Supro 6606 Build - Sluckey Layout

[ebulakowski]

Hello wise hive mind! I recently decided to try and expand my comfort zone and get more into building. The hope is to get more comfortable choosing transformers, layout, etc.

I decided sluckey's 6606 project was a good starting point. I have it almost complete, but working late tonight finishing it up I noticed something I had not seen/didn't understand... The speaker connection. To this point I have always worked on/built fender kits where one side of the OT secondary was grounded. Either by the jack, or an isolated jack that connected to ground elsewhere.
The supro schematic does not indicate a ground, And sluckey's layout does not show the secondary leads.

I guess my questions is what are the differences? Is this an assumed connection and a schematic omission? Or is this specific to particular transformers? And info or knowledge that can be shared would be much appreciated.

I should note that I am using a ClassicTone 40-18052, which to my understanding is OEM for this amp.

Also, Sluckey, thank you so much or your layouts and website

[tubeswell]

Ground the 'ground side' of the OT secondary to the chassis via the speaker output jack sleeve (assuming you have a speaker jack)

[sluckey]

You can connect the speaker any way you wish. I suggest to connect the secondary common lead to chassis. Easy to do if you use a jack. Many of these old cheap amps simply connected the secondary leads directly to the speaker without using any connectors.

[ebulakowski]

You can connect the speaker any way you wish. I suggest to connect the secondary common lead to chassis. Easy to do if you use a jack. Many of these old cheap amps simply connected the secondary leads directly to the speaker without using any connectors.

Okay, I found some other threads with a a similar question. Just to make sure I am understand the fundamentals... 

- Obviously if an OT has multiple speaker taps, the common would be grounded.
- A ground is essential if there is a NFB loop.
- In this amp, there are two leads on the secondary, and no NFB. So I could wire it up direct either way. But grounding one side would be a smarter idea for safety in case there was ever a short.

Is this the right/correct approach? I just want to make sure I have a good understanding moving forward.