Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: shimacm on May 15, 2023, 03:46:35 AM

Title: 22.1k resistor replacement
Post by: shimacm on May 15, 2023, 03:46:35 AM
Good morning everybody!

I need your help.

I removed the Speedball kit, and am reinstalling the standard model coils.

But I can't resolder the 22.1k resistance because the wire was cut very close to the resistance.

In my city I only found the resistance of 22k, 1W, 10% tolerance.

The colors are (red, red, orange and gold).

My question is whether this resistance is a good substitute.

My other question is in which position should I solder it in the circuit.

Thanks.



Title: Re: 22.1k resistor replacement
Post by: Paul Birkeland on May 15, 2023, 04:20:12 AM
That resistor will work to replace what we provided.  I'm not sure about your other question, as you would simply put them back where the manual instructs you to.

-PB
Title: Re: 22.1k resistor replacement
Post by: Larpy on May 15, 2023, 07:05:06 AM
If you mean how to orient the the direction of the color bands on the resistor--either red, red, orange, gold or gold, orange, red, red--it doesn't matter.
Title: Re: 22.1k resistor replacement
Post by: shimacm on May 16, 2023, 03:15:31 AM
I installed the resistors and it worked.

Testing the amplifier I'm feeling an excess of saturation in the bass.

Does the 22k resistance switch have anything to do with this?
Title: Re: 22.1k resistor replacement
Post by: Paul Birkeland on May 16, 2023, 04:11:35 AM
Which headphones are you using with the Crack?
Title: Re: 22.1k resistor replacement
Post by: shimacm on May 17, 2023, 02:05:19 AM
I use ZMF Veritè and HD650 on it.

I redid the resistor and voltage tests and wrote down the results to see if that helps.

Resistor Test:

1 - random from 40 to 70
2 - random from 40 to 70
3 - 0
4 - random from 40 to 70
5 - random from 70 to 120.

6 - 0
7 - 2.9
8 - 0
9 - 2.9
10 - 0

12 - 0
13 - random from 40 and up
14 - 0
20 - 0
22 - 0

B3 - 2.9
B6 - 2.9

Red RCA pin - 90
Black RCA pin - 88
Earth RCA - 0


Voltage Test:

1 - 59.6
2 - 190.4
3 - 0
4 - 191.3
5 - 57.1

6 - 0
7 - 99.5
8 - 0
9 - 98.2
10 - 0

I would like to add to my previous comment the following:

With a little more listening time, I realized that saturation affects all frequency ranges when the volume is increased, that is, the sound distorts at higher volumes.

I installed a 6sn7 socket in place of the traditional 12au7.

Wiring from the volume pot to the RCA jacks is 1.5mm stiff wire. (I had to adapt, because I'm going to install two 8-pin sockets to use 6j5g and I had to lengthen the wiring that goes from the volume pot to the RCA connectors, because I'm going to install two film output caps and I'm going to run the wiring over the caps). The thread that comes with the Kit was insufficient for these changes and in my country I can't find similar thread.

I'll post some pictures of the assembly.


Title: Re: 22.1k resistor replacement
Post by: shimacm on May 17, 2023, 02:08:53 AM
More pictures
Title: Re: 22.1k resistor replacement
Post by: shimacm on May 17, 2023, 02:09:40 AM
More
Title: Re: 22.1k resistor replacement
Post by: shimacm on May 17, 2023, 02:10:21 AM
More
Title: Re: 22.1k resistor replacement
Post by: shimacm on May 17, 2023, 02:11:58 AM
More

I'm sorry for the extra posts to add more photos, but I just now found the option to attach more than one photo in the same post.
Title: Re: 22.1k resistor replacement
Post by: Paul Birkeland on May 17, 2023, 05:13:53 AM
Why do you have pins 3 and 6 grounded on your driver socket?
Title: Re: 22.1k resistor replacement
Post by: shimacm on May 19, 2023, 12:41:21 AM
If I shouldn't connect pins 3 and 6 to ground, how should I connect them then?

In socket 12ua7, there is a central pin to which the ground is connected, and from it, LEDs are connected to pins 3 and 8.

But socket 6sn7 does not have this central pin.

How to proceed then?
Title: Re: 22.1k resistor replacement
Post by: Tom-s on May 19, 2023, 02:15:04 AM
Bias the tube using the leds and it will function. Same as 12AU7 Crack.
Title: Re: 22.1k resistor replacement
Post by: shimacm on May 19, 2023, 02:59:43 AM
I understood. Thank you for the advice. I'll try here and report back.
Title: Re: 22.1k resistor replacement
Post by: shimacm on May 19, 2023, 03:42:41 AM
It worked!!!! The magic happened again!!! Thank you for your help!!!