The Singing Bush

[Nelson Pass]

Nelson may have photos of one of those tubes in pieces, when Econco commented that "God doesn't have enough money for us to rebuild that tube!"

I dug up a few photos from our visit. You will see Cyclotron Guy, and young
Colin Pass and Wayne looking at the big triode.

Also you will see the control room, and other pieces of hardware....

 

[flocchini]

Nelson

Great pictures. Brings back so many good memories.

Thanks and best

Bob

 

[Zen Mod]

 

[flocchini]

More good memories !!!!

 

[Dennis Hui]

BAF was great!

 

[Zen Mod]

yeah

some took opportunity to smuggle some goodies back home

 

[Zen Mod]

Hey Zenmod.. Answer your Gmail preeze

I just did 🙂

 

[flocchini]

BAF was great!

some great conversations

 

[6L6]

Awesome photos!!

Not enough time at BAF to catch up with everybody, but always happy for seeing everyone there.

 

[Ben Mah]

Fun times at BAF!

Thanks for the picture, Bob

 

[flocchini]

My pleasure - so great to meet you guys
Keep us posted on your 180 project

 

[alheiz]

I thought that in Triode the old MZ2-200 Mullar, was the biggest and most powerful for audio..but I see as Colin Pass The monster Triode.🙃⚠️

 

[Dennis Hui]

Thanks for that photo Bob.

 

[cubicincher]

I think, those 'boys' had real fun at university... 😀

Playing with that 'tiny triode' and dimming the campus - lights 🙄.
As bigger the boys, as bigger are their toys.


So, please continue...


Greets
Dirk

 

[AnthonyA]

Everybody look so wise..
I'm otherwise

Great pics

 

[Zen Mod]

.
indra - always finding important and new itsybitsies ...... I have some monstrous 110/220Vac autoformers , will maybe try to see what I'm getting with 32R load with 2SK180 iteration,still sitting on the bench

after several more seconds invested in thinking about said idea ...... adding 2:1 autoformer on output of existing Singing Bush ........ naah ...... there are other ways of making 15W amplifier

 

[cjfrbw]

I think, those 'boys' had real fun at university... 😀

Playing with that 'tiny triode' and dimming the campus - lights 🙄.
As bigger the boys, as bigger are their toys.


So, please continue...


Greets
Dirk

I was wondering where those second order harmonics in the seat of my pants came from at UC Berkeley. I'm glad it wasn't the acid.

 

[Zen Mod]

2SK180 Singing Bush , second specimen

......

I forgot to write down but seen on picture in quoted post, first specimen of pair I have for now was Ser. No. 130130 , having Ugs of -3V69 for Iq 2A2 , with 35V of Uds

second one is Ser. No. 130147 , having Ugs of -3V88 for Iq 2A2 , with 35V of Uds

so , Ugs not exactly matched , but so-so close

graphs following , no pictures of funny setup this time

 

[Zen Mod]

2SK180 Singing Bush , second specimen, 8R load

......

 

[Zen Mod]

2SK180 Singing Bush , second specimen, 4R load

.........

Note for @ggetzofffffffffff :

for 4R load , not shown , ZM lazybztrd - quick and dirt optimisation is same setup ( as for first specimen , see linked post two posts up) - just decrease/set SIT drain voltage to 31V - that'll invoke 2nd harmonic above 3rd , while still keeping overall THD at bay

of course that for proper setting of Singing Bush , one either needs to have simple THD Spectra measuring setup ..... or to trust own ears - pretty much easy with simple iterative process - start with prescribed arrangement for Mu resistances and drain voltage potential (35V) , listen and write down some notes about sound ; increase drain potential for 1V , listen , make notes ;

go back to 35V , then decrease for 1V , listen , make some notes ...... try another volt down or up , from where you been , listen , make notes

read notes , set to best overall

as soon that pair from my Bubba Flocchini stop being Customized , I'll repeat same battery of tests

who knows , maybe something could happen in a meantime , me suddenly cleverer .......... to try some new trick

but , don't hold your breath