Hello! I've just gotten into building pedals a few months ago - completed 6 builds so far - a SHO/black eye boost, EQD Acapulco Gold, DAM Meathead Dark, ProCo Rat2, zvex fuzz factory, deadastronaut X fuzz! I have been creeping on this site for a while, it along with "guitar FX layouts" has helped me tremendously. I think I'm hooked! I think I'm ready for something new now.
I am making a Combo amp - 1x10 or 1x12. I want to make either a Noisy Cricket or a Tiny Giant build, using veroboard layouts from guitar FX layouts. But I would like to add a few extras if I can manage. I want to know if it's possible and how to go about adding a preamp, specifically the Sunn Model T preamp from the vero layouts site. I don't know if it would work better on either of these or if it would be possible at all. Where would I go on the boards to insert / replace the pre-existing preamp?
I'm also thinking about adding reverb, either a pcb or vero or an un-housed retail pedal. How would I go about this? Where would I insert it on either of these circuits? I also have an Ibanez TB25R that I'm considering cannibalizing - could I use the spring reverb tank from it or would that be too far beyond my capabilities?
I'm thinking I could put it all in a "looper" sized enclosure that I'll mount into the speaker cab.
For the record this is going to be a "mini doom rig" - I live in an apartment and can't play too loud. I'd like for it to work decently with drive pedals, esp fuzz.
Is this at all feasible?
Thanks so much! ;D
Welcome to the forum :)
So short answer to your question is yes.
Slightly longer answer:
Both the Tiny Giant and the Noisy Cricket already have preamplifiers, but they could absolutely be removed in favor of the Sunn preamp. For the noisy Cricket remove C6 and everything before it, plug the Sunn Model T pre into pin 2 of the LM386, and voila. Done.
(https://www.electrosmash.com/images/tech/noisy-criket/noisy-cricket.gif)
For the Tiny Giant remove the 1uF capacitor and everything before, plug the Sunn pre into pin 3 of the TDA7240 and voila. Also done.
(http://i.imgur.com/Uill1.gif)
Your other questions get a little more complicated. I am one of the least picky people for reverb placement, as none of my amps have spring reverb or FX loops so I just use a reverb pedal in front of them and it sounds good to me (never had any complaints from anyone else either). So you could easily add an existing reverb pedal before the Sunn preamp. If you wanted the FX loop-ish sound you could probably put the reverb between the preamp and the power stage (depends on what reverb circuit, impedences, stuff like that) and be fine. Personally I wouldn't recommend adding spring reverb. It gets complicated and in my personal opinion smaller reverb tanks just aren't worth the trouble as emulated spring reverb (i.e. Belton digital reverb modules) sound much better.
This should all fit easily into a looper sized enclosure, or if you really like torturing yourself you could probably get everything into a 1590BB. Some people on this forum could probably get it into a 1590A on a dare ::)
Anyway, welcome again, I hope this has been at least somewhat helpful. Keep posting as other questions arise ;D
Woah! Thank you for the excellent reply! You pretty much answered everything perfectly. Exactly what I need to know. I had actually thought first of the 1590BB haha. I only decided on the looper for aesthetics mainly, with the added bonus of it being a breeze to fit everything. I have a rather large empty 1x12 speaker cab that I'm thinking of using for this.
Yeah I figured the tank idea wasn't worth the trouble! I think ill stick to a belton build or maybe find a cheap biyang yri-reverb. Haven't decided yet. Feel like since this is already DIY,I should go all the way and build the 'verb myself!
So, one more question for now, I'm sure I'll have a lot more one I get started :)
Will the different voltage on the tiny giant matter with the other boards?
As far as I understand, the TG would output 12v. Would the preamp etc. be okay with that?
Id say most preamp circuits shouldn't be too fussy. I quite often power my pedals and lm386 amps with an unregulated wallwart that outputs about 13v. Some (most? All?) respond a bit differently.
You could always throw in 9v regulator or go the other way an use a charge pump to get up to 12v where it's needed? I'm no authority on the subject, but those seem like the simplest options if you really need to use different supply voltages. But no I don't think it should matter a great deal in most cases.
Quote from: Jebull on January 14, 2018, 10:27:19 PM
As far as I understand, the TG would output 12v. Would the preamp etc. be okay with that?
First, on the power supply: If you use the LM338 regulator as shown on the vero layout you end up stepping a 19-ish volt rail down to 12-ish volts, which I think is silly, why not just off a 12V power supply? If you have a 12V supply then you can just use a common rail for everything. Otherwise you have to run your 19V rail into the tiny gian board, then take jumpers from the 12V supply on the tiny giant board. That being said it couldn't hurt to make sure you have proper filtering on your power to keep the noise down. I can elaborate on that if you need.
As for your actual question, the preamp won't care at all. It's all discrete components, and the only difference you might notice is an increase in clean headroom with a higher voltage. Just make sure you use properly rated capacitors (hopefully nobody is using 10V rated caps on a 9V build anyway).
The only concern I would have is if you attach a Belton style reverb build. Belton reverb bricks run at 5V (pretty common operating voltage for digital circuits) and get there by using a 5V regulator. In the world of stompboxes we tend to use something called a linear regulator. They're dirt simple and they get the job done with minimal hassle. But the bigger the difference between the input voltage and the output voltage the less efficient they get. In power supplies less efficient means you're losing a lot of power to heat.
Now this still probably won't be a big deal depending on what you build, but it never hurts to be prepared. The small package (TO-92) 5V regulators would be risky. They are capable of putting out 100mA at 5V, but if you look at the Belton reverb datasheet its max current draw is also 100mA. Now I've never had a Belton project draw that much, and they list typical operating current at 60mA, but knocking a 12V supply down to 5V will give off quite a bit of heat even at 60mA, so you would risk the regulator shutting down. I would recommend paying an extra few cents and getting one of the TO-220 package 7805 regulators with the heatsink tab on the back. Much more robust and less likely to overheat on a small load like that. (slightly off-topic: I had a ver power-hungry pedal that used a linear regulator and pulled 600mA, and when I used a 9V power supply it ran fine but with a 12V power supply it overheated in about 2 or 3 minutes.)
Sorry if this answer was overkill to your question, I get excited sometimes and start to ramble ::)
Oh. Hmm. For some reason I hadn't even considered using a 12v supply to begin with. So I could leave off the regulator section entirely. Cool. I guess because of the whole focus on using a "laptop power supply" I didn't think about that. lol Thanks for that tip! I would still need a 4A one correct? That would still easily cover the Reverb, right? That sounds like it would be fairly easy to find too.
Thanks so much for your help guys! Since posting this I've been slowly making my way through the original Tiny Giant thread on here... which is 53 pages.... but I've learned a great deal since posting this! (also I'm sorry for making an entirely new thread for something that's already been beaten to death, but that just seemed like it may already be exhausted)
So without the preamp and voltage reg sections, this vero will be TINY. Nice! Maaaybe just maybe I can figure this out enough to draw up my own layout for it. :) I have a layout making program.. but I'm still sadly almost a total novice when it comes down to it. I'm not the best in the world with schematics yet. I'm basically still just "painting by numbers" from vero layouts. I'm very much working on changing all of that now though! This project has helped tremendously with that!
OKAY. So let me see if I understand this correctly. I would want to go: Reverb > preamp > TG
I could power these all from the 12v. Could I simply run power to the TG, then run power to the other 2 from the TG with a regulator between the reverb and TG? Also, the regular needs caps before and after? or something like that? I'm not entirely sure how to do this. Nor do I have a clue how to word that to google it or I would. I never want to come across as needy or wanting to be spoon fed :P Oh and also, the power filtering. Yes please elaborate! haha
Thank you so much again!
P.S. This would be all I would need of the TG schematic, right?
(https://s17.postimg.org/9tab5cr17/TGnoprenovreg.png) (https://postimg.org/image/9tab5cr17/)
> stepping a 19-ish volt rail down to 12-ish volts, which I think is silly, why not just off a 12V power supply?
At the time it was proposed, 12V supplies cost money, eBay was flooded with Dell flaptop supplies at $4 and less.
The rise of LED lighting has increased the supply (and lowered the price) of 12V supplies. Meanwhile the Dell flood has abated toward $8. So *now* your point may be on-point. There's still the advantage that a Dell-branded lump is a known-good product, while some of the cheap 12V supplies are dubious.
Quote from: PRR on January 16, 2018, 10:55:46 PM
There's still the advantage that a Dell-branded lump is a known-good product, while some of the cheap 12V supplies are dubious.
Which is why I wanted to talk about filtering. The 19V Dell supply explanation makes sense though, I guess I didn't really get into stompboxes (and amp building) until the 12V lighting supplies were around as I've always had something similar floating around. Definitely answers a question I always had and never asked anyone :P
But anyway, to your questions:
Quote from: Jebull on January 16, 2018, 04:21:37 PM
I would still need a 4A one correct? That would still easily cover the Reverb, right?
Yes and yes.
As for the layout, I would recommend trying a layout of your own and I would be more than happy to take a look at it and double-check it. I had been building for quite a while before I felt comfortable making layouts, and to be completely honest I think PCB layouts are a million times easier than vero layouts :P
As for the order, you could go Reverb > Preamp > Tiny Giant or you could try Preamp > Reverb > Tiny Giant. Depending on how you build them it wouldn't be very difficult to try swapping the order, especially if they're on separate boards.
You could run all of your boards off of the same 12V supply, just running a line to each from the power supply. Any reverb circuit that uses a Belton brick will already have a 5V regulator as part of the design, so you just need to worry about getting 12V to there and the regulator will take care of it. But as I said before, I would recommend one of these (https://www.taydaelectronics.com/lm7805-l7805-7805-voltage-regulator-ic-5v-1-5a.html) instead of one of these (https://www.taydaelectronics.com/l78l05acz-l78l05-78l05-5-volts-100ma-voltage-regulator-ic.html) as the regulator for the reverb.
Power Supply FilteringRegulators tend to have capacitors for high-frequency filtering on both the input and the output. Obviously our pedals are powered with DC, but the cheaper the power supply the more likely there is to be some AC leakage (ripple) on the line, which goes back to what Paul was saying about the laptop supplies. You'll notice that if you power a pedal with a cheap power supply you may hear some high-pitched squealing or general "noise," whereas if you use a One-Spot or any of the other specifically designed power supplies they are beautifully quiet. This comes down to filtering.
LEDs are very tolerant of noise on DC power supplies, which is why you can buy 12V supplies super cheap; there really isn't much to them. Audio circuits obviously need to be significantly quieter. This is why most pedal schematics have a 100 ohm resistor in series with the power input then a 100uF and a 100nF (or something similar) between the positive and ground rails. Resistors block AC signals, which means one in series will drop ripple levels, and capacitors allow the flow of AC signals, so the ripple will go through the capacitors to ground, leaving you with a much cleaner line (this is a simplification to a degree, but applies well enough to stompboxes).
Computers and other digital circuits usually require VERY clean power to operate, which is why, as Paul mentioned above, laptop power supplies already have MUCH more filtering than a 12V wall-wart supply will, and therefore don't need as much filtering in the circuit. They are also more stiffly regulated, meaning that you are more likely to get the voltage they are supposed to give you regardless of the load, whereas many 12V supplies with no load will read 14V. Any DC supply you can get for $3 on eBay can work, but you may need varying degrees of filtering (generally with capacitors) to get the same results as you would with a pre-filtered supply.
Quote from: Jebull on January 16, 2018, 04:21:37 PM
P.S. This would be all I would need of the TG schematic, right?
(https://s17.postimg.org/9tab5cr17/TGnoprenovreg.png) (https://postimg.org/image/9tab5cr17/)
Yes. You'll notice you have a couple fat capacitors on pin 6 between the power supply and the chip? Filtering 8)
Never be afraid to ask questions. Everybody needs help and this is a great place to get it. When I first started Paul (PRR) here gave me quite a bit of help on a wide variety of problems I had. There are many extremely knowledgeable people on here (much moreso than me) and everyone is super cool about sharing knowledge. That's kind of what the whole forum is about. Knowledge and sweet, sweet tone. 8)
If you're a bit more adventurous, the vintage but still available TBA800/810/820 chipamps have inputs of sufficiently high impedance so you can plug a guitar directly into the chip without any buffering. You can realize the tone control inside the chipamps' nfb loop. (ie, it's a one-chip affair all in all).
Excellent guys! Thank you again for all your help!
Yeah that totally makes sense about the 12v power supplies! :) I think I see a few nice candidates on Amazon. Nice.
Okay, so I should add a cap or two before the power supply on the Reverb and the Preamp to filter out potential noise. Right? OR I'm assuming find a better PS that is designed for audio equipment. Either way, makes sense! (I'm guessing I should go ahead and add the filters to be safe regardless of the PS used.)
So, I decided to go ahead and take a stab at making a layout since that schem seems so dead simple. Even I could wrap my head around it! (hah, I hope..) Warning: my first attempt at this! It SEEMS that this is right to me, but of course it could be horribly, horribly wrong. :icon_rolleyes: How'd I do? Any ways I could improve it?
(https://s17.postimg.org/44vqpjqbf/image.png) (https://postimg.org/image/44vqpjqbf/)
I tried my best to keep the chip to the side so I could easily use the case as a heatsink or mount a standalone one. The one thing I wasn't so sure about was the "2" terminal of the chip. As far as I understand this is for a "standby" function, which I have no desire to implement. I only want a power switch! So I added a "double link" for the jumper so I could take it to ground, is that necessary? Or could I just leave it open?
BTW I totally agree on PCB being easier, but I don't really want to take that dive yet. I'm totally fine with vero and I'm familiar with it. Plus this is itty bitty!
Now for another question. I've been thinking about the reverb, and I would like to possibly set up a footswitch option for it. I've been reading some about relays and jfet switches and such. How hard would it be to implement this in a 1/4" jack format, with a relay, so I don't have a long audio loaded cable? If I did do it I would still want a bypass (on/off?) switch for just the reverb along side the footswitch, so I could use either. If this is needlessly complicated, I have no problem only using a switch on the amp, I can walk just fine.. I just like options :)
Oh and I do fully intend to try out the order of the reverb and preamp to decide which I like better!
Thanks bool, at some point I'll definitely check into that TBA800etc idea, I'm intrigued!
Thanks again! This forum is absolutely fantastic! I honestly did NOT expect to get this much help, as most sites are very adamant on the whole "figure it out yourself" bit.. Which I 100% understand, but hey we all have to start somewhere right?
:icon_redface: sorry about the long winded post lol..
Your vero layout looks good to me, but if you don't want the standby function you need to ground pin 2, so definitely make that a double link. As for improvements, the only thing i would really suggest is leaving extra space on the corners for mounting holes to mount to the chassis. Mounting is generally kind of optional in pedals, but I absolutely recommend it in amps.
Do you have an idea what reverb you're planning on using? Most will already have some filtering designed in, but obviously it never hurts to add more as long as you've got room for it.
As for relay switching, it really comes down to how much time and money (but mostly time) you want to put into the amp. R.G. Keen wrote an excellent article talking about different methods and considerations for relay switching, I would highly recommend giving it a read: http://www.geofex.com/Article_Folders/rmtswtch/rmtsw.htm
If you decide that's something you really want to do we can definitely figure it out, but I would recommend having a read through that article and deciding how bad you want it :P
Quote from: Jebull on January 17, 2018, 10:49:55 PM
Thanks again! This forum is absolutely fantastic! I honestly did NOT expect to get this much help, as most sites are very adamant on the whole "figure it out yourself" bit.. Which I 100% understand, but hey we all have to start somewhere right?
This forum is my #1 favorite place on the internet. Figuring things out for yourself is great, but giving you a background and a push in the right direction so you can get started is cool too 8) Because seriously, what's the point of a forum if nobody's going to help?
Excellent! I'm proud of myself. haha :icon_biggrin:
Oh yeah! I was already intending to leave room for mounting holes, guess I just forgot. Not a big deal to add though. Especially since I'm probably gonna put it in a huge looper box. Thanks! :)
I'be been eyeing these mostly so far, I haven't done a ton of looking yet though, and I also haven't ruled out PCB builds either:
http://tagboardeffects.blogspot.com/2012/04/box-of-hall-reverb-culturejam.html
http://tagboardeffects.blogspot.com/2016/04/madbean-ping.html
http://tagboardeffects.blogspot.com/2014/07/rub-dub-reverb.html
I'm gonna do some more looking soon! I really don't know an incredible amount about reverb setups. I just know that when I got my current amp without built in Reverb, I've been missing it.. and been too lazy so far to buy/make a pedal.
I'll definitely take a look at that relay article! Sweet. Definitely not a huge deal to have it or not, but I feel like it'd be nice. :)
Yeah, this site is fantastic! I'm so glad I decided to do this project, it has exponentially improved my knowledge and skills as far circuits and pedals and such go!! Thanks again! You've been an incredible help already Vigilante!
Hopefully next month or so I can start actually building this! I've got a busy few weeks coming up. Now I guess soon I'll need to decide if I wanna go through the trouble of tolex or just find some good paint.. Hmm. :P
I've built the box of hall (my first reverb build, using that exact layout actually :P) and I liked it, I've heard good things about the ping (and I trust anything Madbean makes, super cool guy), and the rub-dub is kind of a simplified "bare-bones" Belton reverb. But if you look at the layouts you'll see that all of them have filtering capacitors on the inputs and outputs of the 5V regulators.
So my recommendation is to build everything as-is and trust the filtering already built in, then if you find it to be noisy when you try it with the power supply you can add a separate small board just for power supply filtering and use that as the main distribution to all of your boards.
Let me know when you start building, progress pictures are always cool ;D
As for tolex vs. paint, for an amp that's just for home use and won't be dragged around to gigs and whatnot paint would be fine, but for anything that needs to be more rugged I would lean towards tolex.
Okay, cool! I'll definitely do that. I'm leaning toward the BOH, but knowing me I'll change my mind 6 times before I get to it. lol!
Yeah I figured the only reason I would NEED to do tolex is for ruggedness and travelling, but with this project I'm really more concerned with trying new things and going all out, just for the sake of it. Plus I wanna make it purdy ;) That being said, tolex looks like a huge PITA, so I'm sure I'll be going with paint.
Definitely going to be posting progress pics once I get started! I'm excited! :D
Yeah I've never worked with tolex before as I just had somebody else build the cabinet for all of my amp builds ::) But I'm planning to try it out on the next build (hopefully in the next couple weeks) mostly just to see if I can do it.
Yeah, I'm sure I'll eventually give it a shot with some project, just maybe not this one haha.
So, a few new questions:
1. How on earth do you wire an "on-on-on" switch with a bi-color or rgb (?) LED. In other words, I want the channel selector switch for the Sunn preamp to have 3 different status LEDs. One for Normal channel, one for Bright channel, and one for both. I'm assuming I'll need a 3pdt or a 4pdt? I've been google for a while now and I can't seem to word it right. haha. Plus switches still somewhat overwhelm me in general. :icon_redface: This may not even be worth the trouble (or even possible for all I know), but I thought it might be neat. I suppose I also wouldn't have a problem with 3 separate LEDs, if this would be more doable.
2. Since this is solid state, would there be any need at all for a "master volume" of some kind? Or any use in leaving the volume pot in the TG layout? This amp will be almost entirely for apartment bedroom use (for now) so I'd like to be able to get okay tones at a low volume. I understand usually the only reason for this is with TUBE amps, so you can get your tubes pushed hard but cut back the volume. I'm guessing just the preamp volume control would be all I need, but I'm certainly no expert.
3. For a power switch, I only need to insert an on-off SPST between the power supply and everything else? I found an SPST with a built in LED indicator, but to do this myself I would need to use a DPDT?
4. I suppose the easiest way to make make the combo also a "head and cab" would be 2 jacks and a patch cable? I've seen where you can make it to where when you plug a jack in, the internal speaker disconnects, but I'd like BOTH. I'm assuming doing this both ways - where the head disconnects when another is plugged in OR when a speaker is plugged in the internal one disconnects - is either too much trouble or not possible? I suppose I would have 3 jacks on the back if I could do this, not sure if that is worth it. haha
5. I don't think I feel like implementing the relay switch, at least for now. I'll add it later if I feel like it. It seems a bit too costly for what it is, not worth it! So should I just wire it like normal, with a 3pdt bypass switch? I can just use a toggle switch on the amp, I'm not THAT lazy. :P
Again, some of this may seem overly complicated and over the top, but I am wanting to make this project fancy - mostly so I get to see how/if all of these options and ideas work! I also know that "murphy's law" is basically religion to me, so I may very well be going way more simple on a lot of this. But I looove options! :D
Please and thanks!! ;D
1 - I had written a fairly lengthy response before remembering it can't be done. Obviously the advantage of a toggle switch is you can physically see which channel you're on, so and LED is unnecessary. I was trying to think if there was a good way to do it with a rotary switch if it was really important (I did something similar on a Dumbloid build with three different tone settings) but I can't see it working with the way that switching works.
2 - Master volume is still necessary in solid state amps as you generally just want to be able to overdrive your preamp without overdriving your power amp.I would probably recommend leaving the volume in the TG layout.
3 - Correct. SPST or SPDT and just leaving one lug empty (SPDTs are just more common). I personally like DPDT and an external LED, I just think it looks classy and I have yet to find a switch with a built-in light that I liked the look of.
4 - Do I understand correctyly that you want the option to use internal speaker + external speaker as well as an option to shut off internal speaker when you plug in an external speaker? Because frankly it seems to me the best option is to have a switch that just shuts off the internal speaker, that way you only need one jack. Want to use both speakers? Piece of cake, just plug in another speaker and leave the switch alone. Want to just use an external speaker? Also piece of cake, plug in your speaker and flip the switch.
5 - A 3PDT toggle wired the same way you would in a pedal would work, but if you don't want an LED for your reverb indicator you can just use a DPDT, because, as we mentioned, with a toggle you can physically see whether it's on or off.
Thinking your way through a million different ideas, whether you actually implement them or not, is good problem-solving practice. It's always good to understand how to do a million things, even if you don't ever plan to do them. When I build amps they're usually fairly simple: single channel, no reverb, usually just gain, bass, treble, and volume. There are plenty of people that need more than that in an amp, but that's enough for me. That being said, The first amp I built had reverb, LEDs lining the cabinet, a switchable dummy load (solid state amps don't care if they have a speaker plugged in or not, but tube amps do!) and a headphone jack with its own independent volume. It didn't take very long to realize I didn't need and didn't use most of these features, so all my builds since have been simpler. But everyone has their own style, and your build can be as extravagant as you have the patience for 8)
Excellent!!
Totally fine with no channel indicator. Less work! Like you said, the toggle makes it obvious anyway.
So if I leave the volume pot, do I still need the 1u cap that's after it? Or can I just stick the pot on the front?
Ooh yeah that sounds like it would be prefect with the switch for the speaker. Thanks! :) now to go study switches more. I really need to wrap my head around em better.
Yeah I 100% know I won't end up needing or using half this stuff, but like you said I feel like this is all good exercise! Plus it'll be more fun to show off when I'm done haha. I'm even considering throwing an analog voltmeter in there as that would really nail the look I'm going for.. I've seen a few pedal builders do it and I actually have access to a few where I work, so what the hell? :D I don't suppose you or anyone would have any tips on this? As far as I understand I would need to wire it in series with the circuit somewhere along with a resistor. Not entirely sure though.
I just looked at the schematics again and I don't know what I was thinking, the volume control of the Sunn T preamp will act as the master volume, and the gain is controlled by each channel's gain control. So no you don't need another volume control, and there would be no point in making one.
As for the voltmeter, I've only ever done a digital one that had a 10x LED readout, never done an analog one, so I'm afraid I don't have any experience there. That being said it should be a fairly simple thing to work into the circuit. Do you know the model number of the one you were thinking of putting in? Many (most?) of them have a 600 ohm impedence, so you can take a resistor out of your circuit and add whatever you need to your meter so it adds up to the resistor you took out. Or you can work it into a place where 600 ohms of resistance isn't going to cause a noticeable drop in your signal (maybe after the preamp?). Uncharted territory for me, but you should be able to find a good place with some experimentation (or if someone smarter than me pops in with some advice :P).
Ohh yeah that makes sense, since the preamp literally replaced the other one. That's fine by me, one less pot to worry with!
Heh that sounds almost TOO easy! :P Hmm. Well it is actually an amp meter replacement for old tractors. Looks like it's 30 amps if that matters. The part # is A0NN10670A. I have no idea if that's a standard number or just ours though :/
I actually ended up asking one of the guys that does that with pedals, so let's see if he has any tips.
I guess I could check the meters resistance with a multimeter couldn't I?
You definitely could measure the resistance, but I would be a little worried with that particular meter as you'll be hard-pressed to find a small smplifier that puts out anywhere close to 30 amps! :icon_eek:
So maybe it would work, but I wouldn't anticipate it moving much with guitar signal.
That's exactly what I was thinking haha. 4A power supply. Oh well haha. I can look for another one maybe. Or just stick it in there anyway just for looks!
Quote from: Jebull on January 22, 2018, 02:32:48 AM
That's exactly what I was thinking haha. 4A power supply. Oh well haha. I can look for another one maybe. Or just stick it in there anyway just for looks!
If it has a backlight that can run off a 12V DC power supply it would make a cool indicator light 8)
Oooh. Yeah that would be pretty awesome!!! So. many. Ideas.
Soon I'm gonna have to start building a ton of different things just to try em all out haha
OKAY.
What exactly is the difference between this:
http://tagboardeffects.blogspot.com/2016/09/sunn-model-t-1st-gen-preamp.html
and this:
http://www.guitarpcb.com/Sunn%20T.pdf
Unless of course I'm an idiot / blind and they are the same. I sadly don't understand schematics well enough yet to distinguish the differences. I just noticed that the PCB calls for several parts the vero doesn't have. Just curious, as I have no idea which would be better. I feel like the PCB would just save a good bit of time, plus it comes bundled with the switch and J201s. :D
I will always prefer PCB over vero, but it's a preference thing. I like that PCBs are (usually) harder to mess up :P as they usually have less offboard wiring. They also tend to look a bit nicer, but obviously you pay more for them.
Aesthetics aside, there are only a few differences:
The PCB uses 150K for R6 and R7, whereas the vero layout calls for 470K in those places.
The PCB uses 47K for R10, whereas the vero layout calls for 100K.
The PCB has power filtering (C13), polarity protection (D2), and a status LED (D1).
There will be a slight difference tonally, but overall they are the same circuit.
AH okay! I think it was mostly the polarity protection that was throwing me so bad.
I can always sub out the values if I like the other better. :D
Exactly why I was asking about the PCB. I feel like it'd be better all around! Easier, safer, etc. Thanks!
Now a question about a reverb.
I'm considering the Madbean Moodring.
It seems as though it utilizes a BMP tonestack. I'm curious how this will affect he overall tone of my amp. Would it impart its mid scoop to the overall tone? I'm not so sure if a tone control on a reverb works the same as a normal one. Sorry if this sounds silly.
I'm assuming if it does, and I don't want that, I could modify it using the tonestack calculator. Or use the AMZ mods.. etc etc. I've been investigating the BMP tonestack quite a bit.
(For the record I'm not asking how to mod the tonestack, I think I can figure that out on my own, just if it will impart its qualities on the overall tone)
If it DOES work like normal tone control though, would it be a problem to just leave it out completely? I don't really want TWO different tone controls on my amp.
Yes, I see the irony in leaving out the namesake control (mood). Haha
All of this aside, I'm not sure how I feel about a reverb with so many knobs anyway. 10 total controls on a little combo amp? Ugh. :P
So the Moodring does indeed use a BMP tonestack, but only on the reverb itself. Your "dry" signal will not be affected by that tone control, it's just a reverb filter.
As you may be realizing, the Moodring is A LOT more than just a reverb pedal. It's a very cool effect, but if you're just looking to get reverb into your amp it wouldn't be my first pick. The most common reverb I build is the GGG D-Verb. It's a very simple build, especially on the PCB, it uses fairly common components, it only has one knob, and it behaves very much like a spring reverb unit built into an amp. Granted some people like more options than that on their reverb, but I like the amplifier approach to reverb: "do you want more reverb or less reverb? Here's your knob."
Anyway, just my 2 cents' worth.
AH okay!! Exactly why I asked. I suspected it may not work like I expected!
The more I've thought about it the less I wanted to use that one. Exactly like you said, it seems awesome, but not for what I want. I'll probably still build it sometime, just as a pedal. :D
I was actually kinda thinking about the D-verb when I was looking at them all. I'll definitely take a look, because that sounds like exactly what I want! Thanks!!!
> meter replacement for old tractors. Looks like it's 30 amps if that matters. The part # is A0NN10670A.
So looks like this and fits Ford 2N (most pre-1959) tractor?
(https://cdn3.volusion.com/95emh.zyzq9/v/vspfiles/photos/110410-2T.jpg?1505464040) (https://upload.wikimedia.org/wikipedia/commons/thumb/9/94/Ford_Ferguson_9N_tractor_1942.jpg/270px-Ford_Ferguson_9N_tractor_1942.jpg)
Hah! No, old tractor meters won't work around small audio. That one (that IS a universal number, actually a Ford number) is for charging 70 pounds of lead battery. Unless you have a 2,000 Watt power amp JUST for the meter, it won't twitch. A Voltmeter would be better, less current, but even a 6V meter would need fancy circuit to interface.
BTW-- don't put ohm-meters on sensitive meters, they may burn-up. THIS one you can ohmmeter all day and it won't notice. And it will read "zero". It is actually about 0.003 Ohms. You "could" determine this, with a very dead battery and a revved-up tractor, by reading the volts across the meter (about 0.1V) at high Amps of charge.
Haha!! That makes perfect sense. I have no idea what I was thinking.. :icon_lol:
Maybe I'll just build my amp directly into an old Ford. It would be so portable! :icon_razz:
I've also seen some neat things about VU meters and stumbled across this:
http://www.jlmaudio.com/AT51%20DIY%20VU.pdf
via this:
https://www.jlmaudio.com/shop/vu-buffer-kit.html
Correct me if I'm wrong but, wouldn't this work fairly well and end up being (very slightly) more useful?
Not that I honestly care about usefulness.. It's entirely for looks, but it'd be neat if I could glance at it and get a 'rough' estimate of how loud I am. :P
I still may ditch the "gauge" idea entirely due to laziness and the fact that it would be more room for error in my novice hands. But it's still neat to learn about this if I do, or for future reference.
QuoteHah! No, old tractor meters won't work around small audio. That one (that IS a universal number, actually a Ford number) is for charging 70 pounds of lead battery. Unless you have a 2,000 Watt power amp JUST for the meter, it won't twitch. A Voltmeter would be better, less current, but even a 6V meter would need fancy circuit to interface.
I once disassembled a car dash assembly. The gauges didn't use coils and magnets. They had heating elements wrapped around bimetal strips. I can't remember clearly but I have a feeling they didn't even have a pivot, the needle just hung off the bimetal strip cantilever. Extraordinarily cheap.
Another odd one was from a car battery charger. I'm a bit unclear of the details but I think it had no magnets, the meter was very light. IIRC the charger current passed through a coil to form an electromagnet.
You see some crazy and clever designs in consumer products but they usually design for cheapness rather than goodness.
There is a no-lugs charge ammeter. Inside is a magnet on a spring with a needle. On back is a clip. You just run the battery wire through the clip (no breaking or stripping). The magnetic field around the wire torques the magnet and the needle moves. Fairly insensitive to exact cable location. Not built for accuracy.
Gas gauges were generally thermal. Heater and bimetal coil. 1) easy way to get lots of lag so it didn't jitter on a bumpy road 2) allowed several forms of self-compensation for varying battery voltage 3) the bimetal was an adequate and robust substitute for an actual pivot
Later gas-gauges had a regulator instead of a compensating heater. The regulator was another heater-bimetal which "blinked" so the average voltage was about 5V (and about the same even as 6V cars moved to 12V). It is possible (in 12V work) to replace a busted one with a LM7805, and there was a day when this was easier than getting the right part.
Temperature gauges, since the 5V regulator got common, and especially since a standard Thermistor was mass produced for automotive uses, were again thermal. Way-cold is over 100K, boiling is like 1K. It is not linear, which is why you only get C and H marks, and wonder what the in between means.
Voltmeters actually could be thermal (which would not be easy interface to small audio). None of my rides ever had a voltmeter (unless I hacked one in). If not thermal, likely a hunky 10mA movement with nails for pivots, not a 50uA job which breaks on a hard knock.
QuoteThere is a no-lugs charge ammeter. Inside is a magnet on a spring with a needle.
That's pretty cool. Kind of a budget clamp meter.
Quote1) easy way to get lots of lag so it didn't jitter on a bumpy road 2) allowed several forms of self-compensation for varying battery voltage 3) the bimetal was an adequate and robust substitute for an actual pivot
Yes, I realized at the time it was a tough design and immune to much of abuses present in cars. Didn't realize it had that compensation scheme.
QuoteThermistor was mass produced for automotive uses, were again thermal. Way-cold is over 100K, boiling is like 1K. It is not linear, which is why you only get C and H marks, and wonder what the in between means.
I've got a thermistor here from the 70's that tracks my PT100 RTD to say 0.2C (maybe better). I didn't calibrate it. It was supplied with a resistance to temperature lookup which I fitted a curve to in a spreadsheet. So the non-linearity can be undone via a scale. Another one I did by measurement was only good to +/- 1.0C; that one seems to have repeatabilty issues.
QuoteVoltmeters actually could be thermal (which would not be easy interface to small audio). None of my rides ever had a voltmeter (unless I hacked one in). If not thermal, likely a hunky 10mA movement with nails for pivots, not a 50uA job which breaks on a hard knock.
It's so long since I've pulled one apart I can't remember. The volt meters are usually those
"compressed scale" [Edit "expanded scale"] types which might work with a bimetal strip. The needle ones are likely to have internal zeners which are going to cause havoc for other uses (well unless you open the meter and rip that stuff out.)
All the tacho's I've pulled apart were moving coil needle types. (taco's on the other hand are more thermal.)
I picked up a Guitar PCB PCB of the Model T preamp recently and have been tweaking some 9V amp circuits; the same idea crossed my mind, to splice the Model T front to a LM-386 (or TDA 7052A) amp. It was cool to stumble upon this thread. I've build a Noisy Cricket before and it's great, but the "grit" switch is a bit anemic. It's gritty, but not in a really great or musical way. I think a Model T spliced to the front to go full-bore, or a Trotsky/Electra on a switch for moderate grit, would be much better suited. Obviously this costs battery life, but a second 9V for the optional feature is the best bet, IMO.
Hah, I just ordered one as well! As you can see I decided to go with the Tiny Giant, but I'm also still going to make a Noisy Cricket. I'll probably get enough parts to make a couple of each (stand alone, not combo amps haha) just to mess around with and try out different tone stacks and preamps and such! I'm glad you found this thread! :icon_biggrin: Hope you might find some of my questions helpful to you too.
So. How well will my TG with 12v power supply work with a 16ohm Eminence Swamp Thang?
I've been reading about ohms/power/etc and it's making my head hurt and made me more confused than when I started. lol.
I understand this will lower the wattage, and therefore volume, which is no problem at all. Actually it is preferred. I don't want my neighbors beating down my door with pitchforks! Plus I would prefer the 16 ohm in case I ever decide to wire it up with other speakers.. etc.
Is this feasible? Or will it just sound like poop? I would still like a decent full sound. I can always go with the 8ohm version.
12V bridge (Tiny Giant) with 16 Ohm load is around 4 Watts.
That's not quite a vintage Fender Champ. Which works very well in studio or small venues. Despite a lame 6" or 8" speaker.
It's often more about the speaker than the Watts. That Thang is a Twelve (big air slapper) and highly efficient, also zingy. At 4 Watts, in a small room it sure won't sound like poop; you may poop your pants. Out on the patio it can annoy all your neighbors with ease. (You have to get way sub-Watt to completely avoid pitchfork scratches on your door...)
I agree 100% with Paul. 4 watts through a 12" speaker will be plenty for casual at-home practicing. Fully cranked 4 watts will definitely bother the neighbors. I think the Swamp Thang will be a good fit because it gives a nice full low end. Jamming with a full band you will have a bassist to take care of that, but playing by yourself it's nice to have a rich low end without needing a bassist.
Ohhh man that sounds like exactly what I'm looking for! :) Thanks guys!! So ready to get this started. I'll be sure and post some progress pics!
Hey guys!!! I've ordered all my parts (mostly) and began assembling. Now before I put all these boards together and start wiring them up, is this close to correct?
(https://s17.postimg.org/457gm2uqj/ampmock.png) (https://postimg.org/image/457gm2uqj/)
I'm still a bit confused about grounding: do I take all my grounds and run them to the input where it will be all grounded to the chassis? Would this cause unwanted noise? etc.
Also I have no idea about the power switch, I was sort of guessing. I tried to find some info, but thats the best I could come up with.
Last but not least I'm not so sure on the "bypass" for the reverb either. Look okay?
Any comments or suggestions?
edit:
err I think more like this?
(https://s17.postimg.org/q6xqvwx63/ampmock2.png) (https://postimg.org/image/q6xqvwx63/)
Second one is probably more what you're looking for, otherwise your preamp and reverb will be on all the time and you're just switching your power amp on and off.
Quote from: Jebull on February 20, 2018, 09:07:31 PM
do I take all my grounds and run them to the input where it will be all grounded to the chassis?
Yes. Pulling all the grounds together to a single chassis ground point is called star grounding, and is generally regarded as a good idea.
The bypass for the reverb will work. If you wanted to do true bypass you could do something like this:
(https://i.imgur.com/HF0W1lb.jpg)
This grounds the input of the effect when it's not on, reducing any chance of noise.
Quick question though: Any particular reason you want a voltage doubler in front of the preamp? J201's can handle 24V, just wondering why you decided that's what you wanted.
Excellent!! Yeah I threw that first one together and posted it, then I was looking at it and realized I had the switch in the wrong place haha.
On the Voltage doubler.. I saw where some people said it sounded more "right" with it (etc). I plan on trying it out before I totally commit. I may not use it at all, but it was small and easy enough to build so I figured I'd try it out. :) I even went ahead and made sure all my components could handle the 24v.
Opoh yeah I'll change that switch around for the reverb, thanks! :)
Oh and is that how I would wire up the speaker Jack? I just kinda tacked that on as a placeholder. Is that actually how it would go?
Thanks!! ;D
Quote from: Jebull on February 21, 2018, 11:49:46 AM
Oh and is that how I would wire up the speaker Jack?
Yup. The Tiny Giant layout gives speaker + and -, though if I remember right it doesn't specify polarity, so it will be up to you to decide how you want to wire it.
Okay, cool! Thanks Man!!!
Another ignorant question: what is the most reliable way to tie multiple wires together? Just twist and solder them all to the spot like normal? Twist them all to 1 single wire and run it? I don't want crappy connections for my ground or power lol
OH and do I need a plastic jack for the speaker? Or is that only relevant if the jack is in the metal box itself? I'm assuming since mine will be mounted in the wooden speaker box, I'm free to use a standard metal one?
Quote from: Jebull on February 21, 2018, 01:46:03 PM
Just twist and solder them all to the spot like normal?
That's how I usually do it.
Quote from: Jebull on February 21, 2018, 01:46:03 PM
OH and do I need a plastic jack for the speaker?
The purpose of the plastic jack is to isolate the negative terminal of the speaker from chassis ground. If the speaker jack will not be mounted to the metal chassis then you can get away with a metal speaker jack.
Cool, just what I thought! Thanks!!
Haha you've been a life saver on this project :)
Quote from: Jebull on February 21, 2018, 04:08:46 PM
Haha you've been a life saver on this project :)
Glad to hear it ;D Good luck and keep us posted!
Obligatory progress pic:
(https://s9.postimg.org/m040mj6pn/20180227_201859.jpg) (https://postimg.org/image/m040mj6pn/)
It's awesome to finally be making this happen!! ;D
Quote from: Jebull on February 27, 2018, 09:22:44 PM
(https://s9.postimg.org/m040mj6pn/20180227_201859.jpg) (https://postimg.org/image/m040mj6pn/)
Looks great ;D
Okay. After figuring out a workaround for a pretty serious design flaw, here's what it looks like test fitting everything:
(https://s14.postimg.org/j87std0st/20180304_180630.jpg) (https://postimg.org/image/j87std0st/)
;D
Quote from: Jebull on March 06, 2018, 01:52:41 PM
(https://s14.postimg.org/j87std0st/20180304_180630.jpg) (https://postimg.org/image/j87std0st/)
Hot damn. That looks killer! 8) How are the guts looking?
Haha sadly that would be where I have the least done, but hopefully that'll change the rest of this week or weekend!
The tiny boards look a little lonely in that huge chassis lol:
(https://s9.postimg.org/6rfihvm6j/20180306_205820.jpg) (https://postimg.org/image/6rfihvm6j/)
Well so far I've gotten the preamp and reverb working fine, but I MAY have fried both the amp chips i had while testing out the amp circuit.. (that or I happened to get 2 duds) but I think I may just try to use the tiny giant PCB just to be safe and more stable. I ordered that and a handful of amp chips. If I still leave off the Voltage reg and preamp from the pcb, will I need to run any jumpers or just leave em off, I'm assuming my new input would be where the one leg of that lower 1u goes?
(https://s9.postimg.org/pxsaph60r/tinygiantpcb21.jpg) (https://postimg.org/image/pxsaph60r/)
Your combo is coming along nicely! I've built the TG on the PCB and paired it with a Jensen Mod-8 in a simple box.
It works really well. It's my test amp on the bench and it's plenty loud. I've thought about doing what you're doing
and pairing a TG with a preamp circuit. I think you'll be very happy with the results of your build.
Thanks!! I'm happy with it so far! :D I may do something similar to that for my next one haha. I have a couple old combo amps I'm thinking of gutting and repurposing :) I had actually looked into those Jensen mod speakers when I first started this, they seem pretty cool! Especially for the price!
Anyway, anyone know if I'll need to do any jumpers on the Tiny Giant PCB if I leave off the Voltage regulator and preamp? I'm assuming ill still need one on the standby pads, but other than that I'm not really sure :/
Okay, looks like I need some help. I got my new parts in and assembled the tiny giant PCB then attached my sunn preamp (which I tested separately first - works fine), fired it up.. and nothing. Granted I haven't had a chance to mess with it much but anyone know anything obvious I missed?
I left off all the components on the pcb for the Voltage regulator and the built in preamp / buffer. So I only have the base components for the amp chip on the board. Am I making some obvious stupid mistake? Do I need some jumpers somewhere since I left components off?
I get literally nothing. At least my first one (vero layout) got fairly warm
- still no sound but at least I know it was doing SOMETHING.
I can post pics later if I need, I'm at work now.
Man this project has slowed down, mostly thanks to a massive hailstorm totalling out both my vehicles and I've also been packing and preparing to move, but I'm slowly getting there!! Hopefully after next week when I get moved in I can knock this thing out!!
Have you tested the Tiny Giant by itself? That's where I would start. And I would never object to pictures and voltage readings.
And as for the question about leaving out the regulator and preamp (which I kept thinking "I'll answer that when I have more time"), if you leave out the voltage regulator then you can omit the 120R and 1k resistors and the middle regulator pad is a good spot to be your new 12V input. As for the preamp you can leave off a bunch of parts (everything except the TDA, 2.2R's, 220n's, 22u's, 470u, and the 100n on the power rail) and put your signal in on the leg of the 1u that connects to pin 3, just like you said previously.
(https://s31.postimg.org/t7aqmi7t3/TG-jump.gif) (https://postimg.org/image/t7aqmi7t3/)
Excellent!! Thank you!! Hopefully soon I can mess with it again between packing boxes haha
But yeah I have not tested it alone, I was unsure if that would work or be okay (or not incredibly loud) without the preamp.
Okay, finally got to work on it some more! Update: I now have sound, but it is very quiet. While biasing the j201s, I get 0 at G of q3 and 12.35 at D of q4. Any idea what I have wrong here?
What other measurements would be helpful?
It SEEMS to me like something is wrong with my sunn preamp, which is odd, because it worked fine before. All I did was resolder the output wire.. :/ hmm. Maybe I screwed something else up in the process.
(https://s31.postimg.cc/t7aqmi7t3/TG-jump.gif) (https://postimg.cc/image/t7aqmi7t3/)
Do you have an audio probe? I would recommend running through everything before the amplifier with an audio probe to make sure all the signal that's supposed to get into the amplifier is getting there.
I do not! I've been meaning to make one for ages, ill try to do that when I get home!
Also, I added a jumper there PRR, that's what finally got me sound. :) Just incredibly quiet sound haha. So I've obviously still got something wrong somewhere. Maybe the probe will show me!
So I just need to follow the signal with it to see if it stops somewhere, and that would be where my problem probably is, correct?
Also just for more info: I couldn't figure out which 100n I needed on the TG board, so I just added both, could that somehow cause an issue?
Quote from: Jebull on April 18, 2018, 11:04:22 AM
Also just for more info: I couldn't figure out which 100n I needed on the TG board, so I just added both, could that somehow cause an issue?
There are three. Having all of them probably won't hurt. You could conceivably omit one of the two by the non-existent regulator (with Paul's short, they're equivalent).
Re-purpose the one you don't use in your audio probe! All you need in addition is a 1/4" plug. :)
Ah, I may have added all 3. Either way I couldn't figure out which to omit and I'm not sure, I don't have it in front of me sadly :P but yeah that's not a bad idea! Hopefully I can work on it after work today!!
The way it's acting, it doesn't seem to be a problem with the Tiny Giant, it seems like it's the Sunn preamp. I have no idea though haha
Quote from: Jebull on April 18, 2018, 11:04:22 AM
So I just need to follow the signal with it to see if it stops somewhere, and that would be where my problem probably is, correct?
Exactly. It doesn't necessarily rule out anything after the point at which signal cuts out, but it's generally safe to assume that the circuit is good until you lose signal.
Quote from: Jebull on April 18, 2018, 12:37:31 PM
The way it's acting, it doesn't seem to be a problem with the Tiny Giant, it seems like it's the Sunn preamp. I have no idea though haha
You can plug a guitar directly into the TG. This would likely rule it out.
Quote from: bluebunny on April 18, 2018, 04:31:45 PM
You can plug a guitar directly into the TG. This would likely rule it out.
Ahh okay cool, that will be helpful! :) thanks!!