Depth Mod?

liam5150 · Post by **liam5150** » Sat Oct 19, 2013 1:55 pm

I am adding a depth control to my 2204 build and i have seen it wired in two ways.

1) Wire from NFB resistor to wiper (middle lug) of pot, 4 ohm tap connected to the outside lug. With 0.0047uf cap across two lugs

2) Wire from NFB resistor to outside lug of pot, 4 ohm tap connected to wiper (middle lug). With 0.0047uf cap across two lugs.

Which is correct?

Also neither of the two layout show the empty lug being ground on the back of the pot, is this not required?

Thanks

liam5150 · Post by **liam5150** » Sun Oct 20, 2013 4:38 pm

Figured it out!

GuitarBilly · Post by **GuitarBilly** » Mon Oct 21, 2013 11:56 am

what is the correct option?

liam5150 · Post by **liam5150** » Mon Oct 21, 2013 4:11 pm

The correct way to wire it is:

Duesentrieb · Post by **Duesentrieb** » Tue Oct 22, 2013 9:30 am

add a 100nF after the NFB-R to avoid DC on the pot (scratching noise).

liam5150 · Post by **liam5150** » Tue Oct 22, 2013 2:15 pm

Duesentrieb wrote:add a 100nF after the NFB-R to avoid DC on the pot (scratching noise).

Ah! Cool thanks Olaf.

Will that be the same for the presence too? I the same noise with that too, kinda scaping/wooshing noise.

Duesentrieb · Post by **Duesentrieb** » Wed Oct 23, 2013 1:49 am

If thats the old circuitry with a 5k pot, I'd change that to "modern" with a 25k pot (or even better: a rev log 10k pot) and follow the wiring of the actual 2203/2204 wiring, Liam.

liam5150 · Post by **liam5150** » Wed Oct 23, 2013 2:01 pm

Duesentrieb wrote:If thats the old circuitry with a 5k pot, I'd change that to "modern" with a 25k pot (or even better: a rev log 10k pot) and follow the wiring of the actual 2203/2204 wiring, Liam.

I already use a 25K linear pot for the presence. I'm pretty sure i have wired it al per 2203/4 spec.

How would a reverse log 10K pot be more benaficial?

Duesentrieb · Post by **Duesentrieb** » Wed Oct 23, 2013 2:06 pm

And you still have DC on the pot?

A 10k rev log gives you a better control than lin pots, which are just active between 75% and 100%.

liam5150 · Post by **liam5150** » Wed Oct 23, 2013 3:16 pm

Duesentrieb wrote:And you still have DC on the pot?

A 10k rev log gives you a better control than lin pots, which are just active between 75% and 100%.

There is noise when turning the pot, sounds kinda like the doors on Star Trek (thats the best way i could thing of to describe it :lol:

)

I have it wired like this:

But with a 25K linear pot.

Thanks Olaf

Duesentrieb · Post by **Duesentrieb** » Thu Oct 24, 2013 6:06 am

Please follow the wiring of the Ceriatone amp then, you're missing the 4k7 to ground (if I understand correctly)

http://ceriatone.com/images/layoutPic/m ... iatone.jpg

liam5150 · Post by **liam5150** » Thu Oct 24, 2013 8:12 am

Oh yeah! Sorry I forgot to add that. I noticed the mistake on the metro layout when checking the marshall schematic.

I already have the 4K7 to ground also.

Duesentrieb · Post by **Duesentrieb** » Thu Oct 24, 2013 9:21 am

Well, then just add a 100nF cap between the NFB-R and your depth pot then.

liam5150 · Post by **liam5150** » Thu Oct 24, 2013 3:20 pm

Duesentrieb wrote:Well, then just add a 100nF cap between the NFB-R and your depth pot then.

Alright, i'll give it a go. thanks Olaf!

Telephant · Post by **Telephant** » Thu Oct 24, 2013 3:32 pm

I got no idea what you guys are talking about but it seems pretty awesome.

liam5150 · Post by **liam5150** » Thu Oct 24, 2013 3:41 pm

Telephant wrote:I got no idea what you guys are talking about but it seems pretty awesome.

It is pretty awesome!

Modded Marshall goodness!

Adding resonance/depth control to bring in the lows.

The later post Olaf was helping with a way of blocking noise when the pot is turned.

Duesentrieb · Post by **Duesentrieb** » Fri Oct 25, 2013 2:16 am

Telephant wrote:I got no idea what you guys are talking about but it seems pretty awesome.

Hi Shea,

how are you?

Olaf

100 watt · Post by **100 watt** » Tue Nov 19, 2013 11:25 am

Mine's just a cap hardwired between the NFB wire & the ohm selector switch.

liam5150 · Post by **liam5150** » Wed Nov 20, 2013 2:23 pm

100 watt wrote:Mine's just a cap hardwired between the NFB wire & the ohm selector switch.

No resistor?

Usually a a fixed depth mod would be a cap+resistor in parallel, in series with the NFB

Ostinato Rubato · Post by **Ostinato Rubato** » Wed Nov 20, 2013 3:26 pm

Telephant wrote:I got no idea what you guys are talking about but it seems pretty awesome.

yeah, same here.

100 watt · Post by **100 watt** » Tue Nov 26, 2013 3:50 pm

liam5150 wrote:
100 watt wrote:Mine's just a cap hardwired between the NFB wire & the ohm selector switch.

No resistor?

Usually a a fixed depth mod would be a cap+resistor in parallel, in series with the NFB

Nope. Just a cap

Guitar Gear Forum

Depth Mod?

Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?

Re: Depth Mod?