Solo boost for RK.... Volume Increase in CH. 3, 4....

[RoadKinger483]

Well i've decided that I really prefer the tone of my amp with the effects loop disengaged. I HATE that when you engage the effects loop the low frequencies and punch disappear. I remember somebady here telling me that it was just a simple capacitor change to bring up the bass but I can't seem to find the post. The only problem is that I really like the SOLO function it has. I'm thinking about buying a Xotic RC Booster but, will this give me just a volume increase in CH. 3, 4? That's basically all I want and maybe a tad bit more gain to make the notes sustain better. Thanks

 

[Boogiebabies]

Change the cathode cap on V4B from 2.2uf to a 10uf tantalum.

 

[psycle_1]

I did the mod Boogiebabies has listed. Trust me, it works!

 

[Boogiebabies]

Thanks for the feedback.

 

[RoadKinger483]

My apologies boogiebabies but, I don't know what you mean by V4B. Could you explain a little more in detail where I can locate this (maybe the actual cap if you could) on the amp? I would GREATLY APPRECIATE IT!!! Thanks.

 

[RoadKinger483]

OK, I found out that V4B means that its the B-Side of the V4 position 12AX7 which would control the effects loop return. Is the 2.2uf cap the only cap in the amp or in that signal path? Thanks

 

[NoGlassNoClass]

Sorry for the hijack, but since we have Boogiebabies attention here, does this mod also apply to the 3-ch Recto's as well? (Specifically an '02 triple)

 

[RoadKinger483]

I would think it's the same but, I can't say for sure. Hopefully boogiebabie can get back to us.

 

[Guitarzan]

You might want to go get his attention in the Vintage room...

 

[Boogiebabies]

The DR 3 Channel already uses a 15uf tantalum cap on the return of the loop.

Here's a specific schematic of the RK Loop Mod I made. It is specified to be Tantalum.

 

[Boogiebabies]

You might want to go get his attention in the Vintage room...

Please, I'm only 35.

Now it sounds like a place to sit by the fire, smoke cigars and sip Cognac...

Wait, that's what I was doing.... 8)

 

[NoGlassNoClass]

The DR 3 Channel already uses a 15uf tantalum cap on the return of the loop.

So by what you're saying, I assume the 5uf difference is not significant enough to be worth changing? Thanks a million for the info, my brother.

Guess I'll go sit by the BBQ, chug beer, and smoke some.......

41 here..."vintage" is not nearly as painful as you might imagine 8)

 

[Boogiebabies]

The DR 3 Channel already uses a 15uf tantalum cap on the return of the loop.

So by what you're saying, I assume the 5uf difference is not significant enough to be worth changing? Thanks a million for the info, my brother.

Guess I'll go sit by the BBQ, chug beer, and smoke some.......

41 here..."vintage" is not nearly as painful as you might imagine 8)

Lowing the cap to 10uf would decrease the gain stages bass response in your case. You can however add a 5uf or 10uf in paralell to increase the capacitace to 20-25uf which would give your amp a boost in the bottom end of the effects return. This is easy because you can clip the caps to the one on the board and test to see what value offers you the tone your looking for. 20-25uf should be a pretty beefy cathode circuit. If you find a value you like, just solder it on top of the 15uf and your set. Just watch the high voltage sections. The cathodes only put out about 1-2 volts.

 

[MesaDCLP]

… it sounds like a place to sit by the fire, smoke cigars and sip Cognac ...

Three shots of tequila here, but sippin’ on dark rum and ice yonder way...

 

[RoadKinger483]

Thanks a lot boogiebabies!! I'm gonna open up the amp tomorrow if I can and try to spot the cap. Where could I get a 10uf tantalum cap? Other than Mouser or Digi Key or something like that? Also, what voltage should the cap be? Thanks

 

[Boogiebabies]

You would have get a 10uf from Mouser ,DigiKey or E-Bay. It only has to be 10V.

 

[disassembled]

You can also go through hoffman amps or other amp part suppliers. I modded my valve JR head to reduce the bass going from a 22uf to a 2.2uf and the results are pretty dramatic. You might want to try different values to fine tune the bass.


Greg

 

[RoadKinger483]

Well, I couldn't find the 2.2uf cap. Does anybody know what it looks like? I looked off of pin 8 in the V4 position but, I just couldn't spot it.

 

[Boogiebabies]

Follow the trace off pin 8. It's a tiny yellow bullet shaped cap thats almost hidden under an orange drop between V4 and V5. There should be a 2.2K resistor very close. You may have to take a bit of a side angle to see it.

 

[RoadKinger483]

I found it!!! I actuallt thought that it might be that one the first time I opened the amp. I'll be ordering the 10uf tantalum soon. I know you have to orient them a certain way for them to work. Would it be the longer lead or the shorter lead on the capacitor? Also, are there any good brands or manufacturer's you recommend? Thanks