Fender 6G15 Reverb with Sluckey's Tremonator

[Watto]

Hi Folks,
I don't post much , but I'm a serial lurker,

I stumbled across Sluckeys Tremonator a while back and love it , I love how it doesn't change the characteristics of the amp it's in, I built a 5F1 Champ replica for a customer and they wanted trem, I put all the standard Fender/Gibson etc trems in and tested , but they all took away some of the simple Champ circuits characteristics .

The Sluckey trem was perfect . Customer is blown away .

I had a half built Revibe project and thought I'd change out the Harmonic Trem (not a big fan) with the Sluckey Tremonator .... I'm wondering if anyone has had a go at this .

My only thought would be , where do I tap in ? On the input so the trem goes through the reverb circuit , or on the output after the reverb circuit, It won't be hard to try both , just wondered what you guys think
regards
Watto

[Watto]

I'm thinking I tap the B+ before the Choke on the 6G15 to get the higher voltage B+ and use a smaller resistor to the 470k feeding the Anode .... and I'm going to use a 6AV6 single Triode as I have a bunch in my stash .

I'll post progress if anyones interested

Regards
Watto

[sluckey]

Look at this. Might give you some ideas...

     https://tedweber.com/media/kits/5h15t_schem.jpg

[Watto]

Thanks Sluckey ,
I'll start with the Post choke as per that schematic , see how it goes.

Just finished designing a layout and marrying the two .... I'll start here and see how I go .

NB I haven't built this yet , I've gone over it a few times, I think its correct , but it's late here in Australia ... If you notice any errors , please let me know

Rock on Watto

[sluckey]

I'll be interested to see how this turns out.

[Esquirefreak]

On a side note;
I suggest elevating the ground with a hum loop blocker and putting the ground connections on a bus wire. The bus grounding made a real difference on my latest 6G15 build.

Here's a sketch I made a couple of months back.

/Max

[Watto]

On a side note;
I suggest elevating the ground with a hum loop blocker and putting the ground connections on a bus wire. The bus grounding made a real difference on my latest 6G15 build.

Here's a sketch I made a couple of months back.

/Max

Thanks heaps Max, I'll definitely go down that route ... though I just noticed on you grounded the 6.3v CT to the 6K6 Cathode ... My PT doesn't have a 6.3vac CT .. I'll do the 100ohm virtual CT as it hasn't got a reference to ground otherwise.

regards Mark

[kagliostro]

PT CT or 100+100ohm or Humdinger

All can be connected to the Power Tube K or to a Voltage Dividerr feeded with B+ and take advantage

Franco

[Watto]

PT CT or 100+100ohm or Humdinger

All can be connected to the Power Tube K or to a Voltage Dividerr feeded with B+ and take advantage

Franco

I've used both over the years with good results, I also like to ground shielded cable on the grid inputs to the cathode of the gain stage it's applied to, works better than when it's simply grounded to the chassis directly  ... every little bit helps

[kagliostro]

I'm not sure I've understand what you mean

I hope I've understand or remembered wrongly

What I've remembered was discussed and defined very unsafe here in the forum some years ago

Franco

[Watto]

I'm not sure I've understand what you mean

I hope I've understand or remembered wrongly

What I've remembered was discussed and defined very unsafe here in the forum some years ago

Franco

I probably didn't explain it right ... I use shielded cable for some grid inputs , EG input jack to 1st grid on V! , I trim and heat shrink one end of the braided shielding wire , The end at the input jack, the other end is grounded, either at an earth lug , buss bar etc. But it works on the cathode of that tube, it's conveniently next to the grid lug of the tube socket , and it gets filtered to ground through the cathode capacitor, same principle as you explained with the PT centre tap and 100 ohm virtual tap

[kagliostro]

Now I've understand

I was thinking to something a bit differenti

One side was connected to B+

Your solution seems a bit differenti

If It was the shield of V1 input di you use the cathode of V1 ? And, if so, what of the cathode has not a bypass capacitor ? Do you connect It to One other tube ??

Franco

[Watto]

Now I've understand

I was thinking to something a bit differenti

One side was connected to B+

Your solution seems a bit differenti

If It was the shield of V1 input di you use the cathode of V1 ? And, if so, what of the cathode has not a bypass capacitor ? Do you connect It to One other tube ??

Franco

A cathode with a capacitor is needed as far as I'm aware , It doesn't have to be the cathode of the grid you're using , as it's just filtering the shield to ground and is independent of the core grid wire .

I discovered it a few years back when I serviced a mid 70's Silverface amp, they had the wire coiled around the tonestack cables , it's almost always grounded one end the chassis , but this one amp was at the cathode ... whether it was a mod or a mistake at the factory , I don't know , I've only ever seen it in that one amp, it sparked my curiosity and that's when I discovered after some research it was a mod you can do to shielded cable ... I've been doing it for years.

[kagliostro]

Many Thanks for the clarification Watto

Many Many Thanks

Franco

[Watto]

Hi Folks, It's been a busy new year so I haven't been able to do anything on this project until today .

I decided to redo the layout and split the controls into two seperate side of the output , I also reversed the standard Revibe Chassis' with the input in the middle and output on the right , As I wanted to tap the Vibrato into the circuit at the output jack , I decided to change it all around.

I also decided to do a bit of point to point , Mainly with the cathodes , I do this on my other builds , so I decided to do it here .

I built the board today and populated it using spare parts I had lying around , so there's a mix match of caps in there .

I'll get the next stage done sooner rather than later ...

Here's the new Layout

[Watto]

Today's progress

[sluckey]

I had intended to post this last year but slipped my mind...

Dummyload put the TON circuit in a reverb unit. His reverb is not exactly a 6G15 but close enough. He applied the tremolo to the output so the wet + dry signal gets tremolated. He was pleased. Schematic is in the first post of this thread...

     https://el34world.com/Forum/index.php?topic=26117.msg284698#msg284698

[ac427v]

Wow, Looks like another great Tremonator implementation!I found when adapting Sluckey's Trem on a non-AB763 amp that it allowed too much signal to go to ground through the Intensity pot. This happened even when the trem was switched off or turned down to zero. The easy change was to lift the pot connection between the third lug and the ground buss. Using the pot as a variable resistor cured the volume loss. I tried several intensity pot values until settling on 250K as the best control of the sweep from no trem to BIG trem. Looking forward to hearing how this fits with the 6G15 circuit.

[Watto]

Wow, Looks like another great Tremonator implementation!I found when adapting Sluckey's Trem on a non-AB763 amp that it allowed too much signal to go to ground through the Intensity pot. This happened even when the trem was switched off or turned down to zero. The easy change was to lift the pot connection between the third lug and the ground buss. Using the pot as a variable resistor cured the volume loss. I tried several intensity pot values until settling on 250K as the best control of the sweep from no trem to BIG trem. Looking forward to hearing how this fits with the 6G15 circuit.

Thanks for the heads up  , I'll keep that in mind if I have any issues when I fire it up 

[Watto]

Finished and tested today , very happy but needed some tweaks . Here's a breakdown

#1 Trem volume was much lower than reverb volume - So I cut the pot ground as suggested by AC427V and it was fixed ... The intensity didn't act like a volume pot as suggested it might , but it was significantly lower in volume ... Problem solved , thank you

#2 grounded every ground point through Esquirefreak's ground hum loop circuit .... Brilliant , quiet as a mouse . Thanks for that

#3 weird anomaly , The reverb mix pot acts like a volume pot on the trem circuit ... 1 to 5 on the mix pot does nothing, but 6 to max it drops the volume of the trem, It does this even if the reverb is off , might add some bleed resistors to where both circuits attach to the output jack , this may solve this ... I'm thinking maybe 270k as Fender used in their amps ..

#4 thinking an LED would be cool, to see the pulse rate , any thoughts Sluckey of where to put it in the circuit ?

#5 Also thinking an extra 0.02 cap switched to give it a fast /slow switch .. it's pretty swampy at the moment, but hey ,why not

All in all , I'm one happy camper , Thanks Sluckey for the tremonator circuit, and thanks Leo for the 6G15 circuit ... with a couple of minor tweaks this'll be my favourite effect 

[Watto]

oops forgot the picture

I'll do a demo soon

[sluckey]

#4 thinking an LED would be cool, to see the pulse rate , any thoughts Sluckey of where to put it in the circuit ?

Ordinarily I would say connect the LED between the oscillator tube cathode and ground. But, there's already an LED (inside the VTL5C1) at that point. I'm not sure how putting another LED parallel the VTL5C1 LED will affect the trem effect. I guess just try and see. I don't have any other ideas.

[Watto]

#4 thinking an LED would be cool, to see the pulse rate , any thoughts Sluckey of where to put it in the circuit ?

Ordinarily I would say connect the LED between the oscillator tube cathode and ground. But, there's already an LED (inside the VTL5C1) at that point. I'm not sure how putting another LED parallel the VTL5C1 LED will affect the trem effect. I guess just try and see. I don't have any other ideas.

Thanks mate, I'll give it a try, it's not necessary but if it works , Bonus, I'll let you know 

[Watto]

I tried out the bleed resistors , it really dropped the signal of the amp, even when disengaged , as it's of course not true bypass,
Took them out and the signal is still attenuated a little , but not as much, I've never owned a 6G15 so I'm not sure if that goes with the territory or not. More research needed