SPEC-1, Lower output on the right channel

[ajohnnyz]

he used them (in 2012 and I ain't heard any complaints),

they're cheap.

they're in stock.

get em.

And just to Clarify. In the 2012 post. No KSC1845F or KSA992F were used on the Filter Amp Board (AWM-082)

Q1: 2SC1885: 512-KSC2383YTA
Q2: 2SC1885: 512-KSC2383YTA
Q3: 2SA912: 512-KSA1013YBU
Q4: 2SA912: 512-KSA1013YBU
Q5: 2SC1885: 512-KSC2383YTA
Q6: 2SC1885: 512-KSC2383YTA
Q7: 2SC1885: 512-KSC2383YTA
Q8: 2SC1885: 512-KSC2383YTA
Q9: 2SC1885: 512-KSC2383YTA
Q10: 2SC1885: 512-KSC2383YTA
Q11: 2SA912: 512-KSA1013YBU
Q12: 2SA912: 512-KSA1013YBU
Q15: 2SC1166: 512-KSC2690AYS
Q16: 2SC945: 512-KSC2383YTA
Q17: 2SC945: 512-KSC2383YTA

 

[markthefixer]

That's what it says....

 

[markthefixer]

FYI I have been testing Caps on AWM-082 and a lot are reading high. 10uf's are reading 15.5 and 15.9 4.7uf's are reading 6.2, 3.3's reading 4.3.....

Some of that was the 30+ years old specifications and manufacturing tolerances. They could be as loose as -20% + 80%!!! (type Z for 330uF +)

The most common was "P" which is +50%, -10% according to the Pioneer Tuning Fork 2 capacitors pt 2.

see, all that crap has gems scattered throughout it.

now I can't articulate to you the WHAT or WHY of it, or how it manifests, but capacitance Tan theta goes to hell before capacitance usually drops.

 

[ajohnnyz]

I don't understand much of what you just said. I spent most of the day yesterday looking at Transistor specs, reading and researching and I still just don't know crap! An Electronics 101 class would be good. I don't get any of it, the how and way. So figuring out a circuit or re-engineering anything is defiantly out of the question at this point.

So can you please clarify? What is best to use for 2SC1885 and 2SA912
I have the KSC1845F and KSA992F
I ordered the KSC2383YTA and KSA1013YBU

All new parts, The "right" CAP's, along with Transistors and Resistors will be in by Wednesday.

Thanks.

 

[markthefixer]

So can you please clarify? What is best to use for 2SC1885 and 2SA912

NO

And I don't have time to research it in the time frame you just presented.
Basically it boils down to the idle / operating currents flowing in THOSE SPECIFIC CIRCUITS.
How are they biased, HOW much heat are they dissipating?
No less to try to repackage the knowledge specifically for you.

Just use the goddamn 1013's and 2383's.

you may not have enough 1845 & 992 to cover the extras needed should you change from Matt's list.

 

[ajohnnyz]

NO

And I don't have time to research it in the time frame you just presented.
Basically it boils down to the idle / operating currents flowing in THOSE SPECIFIC CIRCUITS.
How are they biased, HOW much heat are they dissipating?
No less to try to repackage the knowledge specifically for you.

Just use the goddamn 1013's and 2383's.

you may not have enough 1845 & 992 to cover the extras needed for the change from Matt's list.

I thank you for being so Frank. I love it, that's me...

 

[ajohnnyz]

And know worries on time. I just ordered 10 KSC2690AYS today so it will be another week before all parts are here.

I have changed the 4 - 120 ohm resistors in that one section. Once parts finish coming in I will change all Transistors and all Electrolytic Capacitors and then see how the signal is.

 

[ajohnnyz]

Update,

I got all new caps and transistors installed in the AWM-082 board. I tested and all signals are good on the outputs. I haven't put it back in the rack yet but all looks good on the scope .

I am sure I could keep going and do a lot more Caps and transistors on other boards, but right now, I am thinking if it ant broke don't fix it.

Lastly on the power supply board I set VR's 1 and 2 to 48 volts +/- ... then buttoned her up.

 

[markthefixer]

re: not continuing into recap and retransistor, IDK, you've earned your spurs.....

Part of that is deciding when to back off, permanently, or temporarily to seek assistance from collaborators.

You have resolved the initial complaint.


Later you will learn just how unusual laying two traces down right on top of each other really is. Has to do with the tolerances of the resistors setting the gains in various stages.

 

[ajohnnyz]

Thanks, I guess.

And FYI, my wife and daughter are not happy with me as I just hooked up and tested out the pre-amp. they said the whole house was shaking , shes working great.

Thanks again for all you help.

John

 

[ajohnnyz]

Parts I changed.

 

[Young46]

Thanks, I guess.

And FYI, my wife and daughter are not happy with me as I just hooked up and tested out the pre-amp. they said the whole house was shaking , shes working great.

Thanks again for all you help.

John

That’s great. Congratulations!