ATC SCM7 . . . with Papa's diy amp?

[Babowana]

logical solution - change a wife

Sure, why not push Korea to poll position ?

g u y s . . .

I had a discussion with wife . . .
My wife is a good girl . . .
Instead, she accepted me to buy ATC SCM40
or Tannoy Glenair 10 . . .
Hmm . . . no, I will leave the current SCM7 home,
replacing the J-Low . . . crying, crying, crying . . .
and will buy one more set of SCM7s
to bring my new work place . . .
I hate . . . Awoo . . .

 

[jupiterjune]

she forcefully implies removal of the big J-Low.

Well, I am willing to help you out. Just Fed-Ex them to me and I will hold on to them for you. Feel free to send the Babo Zen V5 as well! 😀

BTW, I was away when you started this thread, but I have to say I think small sealed box speakers are the way to go -- especially with Aleph amps. You get the best of both worlds -- good bass, and that incredible midrange.

JJ

 

[Zen Mod]

Well, I am willing to help you out. Just Fed-Ex them to me and I will hold on to them for you. Feel free to send the Babo Zen V5 as well! 😀

BTW, I was away when you started this thread, but I have to say I think small sealed box speakers are the way to go -- especially with Aleph amps. You get the best of both worlds -- good bass, and that incredible midrange.

JJ

🙄 and - unfortunately - Satchmo is always smaller than Satchmo..........

 

[Babowana]

Well, I am willing to help you out. Just Fed-Ex them to me and I will hold on to them for you. Feel free to send the Babo Zen V5 as well! 😀

BTW, I was away when you started this thread, but I have to say I think small sealed box speakers are the way to go -- especially with Aleph amps. You get the best of both worlds -- good bass, and that incredible midrange.

JJ

Fed-Ex refused the size. Babo Zen? No, no, no . . . 😀

I'm with you about the small sealed box speakers.
Babo Zen gives them full and vivid life. Really great!
I didn't try till the clipping (symmetric) yet, but the
sound was big enough for my living room before any
clipping happens.

Blue Haze, songs of Jimi Hendrix . . .
Walter Traut (& the Free Radicals) shouts "Hey Joe!"
to the room air, leaving short and clean echo (delay) . . .
The guitar plays alternative, sweep and economy picking,
hammering on, pulling off and tapping . . . very nice . . .

Just for info,
one Japanese audio critic tested SCM19 with eight different
power amps. And, he chose Pass X150.5 🙂 and Jeff Model 102.


- - -
My 2nd sun likes hip hap too much . . .
while the 1st one likes rock, classical music, and even jazz . . .
My wife loves my obeying . . .
She is Prime minister while I'm a symbolic small king . . .
After all, hmmm . . . cleaned up . . . dammit . . . !
- - -

 

[Zen Mod]

...........
- - -
......
My wife loves my obeying . . .
She is Prime minister while I'm a symbolic small king . . .
After all, hmmm . . . cleaned up . . . dammit . . . !
- - -

..."small king . . ."

aunt we all .......... ?

but we love it that way .......

 

[jacco vermeulen]

Look Ma,

my loudspeaker system fits in my CD-rack.
At least the XZen is cool to watch, never seen a whitty poweramp.
(the front logo likely says that Babowhiner is stuck in a power triangle)

 

[Manu]

Blue Haze, songs of Jimi Hendrix . . .

Ok Babo , you're a serious listener.
But if you forget for a while mister "dead-in-his-own-vomit" or mister "dead in spaghetti carbonara in rue Beautreillis/Paris/France", both named jim,
what about something like Monteverdi?

I would like to agree with Jupiterjune :

"BTW, I have to say I think small sealed box speakers are the way to go -- especially with Aleph amps. You get the best of both worlds -- good bass, and that incredible midrange"

It would be the point.

Manu
Pleasedon'tkillmeifit isasacriledgetosaythat

 

[Babowana]

But if you forget for a while mister "dead-in-his-own-vomit" or mister "dead in spaghetti carbonara in rue Beautreillis/Paris/France", both named jim,
what about something like Monteverdi?

He might have had a soul worn off.
Nevertheless, in front of an invisible veil hiding it,
he must have wanted to stand on the stages,
playing his best for the audiences every time . . .

I don¡¯t have Monteverdi . . .

I feel tired this evening . . .
And, listening to
'Winterreise', Schubert
Peter Pears and Benjamin Britten . . .

 

[Babowana]

I have two tube pre amps of high gain . . .
And, I want to give SCM7 trial of the bi-amping . . .

OK, I will build F4, but mini one of about 8W @ 8 ohms
as I consider that max. 4W output is good enough for my
near-field listening with SCM7.
I will just reduce the rail voltages from +/- 22 to +/- 14V, and
will let all others remian the same. In this my concern is any
probable output distortion increase.

Papa, should I worry about the probable distortion increase
seriously? 🙄

Thanks for the kind advice.

 

[Babowana]

I believe Papa is always very busy . . .

I'm ready for F4, which might cook another dish of SCM7.

Luckily, today I could get these:

- 2SK170BL, Toshiba
- 2SJ74V, Toshiba
- IRFP240, Samsung (Fairchild)
- IRF9240, Fairchild

I'm going to use unmatched sets.

I could not get 8x15,000uF/25V for PSU.
Instead, will use 16x10,000uF/35V.
I cut off two heat sinks sized 150H x 65W x 450D (in mm)
with 14 fins.

And, I have an old 400VA 12-0V/12-0V toroidal.
Will make the common psu covering both channels.

My target is 10W@8ohm power (at reasonable
distortion rate . . .) and maximum about 5A capacity
with DF of about 40.

I will come back after finishing the construction.
Hoping success . . .

 

[Vix]

Hi Babowana!

Sorry to hear that your J-lows had to go...
On the other hand, thank you for the warning.
I take that the moral of this should be: Never replace bigger speakers with the smaller ones. If, however, you have to do so, make sure that your wife isn't at home when you're doing' this dangerous experiment. If, however, she happens to be present, cheat (not with another girl though): deliberately roll of bass on your amp input, so that when you play smaller speakers, it will sound thin, and she will be convinced that Bigger is Better.



P.s. Babowanna, if there's a lot of room left after removal of J-lows, you may argue that you are missing some low bass notes, and the only way to ameliorate this problem is to build something along these lines:

"The Legend of EL PIPE-O"

 

[Babowana]

My wife has learned all my cheating tech for 27 years, except . . .

 

[Babowana]

It takes longer time than I expected.
Maybe, I'm getting lazy or the good sound from the combi
of Babo Zen and the babies is not well motivating me with
this new diy construction . . .

I could finish this F4 r0 tomorrow . . .
The transformer is 400VA of 2 x (12-0V) for +/-14V rails.
I have R8 of 24K and 16 x 10,000uF for the filter caps.
All others are the same as Papa's F4 r0.

I want the listening test . . . mmmm . . . tomorrow . . .

 

[Babowana]

Phew . . . all completed.

I measured the rail voltage as +/-13V.
With this, I met a problem with the ref voltage of TL431.
I could not get enough cathode-anode current so that
I could not get the 2.5V reference voltage.

To get more current to TL431,
I had to replace the JFET source resistors of 22 ohms with
39 ohms. By doing this, I reduced the JFET bias current
from 5.5mA down to 4.3mA. Instead, I could earn more
current through the TL431. This gave me the required
reference 2.5V of the TL431.

As a summary, the changes from the original F4r0 were:

- R3/R4 ----> 39
- R8 --------> 24K
- Rail -------> +/-13V

I adjusted the MOSFET bias current with 0.46A each.
The offset DC was just negligible after all adjustment.

Hmm . . . It is late night.
Will try listening test tomorrow.


o, I wish I had one piece of Pass DIY logo . . .

 

[Zen Mod]

..........
Hmm . . . It is late night.
Will try listening test tomorrow.

good night and sleep well

ya crazy Babo

 

[Cobra2]

g u y s . . .

I had a discussion with wife . . .
My wife is a good girl . . .
Instead, she accepted me to buy ATC SCM40
or Tannoy Glenair 10 . . .
Hmm . . . no, I will leave the current SCM7 home,
replacing the J-Low . . . crying, crying, crying . . .
and will buy one more set of SCM7s
to bring my new work place . . .
I hate . . . Awoo . . .

Try Tannoy Glenair 15" (they are just a "fraction" larger than 10")
😀

Arne K

 

[jupiterjune]

Babo--

I think you stayed up too late working on the F4 -- the swich is a bit crooked!

Did I see a hand painted circuit board for this F4 -- how about a close up of the PCB?

JJ

 

[Babowana]

-- the swich is a bit crooked!

Did I see a hand painted circuit board for this F4 -- how about a close up of the PCB?

JJ [/B]

The switch is not a criminal . . . ! 🙂

I have the hand-drawing of the pcb (the input part) on my
notebook. I will scan it and post next week, for your info.

Attached is the close-up of the pcb, on which the following
components are arranged:

- R1/R2/R3/R4/R5/R6/R7/R8/R9/R22/R24/R25 and P1/P2
- Q1/Q2/Q3 - - - (2SK170/2SJ74/TL431)
- C1/C2/C3/C4 - - - (220uF)
- D3/D4 - - - (1N4004s)

The size is 60mm x 110mm board.


🙂

 

[Babowana]

Another shot.
The star ground is where the three grey-color wires are
connected.

I did p2p for the power gain part.

 

[Babowana]

As my F4 has +/-13V rails, I estimate it would provide me with
the effective time average music power of max 7.5W.
Only 7.5W for ACT SCM7, which is a famous power hungry baby?

I had listening test with F4 plus a tube pre.
Among others, I chose Bob Marley, Chant Down Babylon,
7 Turn Your Lights Down Low.
Waoow . . . ! F4 pulls down the bottom end (electric bass) low
and forms into very good musical foundation. F4 controls SCM7
perfectly, and it was loud. I'm surprised. Bigeyes!
Oh ho ho . . . just from the 7.5W amplifier!

If I compare F4 with Babo Zen, Babo zen gives me a bit heavier
punch while F4 controls the bottom end somewhat better.
I don't know whether the difference is due to different preamps . . . ?
Anyhow, I'm satisfied with both. 😀

I regret that I built only one. I should have built two.

Thanks, Papa!


:darkside.