Do it yourself crew in the house?

[TubularCorporation]

Back in 2011 or 2012 I built most of a Fender Deluxe clone, but I didn't have the skill to wire up the power transformer correctly back then so I ended up leaving it in a box with the transformers and tube socket wirings unfinished for years.

 

Anyhow, I finally finished it last week.  Took about 5 hours today to track down all the mistakes I made with the input and volume/tone control wiring but once that was sorted it worked great.  Only problem is I have no cabinet to put it in (and no money for one), plus it's so loud that there's no way I can use it at home without building an attenuator (and using it at a friend's practice space isn't too practical when it's just a bare chassis).  But the 2 minutes I could get away with playing it at full volume sounded AMAZING. Hopefully my shitty old solder joints won't fall apart too quickly once I start using it.

[user]

I'm looking to add a stereo pre-amp to the Mojo Maestro (https://audioxpress.com/article/you-can-diy-build-the-mojo-maestro) I put together a while ago. Preferably based on a TL072 because there's a bunch of those in my stash. The plan is to add some more diodes (finally found some actual, I mean actual, germanium diodes in different flavours), a couple of transistors salvaged from an old obscure hifi amp and a pair of output transformers that I took from a reel to reel that was beyond repair and put it all on a rotary switch so I can select different diode pairs or just go through the transformers. 

Of course I googled a bunch but get a bit lost every time looking for "tl072 stereo preamp". Any and all tips, insight or banter welcome

[TubularCorporation]

What kind of layout did you use?  I like working on turretboard a lot so I appreciate the thing he did with the DIN jacks, but I'd rather use a simple vero layout to make it easier to fit in a smaller enclosure, or add it as a stage in a bigger project.  I could make one myself, but I'm feeling pretty lazy and making a layout that has all of that off board wiring without being a mess takes a little doing, so if one exists that I'm not finding that would rule.  Otherwise I'll probably make myself some primitive terminal strips with hardwood and nails and build on that.

[user]

I could’ve just responded with “messy nest of wires” but here’s some pics. 

 

Initially I made a version closer to the one in the article but it felt too cramped and when some issues started arising (probably because of inadequate soldering skills) it was very difficult to troubleshoot. Plus I didn’t like the lightweight plastic enclosure sliding around my desk.

This is (hopefully) the inbetween version with dip sockets to try different diodes, or in this case some transistors and the veroboard that I couldn’t be bothered to cut bluetacked to the bottom of the crudely repurposed mixer enclosure. I think I have a dlc file with the wiring/layout on my laptop somewhere, which I would gladly share if it’s of any help. 

[Limo]

Over here I’ve started work on the 73-75 Serge Homebuilt. The boards are spaciously laid out so soldering is not a big deal, but they’re big and I discovered you should really do each board in its entirety to keep things manageable. So it’ll be a while before there’ll be sound output.

[TubularCorporation]

I'm still waiting on parts, some stuff backordered until 2022 but once everything else is ready I'm going to have them send the two orders and source the last couple parts somewhere else.

[thawkins]

The power jack on my QY100 is acting up. I found some tutorial for bypassing a power jack by soldering on another jack. Isn't there some better fix for this? Like if a jack is being touchy dropping power when you move the thing, is there a comparatively easy way to clean or resolder it?

Here's the video. I think I have a very similar problem. The jack is not super touchy so I can still use it, but would be nice to fix it somehow.

 

[user]

I think it depends on where the fault lies; dry solder joint, damage to the pcb pad through mechanical stress or the connector failing or something else entirely. Dry solder joint would be the easiest, if the connector is lifting off the board you could solder in a jumper wire, add some heat shrink for durability perhaps. If the connector itself is becoming damaged then I’d say it’s up to the pcb being single or double sided in how easy it would be to desolder and find a suitable replacement. 
Didn’t watch the video btw. 
 

You’re travelling with the qy, right? If you’re not already doing so make sure to disconnect the barrel connector and anything else before putting it in a bag. 
 

Watched the video now. To me it seems like a viable fix if you don’t have a drop in replacement available or don’t want to desolder anything. 

Edited August 9, 2021 by user

[TubularCorporation]

I've had a bunch of 80s and 0s Yamaha hear get intermittent jacks, in fact I think the first repair I ever did was to stuff bits of paper around the edge of the jack on the Yamaha PSS140 I got for Christmas as a kid when it went intermittent within a year.  Seems to be an issue that's common with the cheaper Yamaha stuff from that period, more than, say, Casio.  The solution is almost always to just reheat the solder joints, I don't know if it's the PCBs, the actual jack, the solder they were using or something else, but they go cold a lot.  If you have a soldering iron with a tip that's in OK shape it should be a 5 minute fix.

 

If you look at the power jack in the thumbnail image on that video you'll notice the legs on it are straight.  Most modern PCB mount power jacks have legs that are more hook shaped so they sort of snap onto the PCB and hold themselves in place, rather than all of the mechanical strength coming from the solder alone.  The Yamaha keyboards I've fixed all have straight legged jacks like in the thumbnail and I think that's the problem.

 

Like seriously, out of all the 80s/90s consumer Yamaha instruments I've tried I think more than half had intermittent power jacks.  The Alesis Wedge s notorious for that, too.  Just something about the design or the parts used makes the solder joints on the power jack get stressed more than they should be and the go cold a lot (that's how I got my Wedge for $18).

 

If it seems appropriate maybe you should record a video of it happening and see if the seller will refund maybe 10% for the hassle of repairing it.

 

Edited August 9, 2021 by TubularCorporation

[thawkins]

Thanks for the advice @user and @TubularCorporation.

I tried opening the QY100 and it's definitely not the case that the connector is loose from the board or anything like that, so this is what makes me think the connector itself may be faulty somehow.

Could it be that the solder joint goes cold even without it being loose?

I might have a soldering iron around here somewhere so might be worth a shot to try and reheat it.

Edited August 17, 2021 by thawkins

[user]

18 minutes ago, thawkins said:

Thanks for the advice @user and @TubularCorporation.

I tried opening the QY100 and it's definitely not the case that the connector is loose from the board or anything like that, so this is what makes me think the connector itself may be faulty somehow.

Could it be that the solder joint goes cold even without it being loose?

I might have a soldering iron around here somewhere so might be worth a shot to try and reheat it.

That could very well be afaik. If you have a multimeter lying around you could check continuity between the solder joint and the connector. Without a multimeter It'd be difficult/cumbersome to establish. Don't know if the despicable Action stores have invaded France yet but over here they sell a multimeter that costs around 3,- I believe and will pay for itself in the studio quite quickly even if you use it only occasionally to check on possible broken cables and battery voltages.

Another consideration is to get a toothbrush and give both the connector on the QY100 and the connector on your adapter a right old scrubbing, maybe either end is just a bit oxidized or something.

[TubularCorporation]

5 hours ago, thawkins said:

Could it be that the solder joint goes cold even without it being loose?

Definitely possible. I haven't bought any used gear in a year or two (I've pretty much reached "If I can't build it myself I don't need it*" zone for everything at this point) but when I do I pretty much always reflow the solder on the power and audio jacks and change the battery if it has one, just on principle.

 

BUT

I may have already mentioned this but my CZ-101 AND the CZ-101 an old roommate had both had this weird issue where every single aftermarket power supply we used with them had a sort of dead zone on it. If you twist the plug a full 360 degrees in the jack there are two poles (let's call them North and South) where the power cuts completely, and the rest of the rotation (let's say SSW to NNW and NNE to SSE) where it works like it should.  I've tried at least four PSUs on my 101 and they all have the same issue.  When I look closely at the jack, it's not perfectly round but very slightly oval - I'm not sure it that's related or not.  I've never found a PSU that doesn't have the exact same issue with it so I just deal with it.

Maybe you've got the same problem.

 

*exceptions made for things that are so underpriced they're cheaper to buy than to build, like the $18 Ali Express Tube Screamer pedals.

Edited August 18, 2021 by TubularCorporation

[thawkins]

On 8/17/2021 at 10:16 PM, user said:

That could very well be afaik. If you have a multimeter lying around you could check continuity between the solder joint and the connector. Without a multimeter It'd be difficult/cumbersome to establish. Don't know if the despicable Action stores have invaded France yet but over here they sell a multimeter that costs around 3,- I believe and will pay for itself in the studio quite quickly even if you use it only occasionally to check on possible broken cables and battery voltages.

Another consideration is to get a toothbrush and give both the connector on the QY100 and the connector on your adapter a right old scrubbing, maybe either end is just a bit oxidized or something.

Thanks, I do have a multimeter. It's back home now so I do not have it with me at the moment.

I think I will try scrubbing it first, because there does appear to be a sweet spot where the connection works.

[TubularCorporation]

Finally finished building my new amp (other than giving it a couple coats of hard lacquer in a week or two after the shellac has fully cured).  Sounds really nice, cost about $400 spread out over a couple years (when I started it I didn't have the skills to do the power supply without potentially destroying it and/or myself, so it was shelved for a long time about 3/4 done).  Most of the cost was because I bought a custom cabinet, the actual amp was around $130 for all of the parts and the chassis. The speaker just came from the small pile of speakers I've salvaged over the years.

 

Waiting for a couple parts so I can add the switchable negative feedback mod (gives it a lot more headroom when the feedback is on, so it works better with pedals) but with a 20k resistor and 50k pot in series, instead of a fixed 56k resistor like most people use, so the amount of feedback is adjustable from almost impossible to overdrive down to only slightly more headroom than the stock circuit.  Will hijack the external speaker jack to make it footswitchable.

Edited August 19, 2021 by TubularCorporation

[user]

Built a MegaCommand last year but fucked something up which resulted in having the screen seated in some headers which made it very difficult to make an enclosure for it. Since I had some extra pcb's left I'd figure I'd redo it some day but kept putting it off because of the price of the apem buttons that are needed. Finally managed to desolder the buttons from the old one thanks to some chipquik and a hot air station. Do hope this is the last time I decide to try to make an enclosure after building something and then taking all the measurements. So tedious and so little room for error...

Might try to put some sort of frame around the screen to hide the wonky indentation at the top and maaaaybe paint it and add some labels but for now it's working and in usable condition, didn't have a good time trying to use this as a bare pcb with an arduino on the bottom and some knobs up top, lot's of skidding and such.

 

[TubularCorporation]

Looks good!  Hand cutting holes like that is a pain in the ass.

[user]

On 9/14/2021 at 11:39 PM, TubularCorporation said:

Looks good!  Hand cutting holes like that is a pain in the ass.

Thanks! Yeah, it really is. Although I've been somewhat enjoying the insight this type of work has given me into how I use my hands/how much force I'm exerting which in turn has resulted in minor improvements over my horrible piano playing and general dexterity I guess.

[user]

Does anyone here work with lead-free solder? I have no other option but to do all my soldering in my small apartment and was freaked out a bit today when I wiped the hood of my soldersmoke sucker and the paper came away covered in gray dust and shiny particles. Then I noticed that I should've cleaned out the thing that holds my iron and the brass sponge that's inside as it's totally saturated with old solder which has started to spill into the tray that the holder is standing in. Obviously not hard to find mixed opinions on this subject in all sorts of places but would be good to hear any of your experiences/views.

[TubularCorporation]

I lived 18 of the last 20 years in historically redlined neighborhoods, if I get lead poisoning it's not going to be from solder.

[user]

On 9/22/2021 at 6:33 AM, TubularCorporation said:

I lived 18 of the last 20 years in historically redlined neighborhoods, if I get lead poisoning it's not going to be from solder.

Fair enough, I've consumed my share of lead enriched water but not entirely sure if that makes me feel more confident about using leaded solder. Otoh it's a lot more likely I'll have a stroke way before the lead gets me.        

[TubularCorporation]

I've seen a lot of contradictory stuff about whether solder is even a lead poisoning hazard, since the melting point is so far below the temperature where any kind of airborne lead would be an issue (the smoke is from the flux core), which is a pretty good argument for it not being a big problem on an individual level (the real concern being that waste from mass manufacturing with lead solder puts a lot of lead into the environment).  But there are also sources that say it's an exposure risk, too.  Lead free solder is awful to work with and I don't really build enough stuff that I'm very worried about it, though. I do have a pretty nice desktop fume catcher but I rarely use it because it doesn't actually work that well. 

Edited October 2, 2021 by TubularCorporation

[e-mertz]

So I've been locked in the house due to being on sick leave. Did a workshop last weekend for soldering together a bastl Kastl drum after not having done any diy for 2 years. Realized again how meditating it is! Now I'm GASing on two diy kits that both use the same megadrive chip as the MegaFM.

First up is the Opera Rotas, a sort of Mega FM drum machine! Can also be played as a 9-voice synth though.

Around 224$ inc shipping for just a DIY kit...a very unique instrument though I reckon!

Anther is the DAFM Synth. No Drum machine, just a plain synth. BUT 4 oled screens, one per operator. And slightly cheaper for around 140 the diy kit!

https://www.tindie.com/products/kassersynths/dafm-synth-genesis-ym2612-ym3438-diy-kit/

Gotta set my priorities what I need more, a new synth or an exotic drum machine

[thawkins]

12 hours ago, e-mertz said:

So I've been locked in the house due to being on sick leave. Did a workshop last weekend for soldering together a bastl Kastl drum after not having done any diy for 2 years. Realized again how meditating it is! Now I'm GASing on two diy kits that both use the same megadrive chip as the MegaFM.

First up is the Opera Rotas, a sort of Mega FM drum machine! Can also be played as a 9-voice synth though.

Around 224$ inc shipping for just a DIY kit...a very unique instrument though I reckon!

Anther is the DAFM Synth. No Drum machine, just a plain synth. BUT 4 oled screens, one per operator. And slightly cheaper for around 140 the diy kit!

https://www.tindie.com/products/kassersynths/dafm-synth-genesis-ym2612-ym3438-diy-kit/

Gotta set my priorities what I need more, a new synth or an exotic drum machine

Sick leave, more like sick beats leave!

[TubularCorporation]

I've been taking stock of all the stuff I built to stay sane in lockdown last summer and I think I'll probably uload most of the Eurrack modules since I don't really use them and I could use a couple hundred dollars to buy a big spool of bulk cable, which would be a lot more useful to me than modules. Or put it toward a networked I/0 expander so I could skip the cable runs altogether and just stick the expander over in the spot half of my gear is but all of my old cables are too short to reach.

 

Even DIY cables with cheap parts cost $10-$20 each so no matter what I do I'm looking at $200-$300 plus hours of work, and that sucks plus I can't afford it.  At that poitn I'd rather just make two long cables, rout half my gear through a cheap line mixer for 6 months and try to save up for the expander.

[TubularCorporation]

Just got another Mouser update, the parts for the Lyra 8 I ordered last April are now delayed until October. Supply chain is insane right now.

 

At least the other order I made later that same week sound be here by I think early May.