Crack finish. Volts problems.

[Paul Birkeland]

The 0V at terminal 5 looks unlikely based on the other voltages, can you double check?

[michael30]

after 30 min run.
terminals:

1)86.8
2)174
3)0
4)174
5)89.5

6)0
7)110.4
8)0
9)112.5
10)0

Yesterday i checked it with 235v.. now im at my brother house and i get around 223v from the wall.
Also I think can hear diff in volume between left and right ( left +1 -2).  not sure yet.

[Paul Birkeland]

Those are working voltages.  You can check the Crack FAQ stickied on this board regarding channel imbalance at low levels on the volume pot.  It's not abnormal and there's an easy modification to fix that. 

-PB

[michael30]

Hey Paul .
Just wandering... I wasn’t able to touch the chassis because it gets really hot, is that normal for the crack ? I only using 1/10 of the volume right now.. after 2 min I can’t touch it.

[Paul Birkeland]

If the voltages in your amp are normal, then the temperature of the top plate is normal (provided you have also installed the rubber feet).

A stock Crack will produce some extra heat in the top plate around where the 3K/10W resistors are and the Speedballed Crack will produce slightly more heat overall under the plate, but less localized. 

[michael30]

Hey there.

After some time with the crack I have a new problem .
Some static noises and chuckles that comes and go...
I tried replace rca + all cables, still there come and go.. also some really low background noise that always there but noting harmful. But the static and chuckle really annoying , what it may be ?
First hours used was dead silent .

Ty Michael .

[Paul Birkeland]

This could be an issue of solder joints or potentially interference from nearby electronics.  Are you using your computer as a source with the Crack?

[michael30]

Computer/iPhone
But I did unplug all, left it only connected with my headphones and it didn’t stop.
For now it stopped .
I will update if it will come back . Also I will upload all my solders ..and re solder any points you will tell me.

Thanks again 🙏🏻
Michael.

[michael30]

Hey.
here is the photos. if something else needed i will update as soon as i see.
https://drive.google.com/open?id=1AIkd22uIUl4odWHvNJ6TgT_yk-UfVJlj

also i swap the 12au7 to cbs jhy 5814a from 10/1960 , for now looks like those chuckles and noises gone.
anyway i would like to fix any bad soldering.

Ty Michael

[Paul Birkeland]

I've found over the years that a lot of times swapping tubes will move solder joints that aren't 100%, which can make it look like an issue is tube related, but it comes back at a later time anyway.

You can also try this mod, which will help with external interference:

https://forum.bottlehead.com/index.php?topic=11676.0

[Deke609]

Hey.
here is the photos. ...

Hi Michael - you should delete your posting of the Crack manual - I don't think BH treats it as public domain.

cheers, Derek

[michael30]

Hi Michael - you should delete your posting of the Crack manual - I don't think BH treats it as public domain.

cheers, Derek

 


My mistake ,
fixed.
thanks Michael

[Paul Birkeland]

Hi Michael - you should delete your posting of the Crack manual - I don't think BH treats it as public domain.

Yes, whenever it gets posted, we get lots of e-mails for "replacement" power transformers

[Deke609]

Yes, whenever it gets posted, we get lots of e-mails for "replacement" power transformers

I'd sell them for $225 with the option to upgrade to the full base kit for just an additional $90.   

cheers, Derek

[michael30]

I've found over the years that a lot of times swapping tubes will move solder joints that aren't 100%, which can make it look like an issue is tube related, but it comes back at a later time anyway.

You can also try this mod, which will help with external interference:

https://forum.bottlehead.com/index.php?topic=11676.0

I have sent you an email asking for the speedball guide , . so it’s me.
And from your answer i understand that all the soldering looks good.