'SPITFIRE' Metal 'n' Blues Pedal...

[J0K3RX]

what is that from? Looks similar to the sansamp active but there are obviously differences... The Spitfire would be totally awesome'r with a real good tone control!!! Not that it isn't already totally awesome but it would just be that much more awesome, ya know! I need something better for the stuff I am working on also!

Have you seen this one?
http://www.diystompboxes.com/smfforum/index.php?topic=71716.0

[deadastronaut]

i lifted it from on here somewhere..no link sorry..but looks worth a try.

that one looks cool going by the write up too..


yeah the spitty could do with a revamp...i always kept it simple, but a nice full 'proper' stack would be brilliant..

ive got the stack from the bass preamp after it at the mo just for the hell of it, , and makes it tighter/punchier instantly...

but loses the flow of the lead sound though i find...as is the problem with hi gain punchy sounds, great for riffin, but feels a bit stiff for leads sometimes..

its just getting the balance right i guess...those stacks are on my list anyway...

[Kipper4]

Rob did you post the voltages. I thought i'd seen them somewhere but i can seem to find them now. Despite trawling through all 23 pages.
Can you pm me a latest v3 thats had the componants (C16) updated if you have a link pls
I still cant get mine to work.
thanks

[Kipper4]

I've got it working i had a bridge at R6. me and my blobby soldering.
It sounds amazing.
That tone stack is so effective.
I might have to rip that one of for use in my piglet.

[Kipper4]

https://www.dropbox.com/sh/7ma9n53c5jqdgsr/d-0TvwYXDL#f:Spitfire%20tone%20stack.jpg

Is this the tone stack or have i included some bit that are not needed? if it was transposed to a differant circuit.?
thanks

[deadastronaut]

hi rich, glad you got it working ok...nice one.

yep that's the tone control...cool init!!..

[Kipper4]

Very ccol mate where did that one come from does it have a name? The tone stack.

It's one heck of a good sound lots of gain. (it's making the amp squeel when in my test box , not ideal test box)
lots of useable sounds from the dark and manacing to biting, responsive, treble screaming and lots of crunch between.

Good job. Thanks again to you Rob and everyone else who helped you.

I like that there arent too many parts. I treid it with 2n5457s but i prefer it with J201s.
Come to think of it it only squeeled when i put the j201s in in the sockets. mmmmm

[deadastronaut]

i made up the stack as i went along..i tried the usual BMP  and others, but was never happy with em....they always lost the chunk, but this one retains most of the chunk even when adding treble..

if you shield the input you shouldn't have any squeel at all..and should be near silent too.....

yep j201's definately...

[Kipper4]

i made up the stack as i went along..i tried the usual BMP  and others, but was never happy with em....they always lost the chunk, but this one retains most of the chunk even when adding treble..

Well done sir excellant work.

[ggedamed]

The tone stack from the Carvin amp is a variation of the James tone control. The active version of the James tone control is the Baxandall tone control. Rob's tone control is a version of the Baxandall tone control. Pretty interesting one also.
You can use the famous Duncan's Tone Stack Calculator to play with the values.

I saw quite a few threads on this topic, from which the main idea seems to be that James/Baxandall tone control is better suited for lower gain, especially when we're talking amps.

BUT Rob's version doesn't have the usual two shelving filters and it is behaving more like an graphic equalizer with 4 wide bands around 60Hz (bass), 700Hz (mid), 5kHz (treble) and 10kHz (presence). The simulation looks like this:



The separation, though, doesn't look that good (bass - blue, mid - green, treble - pink, presence - red):




Maybe you wanna try a gyrator circuit a la Metal Zone. Aron has a Gyrator Filter Calculator that you can use to tune it to your needs.

[Kipper4]

Mine sounded great but i had to do some mods as it made my rig squeel when the tone and gain were maxed out.
I changed the gain pot 1meg for a 100k and its reigned it in a bit and the gain range is a lot more useful now for my needs.
Please say if you think i could do some harm to the circuit with this mod.
I also put 2N5457 in the place of 3 of the transistors.
Someone please explain "Merlin fets" to me too
thanks
Rich

[deadastronaut]

cool, i think i ended up using 47k-100k..

i have my tone at around 9-10 oclock..

'merlin fets'  have to be used on this....= spitfire planes  have merlin engines..

i still don't understand why you get squeel 'if' you sheilded the input from the 3pdt to the pcb you should be pretty quiet

[stallik]

I've built my first spitfire based on the original layout. It's been on my list for some time & I'd downloaded the layout ages ago, then didn't bother to read the full thread before starting...
It sounds pretty good straight off ( actually, it's pretty amazing-thanks Rob)  but I intend to swap a couple of caps to 'tune' the channels. Before I do, I've one problem to sort first. Oscillation. Faint and tuneable using various switch combinations but it only occurs a second or so after I switch the distortion off. I can get rid of it by rotating the gain but the circuit is not in the signal path??
I'm switching both input and output of the circuit so I don't believe I'm loading the output on bypass. I've tried disconnecting the led, it happens with battery and ps but the effect goes when the board is unpowered.
Any ideas where I should look?

I hope it's not a problem with the skew gear......

[stallik]

Ahh. Seems I've sorted my own problem. Turns out that an electrolytic was causing the noise. Put my finger within an inch of it and it went quiet. Had a bit of a theremin thing going on. Quiet now but it's late so won't start swapping caps now.

[deadastronaut]

ok, cool...glad you spotted the possible problem..

love the pics on the pics thread btw...

i think your the first to build the 'spitfire v5' ..

'maik' etched his boxes for the v5 but i never saw the final result...


i have the spitfire v3 on breadboard at the mo, (amongst other projects)  and am modding the tone to be a better 'modern' tighter , punchier one......

so there may be a spitfire v6 soon..

[stallik]

Fraid not on the v5. Mine's a v1! but rest assured - I will be building the newer versions. It would be mad not to and spitfires always looked good in formation

[paulyy]

Just built the spitfire v5 and it works great. Its the best JFET distortion I've built yet. Thanks deadastronaut  for this great project. I have a few questions about adding more gain but need to get some sleep right now.

[paulyy]

So does this make me the first one to build the v5? Anyways, I was messing with it today and put acouple overdrives in front of it and sounds really good. The mods come in handy as well. I'm also running it at 18V's. The 18V's seems to tighten it up some. Either way. 18V or 9V. It still sounds good. I left the cap values the same on the layout. I'll mess with them when I get more time. The fuzz is really cool too.

[Maik]

Mine is just 90% ready. Have to make it 100%. Build V3 and it sound great. Rob made a fine thing!

[deadastronaut]

cool 2 x V5 builds...nice one guys..we must have demo's by law..

today i finally dragged my marshall into my lair....at long last.

and have the breadboarded V3 through it so i can mess with the tone again...ive been comparing marshalls (AVT275) distortion with the V3,

and the v3 is way better....the marshallls distortion is 'thick and flabby' and lacks definition, the sound is 'around' the note if you get me...and is the hissiest thing

on the planet...nasty...that always pissed me off.

..anyway ive been messing around and getting some nice 'variations'  ' varitone'  stuff going on. (much to the annoyance of Rert the cat.)

the V3 is sounding even better now....i'll go through  few 'varitones' and settle on a handfull then sort a full stack out around them  fav's hopefully...


(glad to see the forums back to normal)...