Most Greedy Boy, of them all... or (there is no) DEFiSIT of Papa's Koans

[indra1]

 

[Zen Mod]

after you finish playing ...... observe startup and temp behavior , at least in simulator

after that , in vivo ....... I'm glad that in vivo , things are even better than sim. prediction, judging by experience with Sissy and Babelfish M25

 

[indra1]

... after that , in vivo ....... I'm glad that in vivo , things are even better than sim. prediction, judging by experience with Sissy and Babelfish M25

Sorry to disappoint, the big SITs are just beyond my budget, I am working on a hybrid using regular IRFP240 and remember you guys so I drew up the schematic and sim it as a gift. Current in progress project is as attached.

 

[Zen Mod]

few wicked brain-cells are more worthy than few SITs

 

[lhquam]

I would make this change to Simpler-Spook.asc:

 

[indra1]

I would make this change to Simpler-Spook.asc:

Please note proportion of H2/H3 and phase of H2 has changed.

 

[indra1]

Fourtran SEF

I would make this change to Simpler-Spook.asc:

Thanks to you Lynn, here is the Four Transistor SEF.

 

[Zen Mod]

 

[indra1]

Simpler Spook R1

A TO-220 pnp bjt was chosen to replace the axial lead diode to be mounted on the same heatsink with the TO-126 BD140 for better thermal tracking. An Rbias was also added to trim bias to desired value.

 

[Zen Mod]

OK , that's cheating ...

 

[Zen Mod]

will try it later ..... really interested what's current distribution

 

[indra1]

The topology allows use of SITs that won't bias correctly with the M2 opto bias, but bias becomes dependent on Vbe of the pnp.

 

[Zen Mod]

yup, no free sonic , or any other lunch



speaking of lunch - having some kwayzee name for your intended Enterprise ?


edit: while we are at that , Bob is also sending his greens and greets

 

[indra1]

... having some kwayzee name for your intended Enterprise ?...

I worship Papa for introducing me to the excellent A40, my first diy build during my college days. Decades later Srajan and Sakuma poisoned my sonic digestive system real bad. So my work will be mostly a sprinkling combo of Pass & fanz inspired ideas with direct heated critters. To honor you and Mr. MR, I will try to include at least a piece of iron part in my designs. Still has no thought about any name and the plan is only to contribute a little bit to the diy audio community.

 

[flocchini]

Thank you for all your great contributions

Bob

 

[indra1]

Glad to see some of my ideas can add a bit of fun to our projects.

 

[indra1]

...Hall chips - they simply demand additional gain stage , between them and opto(s)...

Remember the problem with the beasties? I think Pa just handed out the remedy in the genuine article thread, use beefier 8 legged opto, the 6n type, instead of 3n veggies.

 

[generg]

Where is this article?

 

[indra1]

In your friendly neighborhood Pass Labs dealer?

 

[generg]

.???. No article to read?

)