Crack;Bottlehead OTL
Sep 19, 2016 at 8:19 PM Post #7,876 of 12,304
If the noise is occurring at intervals it is possibly due to outside interference from some appliance, cellphone or wifi router. From your description that the noise is there even with the DAC not connected it is apparent that the noise is not coming thru the cables from the DAC. For technical support regarding Bottlehead gear I always recommend posting your inquiry on the Bottlehead forum, as there is a pretty rich experience base.

You might try different tubes to eliminate the possibility that one of them is sensitive to interference.
They didn't say when the DAC was disconnected just turned off and stopped when they pulled the left RCA out of the amp.
 
Sep 20, 2016 at 10:57 AM Post #7,877 of 12,304
He did however say the DAC was disconnected from the USB port. And that the noise persisted with the volume set to 0. So it's fairly safe to assume that it was not coming thru signal hot. That would imply noise pickup is likely to be coming in on the left channel ground somewhere, possibly at the RCA jack or the cable shield, or being picked up by a tube.
 
Sep 23, 2016 at 12:32 PM Post #7,878 of 12,304
Hi guys,
It has been a while since my last visit to this forum. I have had my bottlehead crack for about three years now and recently I started noticing a crackling coming out, even with the source off and regardless of the headphones it is connected to, tried it with Beyerdynamic DT880(600ohm) and Sennheiser HD-650 (more noticeable on this ones).
 
Do you guys think I need to replace tubes on it, I usually use it Mon-Fri for about 7-8hrs. I only had a spare 12AU7 and replaced it but same thing. Your thoughts are greatly appreciated.
 
Sep 23, 2016 at 12:50 PM Post #7,879 of 12,304
  Hi guys,
It has been a while since my last visit to this forum. I have had my bottlehead crack for about three years now and recently I started noticing a crackling coming out, even with the source off and regardless of the headphones it is connected to, tried it with Beyerdynamic DT880(600ohm) and Sennheiser HD-650 (more noticeable on this ones).
 
Do you guys think I need to replace tubes on it, I usually use it Mon-Fri for about 7-8hrs. I only had a spare 12AU7 and replaced it but same thing. Your thoughts are greatly appreciated.

 
I had a bad 12AU7 that was crackling. Replaced it and it went away. 6080's can be had for pretty cheap so it's worth a try. Could be any number of things, though personally I'd start with tubes. Time doth take it's toll.
 
Sep 25, 2016 at 8:05 PM Post #7,880 of 12,304
I thought I would share some anti-vibration stuff I'm using. It's cheap and effective.
 
First, the pads. I got them here:
 
http://www.supplyhouse.com/DiversiTech-MP-2E-EVA-Anti-Vibration-Pad-2-x-2-x-7-8
http://www.supplyhouse.com/DiversiTech-MP-2C-Rubber-Cork-Anti-Vibration-Pad-2-x-2-x-7-8
 
They sell 3x3 and 4x4 too.
 
Pricing is very cheap, but shipping can be tough, so buy dozens. You will use them all over the place. I love them under speakers to both reduce vibrations and to protect surfaces.
 
The wood board under the crack is just for testing, which I just started. So far the isolation is great, so I will make that board pretty.
 
I found that even light vibrations transmit through the crack, so anti-vibration was needed. AV stuff in the audiophile world can be ridiculously expensive. Perfect opportunity for DIY.
 
Next I might try some tube damper, specifically some inexpensive o-rings, and see what that does.
 

 
Sep 26, 2016 at 4:14 PM Post #7,881 of 12,304
  He did however say the DAC was disconnected from the USB port. And that the noise persisted with the volume set to 0. So it's fairly safe to assume that it was not coming thru signal hot. That would imply noise pickup is likely to be coming in on the left channel ground somewhere, possibly at the RCA jack or the cable shield, or being picked up by a tube.

Did some more testing and turns out the crackles were coming from my laptop's Wifi and my phone. 
 
The phone is of course easy to move away, but I can't move my laptop more than 12 inches away due to space limitations. I thought this would be far away enough to not cause interference, but I guess that's not the case.  
 
So I just save my Spotify playlists offline and listen while with the wifi turned off.
 
Thanks for the help guys!
 
Sep 26, 2016 at 6:06 PM Post #7,882 of 12,304
  Did some more testing and turns out the crackles were coming from my laptop's Wifi and my phone. 
 
The phone is of course easy to move away, but I can't move my laptop more than 12 inches away due to space limitations. I thought this would be far away enough to not cause interference, but I guess that's not the case.  
 
So I just save my Spotify playlists offline and listen while with the wifi turned off.
 
Thanks for the help guys!

 
I had that problem! Those tubes definately act as wifi antenna. Setting my laptop  on a different elevation than the Crack got rid of it.
 
Oct 2, 2016 at 11:12 PM Post #7,883 of 12,304
I just installed my Speedball this morning.  Can't really speak to the changes necessarily since I didn't listen too much before the upgrade and also changed the tubes to Mullard 12AU7 and Bendix 6080WB from stock and use this to drive my HD650.  It's a very fun and enjoyable setup with the additional satisfaction of it being DIY.
 
Question for everyone - I have a pretty decent collection of 6SN7, VT-99, VT-231, 6F8G from my main rig (Woo WA22) and ordered some 6SN7 to 12AU7 and 6F8G to 12AU7 (I was sure to get the 6.3V versions) so I can take advantage of my existing tubes instead of investing in 12AU7 and such.  Is there any "consensus" on if either type of driver tube is any better or worse with the Crack?
 
Oct 3, 2016 at 2:54 AM Post #7,885 of 12,304
  I just installed my Speedball this morning.  Can't really speak to the changes necessarily since I didn't listen too much before the upgrade and also changed the tubes to Mullard 12AU7 and Bendix 6080WB from stock and use this to drive my HD650.  It's a very fun and enjoyable setup with the additional satisfaction of it being DIY.
 
Question for everyone - I have a pretty decent collection of 6SN7, VT-99, VT-231, 6F8G from my main rig (Woo WA22) and ordered some 6SN7 to 12AU7 and 6F8G to 12AU7 (I was sure to get the 6.3V versions) so I can take advantage of my existing tubes instead of investing in 12AU7 and such.  Is there any "consensus" on if either type of driver tube is any better or worse with the Crack?


I was fond of running 6sn7 in the driver slot but never got round to trying the 6F8G
 
Oct 3, 2016 at 10:27 AM Post #7,888 of 12,304
  So you prefered the 6SN7 over 12AU7 in the Crack?  Which brands did you try?

 
I rolled a bunch of 12au7 for about a year before moving to E80cc after which I let go of all but a couple of my 12au7 (check out the speedball resistor mod on the Bottlehead forum to switch between the 12au7 and the sweet spot for running the E80cc ).
 
After that I would switch between the E80cc and the 6sn7 for the input tube.I only rolled a handful of 6sn7 but had two firm favourites the National 6sn7 VT231 black glass & the Russian Melz 6sn7 (the perforated anode version) I might add that the Melz I only used when listening to LP's it just seemed to have great synergy in my system but for digital I preferred the National.
 
Oct 4, 2016 at 1:48 PM Post #7,889 of 12,304
Hi. Looking for some help and advice. My Crack with Speedball has an on going issue which I causing the right channel to cut out after about 15 minutes of play. It's been in to a local electronics engineer already once, £140 and its doing the same again. He thought a couple of components on one of the two small speedball needed replacing but having done so unfortunately did not rectify the issue. It will sadden me to do so but it might be the end of the line for my Crack as I cannot afford such costs. The electronics engineer has suggested removing speedball taking it back to original Crack but that would be too much of a retrograde step for me. Any ideas?
 
Oct 4, 2016 at 2:09 PM Post #7,890 of 12,304
Hi. Looking for some help and advice. My Crack with Speedball has an on going issue which I causing the right channel to cut out after about 15 minutes of play. It's been in to a local electronics engineer already once, £140 and its doing the same again. He thought a couple of components on one of the two small speedball needed replacing but having done so unfortunately did not rectify the issue. It will sadden me to do so but it might be the end of the line for my Crack as I cannot afford such costs. The electronics engineer has suggested removing speedball taking it back to original Crack but that would be too much of a retrograde step for me. Any ideas?

 
Sounds like a solder joint problem once the joint heats up as the Crack starts to heat up in your case 15mins a connection expands enough to lose contact. Do you have a soldering iron? If so you could work your way back through the terminals of the effected channel heating up the joints and reflowing the solder. Posting some pics on the Bottlehead forum might be helpful the guys are pretty good at trouble shooting such problems.
 

Users who are viewing this thread

Back
Top