Racking Spectra Sonics 101

[Baltimore]

assuming you have your 10k resistor between the pins labeled "signal in" and "signal out" then i believe it is wired correctly.

 

[3nity]

Thanks Baltimore.

now if you look at the schematic....Between the 2N4248 and 2N5366 theres a capacitor...4.7uf/35V is that polarized or not...if yes negative goes to ground??

I lifted fromt the pcb and the card dont smoke anymore!!!! :green:

 

[3nity]

anyone?

 

[Animatic]

Well it SEEMS to be creating some relative or maybe virtual ground vs 24v power.
In many schematics polarized caps have a curve and a straight line.
and non-polarize is just two straight lines. As show here.
But I am not familiar with the standard of this era.

It is also not on the 1965 drawing. So maybe you can try it with it out.
Of course looking at what was on the board to begin with is a good hint.

 

[3nity]

I did tried a 25uf/25V and its working fine but it has some warmth...altough almost hard to tell but it was there...gonna try a bigger voltage one....

 

[3nity]

I got one of the cards working on theory....but i dont have sound with a mic plugged.... altough for a moment i forgot to unplugged the preamp from my headphones amp and i heard the 1k wave coming from my Generator...hum??

One step at a time! :thumb:

 

[3nity]

cool i got it! i got 1 channel working!!!
Everything was fine but i forgot to wire XLR pin 1 to OEP.

Cool!!!


I think i;ll have to remove the foroidal from the rack cuz i have some RF.

:green: :thumb:

 

[Animatic]

mereveaux c'est bien!

Toroidals do seem to make RF,
maybe a Cinimag in Mu metal can etc?

 

[hairymoses06]

I've noticed it's been awhile since anyone has posted on this site. I've got a pair of 110 cards that I want to rack up. I'm going to buy JLM audio power supply and go between, but I have no idea on what transformers to buy. Does anyone have suggestions for transformers that they have used? I of course need the 600Ohm 1:1 or 1:2. THANKS!

 

[3nity]

I'm not sure but they used triad on input....some of them used Jensen too...
Right now i'm using Jensen 600:600.

 

[maxwall]

Anyone use a T66 trasnformer ? there in a black and look a lot like a Triad HS66 , but the windings seem differentns

 

[rattleyour]

I have four 110s racked up, we used Cinemags on input-- CMMI-2C.

For output I used some old iron that folks here at the lab helped identify as (probably) stancor.

 

[hairymoses06]

Thanks for the help on the Xfrs. I was just given 2 Reichenbach RE 11SSP-6M. I think they're similar to Jensen, but I'll have to put them on a scope and see what they read. I think they're gonna be 600:600. I found a set of Triad A-67J ...but they're in Vietnam...not sure how I feel about that transaction. I'll be sure to post some picks when I get them racked.
Doug J.

 

[goldenGeek]

I just finished racking a SS101 and it seems to be working fine finally. But I stubled upon something that probably is like it should be, but I though I`d ask anyway. Is it correct to connect pin E and F (signal input - and signal output - ) and then connect it to ground? It was the only way I could get sound out of it. The weird part is that if I grounded this at my star gound to the back of the chassis I got a ground hum. If I grounded this anywhere else closer to the front panel the hum was gone. Why did this happen do yiou think?

 

[3nity]

you went unbalanced out or transformer balanced?
E, F and C are 0V, ground reference.
i used F as reference for input transformer, E for 24V reference and C for output transformer reference.

Matta gently posted a ground scheme for this board....they go from certain points straight to star ground.....

 

[bdubya]

Hey now.  Just wanted to extend a big thank you to all ya'll on this thread.  Just finished racking up a 110 card in a case from some old data network equipment, with a jlm power supply run off a wall wart.  Sounds fantastic, quiet, and BIG.  Would never have even known a thing about any of this stuff without this forum. Props.

bw

 

[3nity]

Just to hear what i sounds like i wired the input unbalanced and i'm amazed at how good it sounds..
It sounds louder first thing and i think its not dark like with any 600:600 input.
To my ears it sounds more open and coloured...first real tests....

 

[bdubya]

So, instead of the dual 1k log pad in front of the input transformer, could one use the 600-ohm attenuator that Hairball sells, or am I misunderstanding the affect that the attenuator would have on the input impedance?  I know its more expensive than the the dual-pot, but I like the curve of that attenuator in both the 1176 and the VP26.  It covers the ground evenly, so to speak. 





ben

 

[staras]

Can someone confirm what ratio transformers needed for the 110A model? Are they 150/600:2k5 ohm on input and 600:600 ohm on output?

Thanks.

 

[techardent]

If anybody is interested.  I found this in my Spectra Sonics file.  As I understand it a lot of the components were hand picked for amplifier stability.  I am unsure who filled in the values.  I removed the link between R3 and R4 to make it accurate to the the actual card.

Spectra Sonics 101 / 100 schematic