Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: ffivaz on April 04, 2014, 02:29:06 AM

Title: This is how we learn
Post by: ffivaz on April 04, 2014, 02:29:06 AM
I had a learning experience yesterday. My Crack was working fine for a little less than a year. A few days ago, I noticed a intermittent sssshhhh noise in one channel. I checked the voltages, which were fine. Looks like the problem was with the pot. I tried to clean it, shake it, nothing did. I had a Alps BV sitting on my desk, so I decided to replaced the stock pot with the blue one.

The cables coming from the RCAs were a little short, so I decided to replace them with some shielded cable in excess from my Stereomour build. I cabled the right and left channels. And, as I had two grounds now (one in each shielded cable), I thought it was fine to remove the piece of cable connecting the two grounds on the pot. Bad move! It lifts the ground, the resistance check went crazy and I had a hard time figuring out what was wrong. I even tried to plug the Crack, thinking that my ohmmeter was the problem. Bad move, the lifted ground keeps capacitors from discharging, being a hazard for yourself, and the thing hums like hell!

So, if you decide to replace the braided cable and the pot. Don't forget to bridge the grounds, at the RCAs or at the pot!
Title: Re: This is how we learn
Post by: Paul Birkeland on April 04, 2014, 09:25:04 AM
I'm totally stoked to hear about your adventures, as you used the tools in the manual (resistance checks), then working through and determining where things went wrong.  Well done!
Title: Re: This is how we learn
Post by: ffivaz on April 10, 2014, 09:06:31 PM
Thanks PB, I learned a new english expression "to be stoked" :) BTW, I was quite wrong. Shaking the Crack to put the new things in corrected the noise problem, but it came back when it settled down for some days. I did a chopstick test and the problem was a not well soldered pin on one  of the 2N2222A transistor on the speedball board...
Title: Re: This is how we learn
Post by: Loquah on April 11, 2014, 01:03:26 AM
Nicely written explanations for us to learn from. Thanks Fabien!!
Title: Re: This is how we learn
Post by: Doc B. on April 11, 2014, 06:11:44 AM
Yes, this is a great thread about one of the two ingredients that the kit builder must supply on their own - initiative. The other ingredient would be patience. If you bring those to the table when you work on this stuff you can fix just about any issue you might find and in the process greatly increase your satisfaction level regarding the overall kit experience.

Along those lines I am reading a ripping tale right now, called The Martian. It's about an astronaut who gets marooned on Mars and has to survive with what he has on hand until a rescue mission can come. Apparently the author was advised by real NASA type brains and the McGyverish/Apollo13 stuff this guy comes up with demonstrates that awesome skill of thinking thru a problem logically and with a sense that you can solve any problem with enough perseverance.


Title: Re: This is how we learn
Post by: Loquah on April 11, 2014, 11:25:34 AM
Yes, this is a great thread about one of the two ingredients that the kit builder must supply on their own - initiative. The other ingredient would be patience. If you bring those to the table when you work on this stuff you can fix just about any issue you might find and in the process greatly increase your satisfaction level regarding the overall kit experience.

Along those lines I am reading a ripping tale right now, called The Martian. It's about an astronaut who gets marooned on Mars and has to survive with what he has on hand until a rescue mission can come. Apparently the author was advised by real NASA type brains and the McGyverish/Apollo13 stuff this guy comes up with demonstrates that awesome skill of thinking thru a problem logically and with a sense that you can solve any problem with enough perseverance.

That's the key I think. Without that people give up or can't think past the problem and always get stuck AT the problem.
Title: Re: This is how we learn
Post by: tuffy_puppy on April 11, 2014, 02:38:16 PM
doc,  i am totally blown away by the fact that you have time to read!  great news, sir!  don
Title: Re: This is how we learn
Post by: ffivaz on April 13, 2014, 10:47:08 PM
Well, it is also that the great products and the really well written and self explaining manuals gives enough confidence to take some initiatives. I'm not a NASA brain :)

So, thanks again Bottlehead for what you do for music!