Yet another 124 build

[jabguit]

Forgive my ignorance but I'm afraid I do not know who photographed #124 and made it available-I am grateful to that individual as well.

Well, that would be me, along with Billy Yates -- who had the amp in his shop for servicing before it was put in the market.

Gil

Exactly what Billy told me a couple weeks ago.

cheers,

[Stephen1966]

Those photos are excellent - a benchmark in how to properly document an amp. I still use them and they are still giving up secrets

[GAStan]

Parts have begun arriving so I have been inventorying and checking them. One thing I was concerned about was the connectors for the pedal. Erwin's chassis is cut for a Switchcraft DIN outlet. 61HA5FX is specified on the #124 layout. Looking at the data sheet for this jack shows the pin layout as 5 in 240 degrees. The sheet also shows a 5 in 180 degrees which to me seems more common, 57HB5FX, so I ordered it instead. My concern was that I chose the correct plug to fit it, 05CL5MX. I chose wisely.

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And it fits the chassis perfectly.

[GAStan]

Woo-hoo! I have a complete amp!

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[jabguit]

Woo-hoo! I have a complete amp!

20230826_112750.jpg

How's it sound??

cheers,

[martin manning]

How's it sound?? :lol:

Doesn't pass signal, just makes crackling noises...

[ijedouglas]

Woo-hoo! I have a complete amp!

20230826_112750.jpg

Ikea?

[Stephen1966]

Congratulations... assembling the kit is the biggest practical hurdle... now to assembly...

You are going to build the chassis from the "ground up" so think in layers. Check out Ian's builds - he is a master at it - or check out mine, I like layered pdfs that detail the build order from start to finish. From bare chassis to heater wires. The ODS has something like forty discreet layers if you think of it as I do. You don't have to go to the lengths of pre-planning every single stage as I do - before you even switch on the iron! - but think ahead is my advice. You don't want to install relays after you have fitted your preamp board, for example.

Another piece of advice, I keep having to remind myself of, is know when to stop for the day. You won't be long putting this together now, but it will go a lot quicker if you take time to do everything correctly the first time. When you find yourself saying, "Well! That was a stupid mistake", it's time to shut down the workshop and go make a cocoa

[GAStan]

Woo-hoo! I have a complete amp!

20230826_112750.jpg

How's it sound??

cheers,

Like this so far: " ". LOL

How's it sound??

Doesn't pass signal, just makes crackling noises...

Woo-hoo! I have a complete amp!

20230826_112750.jpg

Ikea?

Heath kit

[GAStan]

Congratulations... assembling the kit is the biggest practical hurdle... now to assembly...

You are going to build the chassis from the "ground up" so think in layers. Check out Ian's builds - he is a master at it - or check out mine, I like layered pdfs that detail the build order from start to finish. From bare chassis to heater wires. The ODS has something like forty discreet layers if you think of it as I do. You don't have to go to the lengths of pre-planning every single stage as I do - before you even switch on the iron! - but think ahead is my advice. You don't want to install relays after you have fitted your preamp board, for example.

Another piece of advice, I keep having to remind myself of, is know when to stop for the day. You won't be long putting this together now, but it will go a lot quicker if you take time to do everything correctly the first time. When you find yourself saying, "Well! That was a stupid mistake", it's time to shut down the workshop and go make a cocoa

A lot of great advice here Stephen, thank you!

During my youth I enjoyed building plastic models, from that I tend to think in steps. However layers also makes sense. I think we are referring to basically the same concept but different terminology. A machinist would call it "order of operations".

My method differs from yours. You describe a more methodical, organized approach. My method tends to be a bit more on the artistic side: I know what the end product should look like and work towards that end. I have a basic order of major steps in mind but accomplish them in small bits as appropriate.

Over the weekend I did get to start on the sub-assemblies. One vendor shipped incorrect parts so I'm not able to complete the filter board yet. All boards still require the Flux to be cleaned, I will wait and clean all at the same time using denatured alcohol.

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[Stephen1966]

Thanks! Whatever way works for you is my motto.

All boards still require the Flux to be cleaned, I will wait and clean all at the same time using denatured alcohol.

Don't wait too long. Flux hardens over time making it harder to remove. Easier to clean it off as you go along.

[GAStan]

Been slowly working on the amp when I get time. Didn't work on it over the Holiday weekend, went to Phoenix to take my son to a Metallica concert

The only solid core 20 AWG I found at any of the vendors I ordered from had cloth over pvc insulation. After working with it on the control wiring I decided to order some stranded topcoat (fully tinned) wire and re-do it all. That cloth over pvc is simply too thick to work with for me.

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The pots are actually as crooked as they look in this photo but will be straight when I replace the wiring. I also found some 3/16" heat shrink for the component leads.

Edit: 3/32" heat shrink is actually what I found.

[Stephen1966]

Okay, the words stick in my throat, but you can find AWG20 solid core online at Ama-Satan's-Butthole-zon. You can get away with PVC sleeved solid core rated to 300V at a pinch, but 600V rated or higher is better. I'm in Europe so the supply chain is very different here, but here's an example of what is available (there are more if you dig into the site deeper): https://modulusamplification.com/cable- ... 2936-p.asp Teflon coated is not necessary except perhaps in shielded cable especially where the shielding is being soldered directly to the back of pots.

Lead dress is just much easier to control with solid core. I consider solid core especially important in the heater circuit even though the leads coming off the PT are most likely stranded. Solid core AWG18 if you can get it to fit in the sockets, can be used throughout. If your noval sockets won't permit that diameter though, you can use a AWG20 solid core on the preamp sockets; AWG18 on the power section, AWG20 on the preamp section.

The reason being a tendency for ringing or oscillation in the AC driven heater circuit. A possible source of noise you want to avoid if possible.

The ideal, silver plated AWG20 solid core, for the signal wires is more about creating a good solid lead dress. It matters

[GAStan]

Okay, the words stick in my throat, but you can find AWG20 solid core online at Ama-Satan's-Butthole-zon. You can get away with PVC sleeved solid core rated to 300V at a pinch, but 600V rated or higher is better. I'm in Europe so the supply chain is very different here, but here's an example of what is available (there are more if you dig into the site deeper): https://modulusamplification.com/cable- ... 2936-p.asp Teflon coated is not necessary except perhaps in shielded cable especially where the shielding is being soldered directly to the back of pots.

Lead dress is just much easier to control with solid core. I consider solid core especially important in the heater circuit even though the leads coming off the PT are most likely stranded. Solid core AWG18 if you can get it to fit in the sockets, can be used throughout. If your noval sockets won't permit that diameter though, you can use a AWG20 solid core on the preamp sockets; AWG18 on the power section, AWG20 on the preamp section.

The reason being a tendency for ringing or oscillation in the AC driven heater circuit. A possible source of noise you want to avoid if possible.

The ideal, silver plated AWG20 solid core, for the signal wires is more about creating a good solid lead dress. It matters

I looked on Amazon for quite some time and did not find anything I'm willing to put in my amp. Ebay as well.

The topcoat wire I got is fully tinned and bends and holds its shape like solid core, and has pvc insulation. Teflon would be acceptable but I prefer to avoid silicone.

18 AWG is what I do plan on using for heaters. Stranded is what I've got, I'm confident I can make it work. The holes in the novel socket terminals are oval shaped so the stranded will hopefully conform better but I'll find out for sure when the task is upon me.

[Stephen1966]

Okay, the words stick in my throat, but you can find AWG20 solid core online at Ama-Satan's-Butthole-zon. You can get away with PVC sleeved solid core rated to 300V at a pinch, but 600V rated or higher is better. I'm in Europe so the supply chain is very different here, but here's an example of what is available (there are more if you dig into the site deeper): https://modulusamplification.com/cable- ... 2936-p.asp Teflon coated is not necessary except perhaps in shielded cable especially where the shielding is being soldered directly to the back of pots.

Lead dress is just much easier to control with solid core. I consider solid core especially important in the heater circuit even though the leads coming off the PT are most likely stranded. Solid core AWG18 if you can get it to fit in the sockets, can be used throughout. If your noval sockets won't permit that diameter though, you can use a AWG20 solid core on the preamp sockets; AWG18 on the power section, AWG20 on the preamp section.

The reason being a tendency for ringing or oscillation in the AC driven heater circuit. A possible source of noise you want to avoid if possible.

The ideal, silver plated AWG20 solid core, for the signal wires is more about creating a good solid lead dress. It matters

I looked on Amazon for quite some time and did not find anything I'm willing to put in my amp. Ebay as well.

The topcoat wire I got is fully tinned and bends and holds its shape like solid core, and has pvc insulation. Teflon would be acceptable but I prefer to avoid silicone.

18 AWG is what I do plan on using for heaters. Stranded is what I've got, I'm confident I can make it work. The holes in the novel socket terminals are oval shaped so the stranded will hopefully conform better but I'll find out for sure when the task is upon me.

I know what you're saying with the silicon type, I prefer PVC as well.

You might try this:
https://www.amazon.com/Silicone-Electri ... =8-24&th=1

If you are using stranded cable for the heaters my advice is to twist it tight. I've used ordinary household copper core stranded in the past and as long as you twist it so that it's very tight (almost solid) it shouldn't give you any problems. A tip though, when you come to do the noval sockets you might be tempted to tin it before you try soldering it into the noval ovals - it's a lot easier if you don't but you have to be especially careful you don't have any stray strands creating a short with the neighbouring pins.