How to add EFX loop to amp.

[served]

Hi!

As Im a huge stompbox fan and I really dont want to change my habit.

I would like to know, how to add EFX loop to my amp. And also series FX loop would be cool, so i could leave out my amps preamp.
I own Yamaha 65D. Its a crappy one, I know, but some why i really like it. I have tried others but still got home and enyoied my own stuff.

All kind of  switches and stuff can be added, im not afraid of them.
I hope there is a way.

A.

If Anyone could explain me the meaning of EFX loop, then i might work out my own way to mod that amp.
Beacause pRe amp and Power amp is seperated and its pretty easy to understand, how it should work.

[served]

Anybody?

I think i need it. Ill start to try it out, may be i can get somewhere on my own.

[tempus]

An FX loop is usually inserted between the preamp and the power amp stages of your amp. So it goes like this:

Gtr => preamp => FX loop => power amp

So if you want to put an FX loop in your amp you have to get 'in between' the pre and power amp stages. Do you have any level of electronics/electricity skills? If you're messing around inside an amp you need to know a few things so you don't destroy your amp, kill yourself, or both.

[Ripthorn]

You will also want to use switched jacks so that when nothing is in your effects loop, the preamp goes straight to the power amp.

[served]

I think i have enough experience. I just finished my Dr Boogey, but it doesnt sound good with my amps preamp.
So i thought that maybe there is a schematic to add FX loop, so i dont have to do something stupid. But ill add some pictures soon. I have a glue how to perform the poeration, i think.

[SteveB]

You can download the manual here:http://www.retrevo.com/support/Yamaha-VX-65D-manual/id/961ci565/t/2/

Insert the jacks right before the master volume. As Ripthorn said, used normally switched jacks, with the the extra lugs connecting both jacks together.

[anchovie]

Measure the peak-to-peak voltage of the Roland's pre-amp output at the point where you want to place the FX loop - it might be too high for the input of a stompbox, in which case you'll need to attenuate it with a voltage divider and possibly add a gain recovery stage after.

[served]

Well yes. This is only needed, i think, when i want to use both of them. But i was planning to skip the amps pre amp and use Boogeys preamp instead.

I have Yamaha 65D JX series.  Channel one's preamp is actually seperated from the powramps circuit. Its connected with the main plate with 3 wires.

They are marked like this: "OUT", "+26", "E"

Can anyone explain these?
I think Out mean signal, this is the wire i will use to send signal to power amp.
+26 might be voltage, power to feed the pre amp. But what is "E"? E is Ground

I tested it by removing Pre amp from CH1 and just connected My DR Boogey to it. Signal to "OUT" and shield to "E"
It was noisy and very cold sounding. Even if i bypassed Boogey the amp was very sensitive, i even could hear clean guitar.
Is there even a way to make this amp sound good with FX loop. Its seemed like crap to me without preamp.


I uploaded some pictures:





EDIT: I didnt try to connect input before the volume know, but I'll try it right away!

[FunkyGibbon]

You might want to look at the Adjusticator:

http://www.geofex.com/circuits/Adjusticator.gif

You can use the two stages for a series effects loop (once you have the output from your preamp, and the input to your power amp sorted): the first stage can be used to attenuate your preamp output down to effects level, the second stage can boost it back up after your effects (or FET-based preamp pedals) before going to the power amp.

You can then build a loop in your Dr Boogey instead of a bypass: where the wire would usually join your input and output in bypass mode, instead have bypass output and bypass input sockets. You can then have the bypass output of the Dr Boogey go to the Yamaha preamp, out to the Adjusticator attenuation stage, back to the Boogey bypass input, and back to the Adjusticator boost stage, then on to the power amp.

That way, you can bypass your Dr Boogey by going to the Yamaha preamp. Then, when you engage the Dr Boogey, the Yamaha preamp is removed from the chain. It just goes:
Guitar -> Dr Boogey -> Adjusticator boost stage -> power amp. It means two extra guitar leads, but you now have a two-channel switching amp!

(Oh, right. You already have two channels. Well now you can have three!).

Have fun!

[served]

Damn FunkyGibbon That was difficult to follow, but ill read more times. Ill get it! I soldered input to Master volume center slug. The sound was still a bit lifeless. I dont know what gives that good punch to Power amp. With Pre amp it sounds more alive. Ill continue on testing. Its actually real fun!

EDIT: Im sorry to ask, but could you make me a drawing? Its confusing. A simple scetch?

[FunkyGibbon]

Hi, sorry, it was a little confusing.

Here is a sketch of what I mean;



You can see that when the Dr Boogey is engaged (not bypassed), only the Dr Boogey board, the recovery stage of the Adjusticator, and the power amp are in the chain, which is, I think, what you want. When you bypass the Dr Boogey, your guitar now goes to the Yamaha preamp, which will give you a nicer clean channel than just going from guitar to power amp.

The Dr Boogey is probably not as loud as a preamp typically is, so you will probably need to a boost stage to follow it before it gets to the power amp. Hence the Adjusticator.

Of course, I am just a novice myself, so do seek a second opinion on this!