990 working!

[ijr]

Hi folks!
Just get pcb's...had no all parts, did it with "what I have"
It was fun.
Thanks to Frank for his help and advice on Sprint-Layout.
Here's some pics of working 990c:
pcb:

top view:

bottom view:

(still haven't small capacitors! These NPO/COG :shock: are hard-to-find
in Israel!)
and...don't forget to put thermal glue/compound on bias diodes and
wilson's mirror(4250's above 394).
Here's picture of out trans./bias diodes:

Have fun)
Igor.

 

[NewYorkDave]

Very cool, Igor. Lachaim! :guinness:

 

[ijr]

Lechaim )
(i.e. :guinness: :sam: :guinness: :sam: )

 

[SSLtech]

Lechaim!!!

Keef

 

[NewYorkDave]

Whoops... My Hebrew is rusty :wink:

 

[SSLtech]

Then let me get you a fresh one....! :wink:

:green:

Keef

 

[ijr]

My engish is rusty too
Someone from folks at this forum called me nurd, and I thought
like a week it is good (like prof or chief))
Now, one folk explained me what is nurd, and I gonna kill
madafaker called me nurd !!! :--)))
Good thing in this forum: you, folks, GREAT!
With rusted russian/english/hebrew/whatever we have our DIY language!
And we understand each other! What can be better!

 

[soundguy]

currently, in NYC, if you are a Nerd, you'd be getting laid, so its not all so bad depending upong where you are....

Anyway, in the brainiac circles being a nerd rules.

How do those opamps sound? What are you using them in? Looks nice!

dave

 

[Marik]

Hey Igor,

Think of a nerd as "nudnik". I guess in many cases this and DIYer is the same.

Hanuka devushki! Lakaem! :wink:

 

[Moby]

Nice Igor :grin: Tell me is that PCB layout from original, or you made it?
And if it works as you say, will you share the files? :green:

 

[Steffen]

hey Igor, great stuff.
how did you match the current mirror Q10/Q3 (Ube, Hfe)?

steff

 

[ijr]

Hi Soundguy,
what for i need gigatone of 990)
discrete console, of course.
There will be not only 990's here, and opa604 in eq filters and am-4 in eq
circuit, and passive tub buss/active (fet d.o.a) buss and lot of fun:--)))
990 was soldered today, compared to original (yes, one f@#k
I get was high a bit offset probably due to I used not 394-(they must arrive within 2-3 weeks) but kinda transistor pair pulled from hp17171a
dc preamplifier, it working for now...slew rate symmetric and seems to be close to original 990...no oscillations/overshoot...three or four hours is was putting 5vrms sin into 500 ohm at +/-24v and did not blew out.
I just putted it into working api preamp instead of 2520 and said"one, two"
into microphone, it is not enough; studio test I can do within few days.
Also, tested it in "20db gain and 20db down; equal level +/- 0.02 dB with bypass" setup. THD from 990 was about 0.012% at 1k, original measured better. Sounded more or less close.
It does not add "bad tones"; sound facture is reach and tight;
but it is not fast as opa604. Not syntethic, too))
but sometimes, opa604 in same 20db configuration was prefereable for me in highs.
I love 990's and use them in pre's/consoles upgrades.
Another great thing for me is am-4 in eq circuits-fast, reach in sound and very dynamically.(need good dc servo, btw, too)))
What I did is just copied original layout of both am-4 and 990
to save some money on doa's for console, and it seems working)))
Also, I gonna use here my opamps on active bus...this subject later)
You folks using doa's too, so, just sharing what I have.
Cheers,
IJ.

 

[ijr]

@ Marik:
ZDAROVA!
@Steffen:
Ube enough, I think
@Moby:
this is original layout, just copied it to learn some tricks

 

[Moby]

this is original layout

:razz: Harasho towarish :wink: Davaj A?

 

[ijr]

BTW, if it does not cross with legal stuff,(990 is public),
layout...why not)
Frank help me with Sprint-Layout and all Deutch work on comp.silkscrreen.
Anyway, there will be some spare pcb's from next time I'll advertise pcb's.
Huh... e'nuff english for me...gonna slleep

 

[CJ]

Shalom!
:guinness:

 

[SSLtech]

Shazam!

 

[mesmer]

Hossenfeffer incorperated!
We're gonna DIY our way

 

[Flatpicker]

[quote author="ijr"]BTW, if it does not cross with legal stuff,(990 is public),
layout...why not)[/quote]The circuit is public, not sure about the circuit board. Not saying it isn't but you may want to find out for sure before marketing them.

 

[Peter Simonsen]

[quote author="Flatpicker"][quote author="ijr"]BTW, if it does not cross with legal stuff,(990 is public),
layout...why not)[/quote]The circuit is public, not sure about the circuit board. Not saying it isn't but you may want to find out for sure before marketing them.[/quote]

Just another !!!

Also is that the "original" "old" 990 layout or the later John Hardy layout ?? dont know if the later modified 900 john Hardy is public ???

Best to ask John and/or Jensen about this so everything is "cleared" and oki-dokey ;-)

Kind regards

Peter