L-10-K output

Rich Young · Post by **Rich Young** » 6 Apr 2004 9:23 am

I have the low goodrich pedel with the opamp in it. It boosts the signal, but I think it is a little too much, it seems to drive the amp input a little too much.
I like the sound of it but would like a little less boost. I opened it and could not see any way to adjust it.
Anyone know?
Thanks.

Bill Terry · Post by **Bill Terry** » 6 Apr 2004 9:59 am

Rich, I have two of those L10Ks and mine don't seem to boost at all. I was under the impression that they were unity gain?

Assuming it's a typical opamp circuit, you could reverse engineer the design and calculate the circuit gain based on the R values around the opamp. Then you could change R values to reduce gain.[This message was edited by Bill Terry on 06 April 2004 at 11:00 AM.]

Rich Young · Post by **Rich Young** » 6 Apr 2004 10:42 am

It seems hotter output than my regular pot goodrich. I guess I should sit down with it and see what the output is, maybe the problem lies elsewhere.

Jon Light · Post by **Jon Light** » 6 Apr 2004 12:31 pm

Hey guys, as long as you're talking about the L-10-K, if you happen to be inside one could you help me out?-----I picked up the guts of one of these with the intention of sticking them in my backup 120 but a wire has come loose and I can't figure out where it belongs and I'm getting nothing but hum. It is a purple wire that runs from the two output jack lugs (the tip lug of TRS) and then-----to where? If it goes to the circuit board it may be difficult to describe the connection point but if there's a way to give me a clue.......
....sorry for the hijack.

Bob Lawrence · Post by **Bob Lawrence** » 6 Apr 2004 1:36 pm

John:

"It is a purple wire that runs from the two output jack lugs (the tip lug of TRS) and then"

On mine it goes to the middle connector of the pot.

Ricky Davis · Post by **Ricky Davis** » 6 Apr 2004 2:04 pm

Rich I would venture to say that your other pot pedal is not opening up all the way when down.
I like the Pot to be all the way open when the pedal is to the floor; for the best use of the pot....>even if the volume does not go all the way off when closing.
Ricky

Jon Light · Post by **Jon Light** » 6 Apr 2004 2:22 pm

I agree with that preference, Ricky--I'll forgo a little silence at the up end of things to get full pickup voice at the down end.

Bob--thanks. That looks right, based on solder evidence. Unfortunately it still won't work and the problem is clearly elsewhere (and unsolvable by my minor skills) so I'll one of these days call Goodrich and see if they'd be willing to try to fix it (and how much $$ they'd estimate it'll run me).

Gracias.

Rich Young · Post by **Rich Young** » 6 Apr 2004 3:16 pm

Thanks, Ricky, I'll try that.
I need to sit down an check them both out with a sound sorce and a VU meter.
The regular Goodrich I've been using on my Stingmaster and I haven't noticed any obviously lower volume.
I'll test both of them tonight.

Rich Young · Post by **Rich Young** » 7 Apr 2004 12:13 pm

Ok, I tested last night -

Used a Peterson tuner as a sound source, constant sine wave type of sound.
I plugged into an old porta studio to use its VU meters, and into the computer with Wavelab for the digital meter.

Through the l-10-k -
With the swithch in the back position - with the electronics out, it measured the same - unity, with the switch on - forward position -

on anolog VU meter was + 2 Db
on digital VU was + 1.6 Db

The 120 Goodrich was pretty close to unity when fully open - down about .05 Db on the digital meter.

So, other than playing with the string, and getting it to a point where it does not fully open the pot (which would be a problem if I don't use the electronics), is there any way to adjust this thing?
Or is it acting wacky?

Thanks.

Bill Terry · Post by **Bill Terry** » 7 Apr 2004 6:38 pm

With the swithch in the back position - with the electronics out, it measured the same - unity, with the switch on - forward position - ...

Hmmm.. neither of mine have switches at all, must be more than one version of the L10K.

Rich Young · Post by **Rich Young** » 8 Apr 2004 10:42 am

This is the one I got and I did get it from Carter - http://www.steelguitar.com/accessor/accedesc.htm#VolPed
The switch is on the right side in front of the input jack. It apparently just turns off the circuitry. When it is in the back position, the output is lower and the tone seems more like a straight pot pedal.

I found this www - http://www.musiccityinstruments.net/inventory.htm
Under "electronics", it has it listed and it says, "3.5 dB more gain than a comparable 500K pedal".
It definetly does boast it. I got my pedal just about a year ago, is yours older?

Bill Terry · Post by **Bill Terry** » 8 Apr 2004 1:11 pm

Yeah, both of mine were bought used, no telling how old they are. In fact, they don't look exactly the same, with different trim. I've had them apart and the circuits don't match exactly either. One has a few more passive components than the other. One of these days I'm going to capture the schematics on both just out of curiosity.

I guess Mr. Goodrich is on a course of 'continuous' improvement.. you can't stand still in this biz...

Bob Lawrence · Post by **Bob Lawrence** » 9 Apr 2004 6:39 am

Jon,

I sent you a few pictures of the internals of the H10K so that you can check the wiring. Hopefully I've reduced the size enough to enable you to receive it via e-mail. If not let me know and I will try plan B or C. There should be about 6 pictures. The first 1 or 2 you can ignore.

------------------

Jon Light · Post by **Jon Light** » 9 Apr 2004 7:07 am

Received loud and clear. Fantastic! Excellent photos, super micro detail, everything I will need to make this thing right. You're a dude, Bob. Thank you so much! I'd send you a pic of a can of Bud but I haven't figured out how the pull tab works yet.