[Build] CAPI LC25-LC40, 500 Series Rotary Graphic EQ's, Official Support Thread

[Christian Rodriguez]

Yes. We probably could not get the J parts when we last ordered. J=5% tolerance, K=10%. Either way good to go.

Copy that, thank you for the quick response!

 

[Spiritworks]

I am curious about the DC link jumper - What setting should be used under normal, one unit operation?

 

[jsteiger]

I am curious about the DC link jumper - What setting should be used under normal, one unit operation?

Set it to "NO".

 

[Spiritworks]

Thanks

 

[TransientAggressionSound]

Just finished my first LC40 and I’m getting no sound when the switch is activated. Audio passes through in bypass. Nothing smoked on the inside and solder joints look good.

Where should I start trouble shooting? Also I am using a cheap 500 chassis (Midas L6) and wonder if that may be an issue.

Thanks!

 

[jsteiger]

Not sure when you purchased but sometime last year we accidentally pulled 24V relays instead of 12V. Please check those first.

 

[TransientAggressionSound]

I

Not sure when you purchased but sometime last year we accidentally pulled 24V relays instead of 12V. Please check those first.

purchased around a week ago but I will double check that!

 

[TransientAggressionSound]

I

purchased around a week ago but I will double check that!

They are 12v

 

[jsteiger]

Firstly, you will have to verify that the relays are switching. When in active mode the #8 and 10 gold fingers go to RR5 and RR6. The output transformer GRN and RED go to gold fingers #2 and 4.

 

[TransientAggressionSound]

Firstly, you will have to verify that the relays are switching. When in active mode the #8 and 10 gold fingers go to RR5 and RR6. The output transformer GRN and RED go to gold fingers #2 and 4.

Those all seem to be in order. I do hear a click when I switch to active. I did notice there was a resistor touching the front plate, could this cause it not to work? Thanks for your help!

 

[jsteiger]

Those all seem to be in order. I do hear a click when I switch to active. I did notice there was a resistor touching the front plate, could this cause it not to work? Thanks for your help!

Yes that 100% can be the problem. The L-bracket is grounded so you could be shorting out the signal.

 

[TransientAggressionSound]

Yes that 100% can be the problem. The L-bracket is grounded so you could be shorting out the signal.

Fingers crossed that’s the only issue! Thanks

 

[TransientAggressionSound]

Yes that 100% can be the problem. The L-bracket is grounded so you could be shorting out the signal.

Ok, solved that issue! Now, I’m getting a significant gain boost when switched to active (like 12db), is this normal?

 

[jsteiger]

Ok, solved that issue! Now, I’m getting a significant gain boost when switched to active (like 12db), is this normal?

No. With all cut/boost switches at 0 it should be basically unity gain.

 

[TransientAggressionSound]

No. With all cut/boost switches at 0 it should be basically unity gain.

Shoot. Where would be the next place to check? Possibly a resistor in the wrong spot?

 

[jsteiger]

Shoot. Where would be the next place to check? Possibly a resistor in the wrong spot?

Most likely yes. But its probably 2 that got swapped. Also make sure no other resistors are touching the L-bracket on the switch PCB.

 

[TransientAggressionSound]

Most likely yes. But its probably 2 that got swapped. Also make sure no other resistors are touching the L-bracket on the switch PCB.

Ok. All good on that end. Multimeter just crapped out on me so I’m often to get another.

 

[jsteiger]

Ok. All good on that end. Multimeter just crapped out on me so I’m often to get another.

You won't get accurate readings with both ends of a resistor soldered in circuit. Some will be right but some won't be. The best way is to verify with the color codes.

 

[TransientAggressionSound]

You won't get accurate readings with both ends of a resistor soldered in circuit. Some will be right but some won't be. The best way is to verify with the color codes.

Ok, I checked every single resistor against the color code and everything seems to be in place. I am slightly color blind so it’s possible I misread some. Is there anywhere else I should check?

 

[TransientAggressionSound]

You won't get accurate readings with both ends of a resistor soldered in circuit. Some will be right but some won't be. The best way is to verify with the color codes.

Some good news: Finished building an LC25 today and it turned out perfect. Sounds amazing. Still trying to track down where my volume boost problem with the lc40 is, is there anything other than some misplaced resistors that would cause the jump in volume?