The Singing Bush

[Zen Mod]

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

why not .... I'll try all tricks known to regular Greedy Boy to make it sing, both THF and 2SK182

except if Papa don't chime in , giving his recipe ....... though - even he's having zillion of them , I'm not sure did he already put them on the bench properly, considering number of projects he's working on

 

[Nelson Pass]

Here's some data on 2SK182 vs THF51S operated Common Source and
Common Drain, biased by a constant current source.

 

[Soundhappy]

Thanks Mr. Pass
CD biased by a CCS graphs show much less distortion.
Could be interesting a try with big inductor load..

 

[Zen Mod]

Here's some data on 2SK182 vs THF51S operated Common Source and
Common Drain, biased by a constant current source.

that's cheating ...... same numbers as I got

more important details , Pa?

rail, Iq , Uds?

I did some polishing work today with THF51, not yet finished .....

 

[Soundhappy]

PSU capacitors price rises up exponentially with voltages from 63V to 100V and +
https://www.mouser.fr/Passive-Compo...4attZ1yx4atu&Rl=75hqwZer3vZ1z0wo8cZ1z0wqf2SGT

 

[Zen Mod]

that's normal ...... laws of market

and, not because of tech. reasons ...... they've just heard of Singing Bush , thus anticipated increased demand for caps

 

[Soundhappy]

Bigger cap's for similar price if screw terminal type Aluminum Electrolytic Capacitors - Screw Terminal | Mouser

 

[AnthonyA]

What's the dissipation of the transistors ?

 

[Ben Mah]

It's 60V x 3.2A per channel, so it's 192W shared by two devices, unless you are blasting your speakers at maximum power full time.🙂

 

[AnthonyA]

Wow. That makes a nice water heater.

Honey louder music pls... Shower too cold

 

[Ben Mah]

My THF-51S amps are definitely cool and cold weather amps - not for summer enjoyment.

I was thinking at higher power output, energy is dissipated by the speakers and less dissipation by the transistors.

 

[AnthonyA]

It's already very hot here... 30vdc 3a.

Need gigantic heatsink for it. And warm up the room even

 

[Michael Rothacher]

Very nice work. 🙂

Does ZM sleep?

 

[cubicincher]

to Michael Rothacher

Hello Mr. Rothacher,


you know that ZM has the opinion, that sleep is overrated!?🙄


Perhaps 'mother nature' has rocked ZM to a comatose nap?


I am joking.... 😀



Greets
Dirk

 

[Zen Mod]

Dodosssesss

 

[Zen Mod]

Oh Boy ...... ZM really trying to be systematic ..... twiddle deeeeee

OK , I tried what I could , some refinement both for THF51S and 2SK182ES , to squeeze what I can and know , in Singing Bush format

objectives and goals:

- do not alter schematic , just values and settings
-do not resort to higher voltages , keeping demands for caps at 75-80V bay
-both lowest THD and dominant 2nd, as must

so , what I did , in general :

THF51S - tested one proper pair (matched solely by Ugs) , to confirm similar behavior ; after that tested two more specimens furthest away bu Ugs , being on my disposal

2SK182ES - two of them tested- lowest Ugs and highest Ugs specimens I have

will break posts - one battery of test per post

manage if you can ......

 

[Zen Mod]

THF51S , Ser. 1Z0081 , first from matched pair, 8R load

Rail 65Vdc

Iq 2A3

output node 37Vdc

Mu resistor string 6 x 0R1

output taken 02R from bottom

this one , Ugs -3V21

 

[Zen Mod]

THF51S , Ser. 1Z0081 , first from matched pair, 4R load

same conditions


again , this one , Ugs -3V21

 

[Zen Mod]

THF51S , Ser. 1Z0115 , second from matched pair, 8R load

same condition

this one , Ugs -3V22

 

[Zen Mod]

THF51S , Ser. 1Z0115 , second from matched pair, 4R load

same condition

again, this one , Ugs -3V22