Re: Gain switch for 9k mic pre?????
« Reply #40 on: December 08, 2008, 01:44:35 PM »
I think that's what JayDee meant.

About sound differences between pot and switch, I'm not so sure you'd hear any, unless the "correlation" or whatever it's called between the two gangs of the pot was really off (they tend to be off, not sure by how much though). And even then, who knows? For a bit more work and $$, what you would get with a switch is precise control and easily repeatable gain settings.


Whoops

Re: Gain switch for 9k mic pre?????
« Reply #41 on: December 08, 2008, 02:24:16 PM »
Yes you're totally right about having  precise control and easily repeatable gain settings.
that's definitely the biggest noticeable difference


Although I think is quite different sending your sound though 1% metal film resistors and trhough a  cheap carbon tracks pot.
as you said I'm not sure if I will notice any differences , but the switch has in Theory a better signal flow.


regularjohn

Re: Gain switch for 9k mic pre?????
« Reply #42 on: July 15, 2009, 07:29:15 PM »
Has anyone thought of using two seperate pots, one to control input gain and the other to control output gain?  I think it might be cooler than just one ganged level control.

Also, what about a 5K rev log pot in parallel with a 5K resistor?  That would essentially give you a 2.5K pot, right?  It would probably mess with the taper, but it would work wouldn't it?
SATANOSCILLATEMYMETALLICSONATAS

JAY X

Re: Gain switch for 9k mic pre?????
« Reply #43 on: August 31, 2009, 04:06:06 PM »
Hi All,

Got my 2k2 rev log pots from audiomaintenance today. I know how to wire them with the 39H and 27H resistors. Ok so far. But ┬┐what about 6.81k Rp1 and Rp2?  I couldn't find any thread that explains where to place or wire them. ???

Thank you for your help,

JAY X


Harpo

Re: Gain switch for 9k mic pre?????
« Reply #44 on: August 31, 2009, 04:44:15 PM »
Hi Jay,

Rp(hantom)1 and Rp2 are optional resistors if you want to power condenser mics from your ssl9k. One side of each resistor (same value is more important than absolute value) connect to Input Hi and Input Lo. The other side of these two resistors joined together and connect to the pole of a SPDT switch (or DPDT switch if you also want a status indicator, powered from a different supply voltage) for +48V phantom voltage. Throw side of this switch connect to +48VDC of your supply with reference/0V always connected to XLR-pin1. The other throw side of this SPDT switch might also connect to XLR-pin1.

-Harpo
A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.  -Douglas Adams

JAY X

Re: Gain switch for 9k mic pre?????
« Reply #45 on: September 03, 2009, 12:35:48 PM »
Hi Harpo,

Thank you for your reply. I see that i have a lot to learn... I think i will go for a JLM audio go between kit, as it features a pad and polarity switch.

JAY X
« Last Edit: September 12, 2009, 09:57:12 AM by JAY X »

ytsestef

Re: Gain switch for 9k mic pre?????
« Reply #46 on: September 09, 2009, 08:06:38 AM »
Any chance of being able to control 2 channels with a single pot? (For stereo setup)
I guess we would want some rev-log quad 12-legged pot..  ::) Is it possible? Or should I go with a switch on this one?
Stefanos.

SNG

Re: Gain switch for 9k mic pre?????
« Reply #47 on: September 15, 2009, 09:35:56 AM »
Any chance of being able to control 2 channels with a single pot? (For stereo setup)
I guess we would want some rev-log quad 12-legged pot..  ::) Is it possible? Or should I go with a switch on this one?
Is possible, use a NSF rotary switch with 4 wafers for 2 channels....

Farnell #116-5268 for mechanic
Farnell #146-049 for the wafers
Farnell #149-173 for wafers on PCB

Not cheap but very nice solution, building it now inside my new stereo SSL 9K, I use the PCB mounting wafers...
my wife don't care I build all the stuff, she is using it... :D
building now a 32 channel analog console with the features I like and miss in many consoles :)

hobiesound

Re: Gain switch for 9k mic pre?????
« Reply #48 on: September 15, 2009, 10:25:26 AM »
Any chance of being able to control 2 channels with a single pot? (For stereo setup)
I guess we would want some rev-log quad 12-legged pot..  ::) Is it possible? Or should I go with a switch on this one?
Is possible, use a NSF rotary switch with 4 wafers for 2 channels....

Farnell #116-5268 for mechanic
Farnell #146-049 for the wafers
Farnell #149-173 for wafers on PCB

Not cheap but very nice solution, building it now inside my new stereo SSL 9K, I use the PCB mounting wafers...

rs components has those same switches under a different brand and slightly cheaper! just so you guys know.  ;)

greetings,

Thomas

ytsestef

Re: Gain switch for 9k mic pre?????
« Reply #49 on: October 06, 2009, 12:11:00 PM »
While I wait for Gustav's boards, I decided on the switch resistors. Since I'll be using a 2Pole/6Position Lorlin, I will use Harpo's advice and keep Ra steady using a single 82R resistor for each board, then each pole of the switch will carry one channel, using 6 positions for steps of roughly ~2.5dB, ranging from +34 to +46 dB of total gain for each channel. I am attaching a picture I drew, please correct me if I am doing something wrong.

Thanks a lot everyone!
Stefanos.


Harpo

Re: Gain switch for 9k mic pre?????
« Reply #50 on: October 06, 2009, 06:49:03 PM »
Hi Stefanos,

looks OK with a MBB lorlin type switch.
Just curious, this ssl9k build is intended as makeup gain stage for your passive summing network with 40dB loss from your other thread ?
When using 6 step positions, level will either be a step behind (+38.5dB) or a step ahead (+41dB), but missing the +40dB center position.
Easiest fix for a unity gain position at step 3 or 4 probably done by tweaking the shunt resistor of the summing network, or by limiting the lorlin to 5 step positions, keeping the 294R and use 1K1, 487R, 261R, 154R between ~3.1dB steps.

good luck,
Harpo
« Last Edit: October 23, 2009, 08:09:12 AM by Harpo »
A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.  -Douglas Adams

ytsestef

Re: Gain switch for 9k mic pre?????
« Reply #51 on: October 06, 2009, 07:26:11 PM »
Hello Harpo!

Yes, it's the same one, I am aware that there is not an exact +40dB setting but I don't mind that much for two reasons:

1) I will have always my GSSL between the 9K output and the 2-track input (when mixing down the tracks) so, the level is going to be changed one way or another by compression and make-up gain.

2) +41 dB is fine even with the GSSL on bypass since when mixing everyone keeps ~3dB headroom anyway, no-one wants their summed level ever reach 0 dB. It's going to be flattened out in the mastering process. I don't worry at all about the 3dB loss in dynamic range, since I'm recording in 24Bit.

Thanks for confirming that I finally got it right, though  ;D ;D
Stefanos.

SNG

Re: Gain switch for 9k mic pre?????
« Reply #52 on: October 28, 2009, 11:02:59 AM »

In picture form:




Maybe a stupid question but I notice that one pin of the switch is not in use, means that this is a 11 steps switch instead of 12 ?
« Last Edit: October 28, 2009, 01:46:04 PM by SNG »
my wife don't care I build all the stuff, she is using it... :D
building now a 32 channel analog console with the features I like and miss in many consoles :)

okgb

Re: Gain switch for 9k mic pre?????
« Reply #53 on: October 28, 2009, 05:49:53 PM »

 just a reminder that the starter of this thread jerrod
is someone who took money for a grp buy & then disappeared
GKB Audio / Greg Boboski

xqqxqq

Re: Gain switch for 9k mic pre?????
« Reply #54 on: April 02, 2010, 09:17:17 AM »
I have a SL911,  where to find the input and output connection method?

Thank you!


 

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