Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: A Jedi on June 22, 2019, 07:48:14 AM

Title: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 07:48:14 AM
Hey gang, just finished my build and I have noise in the right channel. I've looked through the other posts with this issue but haven't found something that exactly matches my situation.

The details:
All build tests and checks are a-ok.
All noise issues are in the right channel.
Both LEDs are working as expected (constant ON with power).
I've visually inspected all connections and see no issues.
Makes no difference if RCAs are plugged in or not.
The noise is volume independent.
I've seated and reseated the tubes several times and it makes no difference.
The first time I turned it on with my headphones plugged in, I was getting loud twangs from vibrations on the chassis. Like if I moved the chassis or tapped it or anything else that causes vibrations. This issue seems to be disappearing as I use the amp more and more.
There is a quiet intermittent noise in the right channel. It mostly sounds like a buzz. Once it sounded exactly like a mosquito next to my ear.
The worst part is that it's intermittent so I can't correlate it to anything.

Any thoughts/suggestions?
Title: Re: Crack 1.1 noise in right channel
Post by: oguinn on June 22, 2019, 07:49:45 AM
If you’re getting noise when you tap the chassis it could be a loose or undersoldered connection. Could you post some pictures of your build?
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 09:51:19 AM
Any area in particular or everything?
Title: Re: Crack 1.1 noise in right channel
Post by: oguinn on June 22, 2019, 10:00:28 AM
The more the better but probably want to focus on the area around the input and headphone jacks and tubes. And maybe take a pass through the hardware and make sure everything is tightened down.
Title: Re: Crack 1.1 noise in right channel
Post by: oguinn on June 22, 2019, 10:01:58 AM
Caveat: I’m just some guy and don’t work for Bottlehead so I might have you focused on the wrong things. This is where I’d start, but you may have to post a couple rounds of photos.
Title: Re: Crack 1.1 noise in right channel
Post by: Doc B. on June 22, 2019, 10:07:41 AM
It could just be a tube that needs to settle in. Try letting it run for a few hours and see if anything changes.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 11:21:34 AM
Caveat: I’m just some guy and don’t work for Bottlehead so I might have you focused on the wrong things. This is where I’d start, but you may have to post a couple rounds of photos.

It's all good. Any suggestions help. I'll post some pics later when I shut it off....can't stop listening to it (even with the damn noise) lol.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 11:23:14 AM
It could just be a tube that needs to settle in. Try letting it run for a few hours and see if anything changes.

Yeah I've had it on for a several hours a day and it did get better but it's reached a plateu in improvement and there is still some noise.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 11:30:58 AM
BTW, is the chassis plate supposed to be hot to the touch? I expect the tubes to be hot but didn't think enough heat would be generated to heat up the entire thing.
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on June 22, 2019, 01:13:32 PM
Sure, the chassis plate will be warm.  What wireless devices do you have around your Crack?  The mosquito comparison makes me suspicious that you're picking up noise from another device.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 01:47:07 PM
Sure, the chassis plate will be warm.  What wireless devices do you have around your Crack?  The mosquito comparison makes me suspicious that you're picking up noise from another device.

My cell phone is next to me pretty much always. The mosquito sound only occurred on one occasion. Will post pics shortly and then start going over every solder point.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 02:07:11 PM
Here are some pics:

Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 02:09:17 PM
And more
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 02:10:01 PM
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Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 02:10:39 PM
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Title: Re: Crack 1.1 noise in right channel
Post by: oguinn on June 22, 2019, 02:26:09 PM
You might want to take a look at the lower lug of the potentiometer on the outboard side of the chassis. It looks like some of the insulation got melted to the lug, and maybe there's some stray solder there too.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 02:49:12 PM
Yup, I'm going back and hitting all the ones MAY be the issue. That one on the volume is the prime suspect. So much easier to see these things when you take pics and blow them up!
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on June 22, 2019, 02:57:44 PM
The black wires on the headphone jack are suspect.  The black wires that meet on the headphone jack are also suspicious, and this is a joint where it's easy to get one wire soldered and not the other.

The red wire connected to 7U also looks like it might not be all the way soldered. 
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 03:12:31 PM
Thanks, I'll look at those again. In the meantime I fixed the lower red on the potentiometer and a few other suspects but no improvement so far.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 04:03:01 PM
Went through all questionables and still no bueno. It's actually a little worse now. Very frustrating. I'll have to do the chopstick test.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 04:09:55 PM
I'm starting to think it may be a tube. The noise gets quieter after the tubes warm up.
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on June 22, 2019, 04:13:44 PM
You can try leaving it on for a few days.  Often times when I have a tube that's making noises, it will stop after the tube has been brought up to operating temperature and left running for a while.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 04:20:02 PM
Cool, I'll do that.

I'm now 99% certain it's the 6080. Whenever a noise starts, if I tap it, noise goes away. It's as if something inside it goes into its resonance frequency and needs an external force to stop it.
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on June 22, 2019, 04:29:17 PM
That could also be related to the solder joints on the octal socket or on the other end of components attached to the octal socket. 
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 22, 2019, 05:00:45 PM
It's possible. But man, I've been through all those joints 10 times. Will take another look tomorrow and maybe get lucky.
Title: Re: Crack 1.1 noise in right channel
Post by: oguinn on June 22, 2019, 06:52:53 PM
You could test the tube theory with a new 6080 or one of the variants listed in the tube rolling thread. They’re not cost prohibitive. If you go that route give the current tube a few days’ worth of burn in while you wait.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 23, 2019, 01:29:19 AM
The amp is on my desk next to my bed and last night when I went to bed and everything was quiet, I started hearing the noise. Nothing was hooked up to it - only power. Stuck my ear close to the chassis/transformer/6080 and could clearly hear it. So it's not just coming through the headphones (although it's louder there). So, got up this am and tightened all the screws to see what would happen - nadda. Will do the chopstick test later today and then order another tube. Dammit.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 23, 2019, 01:56:07 PM
It's def the tube. I flipped it over and powered it up. Poked around every wire and joint and nothing made a difference. Back the right way up, a light touch with a pen tip on the 6080 and buzz stops. Ordered another tube....
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on June 23, 2019, 02:34:37 PM
When you flip things over, gravity moves things around.  Last year I worked on a little Pilot EL84 amp that would work perfectly upside down, but would lose its ground connections when I flipped it over!

I would recommend hanging onto the 6080 you have just in case the new tube doesn't resolve the issue. 
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 23, 2019, 02:38:46 PM
Yep hanging onto it
Title: Re: Crack 1.1 noise in right channel
Post by: Robbo on June 27, 2019, 12:12:14 AM
Hi Guys,
I had the same problem with noise on the right channel. It turned out to be the red/white wires going to the headphone socket running parallel to the group of wires that run under ther big ceramic resistors shown in the manual as neatly grouped together. Lifting the two wires away from that group of wires so they were floating free solved the probem for me. Turnes out the red right channel wire closest was picking up noise from that group. I raise this potential issue in my review article on the hificollective blog.

First pic - Shows the wires grouped together. Has a buzz on right hand channel.
Second pic - Though hard to see because the choke obscures the view you can just about see that the two wires are lifted up. Buzz gone.

Regards
Title: Re: Crack 1.1 noise in right channel
Post by: fromnowon on June 27, 2019, 02:57:34 AM
That's a nice write-up on hificollective!

I'm curious about how you mounted the choke - it looks like you didn't drill at all, just used some two-sided sticky pads maybe and it's held securely?  Maybe there are some benefits from mounting that way.  It helped me a lot to see your choke location and also how you grounded it to tab 16.  I think I'll copy your method for that.

Also, those are really nice interconnect cables running to the RCAs.  Really well insulated it seems.  I wonder where a person could obtain a piece of that cable or something similar to it.
Title: Re: Crack 1.1 noise in right channel
Post by: Robbo on June 27, 2019, 03:12:47 AM
Yep, selotape strong double sided sticky pads in a row accoss the bottom of the choke double layered accross the middle part as that bit is raised slightly higher than the mounting tabs. Then soldered a wire to the ground lug u16 from the corner of the choke to make sure its grounded. It actually stuck really strong, infact i could pick the whole thing up by the choke.

Yeah that interconnect is really nice but not cheap (£58.44 incl vat for 1m), it's like hose pipe and quite stiff (Yarbo Audio silver interconnect), hificollective sell it. I had about a foot of it left over from my ANK EL34 modification work.

And yeah choke should be either mounted as far away from the power transformer as possible or perpendicular to it to avoid or cancel out the effects of the magnetic field respectively.

Be warned getting the solder to stick to the choke needs loads of heat the metal casing disipates the heat quite well so getting it hot enough was hard work. After some trial and error i eventually figured that the little crack in the metal frame on the corner of the choke might give something for the solder to flow into and grip better. I sanded the corner a bit to remove any varnish and expose the metal before soldering and used a bit of rosin flux to help clean the surface at the same time.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 27, 2019, 12:47:17 PM
Welp, problem solved. New tube arrived today. No more chassis noise, no more right channel issues. There is a very slight noise in both channels but that's disappearing as the tube burns in. I'll wait until all noise is 100% gone and mark this resolved.
Title: Re: Crack 1.1 noise in right channel
Post by: Robbo on June 28, 2019, 01:30:36 AM
Welp, problem solved. New tube arrived today. No more chassis noise, no more right channel issues. There is a very slight noise in both channels but that's disappearing as the tube burns in. I'll wait until all noise is 100% gone and mark this resolved.


If its a shhhh noise that goes after 15 - 20min once warmed up its prob a little tube rush, nothing to particularly worry about.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 28, 2019, 01:58:36 AM

If its a shhhh noise that goes after 15 - 20min once warmed up its prob a little tube rush, nothing to particularly worry about.

It's a kind of grainy shhhh....
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 28, 2019, 02:34:33 AM
Come to think of it, it's exactly the noise you hear when you walk by a street lamp. Given that a tube is essentially a bulb, the noise should be tube based. Can't wait for it to go away...
Title: Re: Crack 1.1 noise in right channel
Post by: Robbo on June 28, 2019, 03:26:35 AM
Does it go away once everything has warmed up, say after 15-20min? If its a persistent buzz of around 60hz or 120hz id say maybe check your signal wireing inside isnt butted up against other power wires inside or ground wire inside, paralelle to them perhaps. I thnk 60hz buzz might be power interference, 120hz could be ground interference. Im not sure if the symptoms could be interchaingable though.

As i said in my earlier post i had issues with the red/white wires going to the headphone socket running parallel to the group of wires that run under where the two large wirewound resistors are, lifting them both clear of that group solved the buzz issue for me, my guess is that it was probubly interference from the black ground wire. I could actually change the buzz by waving my hands around the amp hence my guess that ground was my issues cause.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 28, 2019, 10:31:15 AM
It's a higher frequency sound. More in the mid/high range. A light tap on the 6080 makes it go away. When I say "light tap" I mean very light - with the tip of a pen.  It's definitely less noticeable with the new tube but still there for now. At least the chassis isn't generating noise on its own anymore lol. I'll have to flip it over and poke around the wires again but last time I did that there was no change.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 29, 2019, 05:25:29 AM
 >:(

Starting to suspect transformer vibrations getting into the tube.
Title: Re: Crack 1.1 noise in right channel
Post by: Doc B. on June 29, 2019, 05:31:18 AM
Sounds like an oscillation. Those can come about from less than perfect contact of the tube in the socket. Try cleaning the tube pins.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on June 29, 2019, 05:51:50 AM
Sounds like an oscillation. Those can come about from less than perfect contact of the tube in the socket. Try cleaning the tube pins.

Thanks will do.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 01, 2019, 05:38:23 AM
Ok so cleaning the tube pins has helped. There is still a very low hum though. It's hard to pinpoint the frequency but it's somewhere in the midrange...maybe around a thousand-ish Hz? And once in a while there is a louder higher pitched tone - that one goes away if I tap the 6080. Any more thoughts/ideas?

This is my first experience with tube equipment so perhaps I'm expecting too much? Should it be dead quiet or is some noise normal? Should I just call Bottlehead?
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on July 01, 2019, 06:02:19 AM
Tapping the tube jostles all the connections in the amp, and a less than perfect connection can be temporarily restored by doing this.  Perhaps you could take some new photos since you've reflowed a bunch of joints.

While you are certainly welcome to phone in, any details discussed on the phone will not be present on this thread and will complicate providing future tech support.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 01, 2019, 10:05:14 AM
I've had it upside down and running and poked all connections with a chopstick and could not induce/reduce any noise. But here goes nothing:

Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on July 01, 2019, 10:16:05 AM
The 22.1K resistor at 5U is not well soldered or connected, though that is a left channel component.

If you wiggle the wire at A5, does it move in that joint?

The image of the octal socket is out of focus, so it's tough to say much about that.

-PB
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 01, 2019, 10:20:31 AM
Both A5 and 5U are rock solid. I have more pics but site errors when I try to post with attachments...I get a 500 error.
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on July 01, 2019, 10:45:31 AM
You may need to shrink the size down a little bit.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 01, 2019, 10:56:33 AM
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Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 01, 2019, 10:57:12 AM
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Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 01, 2019, 10:57:49 AM
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Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 01, 2019, 10:58:23 AM
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Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 01, 2019, 10:59:01 AM
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Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 01, 2019, 10:59:32 AM
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Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 01, 2019, 12:52:00 PM
One thing I haven't mentioned is that there was a small chip on the transformer when I received the kit. I took pics and emailed Bottlehead immediately and was told it shouldn't be a problem. Is it possible the transformer was dropped and is damaged? And that's why I'm having these issues?
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on July 01, 2019, 02:09:41 PM
The transformer is definitely not an issue.  That little piece of the bobbin that snapped off doesn't serve any function.

The joints that pop out at me are 6U and the 3K resistors attachment point at 3U.  I see a lot of flux at 3U and it's possible that one is really well soldered and the other is somewhat insulated by flux.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 01, 2019, 05:25:04 PM
The transformer is definitely not an issue.  That little piece of the bobbin that snapped off doesn't serve any function.

The joints that pop out at me are 6U and the 3K resistors attachment point at 3U.  I see a lot of flux at 3U and it's possible that one is really well soldered and the other is somewhat insulated by flux.


Went over those. No difference. I give up. Will send it in.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 04, 2019, 02:23:07 PM
Ok fine I guess I haven't given up. Spoke to to Doc B on the phone and ended up cleaning both the tube pins and sockets. Also tried a cheater plug to lift ground. Tiny improvements but still not enough.

One thing dawned on me - the PT had some sort of resin on the contacts. I basically just poked holes in it to slide the wires through and then soldered. Is there any benefit to undoing all PT wiring, making sure the contacts are completely clear of the "resin" and re-soldering?
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on July 04, 2019, 02:33:36 PM
It is varnish, and it should burn right off when you solder.  Also, every connection to the power transformer is common to both channels, so an issue here that made noise would make noise in both channels.  Such an issue should also rather immediately present itself in the voltage checks. 

If you want to check the operation of the transformer, you can measure the AC voltage between pins B7 and B8, then check the AC voltage between pins 18 and 19.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 04, 2019, 03:04:28 PM
It is varnish, and it should burn right off when you solder.  Also, every connection to the power transformer is common to both channels, so an issue here that made noise would make noise in both channels.  Such an issue should also rather immediately present itself in the voltage checks. 

If you want to check the operation of the transformer, you can measure the AC voltage between pins B7 and B8, then check the AC voltage between pins 18 and 19.

Hmmm ok then that's not it. And voltage checks are a-ok.
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 05, 2019, 07:18:47 AM
Went back through all resistance and voltage checks again for a sanity check. All ok. AC between 18 and 19 is 170V, between B7 and B8 it's 1.3V.
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on July 05, 2019, 07:23:52 AM
My guess is that your meter don't have a low AC voltage scale? (Maybe it only goes down to 200V?)
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 05, 2019, 08:38:36 AM
My guess is that your meter don't have a low AC voltage scale? (Maybe it only goes down to 200V?)

Oops sorry - forgot to change range. B7, B8 are 6.17V.
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on July 05, 2019, 11:00:18 AM
That's a good measurement, nothing to worry about there!
Title: Re: Crack 1.1 noise in right channel
Post by: A Jedi on July 05, 2019, 11:47:59 AM
I went back and reflowed all connections. Again. No change. Again. I'm sending this thing to you guys. Hopefully you can fix it. I thoroughly enjoyed putting it together and it sounds great. But the endless noise problems have taken all enjoyment out of it.
Title: Re: Crack 1.1 noise in right channel
Post by: takkos on November 27, 2019, 04:10:58 AM
I have the same issue, right channel, quiet high frequency electric noise (like when your ear is ringing but quieter). When I lift the 6080 tube it gets better and my assumption was also that the transformator noise has been picked up by the tube, as the noise of the transformer can be heard with my bare ears from close. All joints are OK, went through all joints with a chopstick, nothing is changing. Also it is independent from the volume level or anything. And the noise is beginning ~10 seconds after turning the Crack on.
Has your problem been resolved, and if so, what was the problem with your build?

EDIT: Actually it is a buzzing sound at first that becomes high frequency. It is noticeable in the left channel as well but way better then the right.
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on November 27, 2019, 04:36:42 AM
Transformer noise is 60Hz, which will sound like a low hum. 

For anyone who has this type of noise, it's certainly recommended to let your tubes run for a few days to cook in, as we have experienced many noisy tubes go totally quiet after 100 hours of burn in.
Title: Re: Crack 1.1 noise in right channel
Post by: takkos on November 28, 2019, 11:16:44 PM
Hi PB, thanks for your reply.
I matched the noise based on this site: https://www.szynalski.com/tone-generator/
The noise in the right channel is 1970 Hz, so way above the 60 Hz you mentioned.
Do I need to have ~100 hours runtime in the tubes in total, or i have to have it turned on for 100 hours continuously? (It would be a bit unsafety)

One more thing: Is it ok to have music in the right only when I just slightly turn the potentiometer up? And the resistance in the RCA pins is different in the left (89,7k) and right (97,7k), I installed two 3A diodes after the ground pin to avoid PC noises, before that i think these numbers were higher.
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on November 29, 2019, 05:43:58 AM
Do I need to have ~100 hours runtime in the tubes in total, or i have to have it turned on for 100 hours continuously? (It would be a bit unsafety)
100 hours constantly.  I do not know why this would be unsafe. 

One more thing: Is it ok to have music in the right only when I just slightly turn the potentiometer up?
See Crack FAQ #3/#4 (https://forum.bottlehead.com/index.php?topic=4295.0)


And the resistance in the RCA pins is different in the left (89,7k) and right (97,7k)
That doesn't have any audible impact on channel balance. 



 I installed two 3A diodes after the ground pin to avoid PC noises, before that i think these numbers were higher.
This is rather unlikely. 
Title: Re: Crack 1.1 noise in right channel
Post by: takkos on December 02, 2019, 09:47:22 AM
58 hours of constant runtime, still noisy. Right channel is louder, noticeable in the left as well. If I slightly tap the 6080 (RCA) tube, sometimes it gets quiter but after a while the noise comes back. I think that i might got a faulty tube, and the reason why i think this is that the noise only appears after the tube heats up, 10-15-30 seconds after turning on the device. If any of the joints would be the source of the noise, it would appear right after turning the Crack on. I will keep it going until it reaches the 100 hours, but my hope is fading away. :(
Title: Re: Crack 1.1 noise in right channel
Post by: Deke609 on December 02, 2019, 10:17:01 AM
I think that i might got a faulty tube, and the reason why i think this is that the noise only appears after the tube heats up, 10-15-30 seconds after turning on the device.

I'm not sure about this.  After many (PB and probably others would say too many) mods to my BeePre I was getting hum. It wasn't from the tubes, but would only start about 5-10 seconds after powering on as the tubes warmed up and started amplifying signal (including quiescent signal and any noise injected into the signal wiring somewhere else in the amp).

cheers, Derek
Title: Re: Crack 1.1 noise in right channel
Post by: takkos on December 03, 2019, 11:16:47 PM
Waited for the 100 hours to elapse, still noisy. In the meantime i ordered a pair of Lewis & Kaufman 6080 tubes, and with this, the system is dead silent. So unfortunately i got a faulty (microphonic) tube with my order. :(
All in all, this amp sounds superb and i am really happy with it.  8) :D
Title: Re: Crack 1.1 noise in right channel
Post by: Deluk on December 04, 2019, 12:20:45 AM
I'm not sure if anyone else has mentioned this and I think it's unlikely that I'm the only one with this situation. I suffer from fizzes. buzz and crackle now and then. Except for one, just after I built it, I've never found any bad joints. I do swap tubes occasionally and this often helps. I'm putting at least part of the blame on the 6080 8 pin socket. Mine is original and I keep it and the tube pins clean. The tube pins are gripped like a pincer. Fine, but the metal these are made of is soft so after wriggling tubes in and out a few times they get wider and you get a reduced grip with the potential for a poor connection. I know the metal is soft because I can squeeze them together again with just a pair of fine nose tweezers. This usually quieten things down again, until next time. I think I will change my socket to a sleeved type. Teflon ones are very expensive but you can get cheap ones on Amazon 4 for £9.79 with free post. From China of course. If they are better than the pincer type, at that price they could be considered for use as an original fitting. However the Bottlehead stores might still have 528 left from the original order of 1000.
If you've fitted the Teflon ones to cure noise and it's worked please comment. If you've fitted these cheap sleeved ones with good results I'd also like to know.
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on December 04, 2019, 04:29:20 AM
In my repairs experience, teflon sockets can cause a lot of reliability issues. 

If you wiggle the tubes when you tube roll, that will put a lot of extra wear on the sockets and you should replace them.  It's much better to just pull the tube straight out.
Title: Re: Crack 1.1 noise in right channel
Post by: Deluk on December 04, 2019, 10:43:09 AM
Thanks Paul but I've never had much luck getting them out with a straight pull. Getting a good grip on the metal mount isn't easy. Serial tube rollers must have very strong grip or change the sockets often. If there is a recommendation for a good but reasonably price socket that is better than the cheap sleeve type please advise. I read a previous comment by you about unreliable Teflon ones but at about £40 each I wasn't going to buy/try one anyway. I'm in the UK.
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on December 04, 2019, 11:06:41 AM
On the 6080, just grab the glass and pull.

I've replaced a decent number of the sleeve sockets also since I do repairs of tube gear as a small side business.  With the fork type contacts, at least it's very easy to get in there with a pick and bend them tight again. 
Title: Re: Crack 1.1 noise in right channel
Post by: Deluk on December 04, 2019, 12:46:19 PM
Thanks for the advice PB. Still a bit wary of pulling on the glass. Just had a go but didn't pull very hard. There is just a fraction of movement, just perceptible, between the glass and the metal collar and that makes me wary too. I don't fancy a handful of broken glass.
Title: Re: Crack 1.1 noise in right channel
Post by: Paul Birkeland on December 04, 2019, 12:58:33 PM
Between Dan, PJ, and I, we have to have 100+ years of pulling tubes out by the glass.  I can't ever recall one just breaking from being removed.
Title: Re: Crack 1.1 noise in right channel
Post by: Doc B. on December 04, 2019, 02:38:23 PM
The metal collar just floats on the base inside it, held on to it with a crimp. Because of that it's not really a structural element. I have removed and replaced them in the past.
Title: Re: Crack 1.1 noise in right channel
Post by: Deluk on December 06, 2019, 12:11:51 AM
Thanks guys for the reassurance. I just need a bit more courage now.  :)