5G9/Warbler

[Willabe]

I'd like to build a tweed Tremolux 5G9 with the Warbler true pitch shift vibrato built in.

I can't figure out the relay switching between the 2 channels. I think I have to add a 1M grid return to the 1st stage of the Warblers 12AU7 when that channel is not used but that will put the 1M in || with the preamps volume pots? And I might need to  ground the Warblers input tube grid when not in use? I guess it will depend on how the switching is wired up?       

http://el34world.com/charts/Schematics/files/fender/Fender_tremolux_5g9_schem.pdf

    Thanks, Brad Willabe

[tubeswell]

Hi Brad! Looks like there could be one-too-many pre-amp stages in front of the warbler circuit? You might be able to get away with less. I've been conptemplating a similar build using that other SR unit I got off you a while back (which is still in my stash)

[HotBluePlates]

I'd like to build a tweed Tremolux 5G9 with the Warbler true pitch shift vibrato built in. ...

Why put them all in one chassis & have to solve the mess? How about a simple effects loop in the 5G9?

Since both items will be wall-powered, I'd suggest spending the time to figure out how one or the other will have a ground-lift (i.e., isolating all grounds from the chassis except the power cord ground, and implementing a switch to defeat the isolation for grounded-chassis operation).

[Willabe]

Looks like there could be one-too-many pre-amp stages in front of the warbler circuit? You might be able to get away with less.

Hi Pete! 

Warbler circuit uses 12AU7 for 1st gain stage feeding the 3 phase shift, not much gain and I've added a volume and 5E3/tweed Princeton single knob tone after the 3rd 12AU7 phase shift stage, so some extra control and signal loss. That 1M volume could be made 500K or 250K, might help cut some more signal. Plus the Warbler phase shift stages loose signal.

I did a test and plugged in an A/B into my bread board Champ to switch between my stand alone Warbler (with 2nd volume and 5E3/tweed Princeton single knob tone at it's output) and direct guitar into the Champ.

Even with 2- 12AX7's I had to put the Warblers drive and output volume full up to get the Warblers output signal/volume close to the direct guitar in signal.     

Or........ I'll have to add a second (3rd) channel for the Warbler and have relay switching on the input jacks.

[Willabe]

Why put them all in one chassis & have to solve the mess?

Simple plug and play. All in 1 package. 

I can't play without spring reverb, so for me, I need; 1. 5G9, 1. Warbler and 1. Stand alone reverb.
Too much stuff. 

The 5G9 already has LFO and driver tube, so I'd only need to add 2 x 12AU7's to add the Warbler circuit.

It's mainly just the switching I need to figure out and how the preamp should be configured, 1. 5G9 pre > Warbler circuit > LTPI   - OR -   2. 5G9 preamp channel with a 2nd Warbler channel into the LTPI. (Like an AC15/AC30 but with rely channel switching.)

[sluckey]

Don't you have a 5G9? If so, put it on the bench with the warbler. Start experimenting with patching together including your proposed switching until you get what you want.

[Willabe]

Yes I do have a 5G9. I'll try what your saying. 

[sluckey]

Did you ever do this?

[Willabe]

I'm playing around with it. No conclusions yet.

[Willabe]

It works, sounds real good to me. 

I gator clipped in my Warbler with 12AU7's in it into my 5G9 at/just before the LTPI's input cap, 0.02. The 5G9 has a 12AY7 in the 1st stage.

I do have a drive and volume control plus a 5E3 tone control in the Warbler and I had all 3 Warbler drive/volume/tone controls full up. No problem with over driving (it's not) the LTPI/power tubes.

But it's a little dark sounding. So I gator clipped in a 2.2uF/0.68uF/0.1uF bypass cap across the Warblers input gain stage, better.

With the bypass cap, now I can/have to use the 3 Warbler controls. That's good.

Still don't know how to switch it in/out, any ideas? I'm thinking of uses 1 of Doug's relay PCB's I have here, just not sure about pops?

   Thanks, Brad