5E3 with 18watt tremelo

[bevins]

Hi all,

Has anyone built the 5E3 with the 18watt marshall tremelo built in? That is one of the best tremelo's I have heard and would like to build a 5E3 with that tremelo in it. Would like to see how it would get incorporated in the schematics.

Thanks in advance,

Bob

[txstrat]

You could use the complete part of the tremolo circuit and feed the volume pots wiper into the split load PI of the 5E3.
Some preamp parts values are different which might cause slightly different sound/dynamics and besides you'd lose one channel of the 5E3 (otherwise you'd have to use one more tube).
If you like it that much it's worth a try.

[bevins]

I wasn't planning on using the second channel. I was actually planning on adding a 12 AX7.

I have MM iron and was wondering if the MM Tone Clone FTDO-59-S OT would work with it.
I have the MM Axiom FTDP-350 PT which gives 350-0-250 which should be ok.

Any thoughts?

Thanks

[txstrat]

If you're gonna use only one channel there's no need of adding another 12AX7. Just use the one that's already there.
The transformers are right.

[bevins]

I thought the 18watt tremelo used both sides of a 12ax7. Gots to go back and take a look now.

[txstrat]

Yes, look at the Deluxe's schematic. Change the 12AY7 for a 12AX7 and wire it like in the Marshall circuit. That's all.
It's a trade-off, though. But that you have to take.

[bevins]

I just checked and the 18watt tremelo uses both sides. If I remove an input fromt he 5E3, I still would be missing half a tube.

I think I will just add a 12ax7 and use the second half of the 12ay7 for another gain stage, or would that be too much?

[txstrat]

I still would be missing half a tube.

No, just remove both inputs and everything from the 5E3's 12AY7. Then use the two inputs of the 18w trem channel.
Look at it like this: the 12AY7 is the Deluxes preamp, the 12AX7 the phase inverter. Remove the 12AY7 and take the Marshalls complete trem channel (including it's two inputs) as your preamp, nothing more or less.
The values of the Marshalls first half 12AX7 are different from the Deluxes 12AY7 but you can tweak that later.

I think I will just add a 12ax7 and use the second half of the 12ay7 for another gain stage, or would that be too much?

I think that'd be too much gain overall and changes the amps tone too much.

[m-fine]

No, just remove both inputs and everything from the 5E3's 12AY7. Then use the two inputs of the 18w trem channel.
Look at it like this: the 12AY7 is the Deluxes preamp, the 12AX7 the phase inverter. Remove the 12AY7 and take the Marshalls complete trem channel (including it's two inputs) as your preamp, nothing more or less.
The values of the Marshalls first half 12AX7 are different from the Deluxes 12AY7 but you can tweak that later.

I think that'd be too much gain overall and changes the amps tone too much.

I can see ADDING a tremolo to the 5e3, but what you are suggesting is replacing the 5e3 which seems a lot less desirable to me. If he can add another tube and get the trem plus preserve the 5e3 circuit, that would make the most sense.

[txstrat]

Well, the trem of the Marshall actually works on both the preamp triodes which share a cathode resistor. The tone and volume pots sit there in the same place like in a 5E3 (except the second coupling cap and a bleeding resistor in between the two caps).
If you tweak the values of the Marshalls first triode you can come veeery close to (if not spot on) 5E3 specs and don't have to add a tube.
Bevins said he wants both, the 5E3 AND the Marshall trem. You MIGHT have to give up some (I'm not sure here). If it's the 5E3 tone or the Marshalls trem you'd have to decide by yourself.
But anyway, I'm interested in the way you would add a trem. Mind to share your thoughts?

[bevins]

I was thinking coming off the volume pot of the 5E3 before the PI and go into the trem section pin 1 of V3 18watt tremelo bypassing the gain stage as it already is using the 5E3 first stage. whether that is hot enough I don't know. Maybe try a 12ax7 for the input into the 5E3. Then the rest is the tremelo into where we removed the input into the PI. that might work no?

Basically using the 5E3 input into the first gain stage and then ting the tremelo then into the PI.

[txstrat]

Sounds good.
But I don't know how much of the first triode is needed to make the trem sound good (look at the plate resistors configuration).
That's why I proposed to use the complete trem circuit and tweak from there in direction of the 5E3.
The two circuits (aside from the trem) are not that much different anyway.
If you look at one channel of the 5E3 and the first triode of the Marshall there're only a couple different values. Most parts are in the same place. Except the cap and bleeding resistor which I mentioned in my last post.

[m-fine]

I was thinking you could take the "valve 3" setup from the marshal and run it in parallel to the 12ay7 either using one of the 4 input jacks, or adding a 5th. (do you really use both high and low inputs?) You could then combine the signals at the PI.

I am thinking that would let you plug into the 5e3 side and run a jumper over to the Marshal input and then use the volumes (or a foot switch) to control which channel is in use, or even to mix them.

[m-fine]

Sounds good.
But I don't know how much of the first triode is needed to make the trem sound good (look at the plate resistors configuration).

I think the first triode is needed because it works through the interference between the two.

[bevins]

I don't know about any interference the first stage takes care of. As far as I know, the first stage in that tremelo and the reason they use a 12ax7 is for the gain hitting the tremelo. The tremelo sucks the gain, so thats why I thought the 5e3 first stage gain might be lacking a little for the tremelo. I don't know, but I will surely find out.

just wanted to know if anyone has done this before.