The Singing Bush

[AnthonyA]

Which is most most musical of all the sit

Tuby

 

[Zen Mod]

Which is most most musical of all the sit

Tuby

hard question ... in fact easy , when you ask it on some fifi forum , not here

if you did ask , which of SITs is best , taking in account linearity , dissipation and all tech factors , then it's easy - 2SK77B is most probably best of all , easily implemented in whatever arrangement you can think of

not even counting fact that Pa said "this one is The Best"

with Singing Bush type of amp , result heavily depends of amp-speakers marriage; even if 45-50W is respectable for SE amp , you need sensitive and efficient speakers to use all raw and triodish quality of amp , while keeping it in lowest possible power range (using rest for dynamic peaks) , so having least possible THD

same applies to any tube SE amp ......

so , it is really more question of fact what you have (of SITs) on your bench ; if 2SK77/2SK77B then no brainer ; if THF51/2SK182ES then there is little more compromise

we'll see what we are getting with 2SK180 ; though - even if I'm hoping , I'm really not expecting miracles

if you don't have 2SK77/2SK77B and you vary of compromises , just make Schade iteration ...... that one was more cunning from Pa than primary one (with 2SK77B) , meaning - it's easy when you have jewel in your hand , while its harder to make jewel from brick

Pa, Mithrandir , Funny Alchemist

 

[AnthonyA]

Don't need that much powah actually.. Just something that's better than tube se. Slightly more pawah than 300b but better

 

[alheiz]

Perdón a todos.
Gracias por su apoyo!

 

[gpapag]

Please post in English only diyAudio Rules

"Sorry everyone.
Thanks for your support!"

George

 

[Zen Mod]

we'll see

my own personal Wakootalian , Mighty Bubba Flocchini , sent me a pair of these for testing

now they're on Customs , hope to get them sooner than lately was the case with lazy bstrdz

everything will stay the same , possible variations voltage potential of SIT Drain and values of resistances in Mu source

we are hoping that bloody thing is similar to 2SK77B , and as we all know , hope is dying last .......

🙂

while mine , from Bubba Flocchini, are still Customized , got them suckers , freshly arrived to my (local) Buddy

will spend some time these days to test them , and after arriving of second pair , will test these too

as I said - hope never dies - we'll see how they're close to The Best Ones

🙂

 

[V FETish]

as you probably know , I was on Pilgrimage (end of last year) to Sea Ranch .... to have few walks by the Open Ocean , collect some wood flown to shore ..... and to remind Pa that life isn't serious thing at all

Awesome thread and thanks. 🙂

Very nice to see yous standing together and very wonderful to see yous SIT'ing together too!

 

[Zen Mod]

as Pa is getting ......... wiser , it seems he's developing tendency of becoming more serious

so , it'll be cunning to visit him annually , to prevent further increase of seriousness

 

[V FETish]

as Pa is getting ......... wiser , it seems he's developing tendency of becoming more serious

so , it'll be cunning to visit him annually , to prevent further increase of seriousness

Very cunning indeed! 😀

 

[wengtech]

while mine , from Bubba Flocchini, are still Customized , got them suckers , freshly arrived to my (local) Buddy

will spend some time these days to test them , and after arriving of second pair , will test these too

as I said - hope never dies - we'll see how they're close to The Best Ones

🙂

that's very cool
can't wait to see the results

 

[Zen Mod]

Lazy Sunday .......

so no testing 2SK180 today

maybe tomorrow , but most probably day after 🙂

in a meantime , here's Trade post : The Singing Bush Kits

think hard - do you need it , are you happy with 130-180W of heat per channel...... which iteration is right for you etc.

....contrary to some latest concoctions , this one is easy to set and forget , but as any , it demands patience and care in assembly

 

[ggetzoff]

so no testing 2SK180 today

maybe tomorrow , but most probably day after 🙂

in a meantime , here's Trade post : The Singing Bush Kits

think hard - do you need it , are you happy with 130-180W of heat per channel...... which iteration is right for you etc.

....contrary to some latest concoctions , this one is easy to set and forget , but as any , it demands patience and care in assembly

Choky,

I ordered the Singing Bush kit because we don't have enough heat in Arizona 😀

Can't wait for those 180 measurements....no pressure.......😉

 

[Zen Mod]

2SK180: Hope never dies ....... but, Oh Boy , how it's Dodo now!!



pair sent by Bubba Flocchini are still Customized , and I did put today first one (of pair) my local Buddy obtained

initial setup , as hope (that it's close/r to 2SK77B) commands , same as ZMighty Singing Bush - rail 60Vdc , Iq 3A, Mu resistor set 0R2 up, 0R2 down, speaker output from middle ,Drain potential smidge bellow 30V

first stint - 1W THD Spectra measurement - damn!! 1.76%

power down , insert additional 2pcs of 0R1 in Mu string , power up , set Iq to 2A2 , Drain at 35V , try THD with 0R4 up and 0R2 down , then with 0R2 up and 0R4 down

THD shows that better option is 0R4 up and 0R2 down

few pics of setup

 

[Zen Mod]

2SK180 Singing Bush , 8R load

gain is 330mV in for 2V828 out , so 8.57V/V , 18.66db

 

[Zen Mod]

2SK180 Singing Bush , 4R load

gain 338mV in for 2V out, so 5.917V/V , 15.44db

 

[Zen Mod]

2SK180 Singing Bush, conclusion

well , behavior pretty much the same as THF51 and 2SK182 , maybe little more leaning to 182 side

was it worth spendiong money and repeating all measurements , to find out how hope is mortal?

considering that this time I didn't engaged my wallet, ( as was the case with 2SK182 for SissySIT)first part of question my Buddy and B. Flocchini need to answer

measurements - it was my pleasure , as always is , when I have something to play with

hope is maybe mortal , but we Kids are immortal !



one thing more - if you look back at what's posted in #57 , my fave commercial toob amp - EAR 859 - situation with any iteration of Singing Bush is simply more rosy

and , THF51/2SK180/2SK182 iteration , being slightly scaled down to 132W of heat per channel , is somewhat easier to make , as little bonus to decrease in performance , when looking at ZMighty Singing Bush with PapaTokins

I will repeat measurements , probably tomorrow , with second 2SK180 specimen , but now really not expecting Miracles

 

[Zen Mod]

Choky,

I ordered the Singing Bush kit because we don't have enough heat in Arizona 😀

Can't wait for those 180 measurements....no pressure.......😉

well , contrary to Jim , who's flying those sissy little jets for diamond clientele, you can make a pair of these and put in your cockpit

🙂

 

[flocchini]

"was it worth spendiong money and repeating all measurements , to find out how hope is mortal?

considering that this time I didn't engaged my wallet, ( as was the case with 2SK182 for SissySIT)first part of question my Buddy and B. Flocchini need to answer "

It's all part of the experiment and what was learned

no regrets here

Will do the Singing Bush with THF-51S guessing 180s will find a home in another build 😀 (always optimistic

Thanks ZM for all the effort !!!!

 

[ggetzoff]

well , contrary to Jim , who's flying those sissy little jets for diamond clientele, you can make a pair of these and put in your cockpit

🙂

And since I am a spoiled pilot, I'm going to ask you to go a bit farther with you measurements. I have a 4 ohm loudspeaker, can you look at different rail voltages for 4 ohm load to see what rails would give me best case H2 scenarios? I realize the VFets are going to be different. And on that note, I wonder if the higher VGS parts do better with H2 dominance.....

 

[Zen Mod]

will do what I can with specimens I have