| Author |
 Topic  |
|
|
DeFrag
Moderator
USA
3409 Posts |
 Posted - 08/09/2009 : 01:50:20
|
ZVex SHO clone from over at the Orange Forum.. very nice job indeed. 
 |
Edited by - DeFrag on 08/09/2009 22:04:38 |
|
|
Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 08/09/2009 : 06:36:54
|
Hi DeFrag
I was wondering if you would be kind enough to put in the link as well?
It would be nice to know if the builder used the 170 or the 7000 FET.
Technically they are interchangeable.
Looks like they used the LED mount to hold the PCB in place.
Both devices are tricky little buggers to bias properly. 
Regards De. Bob 
|
 |
|
|
DeFrag
Moderator
USA
3409 Posts |
|
|
Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 08/09/2009 : 14:38:20
|
| What is the effect? |
|
|
|
Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 08/09/2009 : 16:44:52
|
quote:
Originally posted by Laurie
What is the effect?
V-Zex "Super Hard On" Clone - FET booster.
It uses a BS170 (2N7000) FET.
From what I have seen to-date, it's the basis of a lot of their other circuits.
He's another link on the Orange forum:
http://forum.orangeamps.com/viewtopic.php?t=36683
Regards Dr. Bob |
|
|
|
Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 08/09/2009 : 16:48:25
|
| THanks! Why do they call the control "crackle"? |
|
|
|
Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 08/09/2009 : 17:21:05
|
quote:
Originally posted by Laurie
THanks! Why do they call the control "crackle"?
The varying DC across the pot as it is turned, is reproduced as annoying Crackle through the output.
In a real V-Zex SHO; It's actually labeled as "Crackle OK"  
This is similar (problem) to the control pot on the Dallas-Arbiter Rangemaster Treble Booster.
Regards Dr. Bob |
|
|
|
Leeroyfunk
Silver Member
United Kingdom
400 Posts |
Posted - 08/09/2009 : 21:17:26
|
quote:
Originally posted by Soulsonic (freestompboxes.org)
I used to think that bias changed as the gain adjusted in an SHO; then I measured it on a breadboard and realized I was mistaken. I believe the Gate Bias divider keeps the bias constant no matter how the Source resistance is set; that's the really clever thing about the original design. As the Source resistance is changed, the bias "wiggles" for a moment and causes the transistor to turn on and off, but after a second, it stabilizes and returns to proper bias... that bias "wiggling" is what causes the crackle. The distortion that happens at high gain is simply because the gain of the circuit is so high that it clips the signal and distorts. The character of the distortion doesn't have that "smashed" quality that you'd hear if the bias was hot.
|
|
|
|
zerksies
Double Platinum Member
USA
3406 Posts |
Posted - 08/09/2009 : 22:43:30
|
| looks very simple |
|
|
|
Heart and Soul
Silver Member
USA
369 Posts |
Posted - 08/09/2009 : 23:57:37
|
| make me one zerksies... |
|
|
|
zerksies
Double Platinum Member
USA
3406 Posts |
Posted - 08/10/2009 : 02:15:40
|
quote:
Originally posted by Heart and Soul
make me one zerksies...
Got a schematic? |
|
|
|
Heart and Soul
Silver Member
USA
369 Posts |
Posted - 08/10/2009 : 06:08:28
|
i'm not the one who said it looks easy...
but it's ok, it's the thought that counts... |
|
|
|
Leeroyfunk
Silver Member
United Kingdom
400 Posts |
|
|
Heart and Soul
Silver Member
USA
369 Posts |
Posted - 08/17/2009 : 06:40:22
|
| well now there's no excuse zerk... |
|
|
|
zerksies
Double Platinum Member
USA
3406 Posts |
|
|
Joske Turbo
Silver Member
Belgium
412 Posts |
Posted - 08/17/2009 : 21:08:11
|
quote:
Originally posted by Dr. Bob
From what I have seen to-date, it's the basis of a lot of their other circuits.
Yes, you're right about that. The Box of Rock, for example , is just 3 SHO's cascading into eachother. |
|
|
| |
Topic |
|
Orphin's Boner Cloner
