[Hypops]

Just to clarify, I never said "whatever" parts will sound the same... however I believe you could purchase the same parts included in the BH kit for ~$30.

I'm a cable believer, I have chased cables for the entirety of my audio hobby career (35yrs+) and experienced a lot of surprising revelations. As mentioned, I have 2 of the BH cables built and another one sitting unbuilt. No, I haven't done a metallurgy study on their copper, but it appears to be standard 14Ga copper wire from your favorite home improvement store. You'd be hard pressed to distinguish it visually... it could be special sure... but the difference in sound from these cables (in my personal experience) has had MUCH more to do with the noise surrounding the system, and the cables' ability to prevent leaching that noise. Cables are a religions debate, and there's no winning that debate, only your personal experience with your personal system.

Totally. And apologies if I came off as snippy. Unintended.

 

[michael2v]

I just experienced a loud pop from the right channel of my Crack while playing music; it had been on for a couple hours already. I purchased it from another user already built, and have put about 20 hours on it in total. I replaced the stock tubes that came with it with a new 12AU7 from Apos Ray and a (supposedly NOS) RCA 6AS7G from TubeDepot.

As far as I can tell the sound is fine; perhaps the right channel is slightly quieter than it was before, but it may just be my brain playing tricks on me.

Is this kind of one-channel noise limited to the circuit itself (e.g. solder joints or components), or can it also be a sign of an issue with one of the tubes? Since the Crack only has one input and output tube, I wasn't sure whether tube issues could manifest on one channel like that or not. Thanks in advance!

 

[Beefy]

Even with a

I just experienced a loud pop from the right channel of my Crack while playing music; it had been on for a couple hours already. I purchased it from another user already built, and have put about 20 hours on it in total. I replaced the stock tubes that came with it with a new 12AU7 from Apos Ray and a (supposedly NOS) RCA 6AS7G from TubeDepot.

As far as I can tell the sound is fine; perhaps the right channel is slightly quieter than it was before, but it may just be my brain playing tricks on me.

Is this kind of one-channel noise limited to the circuit itself (e.g. solder joints or components), or can it also be a sign of an issue with one of the tubes? Since the Crack only has one input and output tube, I wasn't sure whether tube issues could manifest on one channel like that or not. Thanks in advance!

The single tubes still have two different sections for each channel, and they can behave very differently. Matching between sections is particularly important for the input tube, so that they have the same gain.

Extremely hard to diagnose a single pop though. Could be the tube settling, could be a bad joint, could be a failing part, could be cosmic rays transported across time and space from another dimension.

 

[haasaaroni]

Newly equipped Tung Sol 6520 and Telefunken G73-R red label. I can’t believe how good this thing sounds.

 

[HTSkywalker]

I had looked into that and found contrasting opinions, but I'll stop doing that. Thanks for the advice.
The noise is constant. The only moment it leaves is when I turn the amp off.

First thing to try is changing the tube.

 

[HTSkywalker]

Unfortunately, as I mentioned before, I have already tried a number of different tube combinations and cleaned each tube's contacts. I thought I might have dirty or bad connections on the octagonal socket, so I replaced that altogether. Nothing ever changed.
I have also plugged it to my UPS running on its own batteries, and the noise remained.

Did you try using those tubes you tried in another amp ?
How about trying another headphones with this amp ? just eliminating external factors.

 

[HTSkywalker]

I haven't. Since I live in Italy, both the repair and the shipping costs are going to be very high compared to the price of the amplifier itself, and the idea of shipping the built amp in a box overseas does not fill me with confidence so I have been opting for locals instead. Plus, I don't know what I would do if after receiving it back from Bottlehead HQ I still had this problem (if it turns out the issue is somehow not within the amp itself).

Won't recommend the oversees shipping either, I would try to use a power filter (purifier, Anti-interference) and BTW the power transformer could be wired for either 110V or 220V which is the case in your country, I would check the wiring again of the transformer.

 

[HTSkywalker]

If I remember right, the general wisdom is that if you want to go full on super tube-sounding, base Crack. If you want something cleaner and less tube-y, Speedball.

On that basis, I went for just the base Crack. But with Mr. Bottlehead wanting to retire soon, if he does a final run of Crack kits soon, I might pick up a Crack+Speedball kit just to have one example of each before the era comes to an end.

If you wanna go super tubey go DarkVoice

 

[Cowwe]

I appreciate the concern. I have actually solved the issue some weeks ago (one of the resistances in the right channel path was causing the issue).
I have been enjoying my amp every day since then

 

[raindownthunda]

I appreciate the concern. I have actually solved the issue some weeks ago (one of the resistances in the right channel path was causing the issue).
I have been enjoying my amp every day since then

10/10 tube roll my friend! Enjoy!

 

[haasaaroni]

I appreciate the concern. I have actually solved the issue some weeks ago (one of the resistances in the right channel path was causing the issue).
I have been enjoying my amp every day since then

What are those input tubes? I love the look!

 

[Cowwe]

10/10 tube roll my friend! Enjoy!

Thank you! I've been experimenting. I was also lent a pair of nos GEC L63 which I was eager to try, but unfortunately one of them is really noisy, so I'll have to wait for another pair eventually

What are those input tubes? I love the look!

They're Mullard 6J5G's in an adapter made by Deyan. They're very pretty tubes. The sound is very interesting. To my ears they're more dynamic and have much more bass and slam than the 12au7's I am used to (an effect which my HD800s and HD600's can appreciate). If I had to point out a drawback, the mids sound a little congested in comparison.
I will see if anything changes during these initial hours, but for now I like them!
The next ones in my "to try" list, other than the L63, are Brimar 6J5G's.

 

[Cowwe]

I saw a discussion come up, so I started wondering. Does leaving a Crack running with no headphones connected for prolonged amounts of time damage the amp?
I'm used to leaving my headphones connected even while warming up, but never really made sure if it's the correct thing to do.

 

[skhan007]

I saw a discussion come up, so I started wondering. Does leaving a Crack running with no headphones connected for prolonged amounts of time damage the amp?
I'm used to leaving my headphones connected even while warming up, but never really made sure if it's the correct thing to do.

I think this is more an issue for amps that have an output transformer.

 

[Cowwe]

I think this is more an issue for amps that have an output transformer.

Yeah I was aware of output transformers needing a load, so I was wondering if there might be any other reason for a Crack to suffer with no output connected.