Crack;Bottlehead OTL
Jun 20, 2014 at 1:01 PM Post #5,326 of 12,347
I Wish I could spend time modding my crack, but I have too many projects going on. So sad to see all the discussions that I can't partake in :frowning2:
 
Jun 20, 2014 at 6:34 PM Post #5,328 of 12,347
Yeah I would agree that upgrading the attenuator would probably be the most rewarding upgrade after the Speedball. In order to address that we are working on the idea of using a Submissive passive attenuator ahead of the Crack and replacing the stock pot in the Crack with an adjustable crossfeed circuit that can be defeated for those who don't want it in the signal path. We found that designing our own attenuator gave us the best results vs. using other available high end attenuators, and the best sounding stepped attenuators tend to be bigger than the Crack chassis can accomodate. So the Submissive in its own chassis that matches the Crack chassis may have some appeal to those who have the space for a second chassis in their setup.

We will be running some tests on a crossfeed circuit in the next few weeks.

Oh, and thanks for the order!


Very interesting! I have actually been thinking about doing something similar to this for a while. I'm don't like how to stock pot handles channel imbalance at the lower levels. Been think about throwing a passive preamp upstream to let me turn the pot higher. Taking it completely out of the equation sounds even better. Would turning the stock pot to max and then throwing a passive preamp upstream be essentially the same thing?
 
Jun 20, 2014 at 7:00 PM Post #5,329 of 12,347
Yeah, turning the pot up all the way pretty closely emulates a simple grid load resistor at the input, except of course that there are wiper contacts and a carbon track rather than a simple metal film or whatever resistor. On paper that may not make any difference, but the whole point of the conversation in the first place is about changing the resistive materials to improve the sonics. If you are going to go to the trouble to put an attenuator with high quality resistors in ahead of the pot it might make more sense to swap the pot for a 100K ohm MF resistor.
 
Jun 20, 2014 at 7:07 PM Post #5,330 of 12,347
Technically, sure you could do that. Not sure if it would sound better, as my philosophy has always been to use as few gain stages as possible. I admit to being surprised by the recent raves about putting a Quickie ahead of a Crack. I guess I need to play with that myself. We're certainly happy to sell them to anyone who finds that to be a sound that they prefer.

I'm very pleased with Quickie ..skeptical at first (Thanks to Matt and one of his posts) but I'm so glad it's finally here  ,swapped few tubes since I build it and I have to say that Quickie/PJCCS=> Crack/GEC A1834/E80CC Philips =>HD650 sounds superb , it made some tubes shine more then others ,this upgrade is worth every penny  
 
Jun 20, 2014 at 9:23 PM Post #5,331 of 12,347
  I'm very pleased with Quickie ..skeptical at first (Thanks to Matt and one of his posts) but I'm so glad it's finally here  ,swapped few tubes since I build it and I have to say that Quickie/PJCCS=> Crack/GEC A1834/E80CC Philips =>HD650 sounds superb , it made some tubes shine more then others ,this upgrade is worth every penny  

biggrin.gif
...just trying to spread the love. 
 
Jun 21, 2014 at 1:41 AM Post #5,332 of 12,347
Premium tubes for the Crack going cheap:
 
http://www.ebay.com.au/itm/261511534435?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649
 
http://www.ebay.com.au/itm/261511548467?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649
 
wink_face.gif

 
 

 
Jun 21, 2014 at 10:14 PM Post #5,336 of 12,347
  Patience! It will be worth the wait.

I hope so.
biggrin.gif

I have another idea about this Crack i might build it stock and if i really like it i will build another crack using all upgraded parts and sell the stock crack.IMHO instead of squeezing all those big caps choked etc etc inside the crack case mind as will start from the scratch all you really need is plates wood some screws holesaw jigsaw drill/drill press(which i have) drill bits and a bit of know how to work with metals and wood.
 
Jun 22, 2014 at 5:47 AM Post #5,337 of 12,347
Hi There!
 
I am rechecking my voltages after an issue I had. I can't recall how I resolved this question: 
 
I don't understand the instructions 5 and 6 on page 38. If I use the negative probe clip to connect to terminal 12, how can I connect the same lead to the ground buss?
 
What is the ground buss? Is that the negative port on my multimeter? 
 
Jun 22, 2014 at 6:51 AM Post #5,339 of 12,347
Well I just did what I thought was ok, and everything seems ok. Things showing as 0 are showing as 1.8mV, I presume that is ok ? It's strange to me that slightly changing the angle of the contact on a terminal changes the voltage massively. 
 
Jun 22, 2014 at 12:14 PM Post #5,340 of 12,347
Most probably the best place for assistance on interpreting the manual or trouble shooting is on the Bottlehead Forum where you will find support provided direct from the Bottlehead team who designed the Crack and wrote the manual.  I suspect some of us might interpret written instructions differently so getting it straight from the horses mouth so to speak is the way to go imho.
 
I hope you have enjoyed the build so far and welcome to the Crack club.
 

Users who are viewing this thread

Back
Top