Harpo

Re: GSSL HELP THREAD!!!
« Reply #8280 on: July 29, 2020, 03:55:19 AM »
Thank you very much for the indications HARPO, I am going to try to make the connections as you indicate,
Please again, tell us your type and model of your switch.
Could as well be a series LAS1-A from OnPow that comes with an option for AC/DC 220V with LED or AC 220V with neon lamp and additional required parts already built in. The pinout of the switch is differing from previously linked switches from C&K or NKK thou (switches common pole is an outer pin, not the center pin), hence knowing the manufacturer and type of switch is essential knowledge in order to get the corresponding datasheet for pinout or parts parameters/limitations.
Quote
I do not understand all the electronic terms you use because I am a simple fan of electronics, I know it is a lot of work and annoyance but could you draw how all this would be connected?
As long as you can't answer my previous simple requests, it wouldn't make much sense.
A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.  -Douglas Adams


Re: GSSL HELP THREAD!!!
« Reply #8281 on: July 29, 2020, 07:14:38 PM »
the switch has no mark,, has LA160 -16A written ,it is 2-position (self-locking), sunk position and normal position.
I have opened it and it only seems to have a bulb-shaped led with two contacts.
attached images.

in the central pins are the initials NC, NO, C

thank you.

https://drive.google.com/file/d/1gfJiRCdp40pFdpAGtjWcV103YHWW4zNq/view?usp=drivesdk

https://drive.google.com/file/d/1ZIUiy44jEbb_3Jtsyq3lbslCBAcrFDSD/view?usp=drivesdk

https://drive.google.com/file/d/1QTl4gBLErexk2fODXgrsMTDH28VP2v_n/view?usp=drivesdk

https://drive.google.com/file/d/1UZV0VNBexOc-c5r11O0rxzNSGrL9pJwK/view?usp=drivesdk

« Last Edit: July 29, 2020, 07:35:36 PM by Juanaca »

Re: GSSL HELP THREAD!!!
« Reply #8282 on: August 08, 2020, 01:35:16 PM »
Hello everyone, I was finally able to solve the problem of the push buttons.
now I hope I have the last problem.
I want to put an HPF filter with various cutoff frequencies to the compressor.
Could someone please explain in a simple way what I need and how could it be assembled?
I've been doing some research and have found some filter sidechain plates.
is this correct?
I have always thought that the sidechain was a compression in relation to an external input signal not a high pass filter.
thank you

living sounds

Re: GSSL HELP THREAD!!!
« Reply #8283 on: August 10, 2020, 07:10:16 AM »
I bought an ADT console this year and recapped and upgraded it. The console originally used DBX2150 VCAs, which I upgraded to THAT2181A. The owner of ADT, Gerd J√ľngling, is a great guy, very knowledgable and generous with his time. He told me that his circuit didn't require any adaptation to account for the new VCAs and that his was the correct way to impliment them and that the one in the VCA datasheets was problematic. He also let me know that the 2180 (pre-trimmed variant) was the exact same chip as the 2181 (trimmable) version.

I was able to trim the VCAs on all my console's channels so that the harmonics were below the noise level. This prompted me to adapt the circuit in the GSSL the same way. I had never been able to tweak the distortion as low as I wanted with any of the chips in any of my GSSLs before, and the setting tended to drift. With changes applied however, as in the console I suceeded in getting distortion below the noise level in the compressor and have it stay there.

The main changes, aside from a slightly lower bias value (don't remove the resistor entirely) are bypass capacitors added to the THD trim and the bias voltage. It's also possible to trim the 2180 variant, just like Mr. Juengling suggested.

Attached are the necessary changes to be made to the circuit as well as the PCB overlay. As for the latter, I suggest to put the 47n bypass resistor between pins 2 and 4 below the PCB and the 10uf cap below the PCB as well.

living sounds

Re: GSSL HELP THREAD!!!
« Reply #8284 on: August 10, 2020, 07:11:51 AM »
And here is the schematic with the changes. It should work for all THAT2180 and THAT2181 versions as well as DBX2150 and THAT2150 VCAs.

Re: GSSL HELP THREAD!!!
« Reply #8285 on: August 10, 2020, 09:42:47 PM »
And here is the schematic with the changes. It should work for all THAT2180 and THAT2181 versions as well as DBX2150 and THAT2150 VCAs.

Wow amazing! I'll definitely try this out at some point. In the meantime, I wanted to ask. Is it normal for there to be a fair amount of distortion when in 10:1 ratio? I've never really used more than 4:1 before, but recently I was using it and noticed that in 1:10 crushing pretty hard that there is a good amount of distortion. I never really noticed it before because I tend to use 2:1 with 2-4db of compression.


Ryan

living sounds

Re: GSSL HELP THREAD!!!
« Reply #8286 on: August 11, 2020, 08:17:25 AM »
Wow amazing! I'll definitely try this out at some point. In the meantime, I wanted to ask. Is it normal for there to be a fair amount of distortion when in 10:1 ratio? I've never really used more than 4:1 before, but recently I was using it and noticed that in 1:10 crushing pretty hard that there is a good amount of distortion. I never really noticed it before because I tend to use 2:1 with 2-4db of compression.


Ryan

Compression without distortion isn't really possible, so it might just be the normal reaction you're seeing. The GSSL also has some ideosyncracies like higher general distortion in bypass mode, I would have to check if ratio settings in a properly set up GSSL (correct resistors) at a level below the compression threshold made I difference, but I actually doubt it.

Re: GSSL HELP THREAD!!!
« Reply #8287 on: August 11, 2020, 11:58:14 AM »
Good to know. It distorts pretty hard at 10:1 with high threshold but I wouldn't say it's ugly distortion. Maybe your advice will help a little with what I'm hearing.


Ryan

living sounds

Re: GSSL HELP THREAD!!!
« Reply #8288 on: August 11, 2020, 12:01:33 PM »
Did you measure distortion? Clearly audible distortion would indicate a problem with the build.

Re: GSSL HELP THREAD!!!
« Reply #8289 on: August 11, 2020, 02:45:27 PM »
I'm not sure what normal THD is for this device...but I was getting as high as .8% THD on 2:1 and 1% THD on 10:1 at 0db when crushing at max.

Somewhere along the build I heard that I should turn my trimmer resistors to about halfway because it didn't really matter for the 2181B VCA's. But I may have not understood. Gain reduction at at full threshold I just trimmed the THD from 1% down to .16%. Yikes! I knew something was off but yikes.

Most of the distortion is at Harmonic 1 which is 0.065% THD I'm using a 1khz tone at 0db.
Still seems high though. I've never measured THD so I may be doing something wrong.


Ryan
« Last Edit: August 11, 2020, 03:37:42 PM by FarisElek »


living sounds

Re: GSSL HELP THREAD!!!
« Reply #8290 on: August 11, 2020, 06:45:47 PM »
I'm not sure what normal THD is for this device...but I was getting as high as .8% THD on 2:1 and 1% THD on 10:1 at 0db when crushing at max.

Somewhere along the build I heard that I should turn my trimmer resistors to about halfway because it didn't really matter for the 2181B VCA's. But I may have not understood. Gain reduction at at full threshold I just trimmed the THD from 1% down to .16%. Yikes! I knew something was off but yikes.

Most of the distortion is at Harmonic 1 which is 0.065% THD I'm using a 1khz tone at 0db.
Still seems high though. I've never measured THD so I may be doing something wrong.


Ryan

Again, if you are applying gain reduction (the needle moves) higher distortion is to be expected.

Re: GSSL HELP THREAD!!!
« Reply #8291 on: August 11, 2020, 06:48:31 PM »
Ah! must've missed that. Then in that case I've still brought it down by more than half! I'm not getting the clearly audible distortion anymore. Didn't realize how important that potentiometer was in the case of the 2181B. It appears to be .003 after adjustment with no gain reduction.

Ryan
« Last Edit: August 11, 2020, 08:24:44 PM by FarisElek »

gyraf

Re: GSSL HELP THREAD!!!
« Reply #8292 on: August 12, 2020, 04:18:50 AM »
..don't tell anyone but, if you listen carefully, you probably don't want to trim to lowest thd here. I know of at least one well-respected manufacturer that mis-trims on purpose to get a certain character that suits this circuit rather well..

the love for the 202C variant of this circuit is probably also about this :-)

/Jakob E.
..note to self: don't let Harman run your company..


 

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