NPN Boost Version 2 - Vero

[Toney]

 Some time back Gus released a newer version of his superb NPN boost. Bizarrely, it didn't get much traction on the forum which is a shame as its just such a sweet little circuit. Perhaps because first version is also the beginner project ?
Anyway, it is a absolute ripper, one of the best boosts out there.

                   
                    Mounts on the pot.

Thread with schem:

http://www.diystompboxes.com/smfforum/index.php?topic=1056.400

[joegagan]

6 months back,  breadboarded v2 and was blown away. supreme interactivity with playing dynamics and/or guitar vol control. ODs into a BF fender or early marshall style amp beautifully.
could not recommend more highly. gus considers the bias reaction to to the input source carefully, makes a huge difference.

i used a metal can motorola 2n2222.

[petey twofinger]

i had looked into this circuit a few times . i never found that image .

last night i built a stereo ver 1 for a booster in a stereo miniamp with a korg pandora front end ...

i wish i would have known about the update , can i just swap a componant or two , hmmm .

[Toney]

Sure, from the V1 just add the resistor at the input (R6 on the Vero) and the rest are value changes.
Well worth it IMHO.

[karter2000]

I just built this tonight using Toney's layout.  Fired up first thing, and sounds awesome like everyone said (awesome layout BTW)!  I tried it with my bass, so it seems to work really well with bass as well as guitar.

[Toney]

 Good for you Karter.
I would say most of Gus' stuff is awesome. He seems like a pretty low-key kinda guy too. He just said something like "people seemed to like this" or some such thing, tacked on the end of a 21 page thread in the beginner forum when he introduced this.

[Gus]

Thanks for the feedback on the circuit.  I am not  someone who says anything sounds the best or it is great because with tone it all depends.

I do think it is a nice little circuit and friend that tried it liked it.  One friend noted how it makes Fender tone stack sound a little more like a Marshall with the mid increase.

http://www.diystompboxes.com/smfforum/index.php?topic=92478.0  for EQ and gain curves

[Toney]

  Cheers Gus.
Currently I have the original NPN boost and V2 in an A/B box for comparing on the fly. Testing with different amps. I still enjoy the original circuit too, has the edge with my solid state amp but agree entirely. Its all about " this goes with this but not with that" . Tone is entirely gear and taste subjective. Every player's perceptions and every signal chain are different.
Do you have your schems anywhere accessible all at once? I have a folder of your stuff - many hand drawn "notepad schems" in there. Would like to see more- if I can read your writing ().

[HOTTUBES]

How does this compare against the SHO   ??

[Gus]

It is different than the SHO.  Check the link I posted and look at the frequency response curves vs gain setting

[Wag]

I plan to put one of these together soon. What type caps are used for C2, C3 and C4? I have some polarized electrolytics of the proper values. Will these work ok?

[Gus]

I would use a film or ceramic for C2 the 470nf/.47uf cap.

[Toney]

 Wag, C3 and C4 are polarized electros, the grey stripe on the layout represents the negative side.
C1 and C2 are film or you could use an electro if that's all you have. Here's a slight update update to the Vero with spacing to suit a 470nF (0.47uF) film cap.



Pot goes in from the front like so - (image not from this layout)

[Wag]

Thanks guys. I do have some electronic experience but am new to these DIY projects, so I'm trying to learn the ropes here.  I do see the grey stripes now that you have pointed them out.

I may have to use an electrolytic for C2 to start with. I will include a few .47uf films next time I place an order and replace it at that time. I'm finding that getting components for these projects can be more challenging than the actual building of the projects! (and ordering extras when you DO order)

Thanks again and I am looking forward to adding this to my arsenal!

[petey twofinger]

in a pinch i have pulled components off old pcbs ... but .... who hasnt .

[akc1973]

Folks,

quick question: is this circuit transistor dependent i.e. can I substitute, say, a 2N5088 or a BC548 in place of the 2N2222?


Thanks, 

[joegagan]

Yes, try different transistors, socketing is good. That said, gus and i independantly found the motorola 2n2222 to be especially good in this circ. Mine are old metal can motorolas, pretty sure gus using same.

[DougH]

I'll have to give the new version a try. Sounds tempting.

[joegagan]

doug, it has that elusive quality of working with the sensitivity of input, either playing dynamics or guitar vol control. one of the subtle beauties of gus' approach.

try it, it is a quick little build.

[petey twofinger]

i got a nobels streetman "15 watt mini amp (12 volt) off of CL for cheap (15) . gonna cut this in there and make her a lil louder . i tried it tonight and it sure sounds a lot closer to 15 watts , its kinda loud now . this will be my first try with version 2 , curious if i will be able to discern the difference , with my ears .... thanks for this circuit and the layouts too !

the amp will be for my kid . i am gonna slap a 12 volt sla in it , and we can "jam out" at the woods , till the cop comes .