# For What it's Worth



## Paul Running (Apr 12, 2020)

I thought about starting a tip thread for amp component customizing. Here’s one to start. I recently added a cap to a toggle switch. You have probably run across these early model types. With this one, I used a brass cap from a mounting kit for securing lamps to an electrical box…they can be bought from several sources. They are tapped to 8-32 thread. Die the same tread on the end of a regular toggle switch and voila, it’s ready to cap your switch. These switches have a no-fail operation…the little ball does not require fine-coordination to operate.
Your playing away and your amp begins to show signs of failing…quickly rush to turn the amp off…damn, I was in such a hurry, I missed the switch…if the switch had that little cap, I may not have missed it the first time and I guess that cap may not have exploded and made such a mess…I believe that Nigel Tufnel would approve.


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## laristotle (Aug 29, 2019)

So retro. Cool.


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## Paul Running (Apr 12, 2020)

laristotle said:


> So retro. Cool.


Making subtle changes to an amp can spark some curiosity in some people. A person will look at something and look puzzled...can't quite figure it out, it looks original but their spider senses say something is not right.


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## bolero (Oct 11, 2006)

neat idea! where is the best place to get them? don't believe I have ever seen them before

i have no idea what this grid is, posting on my phone

must have hit an icon


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## Paul Running (Apr 12, 2020)

The Home Depot Electrical section supplies a lot of replacement hardware for lamps and fastening. Electrical Distributors are another and if you know an electrician, they can source them for a good price. Some of them come as painted brass.


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## Paul Running (Apr 12, 2020)

HV photo-caps for tube amp proto-types. I do not recommend for production amps because most of these types are only rated to 50°C though, I have not had one let go yet. I obtained these caps between 1997 and 2004…about the time that disposable cameras lost public interest. I used to get them from dept., grocery chain stores and photo shops…talk nice to the sales people and they would just give them to me. The specs on these caps are 100 - 160µfd, with 330VDC ratings. Wire two 100µfd in series and it becomes a 50µfd @ 660VDC…fits neatly in an Octal socket or solder in circuit.


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## Paul Running (Apr 12, 2020)

The effects of screen-grid voltage on input headroom for a small-signal pentode.


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## nonreverb (Sep 19, 2006)

Paul Running said:


> HV photo-caps for tube amp proto-types. I do not recommend for production amps because most of these types are only rated to 50°C though, I have not had one let go yet. I obtained these caps between 1997 and 2004…about the time that disposable cameras lost public interest. I used to get them from dept., grocery chain stores and photo shops…talk nice to the sales people and they would just give them to me. The specs on these caps are 100 - 160µfd, with 330VDC ratings. Wire two 100µfd in series and it becomes a 50µfd @ 660VDC…fits neatly in an Octal socket or solder in circuit.
> View attachment 356975


Where do you add the balancing resistors Paul? On the board?


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## Paul Running (Apr 12, 2020)

If I'm using the octal plug type, I connect the resistors at the socket, for the other type, usually connected at the tag strip...I typically use tag strips, for point-to-point; for proto-typing, it...saves time. Unless it's a tried and true circuit...I do not spend much time with the cosmetics...get lots of practise with the re-work skills, one of the benefits I miss when I retired from the industry...the rework girls.


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## Paul Running (Apr 12, 2020)

Here's an example for the 6V6:


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## Paul Running (Apr 12, 2020)

Guitar amp troubleshooting flowchart.


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## Paul Running (Apr 12, 2020)

Here's some blank voltage charts to record voltages at tube pins for future reference.


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## Paul Running (Apr 12, 2020)

If you are an electronic component junkie, at the 18 minute mark of this video, Mr. Dayton sweeps the table:


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## Paul Running (Apr 12, 2020)




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## Alan Small (Dec 30, 2019)

Paul Running said:


> Here's some blank voltage charts to record voltages at tube pins for future reference.


Thank you


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## Paul Running (Apr 12, 2020)

My collection of 7 & 9-pin tube straighteners. The brass one is a DIY that I made from a plumbing fitting and stuff in my junk box.


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## Paul Running (Apr 12, 2020)

A blurb on output tube biasing and distortion.


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## Paul Running (Apr 12, 2020)

Here's my audio generator that I use for most of my testing purposes.
I bought it at an OVRC auction as is. It was about 90% functional when I first powered her up...after a good visual.
I believe that it is important to eye ball any piece of gear before you do a dynamic, usually a good cleanup is in order.
Anyway, this is a Heathkit which is quite affordable and reliable, truth is nobody else bid on it so, I got it for a buck...I seem to pride a low price purchase; I use mini-clip leads for in-circuit inputs. My other generator is a boat anchor and I only use it for push-pull testing...it will produce a balanced signal up to 80VP-P which will overdrive most tubes...not a 6146 but that's fine; here's an image of the Heath:


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## Paul Running (Apr 12, 2020)

To help you understand a schematic it may help to high-light the active components, according to the wiring colour-code standard. Myself, I use the EIA standard, with one addition: I will typically use dark green as the primary heater supply with a balanced ground, see the table below:










It may also help to break-up the schematic into sections, according to a block-diagram. Here's an example using the 5C4 as an example:

The complete schematic, without colour-coding:









The power supply, coded:










The input-stage, coded:










and the phase-inverter/output-stage, coded:









I hope that this may assist you in reading schematics.


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## Whammer Jammer (Sep 7, 2019)

Really appreciate the charts and colour codes. Thanks for taking the time to share your knowledge.


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## Paul Running (Apr 12, 2020)

Looks like Mr. Dayton has gone full-time with his amp business. He's offering amp building modules as bare boards or full assemblies. If you are interested here's a link:


https://d-labelectronics.com/d-lab-tube-amp-modules


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## Paul Running (Apr 12, 2020)

A few notes on cathode-bypassing.


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## Paul Running (Apr 12, 2020)

A road case for a tube. Repurpose a discarded prescription bottle for an unboxed tube. I made this with the use of a Costco prescription bottle, a toilet paper tube and some foam. A snug fit for shake rattle n roll conditions…protect those tubes on the road.


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## Paul Running (Apr 12, 2020)

If you're in a bind when you ran out of liquid rosin flux, you may improvise by diluting pine sap in alcohol. The main active ingredient in most rosin fluxes is *abietic acid* which is plentiful in pine sap. Here's a small sample I processed recently (what's left). It's very sticky like the real McCoy. Reminds me when I used to play touch football with the lads at work...I used to coat my fingers with flux from my work area, it was great stick-em...they could never figure how I snagged those balls out of the air; some would consider it cheating however, I felt that my size was a disadvantage for high balls.
Anyway, the stuff works real good.


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## Paul Running (Apr 12, 2020)

I have 2 knife switches, in my switch collection. Ceramic base with copper and brass components.
The small one was the one I used for my Grade 4 science project...been a nerd ever since.
The larger one is a job lot purchase from a OVRC auction.
How would they work for switching a heavy load...low DC of course?
Might be suitable for a steam-punk project...


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## diyfabtone (Mar 9, 2016)

I try and follow the EIA colour code too - it really helps when troubleshooting! A lot a great information, thanks Paul!


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