JLM AUDIO

want to add an input attenuator on my V672 and was thinking about using the variable input pad kit.
But now I'm confused because the dual pot is 1K and I've seen somewhere on a different forum Joe's commenting on his gobetween kit when used with a V672, replacing the 470R resistors with 2x 2200 R to give sufficient attenuation on the input ?

permeke wrote:want to add an input attenuator on my V672 and was thinking about using the variable input pad kit.
But now I'm confused because the dual pot is 1K and I've seen somewhere on a different forum Joe's commenting on his go between kit when used with a V672, replacing the 470R resistors with 2x 2200 R to give sufficient attenuation on the input ?

Best way for V672 is to use our Go between kit so you have 48v , 20dB Pad and phase switching. Change the 2 x 470R on each side of the pad switch on the Go between kit to 2k2. You can then plug in our variable pad kit to give and extra 25dB variable pad. This with the switch pad can give you up to 45dB pad. So variable pad from 0 to 25dB with pad switched out or 20dB to 45dB pad with pad switch in.

thanks joe.Now I understand the matching

permeke wrote:thanks joe.Now I understand the matching

Because the V672 has gain control when the 500k log pot is added the variable pad kit is not really needed unless you are using it so the gain can be turned up for different sound.

Otherwise only the Go Between kit and OPtional Fet DI kit are needed.

Old thread I know but I have a slight scratching noise on my B500K pot from minimum to 1/3 of the turn.
Could it be DC ?
Also eliminating the trim, you say bridge point 4 and 5 on the circuit but I can't find it but I guess I'm right with bridging the ones that gives minimum gain.

thanks

permeke wrote:Old thread I know but I have a slight scratching noise on my B500K pot from minimum to 1/3 of the turn.
Could it be DC ?
Also eliminating the trim, you say bridge point 4 and 5 on the circuit but I can't find it but I guess I'm right with bridging the ones that gives minimum gain.

thanks

The pot should be a 500k A log type not Linear B type and if you get DC noise when moving the pot the output cap on the preamp section of the V672 will need replacing. Depending on version this is 15uF from vague memory. Not sure what the point 4 & 5 was a reference to but could be the numbered pins in the V672 trimpot pins.

thanks Joe for the fast reply. Will check