Kick's first build LP-1MQ Red Widow

[Kick]

I had some spare time this morning and I gently removed the pots to have a look at them. They indeed had the a and b marking and guess what... I accidentally used the a pots for tone and the b pots for volume... So I have a job to do!

Unfortunately it will be next weekend because the whole familiy is coming our way for dinner and that means lots of preparations in the kitchen and diningroom

Anyway, I'm glad I know what the cause is!

[Simon Barden]

It's part of the cause, but doesn't describe all the symptoms (and I'm not sure what does).

Hope you all have a great family dinner.

[Kick]

Thanks Simon, family dinner was, as always, very nice and I am very happy that we all meet every weekend and have lots of fun.

Hopefully I have some time shortly to start unsoldering everything and start over.

[Kick]

Let me bump my topic folks... I have been very absent lately but things around the ship were taking up all of my time. Next to that my dentist took out my wisdom tooth that caused a hole in the next molar (is that the correct word?). She cleaned it and filled it but she also told me that the filling was very deep and probably would cause some nerve pain.... Well, it didn't cause 'some nerve pain' but MASSIVE nerve pain! I haven't slept for nights and couldn't hardly eat anything besides painkillers by the dozen.

Just two hours ago I had the molar pulled out by the dentist and for the first time in two weeks I am feeling nothing! What a bless!!!

I hope that all things will settle in short time and that I can finish the Red Widow...

[CascadiaGuitarGeek]

That doesn't sound fun at all. Life does have a way of butting into guitar kit building time.

[wazkelly]

Let me bump my topic folks... I have been very absent lately but things around the ship were taking up all of my time. Next to that my dentist took out my wisdom tooth that caused a hole in the next molar (is that the correct word?). She cleaned it and filled it but she also told me that the filling was very deep and probably would cause some nerve pain.... Well, it didn't cause 'some nerve pain' but MASSIVE nerve pain! I haven't slept for nights and couldn't hardly eat anything besides painkillers by the dozen.

Just two hours ago I had the molar pulled out by the dentist and for the first time in two weeks I am feeling nothing! What a bless!!!

I hope that all things will settle in short time and that I can finish the Red Widow...

Good to hear you are feeling better now Kick.

Have to wonder what hurts more, the bad tooth or the dentist bill.

Sent from my SM-A520F using Tapatalk

[DaveC64]

Hm... I couldn't resist it and I put some strings on it to check if everthing was ok. Unfortunately, there is something weird going on.

One volume pot is ok (bridge) and one tone pot is ok (neck). The bridge tone does not do anything. I hear no difference in the output when I turned the knob. And the neck volume pot is doing something weird; when full open I have output. When I turn it down the output is muted when I'm halfway and when I turn it down further the output comes back. It als makes some weird clicking sound in middle position.

Definately something I have done wrong while watching the videotutorials. I have to check to see what went wrong...

@Simon: I did not have enough coppertape to cover the covers. But I can use other metal tape as well I reckon?

I know you found that you had swapped the a and b types around but that would not cause the click around mid point nor the muting. The Type A is a logarithmic potentiometer so that your ears can hear the volume go up smoothly. If you use the linear pot type B for the volume it will be to loud when it is set low and have a very poor range when you adjust it. If the carbon track is broken in the pot you may experience a click and some strangeness with the volume. Check the resistance from the 2 outside pins it should be 500k with nothing attached than move the pot fully clock wise check the resistance between the 1st pin and the 2nd pin should be more or less a short circuit and 1st pin and 3rd pin should be 500k. then turn it anti clock wise pin 1 and 2 should read 500k pin 2 and 3 short circuit. move the pot to centre and you should read approx 50k to from pin 2 to the ground pin and 450k to the input pin where if a type b is tested in the centre position it will read 250k to pin 1 and 3 from pin 2. and 500k from pin 1-3. Hope this helps.
Dave

[Kick]

Thanks Dave! I think I take the Red Widow to my father in law. He is into electronics his whole life. He was one of the first people in The Netherlands that could repair the first color TV's from Philips and Aristona. I remember well that when I was with him in his repairshop that he loved to play around with an old screwdriver and the unit in the old tv's that created the high voltage to the tube screen. He could 'pull' long lightning flares from it. I think he mentioned it was around 30.000 volt... But he also warned to never try it myself

[DaveC64]

Your Uncle was crazy. There used to be a test tool for that. working out the voltage by checking the distance it could jump is really quite unsafe. Joking aside I used to work for ITT Nokia in the Manufacturing plant for colour tvs when there was a change from the old valve hybrids to full semiconductors. One day I turned down the brightness and contrast and left the chassis on soak test after lunch I came back to my test rig and forgot it was still on. Opened the HV cover which knocked the power off grabbed the live end where I was hit with 25,000 volts for as long as it took the stored voltage in the tv chassis to discharge it threw me around 3 m and thankfully my colleague was not at his station or I would have smashed him into his chassis. I ended up with a small hole in my hand for a few weeks after that.
Anyway good luck and don't let your uncle play with lasers or plasma tubes whilst you are there.
Dave

[Kick]

That's a shock Dave!

Anyway, problem solved. We had to replace one pot that was broken and everthing is working fine now.

I glued in the nut and put my own 3D printed TRC on it. All that is left to do is the intonation and tune her up. So officially I called the Red Widow finished! All is stock except for the TRC and the knobs.

Here are some pics:















Overall I'm very happy and I can honestly say I have learned a lot over these few months. Would I have done things other then I did now? Yes, definately! Like sanding... Oh boy, I should have sanded much more. Also, the next time I'll hold a little on the stain. A little less darker then she is now perhaps. Anyway I'm proud of what I accomplished! And thanks to you guys! For al the helpfull tips and tricks and encouragement I hope you liked my diary!