Building the Tiny Giant amp

[PRR]

> voltage up to 14,5 V

The chip is MADE for use in cars roaring down the road.

Don't try this on a 1971 BSA motocycle after the dynamo diode falls off: that gives 15V at idle going 20V on the road. Also burns out all the bike's lamps in a few minutes, then the battery boils. (Actually, some car-sound chips will take 24V double-jump-starts; they shut-down at 18V and are OK for some minutes at 30V.)  

Any normal/healthy 12V vehicle is fine for this chip.

[jakobmagnusson]

Hi,
Thanks for support, this means that I will build the amp with the 220V power outside the box, so I can change 12V power when needed.

I'm progressing with my planning, some questions:

1) About the tone stack: what kind of capacitors should it be (I've seen different types and I assume they have different power ratings?)

2) I've browsed around ebay, but haven't yet found a supplier for all components (alu box, chicken knobs, potentiometer, capcitiors, tele jack, etc). Do you have any preferred ebay supplier you can recemend? Preferably in EU, but US should be ok as well.

Thanks,
Jakob

[StarGeezers]

  Just like to say , after all this time , I still really Like the sound and performance of the TG ....   No problems to report once we eliminated the Hum by going to a 3 prong power supply ...    Good sounding amp ... !!!!   
  Starting on my second TG ...   Just for FUN !!!   

[masterlk]

Just building mine up and noticed this. I just cut off that little cylinder...do I need it? I was going to hardwire the supply to the board. One other thing, my supply does not have a ground but from the sounds of it, some here haven't needed one? Thanks.

On that note, my laptop DC has something attached to the cord on the DC side (it's a small cylinder - smaller than a size C battery).  I have noticed this on multiple AC to DC converters on the DC side.  What is it?  I already cut the stock end off and soldered my power end, but I want to replace it.  Cutting it again will put me very close to this widget. 

A ferrite bead perhaps?

http://en.wikipedia.org/wiki/Ferrite_bead

[slacker]

Yeah sounds like a ferrite bead, it will work fine without it, I cut the one off my power supply so I could fit the correct plug. Mine is only 2 pin, no ground and works fine, hopefully yours will be Ok.

[masterlk]

Cool thanks for the speedy reply, I am excited to get this thing going!

Cheers!

[PRR]

The ferrite bead keeps the digital trash inside the laptop from getting out the power cord and messing-up your TV and radio reception.

Since this Giant is not a PC, not any kind of digital, the ferrite isn't needed.

[masterlk]

Thanks PRR!

The ferrite bead keeps the digital trash inside the laptop from getting out the power cord and messing-up your TV and radio reception.

Since this Giant is not a PC, not any kind of digital, the ferrite isn't needed.

[jogina111]

is the TG a master volume type of amp?

[Taylor]

Hmm. I don't know if that terminology applies to the TG since it's primarily meant to be a clean amp. My understanding is that master volume amps allow for preamp overdrive because they have tube preamps, but you don't really want to overdrive the front end of this amp. The power amp does sound interesting distorting though.

[Ark Angel HFB]

I have some plans to box mine up with a valvemaster in front of it then tune the valvemaster out put down to not overdrive the TG.

Then add a stomp/switch that will change between clean and dirty on the valvemaster.

Also throw in a simple Bass and Treble EQ for the Gain channel, and maybe just leave it off for the cleaner side....

If I want I could go fine a reverb circuit...  

But in the end...

You could have a two channel 12Watt(driving 8ohm) amp head. All for under about 45 to bucks... that is awesome best part being that you would even be getting the sounds of tube break up.

[jogina111]

I built the TG but  it
sounded like an arriving ferry.
It hums like a giant.. What
could be wrong, Im sure the
components are in correct
places.

[Pyr0]

I built the TG but  it
sounded like an arriving ferry.
It hums like a giant.. What
could be wrong, Im sure the
components are in correct
places.

Sounds like it could be a power supply problem. If you had a car battery you could try that and then if there is no hum it is your power supply.

[Jdansti]

^ http://www.diystompboxes.com/smfforum/index.php?topic=99124.msg874434#msg874434 

[jogina111]

oh! It really is the power supply... Is there something that can eliminate the hum like a filter? Would the huminator from beavis audio help eliminate it?

[StarGeezers]

  On another forum  we're seriously discussing the Tiny Giant , and this was mentioned ...  "One thing I thought of regarding the hum some people are getting with two-prong power supplies: looking at the preamp, I see two 1M resistors forming a center voltage reference, and there's no capacitor bypassing noise to ground. Compare that with virtually every op-amp based circuit at RoG, which has a fairly hefty cap from Vref to ground. Perhaps an electrolytic cap across the 1M resistor to ground would...what's the term I saw on other datasheets..."improve supply voltage rejection"?   "

 Taylor , would you PLEASE join us here to further enlighten us ...  http://www.wattkins.com/node/18421?page=3

[PRR]

> center voltage reference, and there's no capacitor bypassing

The original design has a regulated supply.

If running on unregulated wall power, you probably need to change that bias circuit ala RoG and similar plans.

[mean_dorris]

Hallo,

I just got my tiny giant boxed up and wired and everything, and I'm having a problem. Maybe someone can point me in the right direction?

Basically, everything up until the TDA is good, I'm getting 11.6v where I need it to be, I'm getting signal to pin 3, and the volume pot works just dandy. (dandily?)
However, when I turn up the volume past a certain amount, it starts to clip and then all of a sudden a very loud sputtering sound
I've reflowed my joints and checked for weird connectivity to ground, of which there is none, I've gone so far as to route the speaker wires as far apart from eachother as possible as seems to be prudent from other posters earlier in this thread, but even in a shielded box this is happening. I'm not really sure what else to do but try and source another TDA and pitch this one.
Any pointers are much obliged!
Thx

[Taylor]

At what point on the volume knob does it start to do this? What are you plugging into it?

[jogina111]

got the same problems..when volume pot on 12 o'clock, it gets to stutter mode with my guitar plugged with the bazz fuss. When vol pot is on about 4, it splutters even if Im not strumming...is it the power supply? Cuz Im using a 1.3A power supply and tweaked the TG to run at 12v... Maybe it need more current? How must we connect a preamp directly to TG using the  hole provided to power the preamp? Must it be a cheater connection? Or the ground on the preamp must be connected on TG's ground?