New, proud RM22HB owner here. Looking for mod ideas

[pettymusic]

Hello,

New DIYer here. Interested to know if someone has some mod ideas for a SUVA and XTC? I have changed the C3 on the XTC to a .0022 Orange Drop. Have not done anything to the SuVa.

Thanks,

 

[disk11]

There's some general stuff in here: http://mtsforum.grailtone.com/viewtopic.php?t=15062

 

[pettymusic]

There's some general stuff in here: http://mtsforum.grailtone.com/viewtopic.php?t=15062

Thanks, disk11. I think I will give the 3 way toggle switch mod a go.

 

[matam]

Thake a look at this schematics, it shows the preamp section of the ecstasy.
The second "ROW" in the schematics is the overdrive channel.
If you compare it to yours, i suppose stock, XTC module you'll notice how much is it close to the original red channel with structure switch on.

If you aren't able to read the schematics above and compare it to yours module then i suggest you to not mess with it and ask instead one of the pro-modder here on the board.

You could follow that schematics and do a 3 channel XTC (plexi mode, red/blue channel) clone with structure switches (SW11 on schematics) without cutting traces on the module, thus retaining the possibility to revert it back to stock. (minus the holes you drill on the faceplate, but i don't think you'd want to do it since the modded one has a lot more versatility and tonal option than the stock one)

Now some little explanation of the above schematics:
-SW10 seems to me to be a gain booster.
-SW5/6/7 could be a bright switch.
-SW11 is Structure switch.
-SW8/9/13/14 switch between plexi (2 gain stages) mode and red/blue mode.
-SW12 is the switch between blue (3 gain stages) and red (4 gain stages) mode.

All the control on the module are there, you miss separated gain and level control for plexi and red/blue channel, the rest of the component are almost all in your module.

I've modified mine so it has a 3way cap switch, the plexi switch, the red/blue channel switch and the Structure switch.



Sorry, i forgot to post the schematics for the stock module.
Here you can download a pdf file containing the schematic i traced down (only the "real" preamp part) for the XTC module.

p.s. i plan to share the schematics and layout drawings of the change i've done to the XTC.

 

[pettymusic]

Thake a look at this schematics, it shows the preamp section of the ecstasy.
The second "ROW" in the schematics is the overdrive channel.
If you compare it to yours, i suppose stock, XTC module you'll notice how much is it close to the original red channel with structure switch on.

If you aren't able to read the schematics above and compare it to yours module then i suggest you to not mess with it and ask instead one of the pro-modder here on the board.

You could follow that schematics and do a 3 channel XTC (plexi mode, red/blue channel) clone with structure switches (SW11 on schematics) without cutting traces on the module, thus retaining the possibility to revert it back to stock. (minus the holes you drill on the faceplate, but i don't think you'd want to do it since the modded one has a lot more versatility and tonal option than the stock one)

Now some little explanation of the above schematics:
-SW10 seems to me to be a gain booster.
-SW5/6/7 could be a bright switch.
-SW11 is Structure switch.
-SW8/9/13/14 switch between plexi (2 gain stages) mode and red/blue mode.
-SW12 is the switch between blue (3 gain stages) and red (4 gain stages) mode.

All the control on the module are there, you miss separated gain and level control for plexi and red/blue channel, the rest of the component are almost all in your module.

I've modified mine so it has a 3way cap switch, the plexi switch, the red/blue channel switch and the Structure switch.



Sorry, i forgot to post the schematics for the stock module.
Here you can download a pdf file containing the schematic i traced down (only the "real" preamp part) for the XTC module.

p.s. i plan to share the schematics and layout drawings of the change i've done to the XTC.

Thanks, Matam! Can't wait to dig into this. Hopefully, I will have some
time to trace my Module this weekend.

It is silver with a black strip faceplate.

...and thanks for posting the module schematics. This will help a great deal in understanding the modules.

 

[matam]

I made a mistake in the schematics, C20 should be C18.
Here's the corrected schematics.

Regarding the mod (structure, plexi, red/blue switches) i've drawn the schematics of it but since i lended my xtc to a friend of mine to try it out during the holidays i couldn't check if they're right.

Plexi and red/blue switches control the number of gain stages while the structure switch is a kind of gain booster.

When i'll get the module back i'll check if everything is fine and i'll post the layout drawing for the wiring of the mod if you can't figure it out form the schematics itself.

Going by memory for the "big cap" i've used a mix of 600V Orange Drop (715 series) and 650V Wima (MKP10) in the module, both of them are huge!
I've used the Orange Drop in C1 position and on the relative cap switch (not shown in the schematics) the Wima for everything else.
Then i used 1kV murata for the cermaic cap and a couple of 1/2 Watt carbon composition resistor in slected places (R14 the slope resistor is the first spot that comes to mind).
For the electrolitics cap i left the stock 50V 2.2uF one.
I didn't change the valve as the module sounded already good to me, if i remember correctly they're both Sovtek 12AX7A.

 

[pettymusic]

I made a mistake in the schematics, C20 should be C18.
Here's the corrected schematics.

Regarding the mod (structure, plexi, red/blue switches) i've drawn the schematics of it but since i lended my xtc to a friend of mine to try it out during the holidays i couldn't check if they're right.

Plexi and red/blue switches control the number of gain stages while the structure switch is a kind of gain booster.

When i'll get the module back i'll check if everything is fine and i'll post the layout drawing for the wiring of the mod if you can't figure it out form the schematics itself.




Going by memory for the "big cap" i've used a mix of 600V Orange Drop (715 series) and 650V Wima (MKP10) in the module, both of them are huge!
I've used the Orange Drop in C1 position and on the relative cap switch (not shown in the schematics) the Wima for everything else.
Then i used 1kV murata for the cermaic cap and a couple of 1/2 Watt carbon composition resistor in slected places (R14 the slope resistor is the first spot that comes to mind).
For the electrolitics cap i left the stock 50V 2.2uF one.
I didn't change the valve as the module sounded already good to me, if i remember correctly they're both Sovtek 12AX7A.

Dumb question maybe but:
At position radd2, am I soldering the resistor leads to the existing C10 joints?

 

[matam]

Dumb question maybe but:
At position radd2, am I soldering the resistor leads to the existing C10 joints?

To add the structure switch desolder C10 from the board, then make sure you remove any lead residue.
Now put one lead of the radd2 together with the + lead of C10 and solder them back in the + joint of C10 on the board.
Solder together the - lead from C10 and the other lead of radd2 and wire it to the center lug of the SPDT ON/ON Switch.
Now wire one of the external lug of the SPDT switch to ground (any ground point would be good, you could solder them back in the C10 - joint).

 

[matam]

I've made a revision regarding both plexi and red/blue switches.
Here you can view and download the new schematics

 

[matam]

I've (crappy ) drawn the layout of the revisited schematics above with all the wiring.
You can download it here , if you have any question about it feel free to ask.

Some more info:

You have to lift 1 joint from the pcb (as shown on the picture) on the following parts:
R3 - R18 - C2 - C10 -C12 -C17

You must add 3 resistor and 1 ceramic cap to the module;
RADD1 and CADD1 can be soldered directly on the Plexi switch.

 

[pettymusic]

I've (crappy ) drawn the layout of the revisited schematics above with all the wiring.
You can download it here , if you have any question about it feel free to ask.

Some more info:

You have to lift 1 joint from the pcb (as shown on the picture) on the following parts:
R3 - R18 - C2 - C10 -C12 -C17

You must add 3 resistor and 1 ceramic cap to the module;
RADD1 and CADD1 can be soldered directly on the Plexi switch.

Well, I pulled off the plexi and blue/ red channels but, I.didn't really like having all the. extra switches after a while. So, I think I will go back to the 3way cap switch for sure and try the gain structure switch. I am also wanting to try the Illinois caps.

Newb questions:
Also, the 2.2uf electrolytic cap at C10. It does not look like it affects the tone to me. Is there a certain brand I should get? Does it have to be radial? I also noticed there are non-polarized bypolar options when purchasing. What does that mean?