ODS 124 PCB Build

[professormudd]

Finally got some tube sockets. I had previously ordered an Amplified Nation chassis, but decided to do that build with eyelet boards. For this build I'm going to use a Ceriatone chassis with some custom faceplates (editable artwork is shared in the Dumble files section). I still have to order quite a bit, but I'm trying to take my time.

[professormudd]

I am getting ready to order transformers. I wanted to check to make sure the selections I made were the correct.

• Hammond P-T290FX power transformer
• Hammond P-T1760W output transformer
• Hammond P-C194B choke

On the BOM there is also an entry for Item: 12V Section, 6VAC @450mA Qty: 1

I was not sure what to make of that. I cannot find any other iron on the layout provided. I checked the 124 layout in the Dumble Files section and I see the RadioShack choke in there, but I do not see it on the layout for this PCB. Some guidance would be appreciated as to where to source the component would be appreciated..

[professormudd]

Would Hammond P-T166C12 work for the 12v section?

[erwin_ve]

Would Hammond P-T166C12 work for the 12v section?

Yes that would work, the 186b12 is a more economical choice as you dont need the amount of current the 166b12 can deliver.

[professormudd]

Would Hammond P-T166C12 work for the 12v section?

Yes that would work, the 186b12 is a more economical choice as you dont need the amount of current the 166b12 can deliver.

Oh, cool. Thank you.

Another quick update. I screwed up a couple times.

In drilling the board mounting holes in my Ceriatone chassis, I apparently didn't think about leaving space between the pots and the board, so I drilled a new set and moved it back. I really wish I would have made a paper template of the board before populating it. It would have made it a lot easier to still those holes. I had to measure everything out and make sure it was square, which was more tedious than it could have been.

Next, I ordered a few potentiometers from mouser, and was surprised to find I'd ordered very small pots. Bummer. I am not sure if these pots are still sufficient. The 1M have a pronounced step when it's rolled. They are kinda cute. I went ahead and ordered the size I'm more familiar with but could not find a 2k pot for the presence. I grabbed a 5k for the time being but would like to find a 2k.

[Guy77]

Nice build. I have had good results using the transformers you mentioned.

BTW were did you get that really nice silver Amp Cradle off to the side!!

Cheers
Guy

[professormudd]

Nice build. I have had good results using the transformers you mentioned.

BTW were did you get that really nice silver Amp Cradle off to the side!!

Cheers
Guy

That is a PanaVise 350 Multi-Purpose Work Center. I wouldn't put a chassis in it, but it holds PCBs very nicely.

[drew]

Prof, if you look at the online data sheets for the pots, electrolytics, etc. that you’re ordering, they provide charts and tables that show you how to decode the part number that you’re about to order. It’s a little tedious to go through and double-check your order this way, but at least this way you don’t end up receiving plastic 9mm D-shaft pots with 90 degree PC board terminals, or capacitors that are meant for forklifts or whatever.

I would also not buy parts from random eBay vendors, since there is no way of knowing if the items are genuine.

[professormudd]

Prof, if you look at the online data sheets for the pots, electrolytics, etc. that you’re ordering, they provide charts and tables that show you how to decode the part number that you’re about to order. It’s a little tedious to go through and double-check your order this way, but at least this way you don’t end up receiving plastic 9mm D-shaft pots with 90 degree PC board terminals, or capacitors that are meant for forklifts or whatever.

I would also not buy parts from random eBay vendors, since there is no way of knowing if the items are genuine.

Yeah, I will avoid eBay orders from China from now on, and you are right about tedious. Combing through mouser is my least favorite part of this process. AmplifiedParts seems okay, but they don't have everything and I find their shipping cost/time to be excessive most of the time.

I had actually checked the data sheets for solder lugs and the right shape/size/type of shaft on the pots. They fit the holes in the chassis and knobs I have. It just did not dawn on me to measure the "body" of the pot as well.

[professormudd]

The switches I received for the Rock/Jazz, Mid, PAB, and OD are different than I expected based on the layout.

On the layout it looks like 2 DPDT switches, but the BOM lists SPDT switches (mouser part number 633-M201202). I checked the 124 layout in the Dumble Files section, and there it also looks like the switches are DPDT but they appear to be "bridged" anyway making them effectively SPDT. I just wanted to note it down in case any of the other folks who bought these boards find themselves momentarily confused by the way the lines are drawn on the layout provided by frusciante89.

Also, the switches for the Rock/Jazz and Mid are both listed on the BOM as mouser part number 633-M202301. These are 3 position switches. Again, I referred to the Dumble Files section and the "user guide" does mention that the Rock/Jazz is a 3 position with the middle effectively acting as another PAB switch. However, it is not mentioned whether or not the Deep/Mid switch is a 3 position or not. I am trying to work out how it will behave in the middle position, but it hasn't become clear to me yet.

Anyway, that is it for this entry in the saga of Mudd's Clumsy Part Ordering Fiasco. Stay tuned for more later when I get my next shipment. Can't wait to see what detail I overlooked next.

[martin manning]

On the layout it looks like 2 DPDT switches, but the BOM lists SPDT switches (mouser part number 633-M201202). I checked the 124 layout in the Dumble Files section, and there it also looks like the switches are DPDT but they appear to be "bridged" anyway making them effectively SPDT.

Perhaps Dumble liked redundancy. Be aware that toggle switches (like the part number listed above) connect the pole(s) to the position contacts that are opposite the bat position. If you wire the lugs exactly as shown in the layout for slide switches, then the switch function will be inverted.

Also, the switches for the Rock/Jazz and Mid are both listed on the BOM as mouser part number 633-M202301. These are 3 position switches. Again, I referred to the Dumble Files section and the "user guide" does mention that the Rock/Jazz is a 3 position with the middle effectively acting as another PAB switch. However, it is not mentioned whether or not the Deep/Mid switch is a 3 position or not. I am trying to work out how it will behave in the middle position, but it hasn't become clear to me yet.

The Rock-Jazz switch is the only one where the middle OFF position is useful. In the case of the Mid Boost, the middle position would be the same as Mid Boost OFF.

[professormudd]

The Rock-Jazz switch is the only one where the middle OFF position is useful. In the case of the Mid Boost, the middle position would be the same as Mid Boost OFF.

Thanks.

[professormudd]

I look at some of the other builds by the pros and the seasoned hobbyists and admire the tidiness. So I'm trying my best, but I'm still kinda clumsy.

I do think I'm getting my workflow figured out a little better. It's just taking me a lot of "sit-and-stare" time, which is my favorite part of all this, to be honest.

[professormudd]

Here are some more pics. I already had a supply of ceramic 9-pin sockets, but their orientation is different by 90 degrees. Also, you can see the chassis scars where I misdrilled a few times.

[Strider0007]

I built one with the same PCB. Came out great!