Racking Spectra Sonics 101

[rocksure]

[quote author="JLM Audio"]

I am currently racking a pair of these using Triad A67j input transformers and Jensen JE-123A output transformers. This may seem like a silly question, but looking at the pinout in the picture, if I send the 0v  from the input transformer to pin E, and the 0v from the card ( pin F) to the power supply common, where is the best place for me to connect the 0v from the Jensen output transformer?

 

[rocksure]

I am currently racking a pair of these using Triad A67j input transformers and Jensen JE-123A output transformers. This may seem like a silly question, but looking at the pinout in the picture, if I send the 0v  from the input transformer to pin E, and the 0v from the card ( pin F) to the power supply common, where is the best place for me to connect the 0v from the Jensen output transformer?
Bump....Anyone out there?

[quote author="JLM Audio"]

I am currently racking a pair of these using Triad A67j input transformers and Jensen JE-123A output transformers. This may seem like a silly question, but looking at the pinout in the picture, if I send the 0v  from the input transformer to pin E, and the 0v from the card ( pin F) to the power supply common, where is the best place for me to connect the 0v from the Jensen output transformer?

 

[AJMAC]

So I'm racking up a pair of 101 cards using Joe's diagram (Thanks Joe!)  I am using A67J input wired 600:600 and HS66 on output.  I have a couple questions however..I have the output of the card wired to the primaries of the transformer and the secondaries connected to XLR out.  It works, but after re-reading the thread for the 10th time it seems I've got it backwards.  Since the transformer is 1:1 does it make a difference?  Should I wire secondaries to the card and primaries to the XLR?  Also, PRR mentions using a resistor in series to keep the card from damping out the iron sound.  Could someone elaborate on this in noob terms?  Also, what value resistor would be suitable?  Thanks!!

 

[drew baker]

Hello,
I first want to say what an amazing board this is. It is remarkable how polite and intelligent everyone is here. Thank you all so much for the information on the spectrosonics 101 cards,I am trying to breadboard one as I type. Cannikin, the 103 board you have is a summing card.
I think it might be the unsung hero of the Spectrosonic console. If I understand it is 0 ohm input summing amp. I think it predates the SSL low impeadence summing amp by 20 years. Is thee any way you could post color photos of the front and back of the card,I would love to try
to bread board one. Once again thank you all for your information, I look forward to participating in this great forum.
Drew Baker

 

[rocksure]

I finally got my 2 channels of Spectra Sonics 110 racked and up and running. They sound really good. Nice and warm and fat. Quite a bit of work and time consuming to do, but well worth the effort and cost of racking them up. No issues with noise or hum, as I was pretty careful to ground everything as well as using metal shields round things like power supply and transformers (just to make sure).
I am not too clued up on electronics really, and so I had a few minor problems working it all out, but with a bit of help from a friend who is an electrical technician we nutted the issues out. I have Triad A67-J transformers on inputs and Jensen JE-123-A's on outputs. I used a JLM AC/DC to power them, and JLM go-between and variable pad kits for attenuation, phase and 48V. On the picture I have posted here, I have the labels for these underneath the switches, they should have been on top. I have subsequently changed the labels. I have no output gain control: output is fixed with the use of 42k resistors. I have around 40db of input gain control via the JLM input pots and attenuation switches.
I am very happy to have these. 

 

[bassinyourface]

Hi all,

Just a quick note to say that this topic is fantastic,lots of useful info !

Some pretty neat racking here too : knowledge and ingeniosity go a long way.

I just wanted to add an insert to the circuit ( for connecting an eq or compressor)

What do you think would be the optimal spot ?

 

[superjimmer]

Hi Guys I am looking to trade a pair of SS 110a/502 modules in a really cool rack with PSU and VU meters for some modules for my console.

Here is a movie of the unit at work:

http://dl.dropbox.com/u/5629729/IMG_3001.MOV

Now for the deal! I am looking to acquire more Spectra Sonics modules, so if you have any spectra sonics parts or modules that you never racked up let's trade. I am trying to put a console together and need more 502/110a modules and possibly other parts. I am looking to trade this unit, loaded with two modules, for four of your raw modules etc.

So if you never racked yours up here is your chance to plug and play and help a console get rebuilt. This rack and vintage API meters with FiveFish PSU, custom rack etc plus mod/rewiring labor from a tech has easily cost me $1500.00 not counting modules. But it sounds amazing!

In addition to this amazing rack I have other console parts, bus modules, anodized gold meter panel, some old meters and more. Just trying to get my console running. And lemme tell you I am not one of those guys who famously lucked into one. I have paid through the nose for every part. Just a love affair with this sound.

pm for more info. It currently runs at 17.5 volts, but can go to 24 volts if you want to mod it. Also the attenuation pots you see are very high quality but not wired up as I liked the simple -10 -20 -30db switches. I also have it wired for line in but the XLR's are on pigtails - you can run them out a hole or install the TRS jacks I have included in this deal (pictured).

When I find out how to post pics I will. I have 100% positive trading on ebay since 1998 and Gearslutz since 2003 and can provide references and contact info if you PM me!

 

[superjimmer]

Here is a pic of my Spectra Sonics 110a/502 racked pair with original SS API VU meters.

 

[rocksure]

Here is a pic of my Spectra Sonics 110a/502 racked pair with original SS API VU meters.

It looks really nice. I'm still loving the sound of my racked pair. They really excell on electric guitar cabinet micing among othe rthings.

 

[toddro]

I know this is one year old, but I wanting to rack up a 110/502eq set and my eq's came from an old broadcast console with a custom faceplate.  Can anyone post a straight-on shot so I can see the toggle switch & gain / freq pot positions?  When I pulled them off the console I was forced to leave the faceplates behind and need to build a new one.  Somehow, the photos of the console I took have disappeared and I have been unable to locate a shot clear enough to see what the positions are.

Superjimmer, nice build!!!  That is what I am shooting for!

Thanks.

Todd

 

[Whoops]

So I'm racking up a pair of 101 cards using Joe's diagram (Thanks Joe!)  I am using A67J input wired 600:600 and HS66 on output.  I have a couple questions however..I have the output of the card wired to the primaries of the transformer and the secondaries connected to XLR out.  It works, but after re-reading the thread for the 10th time it seems I've got it backwards.  Since the transformer is 1:1 does it make a difference?  Should I wire secondaries to the card and primaries to the XLR?  Also, PRR mentions using a resistor in series to keep the card from damping out the iron sound.  Could someone elaborate on this in noob terms?  Also, what value resistor would be suitable?  Thanks!!

PRR mentions using a resistor in series to keep the card from damping out the iron sound.  Could someone elaborate on this in noob terms?  Also, what value resistor would be suitable?

 

[duantro]

Getting ready to rack a pair of ss101's and really appreciate all of the info here! Cheers

 

[j.frad]

Hi everyone, what would happen if I lowered the supply voltage to, say, 16v ?
Wondering if I can make 500 series modules with them...

 

[bxt403]

I've realized that Spectra Sonics modules should definitely be sent to Ogden and Spectra Sonics (now apparently called Spectra 1964) for repair and/or refurbishing. I sent two 101s that didn't match (age wise) and Spectra replaced one of them (while also refurbishing them). They did an excellent job repairing my 110s, as well (and converting them to 110As).

In any case: I've just completed racking a pair of 101s so figured I should share some gain resistor values as an alternative to the (I think) "JLM" method of having 3 gain settings and a variable pot at the input transformer.

You'll need a non-shorting rotary switch as a shorting type causes loud thump sounds (from gain instability). I haven't had any issues with gain stability using a non-shorting type rotary switch with my 110 (in that I hear a very faint clicking sound). I noticed the clicking sound is significantly louder with the 101 (likely since the 101 only needs a +24 VDC supply to work while the 110 requires + & - 24 VDC). It's not as bad as the loud thumping I'd hear when using a shorting type switch with the 110 but it's still apparent.

Note that I did the algebra on the gain equation found in the original Spectra Sonics manual and made a spreadsheet to do the calculations. The numbers given are for the EXACT (theoretical) resistor value that'll yield the EXACT gain value number. Since the gain equation is given in the 101 manual: it should be easy to figure out which gain is yielded from the actual resistor values that are available from electronics suppliers.

The data sheets for the 101 and 110 both state the gain for each module is adjustable from 40dB to 55dB (which contradicts the manual that gives a resistance for 35dB). I'd rather stay on the safe side and start at 40dB.


Gain (dB) Resistance(kΩ)
40 11.111
41 12.638
42 14.402
43 16.449
44 18.834
45 21.629
46 24.926
47 28.845
48 33.545
49 39.244
50 46.248
51 54.994
52 66.143
53 80.728
54 100.476
55 128.489 (the "actual" value I got was 127kΩ @ 54.96dB)

Also: Jensen (at the time of this post) makes the line/mic input JT-11SSP-6M & JT-MB-C and the line output JT-11SS-DLCF & JT-123-BMCF transformers (where I suspect the SS might actually stand for Spectra Sonics- like Cinemag's QEE "Quad Eight Electronics" transformer). I'm guessing that the sound from these transformers will be less coloured than using vintage Triad A-67J + HS-66 transformers (albeit the DLCF mentions 50% Nickel content while the 6M sheet doesn't list anything about its Nickel content).

 

[MidnightArrakis]

And FWIW here we have the 110, so with +/-24V supply for more headroom:
http://www.technicalaudio.com/a2z/S/SpectraSonics/SpectraSonics_110A_sch.pdf

So this is the card for which JLM gave the hookup-info earlier in this thread.
So when cloning it's easy to make either a 101 or 110, but I won't really be needing the higher levels possible with the 110. A joint use of +/-24V & 48V for phantom could be considered though.

Anyone toyed around with the 101 & 110 side by side by chance ?


There's some more SpectraSonics info there, thank you Mr. Klett:

http://www.technicalaudio.com/a2z/S/SpectraSonics/

Regards,

Peter

Here is a current and working link for the Spectra-Sonics 101 and 110 circuit cards:

http://www.technicalaudio.com/pdf/SpectraSonics/
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[MidnightArrakis]

heres the schematic:
http://www.technicalaudio.com/a2z/S/SpectraSonics/SpectraSonics_101sch1.pdf

Here is the new link that actually works:

http://www.technicalaudio.com/pdf/SpectraSonics/SpectraSonics_101_amplifier_manual_schem.pdf
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