Lead 12 effects loop?

[Rocktane]

Can the Lead 12 be fitted with an effects loop?

 

[ricksdisconnected]

.

 

[fitz288]

Um, why?
Even if possible, would the results justify the expense?

 

[Go Loud Early]

The mod would probably decrease the value of the amp.

 

[ricksdisconnected]

Um, why?
Even if possible, would the results justify the expense?

depends on the expense.

 

[ricksdisconnected]

The mod would probably decrease the value of the amp.

a amp that cheap i dont see how. a good working loop would only add value
i would think. if not value desirability at the very least. which in a lot of cases equals value.

 

[Matthews Guitars]

It's got a line out jack. Send that to your effects, send the output from your effects to any other amplifier.

 

[Deftone]

Yes. I modded mine to be a tube amp. Wish I had a loop installed as well.

 

[Rocktane]

Um, why?
Even if possible, would the results justify the expense?

Good question. What IS the expense? A couple of jacks? Complete Metro loop kit? I don't know what it would take. I agree that spending $100 on a $200 amp might not be a great idea.

As to why.... I like delay and reverb in the loop.

This would be living room amp and would not be run with any other amps.

 

[fitz288]

As to why.... I like delay and reverb in the loop.

I completely understand.
I use the loops for EQ & TBE on all my amps with loops.
When I posed the question of "results", I was wondering how much of a difference it would make on the little fella...
If I had a loop on my Lead15, I'd use it, but I'm not sure I'd go to the trouble of adding it.

 

[Rocktane]

I found this schematic on another forum. Obviously, I know nothing about this stuff but have modded pedals.

Could the send come off the Line Out Jack, and return go to C8 on the board?

 

[ricksdisconnected]

Yes. I modded mine to be a tube amp. Wish I had a loop installed as well.

explain with pics?

 

[Deftone]

explain with pics?

I asked an amp builder if he could build a small tube amp and stuff it into my Lead 12 head.

 

[ricksdisconnected]

oh so its just a head cab of a marshall then?
i was thinking somehow the guts were used to build
a tube amp.

 

[Deftone]

oh so its just a head cab of a marshall then?
i was thinking somehow the guts were used to build
a tube amp.

I think there are a few original parts left...Transformer? And of course the chassis. I still have the original parts in a box somewhere so it should be reversible.

I did this back in '09. Seemed like a good idea at the time, and I know a few people copied me. There were no low watt Marshall tube amps then. (That I knew of) IIRC architecture is basically a 5w Champ.

From the builder:

"After removing the transformer and PC board several possible configurations come to mind. Since the chassis is upside down you could possible turn it over and start building, just peel off the front panel overlay, drill new holes, and re-apply it right-side up. The problem with this is that it's unlikely that the overlay will come off it one piece.
Another idea would be to install a top plate, either removable or a hinged cover, and build the circuit on that. I elected to build the amp breadboard style with the works in a drawer. The tube sockets (for the 12AX7 and the 6BQ5) are mounted on the bottom of the steel chassis with the 6BQ5 a little lower to clear the top of the cabinet. A plate or a piece of extruded aluminum will be mounted over the top to complete the chassis.
The power transformer used here is an open frame type but the core size is about the same as the Champ or Princeton single 6V6 transformer. Mounting holes for the choke (on the chassis bottom) and the output transformer (on the chassis rear) have been drilled. The component board has been added and will follow the layout of the Blackface AA-764 Champ, just mirrored to match the reverse layout found here."

 

[tschrama]

I found this schematic on another forum. Obviously, I know nothing about this stuff but have modded pedals.

Could the send come off the Line Out Jack, and return go to C8 on the board?

View attachment 102180

I dont see a line ouput, except a DI output from the power amp. Dont use that.

But if you just take the signal from the wiper of the volume pot, and use that as FXsend, and use C8 as the FXreturn, it wil prolly work. Allbeit a bit low-fi and maybe with lowish output. But you wouldnt even need electronics, just two jacks.

For a better solution you need a buffer for the output and a recovery stage fir the return to bring to signal back up. This would involve two opamp or discrete gain stages.

A metro-type loop needs a high voltage supply which is not available in that amp…atleast not high enough I think.

 

[Rocktane]

I dont see a line ouput, except a DI output from the power amp. Dont use that.

But if you just take the signal from the wiper of the volume pot, and use that as FXsend, and use C8 as the FXreturn, it wil prolly work. Allbeit a bit low-fi and maybe with lowish output. But you wouldnt even need electronics, just two jacks.

For a better solution you need a buffer for the output and a recovery stage fir the return to bring to signal back up. This would involve two opamp of discrete gain stages.

A metro-type loop needs a high voltage supply which is not available in that amp…atleast not high enough I think.

Thank you, this helps a lot! I really appreciate it. This is pretty much what I was expecting to hear. Even wondered if putting a GE7 EQ in the loop would help as a buffer and raise the signal level. I should probably just look at other options for a living room amp that is somewhere between a desktop (THR-10) size, and a full-size combo.

 

[ricksdisconnected]

Thank you, this helps a lot! I really appreciate it. This is pretty much what I was expecting to hear. Even wondered if putting a GE7 EQ in the loop would help as a buffer and raise the signal level. I should probably just look at other options for a living room amp that is somewhere between a desktop (THR-10) size, and a full-size combo.

SPARK 40.

 

[matlevo12]

But if you just take the signal from the wiper of the volume pot, and use that as FXsend, and use C8 as the FXreturn, it wil prolly work. Allbeit a bit low-fi and maybe with lowish output. But you wouldnt even need electronics, just two jacks.

+1

 

[gorn]

Good question. What IS the expense? A couple of jacks? Complete Metro loop kit? I don't know what it would take. I agree that spending $100 on a $200 amp might not be a great idea.

As to why.... I like delay and reverb in the loop.

This would be living room amp and would not be run with any other amps.

if you can show me a $200 Lead 12 head these days, I'd be impressed