The BA-3 as preamp build guide

[Marra]

Thank you Jim I'll check and see what Farnell has in stock.I was unsure of what C/W they needed to be.

 

[vdi_nenna]

Be sure to use thermal grease with any heat sink unless you are using thermal pads.

 

[Marra]

The Toshiba mosfet's are fully encapsulated so goop is all that I'll need.
Would there be any benefit to thermally coupling the output mosfets?

 

[Zen Mod]

generally - more stable voltage (offset) in output node

worth pursuing

 

[6L6]

...not that any DC will get past the 10uF capacitor on the output...

🙂 🙂 🙂


But Thermal coupling is a good idea if there is someway to do it.

 

[Zen Mod]

 

[Marra]

Thanks.I'll figure out a way when the boards arrive.

 

[6L6]

Connect them together with a Mithril bar. If you can't source that, I understand Cavorite works quite well.

😀

 

[Marra]

The sound would be out of this world 😀

 

[generg]

So you will hear nothing……

😀😀

 

[Zen Mod]

boyyyzzz

I was serious , for a change 😉

AC or DC coupled , temp stability is temp stability

 

[Gooch]

Hello
I am gathering parts together question with a wirewound resistor work for R13
Because it looks like the Panasonic in 330R are not available any more.

Thanks
Dave

 

[6L6]

CPF3330R00JKE14 Vishay / Dale | Mouser

 

[Zen Mod]

R13 on which exact schm?

 

[Gooch]

CPF3330R00JKE14 Vishay / Dale | Mouser

Thanks

R13 on which exact schm?

on the preamp board

 

[Russellc]

Hello
I am gathering parts together question with a wirewound resistor work for R13
Because it looks like the Panasonic in 330R are not available any more.

Thanks
Dave

I just bought some from digikey. 330R 3 watt. 59 cents each

Through Hole Resistors | Resistors | DigiKey

 

[Gooch]

I just bought some from digikey. 330R 3 watt. 59 cents each

Through Hole Resistors | Resistors | DigiKey

I searched both Mouser and Digikey and they didn't come up 😕
Thanks for the link

Dave

 

[Russellc]

SAY 6L6 what's the cap to use for the 10uf? Any readily available good stuff?
Or, are there ones to be avoided for best sound? Looks like you used some nice ones!

Russellc

 

[Russellc]

Marra -

The specific ones in the photos were obtained at a local electronics surplus store, so I have no details.

Here are two choices that should work well -

This is a clip-on -- 6237BG Aavid Thermalloy | Mouser

This is a screw-on -- 577202B00000G Aavid Thermalloy | Mouser

I bought the screw on versions you recommended here, for both BA-3 pre and BA-3 Power amp. I note they are considerably smaller than the monsters you used, are they sufficient for both pre and power, or are yours just massive overkill?

Russellc

 

[Russellc]

I searched both Mouser and Digikey and they didn't come up 😕
Thanks for the link

Dave

Its easy to go "search blind" on these parts! If just the right term isnt searched it turns up nothing. I went to panasonic, then resistors, through hole and finally, there were the little blue beauties!