Anybody ever build/try Sluckey's Trem-o-Nator?

[Huddy]

I used it in a 74 MV twin I couldn't get the tick out of. I thought it sounded fantastic.

 

[joulupukki]

This is very cool. I think I’m going to use some flavor of the LND for my next single channel AB763 build. that should help me get a bit more space in my 20” wide cab and one less tube.

Hmm. Can’t seem to find an LND150 in stock anywhere. I did just order a VTL5C1 though and will mod my B-Verb amp to check it out. My intensity pot is a 250KL – maybe not optimal but should still function.

 

[Paul-T]

Hmm. Can’t seem to find an LND150 in stock anywhere.

apparently this is a thing - global backlog, I've seen five months quoted.

 

[joulupukki]

Well, I just replaced my smooth-sounding bias tremolo in my AB763 single channel amp with the version on the left in @King Fan ’s first post and …

It sounds like junk. Ok, well it does “work” but it sounds thumpy/choppy and not smooth. Reminds me exactly of why I don’t like the trem in the DRRI. Maybe I did something wrong or the VTL5C1 I used isn’t good enough (ordered it from Amazon – came in a 5-pack: ). My intensity pot is still the 250KL so the trem doesn’t kick in ‘til you’re almost at the very top, but that’s really not the issue.

Perhaps the Supro version on the right is actually smooth like bias tremolo?

 

[Bitsleftover]

Here’s a quick clip I just made on my phone.
Sorry it’s not very loud or good, we’ve got customers in the next room so didn’t want to disturb anyone.
I’ve recorded a loop so I can adjust on the fly.
1st click - Kill switch
2nd click - Foot switch
Intensity 0, 2, 4, 8, 10 (or their abouts.
Ends with adding a bit of “One Tube” reverb.

 

[Bitsleftover]

View attachment 1083432 View attachment 1083432 And that’s its dedicated board crammed inside my chassis

 

[Bitsleftover]

 

[mk_716]

Both versions were very smooth, I suspect something else is up. I had a NOS Vactrol from 20 years ago, fired right up and smooth. (not as slow as I wanted, but smooth) It was good out of the gate.

I read a bunch of tweaking threads, slight changes in the pot values/insertion points - def. remember trouble with 'knockoff' VTL5C1s.

m.

 

[joulupukki]

Yeah, potentially a bad VTL5C1. I swapped it for a different one too from the 5-pack batch and same result. This is how it sounds…sorry – bad video, doing it quickly and one-handed.

 

[mk_716]

hey @joulupukki ,
yeah, certainly in the ballpark though, right?

I can get to choppy (that's cool, right?) but I don't get thumpy. Maybe try the 50K pot too, or drop a resistor across the pot just to get it down to test. When you have the intensity all the way down are you still getting chop?

m.

 

[joulupukki]

hey @joulupukki ,
yeah, certainly in the ballpark though, right?

I can get to choppy (that's cool, right?) but I don't get thumpy. Maybe try the 50K pot too, or drop a resistor across the pot just to get it down to test. When you have the intensity all the way down are you still getting chop?

m.

Yeah, it’s just as good as the opto-coupler in a deluxe reverb. I just don’t prefer that type of trem. I was hoping it’d be smooth like the bias tremolo of a Princeton Reverb. You know, smooth transition between loud and quiet instead of it being a drastic sudden change. The YouTube video makes it sound better than it does in person.

I do have a resistor across the pot right now so that it’s essentially a 50KL pot. I guess I wouldn’t say it’s chop, just not a smooth transition. It certainly has a lot of speed range and depth.

The other thing I notice is that it cuts the volume down vs when the foot switch is off. But that just could be where I’ve got the signal inserted (right before the PI coupling cap). My build follows the Hoffman 1-channel AB763 so it has the 47K resistor to ground right before the PI coupling cap. I disconnected that resistor temporarily just to see if there was any difference – just a bit louder initially but with this trem on the overall volume is reduced.

 

[mk_716]

Hey @joulupukki,
Fair enough. The biggest difference I noticed between the original and Supro versions is that both controls seemed smoother.
m.

p.s. sent you a message

 

[joulupukki]

I think I am going to abandon ship on the Trem-O-Nator for now and go back to the bias trem that was sounding good but just needed a little more depth. I'll bet with one (or more) of these mods, I'd have it singing beautifully: https://el34world.com/Hoffman/files/Hoffman_AB763_Mods.pdf

Edit: Reverted back and really happy. I used an LED in place of the 25uF and 4.7K cathode and changed one of the 470K to 270K (to give deeper trem). I may have never found this fix had I not venture down the Trem-O-Nator. So thank you KF!

 

[Ten Over]

Hmm. Can’t seem to find an LND150 in stock anywhere.

I've been redesigning my LND150 circuits to use IRF820 a.k.a. IRF820PBF. Not very well received over at TAG, but then nothing else is, either. Anyways, I came up with this for an IRF820 Tremor-Lator:



If IRF820 becomes unavailable, a bunch of similar MOSFET's will also work.

 

[Ten Over]

Well, I just replaced my smooth-sounding bias tremolo in my AB763 single channel amp with the version on the left in @King Fan ’s first post and …

It sounds like junk. Ok, well it does “work” but it sounds thumpy/choppy and not smooth. Reminds me exactly of why I don’t like the trem in the DRRI. Maybe I did something wrong or the VTL5C1 I used isn’t good enough (ordered it from Amazon – came in a 5-pack: ). My intensity pot is still the 250KL so the trem doesn’t kick in ‘til you’re almost at the very top, but that’s really not the issue.

I ordered in one of those 5-packs. Then I ordered in another of those 5-packs. The first one had a tag that said "VTL..." and the second one came in today with a tag over the original tag that said "VTL5C1". They are both the same device and neither is VTL5C1. Whatever these things are, they are not useable in sluckey's Trem-O-Nator.

The other thing I notice is that it cuts the volume down vs when the foot switch is off.

Yeah, that's because the resistance range is way lower on these devices so that it puts a heavier load on the tube which lowers the gain throughout the entire tremolo cycle. It also causes the tube to have a long "nearly off" portion and a short pulse of "on", which is undoubtedly what is causing the choppy nature of the tremolo.

VTL5C1 is still available at tubesandmore.com. Click on "Switches" then select "Optocouplers". A lot more expensive, but then you are far more likely to get an actual VTL5C1.

 

[King Fan]

Cool experiment. And I guess “it sounds like junk” was the right diagnosis.

 

[joulupukki]

Dang. I assume it’s not returnable because I have a lead clipped on one of them. I should have realized … 5-pack off of Amazon. I really like the idea of the Trem-O-Nator and if I had the regular opto-trem in an amp I’d switch to it in a heartbeat (with an actual VTL5C1).