

3) Is there anything that's easier to do before you do the Speedball, say coupling caps, the last PS cap, chokes, etc?

4) I would like to experiment with tubes that include octals. Is it better to install an octal socket and then go to the 12AU7 stock tube with an adapter or am I better off building with the sock socket and then using an adapter to get to octal tubes?

5) Follow up to #4: Is there any sonic drawback to leaving the socket adapter installed for the life of the device if the tube I finally settle on requires the adapter?

6) Speaking of sockets, is there anything to be gained, really, from teflon sockets, ceramic sockets, socket PCBs, etc?

7) What's up with people replacing the headphone jack and RCA jacks? Is there anything to be gained sonically, or are they just pretty?

Is there a Sweet Whispers-type product to upgrade to a stepped attenuator?

9) Is it worth using fancy wire and fancy solder, or is that mostly extra money for little extra sound?

Beyond that, any other words of wisdom?

[Paul Joppa]

1) There are two reasons to build stock first. One is the "listen to this, change it, listen to that" thing, but they other is that there is no manual for building it modified.

4-5-6) In my humble opinion, adapters are not a long-term solution. Twice as many connections to get worn, and much less mechanical stability. They can be great for trying and comparing various options though. An octal-size hole, with a hole shrinker for the 9-pin, allows you to build it well either way, once you decide. See the sticky on custom chassis plates.

Again IMHO, solid reliable connections will make you happier in the long run than magic insulating material in sockets. Too many modern sockets are shoddy engineering, shoddy construction, shoddy materials, or incorrect dimensions. Teflon for example is not mechanically stable (it flows, though very slowly). I don't have the answer, but I think I do know the question! Ask on the Tube DIY asylum (wear your flame suit) - I think that a wider variety of sockets have been tried on that forum than any other I know.

7) Similarly, I think well-built, long-lasting, reliable connectors make better sound than exotic materials with unreliable connections. Did I mention that not everyone agrees with me?  :^)

Stepped attenuators are widely available.

[williaty]

Paul, I'm guessing that, in your opinion, the tube sockets, RCA jacks, and headphone jack included in the basic kit are "solid reliable connections"?

Also, I didn't see a power cord in the kit picture, do you have thoughts on buying the Bottlehead power cable kit vs using a $2 power cable from the computer store?

[anson67]

Regarding #2, please see my post in the Gallery forum, the recent Red/Gray Crack thread.

[Paul Joppa]

Paul, I'm guessing that, in your opinion, the tube sockets, RCA jacks, and headphone jack included in the basic kit are "solid reliable connections"? ...

Hmmm ... well, sort of. We have always focused on cost-effective parts, and I believe all our parts meet that specification - they are the best quality we can find at a more or less "normal" price, but they are not boutique parts. I just meant that there are (for example) a lot of expensive gold-plated connectors out there that are the wrong size, or have inappropriate spring materials, or won't maintain their dimensions, etc. - that are not well engineered to obtain and maintain a good connection. There is good stuff out there too, better in a real sense than what we supply, but it is much more costly - at a guess, at least five times as expensive. Look for instance at the custom Tube Phono preamp, with nearly the same circuit as the Eros but exotic components, expensive switches, an added line driver output stage, and other differences.

Take headphone jacks for instance. The 1/4-inch plug and jack standard came out of the telephone industry, where operators would make the physical connection hundreds of times a day for decades, and the connection had to be reliable. They were large and very long, so that the switch springs were not stressed; insulation was usually bakelite, and switch contacts would be heavy silver. I remember these jacks but have not seen such construction for sale in decades.

[Grainger49]

   .  .  .   Also, I didn't see a power cord in the kit picture, do you have thoughts on buying the Bottlehead power cable kit vs using a $2 power cable from the computer store?

There is a power cord with the kit.  The Bottlehead kit power cord is an upgrade and a $2 computer cord might be a downgrade.

Regarding #2, please see my post in the Gallery forum, the recent Red/Gray Crack thread.

Anson gives some excellent ideas for building with the upgrade in mind. 

[williaty]

Well, called in and placed my order today. Picked up a Crack, Speedball, Hole Shrinker, and Bottlehead power cord.

Doc, any of that available or is all of it waiting on parts?