Adaptation of Crack to use 6sn7, problems with sound distortion

shimacm · 1237

0 Members and 1 Guest are viewing this topic.

Offline shimacm

  • Jr. Member
  • **
    • Posts: 12
Hello everybody!

I made the adaptation of my Crack to use 6sn7 as default in the valve driver.

As a result I'm having problems with distortion in the sound, especially when I turn the volume up from medium to high.

I did the Resistence test and this is the result:

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 onwards
14 - 0
20 - 0
22 - 0

B3 - 2.9
B6 - 2.9

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


And these are the results of the 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
 
Follow the photos of the wiring to see if anyone can detect any errors.

Two details to report:

The 22.K 1/2w resistors have been replaced with 22k 1w resistors.

Wiring from the volume pot to the RCA inputs is 1.5mm stiff copper wire. I did not find a replacement wire like the one in the Kit to put in place.

I changed the wire because I had to lengthen it because my project is to use two 8-pin sockets (which are already installed on the board) to feed two 6j5 and also install two film capacitors in place of the two output electrolytic capacitors. That's why the wire is loose to accommodate these adaptations underneath it.
« Last Edit: May 18, 2023, 02:33:40 AM by shimacm »



Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19584

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man