The best noise gate?

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Spencerleehorton said:
from the base of the first 2N3704 down to gnd?
That one is probably AOT; it must be so that the FET is off without signal.

and after the third 3704 connecting to the release pot?
According to specs, the relase time is adjustable from 30ms to 5s. 2Megohms for 5s imply 12kohm for 30ms. There is already about 2 kohm (10k//2.7k) at the foot of the pot. I would vouch for 10k.
 
Spencerleehorton said:
ah ok, i understand now, so would 50k trim be too much in here or does that sound about right? or should i go 500k?
My simulation shows very little difference between 50k and open circuit. I would suggest a 500k trimmer with a 50k padding.
BTW I think there are some errors (or red herrings) regarding the values of some resistors; the 33k in the collector of the 4th transistor (3704) seems a tad high, and the 3.3k across e-b of same transistor should be increased. With the values on the schemo, the voltage at the collector of the 5th transistor (across the 0.47uF cap) never gets negative enough to open the FET.
I know that sim is not the real world, but this needs to be investigated.

On another subject, I think that EQing the side-chain is vital in any noise-gate; the second product I put on the market was a noise-gate I co-designed with an ex-Dolby guy. The gate in itself was nothing fancy - unashamedly inspired by MXR (!), but the filters (2nd-order Sallen & Key) made a difference. It was an instant hit. There was nothing comparable on the market at the time.
 
All great info thanks, I will put this together first and put trimmers in those places so it can be tweaked!
Once done and working I think the next step is putting something in the circuit for sidechain eq’ing for better gate response.

Any thoughts on how to implement the sidechain with eq?
 
Spencerleehorton said:
All great info thanks, I will put this together first and put trimmers in those places so it can be tweaked!
Once done and working I think the next step is putting something in the circuit for sidechain eq’ing for better gate response.

Any thoughts on how to implement the sidechain with eq?
I have already posted about that, perhaps more than once..

#1 Easy and most powerful is an insert jack that allows you to patch in a powerful external EQ for problem tracks.
#2 2- knob Baxandal type shelving treble/bass tone control Eq
#3  1-Knob tilt EQ

A classic concern when putting multiple gates with side chain EQ inside a single chassis is front panel space for all those knobs, not to mention gate threshold, (optional) hold time, (optional) attenuation depth, etc.

Pick your poison. (I've used door #1 and #3 before).

JR
 
JohnRoberts said:
#1 Easy and most powerful is an insert jack that allows you to patch in a powerful external EQ for problem tracks.

I would debate that this is easy because you either need to tie up an eq or need to build some eq's to insert.    If you happen to have a bunch of patchable eq's that you don't use then  maybe it is easy.
 
Rob Flinn said:
I would debate that this is easy because you either need to tie up an eq or need to build some eq's to insert.    If you happen to have a bunch of patchable eq's that you don't use then  maybe it is easy.
Easy from a design perspective...

I ASSume this is a recording interest so tracks are not all happening in real time, all at same time.

Like I said pick your poison. Don't argue with only one option when I offer multiple choice.  8)

JR
 
Funnily enough I have a 2524 eq project on the shelf which I still haven’t done anything with, it’s the api 3 band eq which I’m sure could help this project, space wise I think i could get 4 x rm68 and 4 x api eq in a 2U with Psu space hopefully.
Front panel design would be tight, but defo possible I reckon!!
 
Mostly you want to pick a narrow range of frequencies to trigger your gate , LFcontrol  on the ds201 goes all the way from 25 hz upto 4khz and the Hf control is from 250hz upto 35khz so you can really narrow down the range if needs be ,this really helps the gate to open and shut smoothly and when you want it too . If say your gating a tom , you want to minimise any spill in the control signal so that the gate doesnt trigger falsely , the key filter on the Ds201 is near perfect for this job .

For me theres two distinct reasons for gating , one a simple noise gate , very much like used in basic guitar stomp boxes and to some extent large console gating, its on or off with a miniumum of artifacts  , then you have  gating with manual settings for threshold ,attack, hold, release and range ,this is a different beast completely and its usage goes far beyond noise control .

Sorry .Png wont post for some reason ,
Its all included in the link to the service manual I put up

 
Just had a quick look at my Ds 201 , sure enough its unbalanced ,with only the ground  and tip of the plug connecting on both input and output jack.
The spec sheet quotes 10k unbal 20k balanced  ,but the unbalanced version must be more like 1 meg instrument input .

 

Latest posts

Back
Top