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Wiring the Thumbnail Switch

PostPosted: Wed Jan 02, 2013 4:29 am
by Kiwi
Greetings and Happy New Year to everyone. Just need some help on how to wire the thumbnail switch RS No. 337-447 which I am using instead of the rotary switch. It has 9 soldering tags and the circuit board has 4 poles so I am uncertain which ones to use. Thanks & regards, John

Re: Wiring the Thumbnail Switch

PostPosted: Wed Jan 02, 2013 7:31 am
by ecca
Hi John, you mean thumbwheel, I think.
You should use the numbers 1,2 and 4 and also C ( common)
The numbers with the minus sign over them are the BCD complements.[ don't use them )
Did you get the side cheeks 337-419 ?
Happy new year.
Ecca

Re: Wiring the Thumbnail Switch

PostPosted: Wed Jan 02, 2013 8:14 am
by Kiwi
Thanks Ecca, This is the numbering I can see on the tabs starting from the top.
Postion 1 is numbered 1
postions 2 & 3 are not marked or numbered
position 4 is numbered 8
position 5 is marked C
position 6 is numbered 8
positions 7 & 8 are not marked or numbered
position 9 is numbered 1

So I will use position 5 for the common but which of the others? Yes I got the side cheeks so almost there after a long unavoidable delay getting started. Thanks for your help Ecca I had a small bet with myself that I would hear from you if you were around. Much appreciated. Regards, John

Re: Wiring the Thumbnail Switch

PostPosted: Wed Jan 02, 2013 10:52 am
by Kiwi
OK hopefully I have worked it out :lol: . Switch Position 1 is A on the circuit board, position 2 is B, position 4 is C therefore position 5 (C) is E on circuit board. I shall wait for expert advice before I heat the soldering iron ;)

Re: Wiring the Thumbnail Switch

PostPosted: Wed Jan 02, 2013 2:39 pm
by ecca
Correct.
You won't hurt anything if you get it wrong, it will still work but it won't do what you expect.
I don't know how capable you are but you can check the bcd inputs with a multimeter against the truth table on the echotapper site.

Re: Wiring the Thumbnail Switch

PostPosted: Tue Jan 08, 2013 9:28 am
by Kiwi
Thanks Ecca, It's been great to have your help. I had a faulty thumbwheel so I replace this and tested the BCD inputs which were correct. Can you please check me on the pots. I think Pot 0 is Dry/wet, Pot 1 - Heads and Pot 2 - Feedback. I just can't seem to get the tone I expected compared to demo mp3's I have heard. It may well be my amp/guitar which is a VOX Valvetronix AD15VT and Mexican Fender. I may just need more time getting use to the controls. Thanks again & regards. John

Re: Wiring the Thumbnail Switch

PostPosted: Tue Jan 08, 2013 9:58 am
by ecca
Hi John, your thinking with the pots is correct .
Perservere with the sound, sometimes you can listen too hard and miss the big picture.

Re: Wiring the Thumbnail Switch

PostPosted: Tue Jan 08, 2013 10:50 am
by Kiwi
Wow - you sure are quick to reply - awesome!! I just read a post where Piet said to keep the gain control to 50% to avoid harmonics. That has help my tone a lot. Any way I am going to give myself a pass mark. I guess if I did another one it would be lot easier to do but there is no way I can compete with your great building efforts and knowledge. My unit may well be the only one in New Zealand. It would be nice to find some one else with one in N.Z but I am not optimistic. Cheers, John