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Crack;Bottlehead OTL - Page 93

post #1381 of 1888
12/31/12 at 8:38am
Yes, the IEC power cord socket is a universal kind of connector. You will just need to find an IEC style power cord with the proper plug for your local AC mains sockets.
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post #1382 of 1888
12/31/12 at 11:04am

How does O2 compare with the Crack on HD 650's? Looking to upgrade to a Crack and possibly with speed ball but I'm not sure if it is worth the upgrade if I am only going to hear a slight difference. 

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post #1383 of 1888
12/31/12 at 11:19am

Not sure there is an easy answer to that scjarrett87. Maybe you can find someone locally who has one you can audition? Are you in/near a major city? 

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post #1384 of 1888
12/31/12 at 12:02pm
Quote:
Originally Posted by T.F.O.A View Post

What difference do you get when you upgrade the caps? Does it change the sound character? and is it really noticeable?

Yup - since the coupling caps are directly in the signal path in an otl amp, they do audibly change the sound, much akin to rolling tubes IMO. Two sets of *perfect caps, of identical spec and tolerance, and with "inaudible esr" would presumably sound the same, but I suspect you would have to spend big bucks to hit that threshold (assuming it can even be done from a manufacturing standpoint) when we are talking about quality film caps of ~100 uF and at least 250 V (as required in the crack output stage). The stock electolytics, axons, and obbligato's I've tried all do sound different from one another in the crack, and there are a couple of good threads on the topic on the bh forums where you can find more condensed info along these lines.

Bob Crites also has a nice q&a style discussion regarding caps in relation to the xovers he makes for vintage klipsch speakers: http://www.critesspeakers.com/frequently-asked-questions.html.
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post #1385 of 1888
1/1/13 at 1:52am

is it possible to upgrade the caps right away when you're building it? how do you pick the upgrade caps? (sorry if it's sounds like a stupid question, but i'd rather get it all done on the 1st time then going back and redo some stuff)

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post #1386 of 1888
1/1/13 at 6:11am
Quote:
Originally Posted by T.F.O.A View Post

is it possible to upgrade the caps right away when you're building it? how do you pick the upgrade caps? (sorry if it's sounds like a stupid question, but i'd rather get it all done on the 1st time then going back and redo some stuff)

 

How about going back one page in this thread and reading post 1376.

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post #1387 of 1888
1/1/13 at 6:17am
Quote:
Originally Posted by BmWr75 View Post

 

How about going back one page in this thread and reading post 1376.

Hey thanks for the tip! Didn't realize it's only one page behind.

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post #1388 of 1888
1/1/13 at 2:46pm

Whohooooooo~ I have just finished building my crack + speedball this morning. And it sounds aweeeessoommeeeee!! atsmile.gif
Highs are crystal clear, mids are sweet, and bass, oh the bass is sooo tight and warm. Soundstage is, too, amazing. Feels like listening to a live concert biggrin.gif. My HD600 has never sounded this good before.

 

Is it weird if I enjoy looking at my crack? I smile every time I flip the chassis over, maybe somewhat proud that I have built this baby with my own hands.. tongue.gif

 

 

1000

 

1000

 

1000

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post #1389 of 1888
1/1/13 at 2:49pm

Gorgeous! Great point to point work. I love the braiding on the long cables!

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post #1390 of 1888
1/1/13 at 3:32pm

Re Manual;

 

Load Plate Resistors. Can I trim the ends on that and the LED Leads once I have soldered?

 

My DMM doesn't have a clip lead, what else could I do to make the earth lead stay in place that won't affect the results?

 

How much wire would you expect to have left over at the end of build?

 

Thanks in advance.

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post #1391 of 1888
1/1/13 at 5:14pm

Yes, once soldered you can just trim the leads. In fact, it is recommended not only for tidiness but also to prevent accidental shorting.

 

For resistance measurement, you can just hold the ground/black probe by hand and use the other hand to move the red probe. You COULD do that for voltage measurement, but I don't recommend that! As Doc said in the manual, try not to work on a live equipment with both hands to reduce the possibility of getting shocked. You can try to use a paper clip or some other trick to hold ground probe in place.

 

As for the wire, if you follow the manual and cut wires with lengths as specified, you'll have about a foot left once done. I don't think you need to cut more than what is said in the manual. Thanks to the mindful Doc, those are already pretty long such that you'll still make it even though you accidentally clip both ends when stripping the wires.

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post #1392 of 1888
1/1/13 at 5:29pm
Quote:
Originally Posted by j123my View Post

Whohooooooo~ I have just finished building my crack + speedball this morning. And it sounds aweeeessoommeeeee!! atsmile.gif
Highs are crystal clear, mids are sweet, and bass, oh the bass is sooo tight and warm. Soundstage is, too, amazing. Feels like listening to a live concert biggrin.gif. My HD600 has never sounded this good before.

 

Is it weird if I enjoy looking at my crack? I smile every time I flip the chassis over, maybe somewhat proud that I have built this baby with my own hands.. tongue.gif

 

 

Beautiful work!!

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post #1393 of 1888
1/1/13 at 5:44pm
Quote:
Originally Posted by longbowbbs View Post

Gorgeous! Great point to point work. I love the braiding on the long cables!

Thanks, longbowbbs! To be fair, that is my third crack build. I have build 2 cracks for my friend before, so I already know what I am doing when I build mine. For the first one, I just followed the manual closely and got a pretty standard-looking crack:

 

1000

 

The wires given by the manual are somewhat long. Then on the second build I tried to measure the actual length from point to point and cut only what needed for a prettier look:

 

1000

 

It took me much longer (~18 hrs) to do since I have to re-measure everything, but I think it is well worth it, IMHO! biggrin.gif Then I think I am only getting better from there onwards. The third one took me only about 12 hrs to do (with speedball!)

Anyway, I never thought building it to be that fun! I doubt that my crack will be the last crack I build. In fact if any head-fiers need help, I would consider helping them build one when I have time. Just PM me. But they should be warned: they'll be missing half of the fun! biggrin.gif

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post #1394 of 1888
1/1/13 at 6:09pm

j123my,

 

You effort is certainly worth it. This is one of the cleanest builds I have ever seen. Congrats on a job well done!  

 

beerchug.gif

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post #1395 of 1888
1/2/13 at 8:57am
Quote:
Originally Posted by skeptic View Post

So I had a chance to do a little monkeying around with my crack over the holidays, including the installation of a pair of 100 uF / 400 V obbligato's in place of the 91 uF axons I was previously running as output caps. The folks in the bh forums weren't kidding about the easily audible improvement you can get from changing up these caps! Treble instruments are now totally grain free, and the bass response is bigger and better than it was with the axon's - although I imagine the latter has more to do with the change in capacitance than anything else (based on Doc et al.'s comments about expected bass roll off from using lower value caps).
In any event, if any of you are looking for a <$100 upgrade with an obvious impact on sound quality, this is definitely worth considering and only takes about 10 minutes if you already have zip tie pads in place. Happy listening and new year to you all!


Wow so I guess you are using 100uf Obbligato PSU caps? Are they worth the price compared to the axon/solen 100uf caps?
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