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Title: AD-3208 problem
Post by: nedyoung on August 06, 2004, 06:20:41 AM

Hi all:

I just finished ad-3208 few days ago,and it sounds great! After finishing it,I want to do some mod on it. So I follow the mod on GGG --lower the resistor connect to pin 12 of SA571 to do more repeats. After I change the resistor ,this stuff dont produce delay sound :cry: .I trim the pot to adjust the Bias of MN3205,but how matter I trim, it wont work.So I change back the 100k resistor ,trim the pot,still dead... :shock: Does anyone knows the bias voltage of the MN3205? I've try for 4,5 hours ,and it deosn't work ...can anyone helps? thanks!!

Title: AD-3208 problem
Post by: puretube on August 06, 2004, 06:53:02 AM

Vbias = Vdd/2;
Vgg = 14/15Vdd;

Title: AD-3208 problem
Post by: nedyoung on August 06, 2004, 01:40:00 PM

Is the Vbias=Vin? thx~

Title: AD-3208 problem
Post by: puretube on August 06, 2004, 01:42:34 PM

it`s the one that is adjustable in the AD3208, at the input of each BBD.

Title: Re: AD-3208 problem
Post by: mgmusic on August 18, 2004, 06:27:41 PM

Quote from: nedyoungHi all:

I just finished ad-3208 few days ago,and it sounds great! After finishing it,I want to do some mod on it. So I follow the mod on GGG --lower the resistor connect to pin 12 of SA571 to do more repeats. After I change the resistor ,this stuff dont produce delay sound :cry: .I trim the pot to adjust the Bias of MN3205,but how matter I trim, it wont work.So I change back the 100k resistor ,trim the pot,still dead... :shock: Does anyone knows the bias voltage of the MN3205? I've try for 4,5 hours ,and it deosn't work ...can anyone helps? thanks!!

hello !!
I put together a AD3208 from GGG with 02 mn3205, but I cant find them anymore, so I thought I could use 4x BL3208 to get the same 600ms... do you thinks this is possible ??
do you have another idea??

thanks !

Title: AD-3208 problem
Post by: Yuan Han on August 18, 2004, 08:10:22 PM

its possible, but having 4 more trimpots will make calibrating it tough !
just send the signal output from the last 3208 into another 3208 like what has been done... and then do it again.

i think maxon's ad999 delay uses 4 3208s....

Title: AD-3208 problem
Post by: mgmusic on August 19, 2004, 12:43:32 AM

Quote from: Yuan Hanits possible, but having 4 more trimpots will make calibrating it tough !
just send the signal output from the last 3208 into another 3208 like what has been done... and then do it again.

i think maxon's ad999 delay uses 4 3208s....

thanks for your help man !!!

do you know where can I get a circuit board for the 4x 3208s ?
is it that simple ? just 2 more 3208 , nothing more ?
sorry, I'm not a technician......

thanks again !!

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DIY Stompboxes => Building your own stompbox => Topic started by: nedyoung on August 06, 2004, 06:20:41 AM