Amps

[GRIMESPACE]

Originally Posted by Edge11

I recorded some clips this weekend. I did scoop mod with neck pick up on clean. It's my first time playing around with recording, does any one have any recording tips?

Mac or PC? Garage Band works good for me, and I've heard good things about Reaper for the PC. What interface do you have?

[Edge11]

Originally Posted by GRIMESPACE

Mac or PC? Garage Band works good for me, and I've heard good things about Reaper for the PC. What interface do you have?

Pc using reaper. sm57 to lexicon omega.

[Edge11]

Just posted up the "predator mod". it's the natural evolution of the "sucker punch mod" Makes the whole amp more aggressive. Tighter bass and more aggressive gain on both channels.

[GRIMESPACE]

Originally Posted by Edge11

Just posted up the "predator mod". it's the natural evolution of the "sucker punch mod" Makes the whole amp more aggressive. Tighter bass and more aggressive gain on both channels.

Very cool - definitely gonna check it out. So at this point, have you decided which you like better between the 20 & 50?

Did you have any luck with recording? I just downloaded Reaper to give it a try. I'm using an M-Audio Fast Track Pro with Garage Band and it was pretty straightforward to get going - only problem for me is my SM57 that I've had in a box for the last 10+ years isn't working. Gonna have to get that fixed. I wish I could be more help with that.

Keep up the great work!

[Edge11]

Haven't had the time to record. I've been pulling 12 hour shifts at school.

[GRIMESPACE]

Holy shit!!!

Just put the depth control together

Kick ASS!!!!!!!!!!!!



Massive body to the sound - all I've heard is that it affects the low end - I had the thing dialed up to 5 on the master, and it hits it all the way!!!!!

Did I say holy shit yet?

[Edge11]

Originally Posted by GRIMESPACE

Holy shit!!!

Just put the depth control together

Kick ASS!!!!!!!!!!!!



Massive body to the sound - all I've heard is that it affects the low end - I had the thing dialed up to 5 on the master, and it hits it all the way!!!!!

Did I say holy shit yet?

Good, good.
Now do some more mods

[GRIMESPACE]

Originally Posted by Edge11

Good, good.
Now do some more mods

Actually had a bunch lined up today, but more questions came about...

I've researched what I could about discharging the caps, and built a resistor drain (470 ohm resistor soldered & shrink-wrapped in the middle of a jumper wire). I probed around pin 1 & 6 of V1 (it appears that both of these are plates), and realized that I hadn't seen anything about whether or not the tubes should be left in during this step - I had taken them out so they would be safe while I was taking the chassis out of the headshell & flipping it over. After watching the video again and looking over the schematic, I'm thinking they do need to be in, but I have not way of verifying that what I'm doing is right. What's the correct procedure - tubes in or out? Is there some way I can probe voltage to make sure I've got it drained? It looks like R1 & R2 are connected to the bigger filter caps - can I check there?

Also, you said something about taking the board out to do your desoldering / soldering. After removing the nuts from the pots and pulling about 12 screws holding the board down, I've concluded that it also means pulling all the jacks off the back panel and possibly desoldering wires off the small transformer (or is it a choke?). How did you go about pulling the board out without major surgery?

Thanks

[clay189]

This is probably already in this tread and but I am wanting just straight forward instructions for a beginner wanting to add the depth mod to my JCA50h. I am new to this and am ready to begin modding my amp. this is the best thread ever.

[GRIMESPACE]

Originally Posted by clay189

This is probably already in this tread and but I am wanting just straight forward instructions for a beginner wanting to add the depth mod to my JCA50h. I am new to this and am ready to begin modding my amp. this is the best thread ever.

Edge11 may beat me to this, but I'll try to put something up this week if he doesn't. Actually, he's covered it pretty extensively in the JCA 20H thread, but the NFB resistor is labeled differently.

Here's the basics along with some tips. It's only 2 components and some wire - a 1 meg audio taper pot and a .0047uf 400v orange drop cap. Hardest part was drilling the front panel (I wanted mine right next to the Presence knob, like the 100HDM) without dropping metal shavings into the chassis or running right through the filter caps, which are only about 5/8" from exactly where I placed the pot . I clamped a scrap piece of 5/8 wood on the inside where I was drilling so that my drill wouldn't punch through wildly, and was really careful about shavings. The pot basically gets inserted between the NFB (negative feedback) resistor and the 4 ohm output at the back panel. There's a red wire going to the pcb (pad label: FB) that I desoldered from the output jack and ran to the front panel where the new pot was being installed. A new wire was put in from the output jack to the other lug on the pot, and voila - done.

Well worth the effort, in my opinion. As I said, I'll try to put something better together soon.

[Edge11]

Originally Posted by GRIMESPACE

Actually had a bunch lined up today, but more questions came about...

I've researched what I could about discharging the caps, and built a resistor drain (470 ohm resistor soldered & shrink-wrapped in the middle of a jumper wire). I probed around pin 1 & 6 of V1 (it appears that both of these are plates), and realized that I hadn't seen anything about whether or not the tubes should be left in during this step - I had taken them out so they would be safe while I was taking the chassis out of the headshell & flipping it over. After watching the video again and looking over the schematic, I'm thinking they do need to be in, but I have not way of verifying that what I'm doing is right. What's the correct procedure - tubes in or out? Is there some way I can probe voltage to make sure I've got it drained? It looks like R1 & R2 are connected to the bigger filter caps - can I check there?

Also, you said something about taking the board out to do your desoldering / soldering. After removing the nuts from the pots and pulling about 12 screws holding the board down, I've concluded that it also means pulling all the jacks off the back panel and possibly desoldering wires off the small transformer (or is it a choke?). How did you go about pulling the board out without major surgery?

Thanks

I didn't desolder any transformer wires. the rest of that stuff i did do though.

[clay189]

Thanks I would greatly appreciate this. I have built a guitar from scratch and figured if it sounded like shit no biggie it was from scratch (turned out good though) but I have never bought something then tore in to it so I am just a little nervous. Thanks

[Edge11]

No worries we're going to pop your modding cherry. The depth mod is mega easy to do.

if you need more than that let me know.
I'll draw something specific to the 50h tomorrow or a bit later today.

[clay189]

Man i really want thank you guys, be looking forward to the drawing for the 50.

[Edge11]

Well it's up not really that different from the picture posted above

[clay189]

EDGEand GRIM I am getting ready to start mods next week got all the parts ordered. haveing shoulder surgery on wedsday so I will have lots of time on my hands. one ? before i do these mods what is the best way to drain the filter caps on the jca50h.

[Edge11]

Originally Posted by clay189

EDGEand GRIM I am getting ready to start mods next week got all the parts ordered. haveing shoulder surgery on wedsday so I will have lots of time on my hands. one ? before i do these mods what is the best way to drain the filter caps on the jca50h.

You can leave it unplugged for a day or so. Just to be safe you want to short the plate pin of v1 to ground.
http://www.youtube.com/watch?v=Rg3-dZC5Fww
This explains it alright.
Good luck with your surgery.

[clay189]

Thanks, I know you and the other guys probably get tired of these rookie questions but I do appreciate the help. it

Originally Posted by Edge11

You can leave it unplugged for a day or so. Just to be safe you want to short the plate pin of v1 to ground.
http://www.youtube.com/watch?v=Rg3-dZC5Fww
This explains it alright.
Good luck with your surgery.

[Edge11]

Originally Posted by clay189

Thanks, I know you and the other guys probably get tired of these rookie questions but I do appreciate the help. it

Nah no worries dude.

[GRIMESPACE]

I've been trying to track down info on a boost mod that uses a second master volume pot in parallel with the primary one. Any thoughts on this, and making it footswitchable?