String Ringer build.

[Strategy]

Yeah we are exchanging messages back and forth now...

[Strategy]

well this is interesting and should provide some potential information for people seeking LT-44 alternatives. This is from the Ebay seller providing responses about the transformer/diode parts kits:

Seller's message:
"Hello, Ah! On these LT44 replacements I've cut the middle wire on the correct side so that the pin-out is correct to drop straight in to a ring-mod with the impedances the right way round. You should ignore the 'P' marking. There's sometimes confusion with the primary and secondary sides because in the original inter-stage application in 1960's transistor radios, the secondary was the side with the centre-tap driving forwards into the two pnp output transistors as a phase splitter which doesn't make much sense in a ring mod. Those are Xicon devices as seen here: http://www.usefulcomponents.com/ebay/pictures/transformers/xicon/xicon_42tm_series_s.jpg If you trawl through the spec you should see it's correct. They are actually better transformers than the current P631M Eagle part which is generally sold as LT44. Henry."

[LaceSensor]

Id just buy these in the UK... I used them in 2 stringers, work great

cheaper, too, Id wager, if you have a maplin nearby and dont need to pay the postage.
Maplin also stock the actual lovetone knobs as used on the real deals.
who'd have thunk it?!

http://www.maplin.co.uk/p/miniature-audio-matching-transformer-200mw-hx82d

[Strategy]

I'm not in the UK and already have the transfomers I got from the ebay guy, so I'm going to follow his instructions and see how it sounds! Getting very close now just missing a few more parts. Down to the last questions, for now I think:

- What's a good part to get for the VCO depth input jack? ...smallbear part # maybe?
- do switches and pots solder onto the component side or trace side of the board?

Thanks to everyone here for the big help on this complex project. I'm trying the v.1.3  build out of it

Strategy

[digi2t]

Isolated switching jack;

http://www.smallbearelec.com/servlet/Detail?no=724

Everything mounts on the component side. Pictures of my build;

http://s214.photobucket.com/user/digi2t/library/Ring%20Stinger?sort=3&page=1

Notice that just below the VCO selector switch (next to the green LED) there is a small rubber plug. I drilled a hole there for access to the LDR trimmer. Rather than have everything hanging out to adjust the LDR, I could simply pop off the plug, and adjust the trimmer directly with my trimmer tool. I'm going from memory here (so I might be wrong), the LDR determines the transition point in the signal decay where the VCO kicks in, so adjusting it is somewhat of a taste thing. Having easy access to it is a good thing, and if you're using an LED/LDR arrangement, rather than a Vactrol, keeping everything dark inside is best.

[Strategy]

Thanks! I elected to use the vactrol. I meant lfo depth jack, i think you figured out what i meant though thanks!

[digi2t]

Thanks! I elected to use the vactrol. I meant lfo depth jack, i think you figured out what i meant though thanks!

Not really. It was a process of elimination deal. It's the only weird jack in there. 

[Strategy]

Two more questions...

Any musical usefulness in bringing the waveshape tuning to panel as a control?

And, does anyone have a trustworthy drill guide? Drilling enclosures for these loveclone projects w/ mult rotary switches gives me the heebie jeebies

Thanks! Just waiting on my smallbear order now...

[digi2t]

Any musical usefulness in bringing the waveshape tuning to panel as a control?

None that I can think of.

And, does anyone have a trustworthy drill guide? Drilling enclosures for these loveclone projects w/ mult rotary switches gives me the heebie jeebies

What I did was print the PCB layout 1:1, mark all the centers on the page, and compare that to the built board. When you're satisfied that your X's and O's are in the right place, then transfer the page to the enclosure top. Tape it down, and then center punch your marks to the enclosure.

I always drill my holes about 1mm oversize, to allow for some wiggle room. 

[alanp]

And, does anyone have a trustworthy drill guide? Drilling enclosures for these loveclone projects w/ mult rotary switches gives me the heebie jeebies

For mine, I took Electricstorm's 1550G template for the Lovetone flange, taped the PCB transfer artwork on top of it, and measured distance from the pot wire holes to the shaft for the pots, with the rotaries at the centre of the artwork for them. Good thing is that this board is symmetrical, controlwise.

[Strategy]

Well been prodding at this bit by bit and have it substantially wired up. Am now in possession of the necessary 2-switch LFO depth jack and totally puzzled at how the pinout relates to the diagram in the build doc. Any advice in unraveling this mystery?

Had a run of great DIY successes lately but when I run into a new type of switch or switching jack it tends to result in some slowdown...

Thanks for any help...!
Strategy

[digi2t]

Well been prodding at this bit by bit and have it substantially wired up. Am now in possession of the necessary 2-switch LFO depth jack and totally puzzled at how the pinout relates to the diagram in the build doc. Any advice in unraveling this mystery?

Had a run of great DIY successes lately but when I run into a new type of switch or switching jack it tends to result in some slowdown...

Thanks for any help...!
Strategy

Does this help?

http://www.mouser.com/ds/2/209/KC-301403-193175.pdf

Let me know if you're still in the Land of Perplexion if the above doc doesn't help. I'll open up my unit and trace it out for you.

[Strategy]

That's looking promising, the diagram has numerals...going to give it a shot!!
thanks a ton!
Strategy

[digi2t]

That's looking promising, the diagram has numerals...going to give it a shot!!
thanks a ton!
Strategy

No problemo. Like I said, if yu hit a road block, PM me, and I`ll open up my unit, and I`ll draw up a connection diagram for you.

[Strategy]

Hi Digi2t,
I did indeed hit a roadblock with the LFO Depth jack wiring...a trace or other diagram would be helpful...the datasheet you linked shows a few more connections than what is shown in the jack diagram in the PDF, I got nervous trying to extrapolate...I'm sure there are unused terminals on the jack but now I'm not sure which ones...but in any case...

IT WORKS!   ....80% anyways!

I decided to put some power through it even though the LFO section is basically disabled without the depth jack. I get ring modulation, voltage control, controls seem to do what they're supposed to do, etc.

Aside from the incomplete LFO wiring, I only have 1 issue. VCO Frequency pot does not seem to go very high range. It goes from sub-audible (like tremelo) lows to not very high. Under voltage control - 0-5V LFO signal from my modular synth - I get the full range from glassy ultra high frequencies down to the tremelo type low's.

Could the limited range of the VCO freq pot be associated with the incomplete LFO wiring? I have verified I used the correct pot value here (B100K). Or, is it also possible that this is supposed to be the range of this pot and its only with the onboard LFO or with an external CV that you can actually reach a greater range? Not having ever played an OG ring stinger I'm not certain what the pot range is supposed to be.

I don't have a scope, but I'll see if I can get a simple oscilloscope VST plugin or something, so I could post the floor and ceiliing values for the VCO frequency as it stands under control of just the potentiometer.

Thanks to everyone on this thread for the help...Getting this thing done is a dream come true literally years in the making...I think I've had this on my bench since 2006 LOL

Strategy

[njkmonty]

i post this elsewhere in this forum without answer can any one help?

i just received from ebay a IRFU9024   and i noticed they where way small i was expecting a TO-220  package size

http://www.ebay.com.au/itm/2PCS-MOSFET-IR-TO251-FU9024N-FU9024-IRFU9024N-IRFU9024-/200994856749?pt=LH_DefaultDomain_0&hash=item2ecc3a1f2d&_uhb=1

did i buy the right ones, they look half the size of a to-220

is this what is needed?

[Strategy]

Hi! I used this same one and it works great. It also looked small to me but I haven't done a lot of projects with this type of rectifier part.
Strategy

[digi2t]

Yeah, that's fine. I used the same one.

[glops]

Been working on mine slowly since the turn of the year. Just need the off board wiring soldered and a few misc bits mainly the ldr and green led. It's so mammoth that's its daunting to think about testing before boxing and daunting to think about boxing before testing. Yikes!

[Strategy]

Glops, you know I found a cardboard box that was sized appropriately and created a cardboard mockup for testing. Just poke holes, put in your controls, label, make sure it's one where the lid lifts off easily so you can pop it open and work on it. Be aware not to burn the cardboard with your soldering iron.

there is a ton of trouble shooting. I am pretty sure my wiring is correct but there are still some glitches for me. But so close now. I've been working on this incrementally for like 5 years! A lot of the components are from the surplus shop, I'd just populate it a little bit at a time. SO close now.