The Singing Bush

[cubicincher]

to jjasniew

As I know: the multiple JFets in phonostages are used to lower noise and to
increase amplification - especially in MC-stages.


I think Zen Mod is using 3 Toshiba 2SK2145 paralleled to increase the transconductance of the devices instead of using one Toshiba 2SK170.
And I think they sound really good?



But it is better to ask Zen Mod himself. It is his design!


Greets
Dirk

 

[Zen Mod]

oh yeah

Mum , see ....... I invented The Wheel!!

You gonna see me on The Telly!!



JFets in parallel are functioning same as well trained Horses , drawing Carriage; together they're making lesser rumble , while being able to pull much more and more abrupt than sole one

in this case , I'm using 3 double ones in parallel , to be same as Brave Tailor Mickey , and to have greater Iq , lesser Rout, while still sane dissipation per each tiny bugger

nicely low and shaped THD is pure bonus and beginners luck

 

[Zen Mod]

aha!

my Petri Dish did bring whatever she's bringing home from School every Winter .... I felt so sleepy last few (or even more than few) days , knowing that some Virosis is there ...... anyway - yesterday I did plan several things , first o them being test of MosPuck gain pcb in Schaded Singing Bush

after lunch I came to idea of wasting 1L of Uberstrong Tea, with EEEEeeeverything in it (too much things to even start mentioning) and I did ...... after finishing second cup I fell to sleep

dunno , I did woke up several times after that (that's Tesla Spirit in me) but I can't clearly remember ; it seems I posted something at least few times, but I cant't clearly remember that also

in a meantime , I know I dreamt at least one original movie , at least one line level stage and at least one speaker construction

bummer is that I'm remembering just the movie 😛

so , Schade definitely today

 

[Zen Mod]

The Singing Bush Schade ......

Ok , that's it

Early morning coffee , then up to Workshop , another coffee in da coffee-maker

lazy finishing assembly of Schade pcb on heatsink , some wiring re-work ad that's it

funny behavior - RC constants are sooo big , it biases after few minutes ; output node voltage rises fast to full rail , simply because both mosfets aren't conducting ..... then it goes down softly and slow

besides - output node voltage stabilizes really at temp. equilibrium , and then everything is rock stable

 

[Zen Mod]

The Singing Bush Schade, 8R Load

Rail 60Vdc

Output node at 28Vdc

Iq 3A2

gain for 5Vrms out

8R load, 514mVrms in ; A=9.72V/V = 19.76db

 

[Zen Mod]

The Singing Bush Schade, 4R Load

Rail 60Vdc

Output node at 28Vdc

Iq 3A2

gain for 5Vrms out

4R load, 554mVrms in ; A=9.19V/V = 19.26db

 

[Zen Mod]

😛

 

[Tea-Bag]

Very nice. Let us know what your ears say.

 

[Zen Mod]

will try to polish THF51 version and will listen to that

and 2SK77B will just build ...... slowly ..... 🙂

 

[Russellc]

Zenmod, how does this differ from SissySit, in dumbed down layman's terms....I do have extra set of TH51....
But waiting to get final version to finish SissySit.

Or, should I make that one M25 and proceed with Burning Bush....assuming boards will be available.


Or, wait until new SissySit boards are available with latest changes?

Russellc

 

[cubicincher]

to Zen Mod #64

My 50W - SE- Schade - amp behaves exactly like yours.
It needs a long time to turn on and to warm up but then it is rock stable.


Only my node voltage at speaker output is much higher. But I am still testing / adjusting. 🙄



Greets
Dirk

 

[flocchini]

Schade version - very interesting and affordable 😀

 

[Zen Mod]

Zenmod, how does this differ from SissySit, in dumbed down layman's terms....I do have extra set of TH51....
But waiting to get final version to finish SissySit.

Or, should I make that one M25 and proceed with Burning Bush....assuming boards will be available.


Or, wait until new SissySit boards are available with latest changes?

Russellc

First ....... SissySIT is one heluva nice amp , special in character ( blame Papa, as always) ..... having measured 18W per channel , being wicked just enough and then little more;

what one can expect from pure SE , little higher in THD than usual , 50W SE amp made with SIT ? ........ think what's difference between nice and holographic 300B amp and cousin made with 845 , not sparing with iron and copper and caps ....... in other words - that's pure madness ...... completely other side of already borderline hobby

kits for Burning Bush will be available , but remember that main thing - all Lego Puzzles are long known and you can make it in whatever level of complexity you prefer .... even on Veroboard

so - is time for you to sin big , only you can tell and decide

me personally - I don't need that amount of power ....... and I would certainly skip that train if Papa didn't leave Workshop , making a situation for me to rummage through his most precious Shoe-boxes ...... so now I must make a pair of these Kudos amps


new SissySIT boards will be available first moment when someone shows interest in them , but if you already have them , decision will you proceed with these - with original opto arrangement , or later tweaked ones , or you prefer new ones , that's up to you

My 50W - SE- Schade - amp behaves exactly like yours.
It needs a long time to turn on and to warm up but then it is rock stable.


Only my node voltage at speaker output is much higher. But I am still testing / adjusting. 🙄
Greets
Dirk

I opted for that value (28V at output node) counting on fact that Papa is always putting his AP1 to good use ...... for what one needs to have a brain

that's why I'm using EMU1212 and I don't have AP1

there is slight possibility that Pa simply left that value from previous schematic - with 2SK77B , even if it not reflects real situation with mosfet pucks , and you always must count on possibility of some slight mistake in his schematic ..... but that's Nature of the Beast , his way of keeping Greedy Boyz on tips of their toes ....... and that's good thing - resulting sometimes in some gray cell engaging , not just blind copying what he drew

Schade version - very interesting and affordable 😀

yup, Bubba 🙂

 

[Russellc]

First ....... SissySIT is one heluva nice amp , special in character ( blame Papa, as always) ..... having measured 18W per channel , being wicked just enough and then little more;

what one can expect from pure SE , little higher in THD than usual , 50W SE amp made with SIT ? ........ think what's difference between nice and holographic 300B amp and cousin made with 845 , not sparing with iron and copper and caps ....... in other words - that's pure madness ...... completely other side of already borderline hobby

kits for Burning Bush will be available , but remember that main thing - all Lego Puzzles are long known and you can make it in whatever level of complexity you prefer .... even on Veroboard

so - is time for you to sin big , only you can tell and decide

me personally - I don't need that amount of power ....... and I would certainly skip that train if Papa didn't leave Workshop , making a situation for me to rummage through his most precious Shoe-boxes ...... so now I must make a pair of these Kudos amps


new SissySIT boards will be available first moment when someone shows interest in them , but if you already have them , decision will you proceed with these - with original opto arrangement , or later tweaked ones , or you prefer new ones , that's up to you



I opted for that value (28V at output node) counting on fact that Papa is always putting his AP1 to good use ...... for what one needs to have a brain

that's why I'm using EMU1212 and I don't have AP1

there is slight possibility that Pa simply left that value from previous schematic - with 2SK77B , even if it not reflects real situation with mosfet pucks , and you always must count on possibility of some slight mistake in his schematic ..... but that's Nature of the Beast , his way of keeping Greedy Boyz on tips of their toes ....... and that's good thing - resulting sometimes in some gray cell engaging , not just blind copying what he drew







yup, Bubba 🙂

I will wait until your mods to Sissy are done, if I think I can do it "gracefully" I will go that route. If not, will PM about new boards, and make this one M25. I have your M25 outputs, as originally that is version I bought.

All said, something whispers to me that I need the SissySit.....good sleep notwithstanding!

Thanks,

Russellc

 

[flocchini]

The SissySit is very very nice - I think ZM is modest 😀

I will do a Singing Bush just because its an experiment and I wand to compare.

I did the Schaded M2 for the same reason - it will remain at the house as a back-up to the Sissy.

Best

Bob

 

[Russellc]

The SissySit is very very nice - I think ZM is modest 😀

I will do a Singing Bush just because its an experiment and I wand to compare.

I did the Schaded M2 for the same reason - it will remain at the house as a back-up to the Sissy.

Best

Bob

is yours (Schaded M2) from M2, (mine is Teabag board M2) or schaded M25?

Russellc

 

[flocchini]

Mine is modded TeaBag board using 240s and Harris 9240s

Also have tea Bag board with Toshibas

Thinking of modifying it 😀

 

[Zen Mod]

I did explain in Babelfish M2-SEF amp thread how to Schade any M2 ...... matter of one additional resistor and re-setting DC Offset

I didn't tried Schade Babelfish M25 , that horse is for other course

regarding modesty , what Bubba Flocchini mentioned - it wasn't my intention to be modest ( nor is that my habit ) ...... I know how SissySIT is faring with DEFiSIT ( and SIT-3) , and I'm damn satisfied

 

[grimberg]

will try to polish THF51 version and will listen to that...

How about the 2SK182ES version? I purchased some recently because THF51 was no longer available from reputable sellers.

 

[flocchini]

per ZM
"I know how SissySIT is faring with DEFiSIT ( and SIT-3) , and I'm damn satisfied"

Ditto for me 😀😀😀😀😀😀😀😀😀😀😀😀😀

Best

Bob