POD MULE

[RWood]

A friend of mine has asked me to build a 50w power amp to run his Line6 pod into. I was thinking of 1987 type power amp without preamp or tone stack coloring his pod tone(just presence control maybe). I am unsure on input to PI design and any help would be appreciated.

.

[SilverFox]

If you find a schematic with a Line In/Out that's pretty much all your looking for. You will also want to know what level the POD is outputting, 2V ?, so you don't overload the input. A MV is another good thing to have. Have him take it to a store and plug the POD into the line in on some tube amps like the Peavey Vintage 30. That would provide you with a base line schematic.

I recently built a JTM-45 and changed the preamp tubes. This has worked very well as it gives me a means of adding some grit to the input signal and fine tuning the tone. I do have to adjust the power supply and some other things but basically it has worked out well.

silverfox.

[strelok]

I can't imagine you would need more than a single gain stage before the phase inverter to drive the output to full power. Especially since the pod probably has a pretty decent output level. You could always stick a voltmeter and a signal generator on it if you want to be precise. A MV is a good idea as said before. PPIMV is probably unnecessary since overdriving the amp is probably not what you're looking for in this application.

I would put a 1meg pot at the input as a bit of added versatility and then another after the first gain stage so it would look like:

Input>Input trim>Gain stage>volume>PI>Output

This will allow the amp to handle a wide variety of signal levels in case he wants to use it with other pedals or effects units.

[Reeltarded]

No need for another stage. Pods have way more output than any previous tube stages. Simply build everything from the PI input to the output jack.

[SilverFox]

I'm not suggesting the POD won't drive a power amp. What I'm talking about, from my experience is: Often times these emulators sound 'Sterile' laboratory tones. I've found that a gain stage that can be overdrive a little is a real benefit in adding some real tube grit to the tone.

What I found though with a JTM design is, the 12AX7's had too much gain so I substituted them with lower gain tubes and now I can get some nice Over Drive by simply turning the dial. With the POD that may not be required since I know there were a gagillion stomp boxes in mine- Before I sent it back to the President of the company. But that's another story and not everyone has had my experience with a Line6 Box.

Silverfox.

[RWood]

No need for another stage. Pods have way more output than any previous tube stages. Simply build everything from the PI input to the output jack.

In 1987 plexi, is the PI grid referencing ground through LTP/Presence pot or do I need to add a 1m and grid stopper also before it?
Maybe I might need a low gain stage (12ay7) anyway for pedals.

[M Fowler]

AX84 50w power amp for comparison.

[Reeltarded]

^^ Just build it like a Marshall 4 holer with the signal cut after the treble control, just like adding a simple loop.. just no front end to send. Return jack to the speaker outs. Works great.

You can SO push the power section.. you can melt the power section with the POD dimed.. No, I mean you really can melt the power section with a POD.. lol really. It's wicked.

[RWood]

Great Idea.
Thanks Miles.

[drew]

Of course, if your friend is going to be paying for all the expensive parts of a full Marshall head anyway . . . do you see where I'm going with this?

[Reeltarded]

It's actually a really good point.

[vibratoking]

...What I'm talking about, from my experience is: Often times these emulators sound 'Sterile' laboratory tones. I've found that a gain stage that can be overdrive a little is a real benefit in adding some real tube grit to the tone.

Why would you destroy the sterile POD tones with some tube grit? They wouldn't sell so many if it didn't already have what everyone wants.

[RWood]

Of course, if your friend is going to be paying for all the expensive parts of a full Marshall head anyway . . . do you see where I'm going with this?

It's gonna be a birthday present from me...do you see where I'm going with this?

[Regan]

What about using an organ power amp, or possibly a tube pa like a bogen? would probably need next to no modding and cheap as could be.
Regan

[M Fowler]

Without effects loop.