Zvex - Box of Rock  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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Torchy
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Post by Torchy »

Ok, my contribution - a bit smaller ... change boost section values and you got a mini sized SHO.

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s.r.v.
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Post by s.r.v. »

is that verified? so far i have built 2 sho's from vero layouts, and neither of them have worked :(

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alteredsounds
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Post by alteredsounds »

never had a torchy build that didnt work and i've made a fair few of them

lefty
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Post by lefty »

While I don't doubt the validity of the SHO layout above, I have more than 7 layouts and at least 3 differing schems for the SHO on my computer.
The above is the first one I've seen with only one diode. All other have either had none (japanese site) or two at the input (I believe analoguru may have made the one I'm thinking of). More recent SHOs also have a zener diode; confirmed by Zach in a DIYStomp thread.

I threw together this layout from a schem and can confirm it works well as I have two of it already and they sound pretty good. It could be smaller and I'll probalby do so, but as it is, it's known to work.

h t t p :// notinteractive . com /stuff/guitar/sho-perf.png

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briggs
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Post by briggs »

alteredsounds wrote:never had a torchy build that didnt work and i've made a fair few of them
+1. Great to see the great Vero's again torchy :D Respect to the vero!
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I am Klon.

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alteredsounds
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Post by alteredsounds »

I built the 1st one I saw here, Igloo's I think and it worked fine, what problems are u having?

Torchy
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Post by Torchy »

lefty wrote:While I don't doubt the validity of the SHO layout above, I have more than 7 layouts and at least 3 differing schems for the SHO on my computer.
The above is the first one I've seen with only one diode. All other have either had none (japanese site) or two at the input (I believe analoguru may have made the one I'm thinking of). More recent SHOs also have a zener diode; confirmed by Zach in a DIYStomp thread.
This not the SHO, it is the boost section from the BOR.

I said if you change the values (ie to the SHO schem) you can use it to build a pot-mounted SHO.

The diode clamp is superfluous (the "two at the input"), and you can use either an LED/small-sig diode/zener/whatever across the G-S junction as its only spike protection. I have seen several different version of the genuine (original) SHO with different guts as well.

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Post by lefty »

Thanks for clearing that up Torchy, much appreciated :)

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Post by s.r.v. »

I think i'll try torchy's vero, and the SHO perf someone verified. thanks guys, much appreciated.


i'll definilty keep you guys updated on what works

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Post by audioguy »

Im building one right now using Madbeans layout... I'm all out of 9v Zeners, but I have some 8.2v. Can I use them without any problem?

Thanks!

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Post by nokaster »

finally i 2 can confirm igloo's vero layout is A-OK!

i tried this one with BS250 transistors, swapping the poles of the elco's and diodes, but somehow it didn't work...

i'm a futurlec shop a holic and i received some bs170's friday, stuck them in there and swapped the elco's and diodes around, works like a charm!

i did the 1N4001 like on torchy's layout instead of the igloo way however.

not a bad sound from this circuit...

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Post by Igloo »

I am pleased to see your build worked out, Nokaster.

It's always good to have further verification...

My layout (page 1) the conscious addition of a little more space, to accommodate the realities of various cap sizes.
It's very tempting to compact the tightest layout on the drawing board. I have had to learn to give the boards a little more room for this purpose.
Please post a pic or two, if you have time.

Anyway, well done!! :D

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Post by twostring »

I cannot seem to find a 1N5187...what alternatives are there. I've searched mouser and can't seem to find any 9V diodes. I'm much the noob when it comes to sourcing out these parts. Any help would be appreciated.

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Post by Igloo »

Hi Twostring,

The In5187 is there, only because it appears on the ZVex schem.
You can sub in any of the 1n400(1,2,3). It's only serving as polarity protection.

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Post by Grimgrim »

Does anybody have any suggestions on what changes you might make to reduce the bass response of this pedal? I am a relative noob, and have a few meager thoughts, but would like some input from you wonderful folks who really know this stuff. Thanks!

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Post by bajaman »

to reduce the bass response of this pedal?
try reducing the coupling capacitors - try half the original values and see or hear what it sounds like :wink:
bajaman

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Post by twostring »

Igloo wrote:Hi Twostring,

The In5187 is there, only because it appears on the ZVex schem.
You can sub in any of the 1n400(1,2,3). It's only serving as polarity protection.
Thanks Igloo...like I said, I'm a noob, but I'm learning a lot from this forum. Every post is like another day in school for me :D

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Post by earthtonesaudio »

Regarding the posts about fixing the "crackle okay" control, I saw something about this posted by Roger Mayer, I believe...

Can't post links yet, but I don't remember where I saw it anyway. But the solution was somewhat similar to the fuzz face gain control:

Stick a large value cap between the crackle pot and ground, and parallel all that with a 10k resistor.

I haven't tried this, but if Roger Mayer said it then it must be true, right? :shock:

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Post by earthtonesaudio »

Never mind, I just found the thread that goes over how to de-crackle the control. Current mirror. Go figure.

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Post by orogeny »

Grimgrim wrote:Does anybody have any suggestions on what changes you might make to reduce the bass response of this pedal? I am a relative noob, and have a few meager thoughts, but would like some input from you wonderful folks who really know this stuff. Thanks!
I wish ZVEX would incorporate some kind of bass reduction into the standard circuit because the tubby bass made the pedal useless IMO.

My question is WHY does the bass response increase as the gain goes up. This seems odd to me and the BOR is the only pedal I am aware of that does it. I own a BSIAB and it does something similar I suppose but the bass never gets overbearing and is perfect when the pedal is in the sweet spot.

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