Tweed 5e3 PLUS! with reverb??

[Ranalog]

Hello.
A few months ago I finished the construction of a 5e3 with several modifications: Cascade switch, NFB, half power reduction etc.

The result is incredible.

now I want to put REVERB.
At the time I already thought about it and bought the right transformers

In fact I have already done two tests but ...

and I have placed it in two places, before the stage just after the tone and just before the MASTER.
But the result has not satisfied me.

I have placed a switch to activate or deactivate the reverb. SW X

The fact is that when I activate the reverb I have a very large signal drop, in addition to a change in the general sound that looks like another amp.
By activating the reverb I lose the beautiful sound of the amp.

Any suggestion?

[Brebar]

Hello I'm trying to add reverb to 5f2a so far without success. I started a thread and have gotten some suggestions that I will try. Were you able to get it running to your liking?

I tried hooking it up like I thought Fender did and it didn't work at all. I can't rule out user error though! I'll be watching this thread with interest.

Good luck

[maxkracht]

Perhaps showing exactly how you implemented either option would be helpful. You don't want to send ALL of the signal through the reverb, it needs to be split into wet and dry, then recombined. My hunch is you are sending all of the signal to the reverb and then the reverb control would also be a master volume. Check out how this is done in a Princeton reverb.

[Ranalog]

I used a 3M3 to WET/DRY SIGnal
I tryed in two places. RED LINES
After TONE, and Before MASTER

In this moment I have it after tone.
The switch of the reverb is a push pull on the reverb pot, when its push the reverb is off and a part of the switch bypass the 3M3 and the cap,
When I pull it, the signal have two way to go, by the 3M3 and the reverb circuit.

[pdf64]

Signals have a source impedance, so mixing signals inevitably reduces signal level.
A mixing resistor and, for the master vol, a DC blocking cap, is needed on the reverb circuit output.
Like on any Fender.

[Ranalog]

I think that I have all you said.

Can you put me a link of a schematic to see what ?

THANKS

[pdf64]

Can you put me a link of a schematic to see what ?

See R30 470k, connected to the grid of V3B https://www.thetubestore.com/lib/thetub ... ematic.pdf

[Ranalog]

Yes I dont draw it but I have it, I put the 22n cap also.

The sound change a lot when I connect the SWX switch, the volume dows to a 1/4 and desapear the tweed sound.


I tried change 3M3 for 470k, sounds better, but I only have TAILS of the reverb....

[maxkracht]

I think redrawing the relevant sections with exactly how you have the ins, outs, and switching, would help make sense of things for you and others. Photos of the actual amp might help as well.

[Ranalog]

well.

The amp without activating the SWX switch Sounds amazing! spectacular!
When I activate the SWX (active reverb) with the typical values ​​of fender on RX and CX 3M3 and 10pf the volume drops a lot, it seems like another amp.
If instead of putting 3M3 I put 470K It improves a lot but I lose a lot of reverb and above all I hear tails.




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[maxkracht]

When I activate the SWX (active reverb) with the typical values ​​of fender on RX and CX 3M3 and 10pf the volume drops a lot, it seems like another amp.

Well, that resistor is always in circuit for ab763 amps, so you are making it more like another amp. The lower that resistor is, the less signal goes to the reverb. You need to balance that resistor value with everything else in that reverb circuit. A good place to start would probably be the reverb pot and 470k resistor after it. You could also put in a pot as a voltage divider, even temporarily, in place of that 3m3 to find the right balance. The cap across the 3m3 resistor is just a bright cap, probably worth experimenting with if you are changing other values. Someone with more experience will probably chime in with better advice, but that's where I would start.

[sluckey]

That's a terrible way to switch reverb on/off. Plus, with the switch in the position as shown, the following triode has no grid resistor to ground! That cannot work properly.

I suggest you dump that switching idea, hard wire the reverb input and output circuit, and turn reverb on/off by shorting the tank output, just like the original Fender circuit.

[maxkracht]

I did think the switching was odd, but there are production amps with similar arrangements that work fine and it takes the reverb entirely out if that is what's desired. Lots of ways to do the same thing.

SC200HB_pg1.pdf

[bepone]

well.
The amp without activating the SWX switch Sounds amazing! spectacular!
When I activate the SWX (active reverb) with the typical values ​​of fender on RX and CX 3M3 and 10pf the volume drops a lot, it seems like another amp.

you can try something like this, reverb taken after first stage and inserted to cathode circuit to the next stage, you will keep the orig,. sound but you will add also the reverb, 470k-1M grid leak resistor is mandatory.cathode on the mix stage is now input and cannot have bypass cap anymore, so omit 25uF cap

edit. this cathode input will not work..now i see that i need the mosfet buffer after the reverb stage to lower internal impedance to match cathode imp. od 1.5k.-.

[Ranalog]

UF, I see thats is difficult that seems.

I have half tube more to try markracht tellme.
But i dont know where take the send and the return.


thanks