Sluckey Dual Lite British - New Build

[Raoul Duke]

Hi All,
Planning my next build - Sluckey’s Dual Lite British - and looking for any info that may be helpful to this project; specifically:

1. Has anyone tried the “Jump” or channel select mod on this amp? My understanding is that channel select does both - hence the on/on/on switch?

2. The rotary switch cap values - leave as is or are there better values that would give more versatility?

3. Looking to use Heyboer 18w Marshall type iron unless there are other suggestions?

4. On the fence about building it with the MV. Any opinions regarding its’ performance?

5. Any hints or wisdom to impart based on experience with this (or similar type) build.

Torn between mods and simplicity - but leaning toward simplicity. Fairly certain on the MV mod, not convinced about “jump/select channels mod” just yet. Thinking that half Marshall and half a tweaked-up, slightly Trainwreck-like AC15 would be pretty ideal - but still looking at how to “Liverpool” an AC15 without reinventing numerous wheels or undoing Mr Luckey’s excellent design.

Here’s the documentation:
Dual Lite: https://sluckeyamps.com/dual_lite/dual_lite.pdf
Mods: https://sluckeyamps.com/VAC15/Vox_AC15_mods.pdf

Any ideas, advice, or wisdom is always welcomed! Looking forward to this project and learning more!

Thanks All!

[TUBEDUDE]

I haven't built one of these but it looks like an interesting design. The only thing I'd change is using a 5879 pentode instead of the EF86. It may be hard to source an EF86 that is not microphonic, and the 5879 was actually designed for audio, and is always my go to for s small signal pentode. There are plenty NOS tubes available and they can be had for under $10.

[sluckey]

I suggest reading this thread on Hoffman's forum. It answers many of your questions and maybe even some you haven't thought of.

https://el34world.com/Forum/index.php?topic=18330.0


Concerning jumping channels... Can't be done without a slight mod. Here's a link that shows how to modify to be able to jump channels.

https://sluckeyamps.com/dual_lite/dual_lite_r1.pdf

I find the brilliance switch cap values to be plenty versatile for my simple needs. Heck, the original Vox AC-15 only had one cap! And my friend Ed Chambly used a 12 position switch! I consider that a bit overkill, but Ed was just that kind of guy. He also had much better ears than me.

Heyboer makes a fine set of 18 watt iron. If I had to buy, that's what I'd get.

I didn't have enough front panel space for a MV. I don't miss having one. I really like keeping this little amp simple. I think you will too.

Don't bother with any of those AC-15 mods. I've removed all except the rotary brilliance switch from my AC-15.

[Colossal]

Heyboer makes a fine set of 18 watt iron. If I had to buy, that's what I'd get.

I didn't have enough front panel space for a MV. I don't miss having one. I really like keeping this little amp simple. I think you will too.

Don't bother with any of those AC-15 mods. I've removed all except the rotary brilliance switch from my AC-15.

Steve, well done, as usual.

Do you have part numbers for the Heyboer iron, off hand? They have a quite a few variations on the 18W theme.

Raoul,

Regarding a MV, I tried them extensively in the 18W Lite IIb and didn't find much utility for them either. Just another source of noise. A post-phase inverter master would be the one to use. I tried the Crossline and it did not have a good sweep, more of an on/off effect. A change in pot taper could have probably dealt with that, however. The absolute magic in these circuits is keeping them dead simple and letting the power amp work and breathe. The preamp in the Lite IIb is very linear and as you turn up the Volume, on a scope you can watch the EL84s round off and compress. I would expect the EF86 preamp to be very similar. These amps are about touch sensitivity and pushing the EL84 power stage and a master volume just gets in the way of that. I have modded those 18W amps exhaustively and nothing really gets better than the simplest setup, IME. I had a test platform that I used for modding and while some mods were useful and/or fun, I almost invariably end up picking a value, setting it, and forgetting it.

For what it's worth...

[Raoul Duke]

Understood and thanks guys!
This is just the type of practical and experiential type of info I’m looking for; very much appreciated! At this point I’m pretty certain I’m going to build it as Steve has spec’d it and play it awhile before considering any modifications - although it’s sounding like they won’t be needed.

The iron I was looking at was the Heyboer 8035H PT and the 8037A-H OT from Amp Parts Direct; but I’m open to any recommendations and would welcome them.

This will be my first build with turrets as well as EL84s, so I’ll probably have a couple of questions about technique involved; but looking at the schematic and drill guide - it seems pretty straightforward.

Thanks again

[sluckey]

Do you have part numbers for the Heyboer iron, off hand? They have a quite a few variations on the 18W theme.

These are made by Heyboer. I have these in my 1974 18 Watt amp. Bought from Hoffman back when he was still selling transformers.

https://www.mojotone.com/British-Style- ... ransformer
https://www.mojotone.com/British-Style- ... ransformer

[Colossal]

Steve,

Which rotary switch/tone cap setting do you use most often? Are you a humbucker or single coil player? Or do you change settings with the guitar and mood?

[sluckey]

Which rotary switch/tone cap setting do you use most often? Are you a humbucker or single coil player? Or do you change settings with the guitar and mood?

I mostly use positions 1, 2, and 3 with my Strat. 4, 5, and 6 are a bit too trebly for me. I don't know firsthand, but the 6 positions would probably cover humbuckers and P90s too.

[Colossal]

Which rotary switch/tone cap setting do you use most often? Are you a humbucker or single coil player? Or do you change settings with the guitar and mood?

I mostly use positions 1, 2, and 3 with my Strat. 4, 5, and 6 are a bit too trebly for me. I don't know firsthand, but the 6 positions would probably cover humbuckers and P90s too.

Thanks, I was just curious. I find 10n to be plenty with a paralleled 12AX7 with humbuckers. Plenty of low end, but not tubby. I tend to prefer things very balanced and articulate.

[Raoul Duke]

I haven't built one of these but it looks like an interesting design. The only thing I'd change is using a 5879 pentode instead of the EF86. It may be hard to source an EF86 that is not microphonic, and the 5879 was actually designed for audio, and is always my go to for s small signal pentode. There are plenty NOS tubes available and they can be had for under $10.

Great advice and I’d definitely jump on that just for the tube cost alone. However…

I used to have a Matchless DC30 and thought I sent my EF86 “collection” with the amp when I sold it. Found a box the other day and discovered nine EF86 tubes I forgot I had. Three current production and six NOS that were all tested about 5 years ago. All were healthy at the time; hopefully they still are.

Now you have me curious about trying the 5879 out. Thank you for the suggestion!

[dorrisant]

What are the alternate values for the 5879. I have a nice stash of these and half are NOS.

[sluckey]

What are the alternate values for the 5879. I have a nice stash of these and half are NOS.

I would start with the EF86 values and experiment.

The values in the attached schematic were used a lot over at Hoffmans. I have no idea how it would sound. The plate resistor looks a bit low but I could be wrong.

[TUBEDUDE]

Those values look good. Mine vary a little here and there.

Screenshot_20241210_161641_Gallery.jpg

Screenshot_20241210_161837_Gallery.jpg

Screenshot_20241210_163224_Gallery.jpg

20241210_163304.jpg

[sluckey]

The Dual Lite will be a great companion for your Tweedle Dee. Gonna cover a wide range of tones.

[dorrisant]

Thanks for the info guys. I will build one of these soon.