GSSL HELP THREAD!!!

[fucanay]

Hello, I think this is my first post on this topic. I have a couple of Gustavs board that I'm building. One I'm building for me to use with unbalanced inserts on my console and the other I'm building for a friend to use on the balanced inserts on his console. His seems like a standard build, but I'm not so sure about mine. It seems that there are issues with running unbalanced with this unit. And since I never plan to use this during tracking, I thought it would be a good idea to avoid those problems from the start.

So how do I go about solving this? I've seen the info in the 15k resistor being changed to 27k, but is that all I need to do? Should I be using TS jacks instead of TRS? If so how would I hook them up?

I'm sure this is pretty basic, but I have yet to actually finish anything yet. I've got a dual green and two GSSLs being built at the same time. I'm getting way closer to being finished with everything, but these little details are slowing me down big time and I also don't want to be ordering the wrong parts.

Also, one more thing. Would it be ok to use an IDE ribbon cable cut down for the control panel PCB to main PCB cable? I think it would look so much better than a bunch of loose cables.

Thanks,

Matt

 

[kryckmeister]

I HAVE been looking around, so don't tell me I'm lazy, just stupid if I missed something obvious .

With my SSL the meter drops all the way down when moving the threshold past like 12 o' clock. I'm definetly a n00b at this, but I passed it on to someone who's capable of dealing with this but I thought it might be decent to try and find the solution to the problem.
Any idea of what it might be or where to look?

The n00b salutes you!

 

[mathflan]

I'd like to know if I can Put a Toroid Transformer 220V->2*15 with 30VA??

30VA is it too much??

 

[Greg]

30VA is fine. The compressor will only use what it needs. You'll just plenty of spare "juice" for LEDs and lamps if you want.

 

[mathflan]

Ok, thanks greg :wink:

 

[khstudio]

[quote author="fucanay"]
Would it be ok to use an IDE ribbon cable cut down for the control panel PCB to main PCB cable? I think it would look so much better than a bunch of loose cables.
[/quote]

I would like to know this too.

So how do I go about solving this? I've seen the info in the 15k resistor being changed to 27k, but is that all I need to do? Should I be using TS jacks instead of TRS? If so how would I hook them up?

Those resistors have to do with volume only.

 

[Greg]

Yea some people around here have used IDE ribbon cables. It'll work fine. Regarding the 15K/27K, it just changes gain. With the 15K, the unit has +6dB gain, with the 27K, it runs at unity.

 

[fucanay]

[quote author="Greg"]Yea some people around here have used IDE ribbon cables. It'll work fine. Regarding the 15K/27K, it just changes gain. With the 15K, the unit has +6dB gain, with the 27K, it runs at unity.[/quote]

So would it be good to change them both to the 27k resistors? I stuffed the boards with the 15k because that's what is shown on the boards, so I'll need to remove them if I have to do this.

Thanks for the affirmation on the ide cable, I think that should work pretty good to keep things neat.

Also, what about using TS jacks on the one that will always be used on unbalanced inserts? Is it necessary or will an unbalanced cable into a TRS jack work without issues?

Thanks,

Matt

 

[Greg]

Yes, replace the 15K with the 27K. That's what I used in mine. I want unity from comps most of the time.

 

[gyraf]

But if you plan to use unbalanced-out, you need the +6dB (i.e. 15K resistors) to acheive unity gain in bypass..

 

[mathflan]

DO you know if this meter is appropriate with the SSL??

I can have This meter with 1ma.


http://www2.produktinfo.conrad.com/datenblaetter/125000-149999/134945-da-01-de-Einbauinstrument.pdf

thanks

 

[fucanay]

[quote author="gyraf"]But if you plan to use unbalanced-out, you need the +6dB (i.e. 15K resistors) to acheive unity gain in bypass.[/quote]

This is all pretty confusing to me. I guess it's that I'm pretty new to all of this analog stuff. I was using outboard preamps straight into an interface and mixing in Logic Pro before. But now I have a large console that I want to use and need to make my DIY gear to work with it. I have 8 busses and 32 channels with unbalanced inserts that I plan to hook up to a patchbay with Y cables to patch in the GSSL and in the future a couple of G1176s.

I think I need a good tutorial on signal routing and gain staging. :?

Matt

 

[gyraf]

I can have This meter with 1ma.

A 1mA version would do fine. ANY 1mA version would do fine.

But you need to check yourself if it will fit your front panel.

Jakob E.

 

[mathflan]

thanks gyraf for the meter :grin:

 

[khstudio]

Meter lamp Help

I know very little about how to use ohms law to find a dropping resistors value - could someone help me.

#1 Is it safe to use the secondarys off the power transformer?
(30v or even one side/half - 15v)

#2 I have (24volt / 3 watt) bulbs I thought would be close but don't know how to do the math... & would like to learn.

(I need the value & wattage.)

#3 How do you guys do it? I tried a single LED but didn't like it.

Kevin

 

[khstudio]

Nobody?

 

[CJ]

safe to use sec.

figure out current you want thru lamp first.

3 watts (man, that might be too much heat, keep it away from meter plastic)
you can increase R to drop heat and stll have good light.

watts is volts times amps,

so a 24 volt bulb means we use 24 for our calculation,

to get amps, we use watts and volts,


3/24 = 0.125 amps

ok, how many volts from transformer?

we need more than 15, that's for dang sure,

so use your 30 volt winding.

30 volts, series circuit, current the same everywhere,

24 volt lamp, we have 6 extra volts to kill. this is the resistors drop.
but how many ohms?

easy:

6/0.125 = 48 ohms on this side of the Atlantic.

done!
no. :sad:

watts needed, and we double our answer for saftey and low stress

watts is volts times amps, and so we can simply use 6 times 0.125
for 0.75 watts, double that and you ask the man for a 2 watter at 48 ohms.
47 is standard, 51 is standard, so get the 51 for less current and less heat.

 

[khstudio]

CJ your the man. :thumb:

Do you think it would be better to use a 6 volt bulb off one side = 15 volt?

 

[Greg]

Assuming the same power, the higher the voltage bulb the less current it will draw, so I guess in general the higher voltage bulb is the way to go. I usually try to use 24V bulbs.

 

[khstudio]

I was reading the post on the ratio adjustment & need some help. I built 2 units - 1 with 2151's & the other with 2180 - less trimmers (2151 in side chain) & both seem to have the negative 10:1 ratio going on. I tried the 100k to 120k change, it did work but I'm not sure I liked what it did to the sound of the unit.
I'm confused because I thought that with the 215x series everything would/should fall into place & from testing my own it seems they both have this problem.

Has anyone compared the GSSL to a real SSL 384FX (? model)

I really like these units & just want to be confident with my builds.

The first one I built (without the ratio mods) with the 2151 all around (Poly caps) sounds great on a parallel drum buss & I'm afraid to change it... unless I install a switch (for the ratios) to go back & forth.

The 2nd has Metal films, 2180?s, 2151 sidechain. I was thinking of adding the trimmers like the SMART C1 does to the 2180?s? maybe they?re too clean or the circuit isn?t set up for them correctly.

1 more thing? I added a resistor to the + leg of the threshold (with a switch so I could compare) & it worked but when I set it to a similar level (switch on/off) it wasn?t the same. It seemed to affect the ?attitude? of the compression more than it should? is there something else happening when adding this resistor? I think it might sound better stock even with the limited range.

Kevin