Danelectro Tuna Melt Tremolo re-housing guide

Note: the material presented in this thread is for informational purposes only. Any action taken as a result of this thread is at the reader's sole responsibility. Neither I (theelectic) nor TGP (The Gear Page) can or will be held responsible as a result of any use or misuse of the information presented in this thread. In other words, if you break anything or do anything it's your own responsibility! Be careful!

Also please do NOT PM me personally for help regarding this project. All the time I have to devote to the project will be going into posting in this thread and answering questions in the thread. If you do not receive a response please do not take it personally, use the many online resources available to help yourself. To the best of my knowledge, there has been only one version of the Tuna Melt ever made - the model pictured in this guide was recently purchased online. This guide is meant to be used with the model pictured only - if yours happens to differ in a major way, do not use this guide!

As the author of this guide I retain copyright so please do not copy/paste any text or photos and host or distribute them anywhere else. Feel free to link back to this thread. Be sure to read this guide completely in its entirety before starting anything!

Like this re-housing guide? Made a few bucks doing some re-houses for a friend? TGP has graciously hosted this guide - why not take a minute and scroll all the way to the top of the page and click on the "Make A Donation" button. You'll become a TGP Contributing Member and help support TGP!

Enough of the mind numbing stuff, let's dive in!

Inspired by CS Jones and his "6 in 1" thread, I will be presenting a step by step guide to re-housing the Danelectro Tuna Melt Tremolo. The Tuna Melt is a great sounding little trem, but like all Danelectro mini-pedals, it suffers from an electronic bypassing system and a less than roadworthy plastic case. In this guide, we will be re-housing the Tuna Melt in a solid die cast aluminum case (the standard Hammond 1590BB, choice of many boutique and mainstream builders) and installing a true bypass switching system.

This is an advanced project and is not suitable for beginners! It requires solid soldering AND de-soldering skills, machining (drilling holes in metal), and wiring up complicated switching schemes. If you have never built anything electronic before, I would recommend starting with a simpler project first. If you can build a complete effect pedal from scratch without any help, you should have no trouble - but then why are you reading this when you can do it yourself? :-) If you can put together a BYOC kit without any help and have it work the first time, you should be OK. Otherwise, we'll be going slow but seek help from your local electronic geek friend. Your question(s) may also be answered in this FAQ:

http://www.diystompboxes.com/cnews/FAQ.html

As with most DIY effects, this is NOT a cheap project! You've got to really love the tone of the Tuna Melt in the first place. Put any thought of "oh, I can build that for $20" out of your mind - the section of the Guitar Effects FAQ linked below explains it best:

http://geofex.com/effxfaq/bldfx.htm

Let's break down the costs before starting:

Danelectro Tuna Melt Tremolo - $38.99 + $5.95 shipping from Musician's Friend (less elsewhere)

Cost of required parts from Smallbear Electronics: $43.10 + shipping (depends on location)



Rough cost: $80-90

That's just the parts required for the re-housing. If you don't already have a drill, soldering iron, drill bits, wire cutters, etc. figure to add some more $ to your shopping list. Of course, if you already have the parts lying around or can get them from a cheaper source, subtract as necessary - but figure to spend at least $50-75.

Besides the obvious stuff (soldering iron, solder, drill, drill bits, etc.) you should also have a digital multimeter handy. At the very least, one with DC volts, amperage (current) and continuity functions. It will be invaluable if/when troubleshooting is required!

Note: I will be referencing the parts as found at Smallbear Electronics and will not answer any questions about substitutions - it just makes things simpler than to have to answer dozens of questions about this or that different part, even if it's an equivalent. I have no affiliation with SBE, however as a company they are the main source for parts for many in the boutique pedal industry. You could do worse than to support them!

When this guide is complete, the finished re-housed pedal (with some extra mods/tricks I won't be illustrating) will be sold and the profits donated to TGP. So if you have no electronic skills but still want a re-housed pedal, keep your eyes peeled!

The re-housing can be broken down into the following steps:

1) Dissassembly
2) Part removal
3) Re-wiring
4) Machining & fitting
5) Wiring

We'll be using CS Jones's Tuna Melt schematic as a guide to help us along (thanks Clay! note: DO NOT try to build a Tuna Melt from scratch using this schematic):



The photos below are thumbnails, click on them for larger versions (note: most are over 600k and will take 20-30 seconds to load on a 56k dialup connection).

One other warning: the parts in the Tuna Melt are not particularly ESD (static electricity) sensitive, but you may want to play it safe and discharge yourself by touching something metal or wear a wrist grounding strap.

PART 1 - DISSASSEMBLY

Time required: approximately 15 minutes

1) Here's the victim, ready and willing in blister pack prison:



2) Warranty schmaranty!



3) Take off the back cover by using a flat bladed screwdriver on the black nut (unlike FAB series, too cramped for fingers):



4) Remove battery and store somewhere else for another effect.



5) The Tuna Melt contains two PCBs, each held with three screws (circled in red). Let's remove the first PCB with a small Philips head screwdriver:



6) Carefully lift and pull the PCB towards the footswitch end:



7) Lift the bottom PCB and you'll see it's connected to the top PCB with some rainbow wires:



8) The PCBs are connected with a molex connector - GENTLY rock the male portion of the molex out of the female part - the bottom PCB should come off. Set aside.



9) The top PCB is connected with three screws, remove them:



10) You'll notice the top PCB still isn't coming out. That's because it's also held in place by the knobs. Turn the pedal over and using a small flat blade screwdriver, pry off the knobs. Do this and the top PCB should fall right out:



11) The two PCBs together. Notice how Dano used cheap trimpots with glued in knobs instead of real pots - don't worry, we will replace the pots with good ones later!



Even though we may not need them later on, keep all the loose parts together in a Ziplock bag, cup, plate, etc. since they may come in handy later on.

That's it for today, part two will be presented later on this coming week.

[braughwd]

I might do this for the tremolo I'm building. It would've been a bit more hassle but quite a bit cheaper not to buy all of those parts from smallbear. I think this will be pretty cool.

[Gibsonchild]

theelectic-I hope you don't mind me posting this. I don't mind deleting this if you do.


Here's a Tuna Melt I did about 5-6 years ago. I stomped a few to death and then decided that this was the best remedy. I also gutted and wired up an old dunlop wah for an exp pedal for the speed control. That's what the "on/off" switch is for, changes from exp ped control to the knob on the pedal. All in all, cost me about $70-$80 bucks (the wah was free, didn't work). Took me one evening to drill/paint/bake/label the case and another 3-4 hours to swap it over. Ran into some issues w/ the exp pedal. Had to make the pedal work w/ rev polarity and completely isolate the exp jacks cause the unit was grounding out. I still need to add TB, as I knew nothing about bypass at the time. I found a heavy duty momentary footswitch at a local electronics store. The insides look like shite, so I'll keep that to myself.

I recorded w/ at a very well known studio a few years back. The engineer/producer prefered the sound of this thing over any of the rack stuff. Gotsta love the Tuna Melt!!

[Antero]

Thanks for doing this.

[getbent]

this is awesome! I had a bookmark for a thread on this board for the 6-1 dano pedaboard and now the link is dead.... anyone know what happened to it? I also noticed that all traces of CS Jones are gone.... I'm new here did something happen? Thanks.... (I went and bought the dano GC and Hot Coffee to pursue the cool sound that mena50 had here that was mentioned in that thread... if someone has a copy of what that mod was or could point me to the thread I'd be much obliged!

Originally Posted by getbent

this is awesome! I had a bookmark for a thread on this board for the 6-1 dano pedaboard and now the link is dead.... anyone know what happened to it? I also noticed that all traces of CS Jones are gone.... I'm new here did something happen? Thanks.... (I went and bought the dano GC and Hot Coffee to pursue the cool sound that mena50 had here that was mentioned in that thread... if someone has a copy of what that mod was or could point me to the thread I'd be much obliged!

Best left to another thread/discussion, I'd like to keep things focused on the Tuna Melt in this thread - although a lot of what's in the Tuna Melt also applies to the other Danelectro pedals, so keep reading! You can try posting in the Harmony Central DIY Forum (http://acapella.harmony-central.com/...?s=&forumid=94) I know CSJ read there.

[PB Wilson]

Great idea! Thanks for doing this. I've got a bunch of dano minis and while I doubt I'll rehouse many of them, I'm curoius about what each of the rainbow wires is for. I'll be reading this thread with interest.

[trumpus]

Absolutely awesome. Thanks for the walkthrough! I;ve been waiting for this to finally be spelled out!

brian

[asdf]

Not to try and side track this thread but getbent the reason you can't find any posts by Clay is that he recently deleted them all.

[n.j.]

This is cool stuff. It's like a serialized pedal drama. Thanks for doing this, theelectric.

[getbent]

I'm buying a tuna just to do this... this is really fun and enlightening... thanks man!

[AL30]

Interesting. Are you going to pull the flip-flop and hard wire a mechanical switch in?

AL

[doctorx]

I have a dano chicken salad vibrato (poor mans univibe) I would love to rehouse with true bypass, but I have no idea how to do it.

[AL30]

doctorx,

The switching is happening in the 4013 flip-flop so that's going to come out. The question I have would be what's happening with the 4053 chip (multiplexer). Pins 9,10 and 11 are inputs according to the datasheet so they are also doing some controlling. But my logic, which was never that good to begin with, is waaaaay rusty.

data sheets are here
http://info.hobbyengineering.com/spe...D-CD4013BC.pdf
http://www.st.com/stonline/books/pdf/docs/7731.pdf

AL