I just installed a board in a newer RI w/ FX loop

Post by **VelvetGeorge** » Wed Apr 13, 2005 6:44 pm

It seems Marshall has made some changes on the newer RI's. Two of the board mounting bolts are moved. There are 56K resistors on the voltage doubler caps. A heater voltage balance pot has been added. The presence cap is on the board. And a few other things.

The FX loop requires a 10 watt 47k, which was mounted on the board. I had to find a way to install that. The loop does integrate just fine with the PTP board.

The V2 tube socket is wired opposite of the old amps. I've seen this on RI's for a while now, but thought it is worth mentioning.

Just thought I'd post on these things. Hopefully someone installing a board in a newer RI will be able to use the info.

George

cfljames · Post by **cfljames** » Wed Apr 13, 2005 11:03 pm

George,boy I am glad I had you do this project instead of me if this is my amp!If you really need to shitcan the loop I don't need it! It just so happened that this was the head I ended up with instead of a slp without the loop

JAMIE.

Flames1950 · Post by **Flames1950** » Wed Apr 13, 2005 11:46 pm

There are 56K resistors on the voltage doubler caps.

By that I assume you mean all four cans in that grouping have them, like Jason's (jjjafar) JCM800 reissue did?

Dax · Post by **Dax** » Thu Apr 14, 2005 12:01 am

Pics!!!

Post by **VelvetGeorge** » Thu Apr 14, 2005 12:55 am

I also had to change the bias resistor. There must be a higher raw supply.

The FX loop works just fine. And the amp sounds great. I think you'll be pleased. I went with a 100pf bright cap. That seemed to make the entire sweep of the volume control usable.

I found a great tone with the volume on 6-7. Lots of sustain and not over the top. Perfect for those Allman Bros tones you're after. And many others, too.

George

cfljames · Post by **cfljames** » Thu Apr 14, 2005 8:27 am

Thank you George for all of your great work and suggestions,plus putting up with all my new and sometimes dumb questions.How do those N.O.S. mullard preamp tubes I needed a second mortgage for sound?I look forward to getting it back,I just did over both of my 58RI'S w/rs kit's,one I used with the treble tamer kit that comes w/300 tone pot's instead of the 500's and wagners fillmore pickups,the other I used 500's and wagners darkburst pickup's because they are a much fatter pickup versus the hotter and brighter fillmores.I wanted to get some variations between both guitars and the both sound great through the DIAZ CD100, but I can't wait to here it through the marshall you did George thanks again,Jamie.

Eoin · Post by **Eoin** » Wed Apr 20, 2005 7:25 pm

Where is the effects loop in the RI?

Flames1950 · Post by **Flames1950** » Wed Apr 20, 2005 10:30 pm

Eoin wrote:Where is the effects loop in the RI?

Earlier RI's don't have one. It started showing up around 2000 or a little later. It's on a separate PC card if you've got it.

Flames1950 · Post by **Flames1950** » Thu Apr 21, 2005 7:47 pm

So George, did you get any pics of the chassis with the FX card to flash us?

Eoin · Post by **Eoin** » Thu Apr 21, 2005 10:04 pm

Actually just curious where it appears in the circuit.

Guest · Post by **Guest** » Thu Apr 21, 2005 11:05 pm

Pics!!

Flames1950 · Post by **Flames1950** » Thu Apr 21, 2005 11:52 pm

Eoin wrote:Actually just curious where it appears in the circuit.

It's between the tone stack and the phase inverter, the wire returning from the treble control to the .022uF coupling cap.

Dax · Post by **Dax** » Fri Apr 22, 2005 2:25 am

Yeah, i would love to see pics of this Jewel!!!

cfljames, Help!!!

Dax-The-Ax · Post by **Dax-The-Ax** » Fri Apr 22, 2005 2:35 am

By the way, has anyone tried this FX loop in a Lead or Superlead? It looks really simple, doesn't look like there is much to affect the tone, maybe i'm wrong. I'm Tempted to put this in my 1987. I guess i could wire it up first and try it without cuttting holes to see if i like it.

Dax

Billy Batz · Post by **Billy Batz** » Fri Apr 22, 2005 7:57 am

Dax-The-Ax wrote:By the way, has anyone tried this FX loop in a Lead or Superlead? It looks really simple, doesn't look like there is much to affect the tone,
Dax

Except the pedals in the loop and therin is the problem. Still it absolutely doesnt hurt to have a passive loop. You can always use an outboard buffer. And you have access to the Marshall 100W poweramp section.