Here's a collection of vero (stripboard) and tagboard guitar and bass effect layouts that we have put together covering many classic and popular effects in growing numbers. Many of these have been posted on freestompboxes.org, so check that site out for great discussions on building your own effect pedals. Enjoy the builds and please also visit us on Facebook and Twitter
Pages
▼
Saturday 4 February 2012
Skreddy Screwdriver Deluxe
Get your big boxes out for this 5 knobber! :o)
Although having said that it is only 21 columns wide and so will fit into a 1590B if you're feeling adventurous (and you're more precise with your measurements than I am)
I'm pretty sure someone on the BYOC forum built this one successfully so I think it should be verified. Send me a front and back pic if you want and we can see if the extra set of eye can pick something up.
The Brilliance pot is basically a lowpass filter in conjunction with the 3.3n cap. If you want to omit it that's no problem, just take the wire connection for Brilliance 1 & 2 directly to Volume 3. The existing Brilliance 3 / Volume 3 wire can be removed completely, as can the 3.3n cap if you can be bothered desoldering. There's no problem leaving the cap in-situ if you want though because it won't be making any electrical connection to anything anymore (other than ground).
so this is a Positive ground circuit right? just use a battery? I have some russian gt402 germanium's that are supposed to be kinda like ac127's. (anyone know if that's true at all?) Is there a gain range recommended for any or all the transistors on the board?
No it's negative ground. The AC127's are NPN so you'd want some GT404B's rather than GT402B's. The GT404B's that I have had have been very hit and miss though in terms of leakage, so I'd suggest looking at the MP38's instead. They're lower gain but very low leakage.
Just built this one and it sound fabulous. The only issue is the master volume. I have to have it cranked for unity. Any ideas on how to increase the volume?
Assuming you've checked for the usual dodgy solder joints and unwanted bridges, have you socketed the transistors? And if so have you tried swapping another germanium? With the exception of a few Russian ones, the vast majority of NPN germanium transistors that I've bought have been a crap shoot. What voltages are you getting at the transistor pins just to see if anything stands out.
Yes something doesn't sound right with Q3. If it's increasing it suggests a problem with the resistors supplying it (2K7, 8K2 or maybe the 100n from that junction), or more likely the transistor itself. Do you have a silicon transistor that you can try in that spot? It may not sound right because it won't be properly biased, but if that gives you a volume boost then you know the transistor is responsible.
And if you want some NPN germanium transistors I can highly recommend the Russian MP38A. It's the only NPN germanium transistor that has ever had any consistency for me. Out of a batch of 50 the gain ranged from 54 to 90, and all were very low leakage. NOS Newmarket transistors, particularly NPN ones have been very expensive gambles for me in the past, and the chances are you're more likely to get a duff one than one with perfect gain and leakage. Unless they've been measured beforehand and are guaranteed to meet that spec, I just stay away from them now.
Do you reckon you could use a very low gain silicon transistor in Q3? All my npn germaniums are either around 10 hfe, low leakage or 150 hfe with high leakage. Just a thought...... I did order some new ones from russia but they never made it to Oz. Must have had a stopover at Germania (ok, that was BAD!!), hehheh. Cheers for any help at all.
I just put one together, but at the moment the output is below unity gain. If anyone were able to post voltages from a working board, I would be grateful. I've been over the board several times. All the joints are good, no bridges, etc... I'm guessing it might be an issue with one of the transistors.
What was causing the problem with your pedal? I am facing the same thing now. Volume is below unity. I have tried 4 ac127 but there is no difference. Thanks
Is the brilliance knob known to cause a volume change across its sweep? My pedal's volume is very low at the lowest brilliance setting and increases significantly as I turn it to max brilliance. I leave it at max now but its not very useful at other positions.
How would I sub the germanium for a silcon NPN transitor. Or do you have a layout of a great cranked tweed style od that is nice and saggy but it can't use a jfet. I don't have any j201 or equivalents right now. Tons of mosfets and npn transistors
AC127 (the germanium transistor) is NPN so you could just pop in a NPN silicon transistor. Just check the pinout of your transistor and follow the CBE labels on the layout.
You might shoot for a relatively low hfe to approximate the performance of the AC127
It's definitely worth buying some JFETs and germanium transistors in the future
Hi , Apart from the Cry Baby is there a pedal circuit that can be made to reproduce the Orca/seagull sounds in PINK FLOUYD ECHOS Album. I would really love to make a pedal that can produce this sound . Any ideas.
Im no expert, but I believe you just made an excellent point. You certainly fully understand what youre speaking about, and I can truly get behind that. Cordless Screwdrivers Review
Great things put in this blog, thank you so much for sharing with us this informative blog. Visit Ogen Infosystem to get creative and responsive website designing services. PPC Company in Delhi
Nice Information presented you by this blog, thank you so much for sharing this informative blog. Visit for Mutual Find Schemes and Advisors. Best Performing Mutual Fund
Nice Blog, Visit for the daily lifestyle activities and about Health, Wealth and Lifestyle Events by Lifestyle Magazine in India. Lifestyle Magazine India
Search our best SEO Services in India. Provide professional SEO Services increase Visibility of your Website on the Search Engine. CSS is a top Rated SEO Company in India.
just tried it. no luck yet. might have a troubleshoot this arvo.
ReplyDeleteI'm pretty sure someone on the BYOC forum built this one successfully so I think it should be verified. Send me a front and back pic if you want and we can see if the extra set of eye can pick something up.
Deletetrying to do a 4-knob one without the brilliance. what should i be wiring to just leave it maxed at 0k instead of 2k?
ReplyDeleteThe Brilliance pot is basically a lowpass filter in conjunction with the 3.3n cap. If you want to omit it that's no problem, just take the wire connection for Brilliance 1 & 2 directly to Volume 3. The existing Brilliance 3 / Volume 3 wire can be removed completely, as can the 3.3n cap if you can be bothered desoldering. There's no problem leaving the cap in-situ if you want though because it won't be making any electrical connection to anything anymore (other than ground).
DeleteOoh, just noticed you said 2K, the Brilliance pot is 100K. Do you mean Pre-Gain?
DeleteJust built this and it works perfectly, cheers for another great layout Mark.
ReplyDeleteI've built one before using a schem from freestompboxes that's since disappeared, so this one came in handy.
Last time I used an AC176 for the germanium transistor, and my two builds sound exactly the same, so that's a good sub if you can find one.
That's great, glad you're finding the layouts useful, and thanks for the transistor info
Deleteso this is a Positive ground circuit right? just use a battery?
ReplyDeleteI have some russian gt402 germanium's that are supposed to be kinda like ac127's. (anyone know if that's true at all?) Is there a gain range recommended for any or all the transistors on the board?
No it's negative ground. The AC127's are NPN so you'd want some GT404B's rather than GT402B's. The GT404B's that I have had have been very hit and miss though in terms of leakage, so I'd suggest looking at the MP38's instead. They're lower gain but very low leakage.
DeleteHmm. Seems like missing "Verified" tag on this one :)
ReplyDelete+m
I've used an AC187. Sounds great! Thanks for the layout!
ReplyDeletei see all these recommendations for transistor model numbers, but no recommendations for hfe... anyone?
ReplyDeleteGoogle is your friend: http://www.diystompboxes.com/smfforum/index.php?action=printpage;topic=76199.0
Delete+m
Just built this one and it sound fabulous. The only issue is the master volume. I have to have it cranked for unity. Any ideas on how to increase the volume?
ReplyDeleteAssuming you've checked for the usual dodgy solder joints and unwanted bridges, have you socketed the transistors? And if so have you tried swapping another germanium? With the exception of a few Russian ones, the vast majority of NPN germanium transistors that I've bought have been a crap shoot. What voltages are you getting at the transistor pins just to see if anything stands out.
DeleteHi IvIark.
DeleteDouble checked all the joints and no bridges.
Q1
D: 6.65
G: 4.02
S 1.969
Q2
C: .579
B: .547
E: 0
Q3
C: .878 and continually increases
B: .575
E: .497
I used an AC127 from Pedal Parts Plus ($4!). Its HFE measures 92.
Again, it sounds exactly like it should -- I own a real Screwdriver. The only issue is the overall volume.
I'm guessing it might be Q3 but I don't have any others lying around right now. I think I may get a few AC187s, OC140s and CV7112s and try them out.
At the end of the day it's not a deal breaker since I usually play at unity volume. It would be nice to be able to turn it up past that though.
Yes something doesn't sound right with Q3. If it's increasing it suggests a problem with the resistors supplying it (2K7, 8K2 or maybe the 100n from that junction), or more likely the transistor itself. Do you have a silicon transistor that you can try in that spot? It may not sound right because it won't be properly biased, but if that gives you a volume boost then you know the transistor is responsible.
DeleteAnd if you want some NPN germanium transistors I can highly recommend the Russian MP38A. It's the only NPN germanium transistor that has ever had any consistency for me. Out of a batch of 50 the gain ranged from 54 to 90, and all were very low leakage. NOS Newmarket transistors, particularly NPN ones have been very expensive gambles for me in the past, and the chances are you're more likely to get a duff one than one with perfect gain and leakage. Unless they've been measured beforehand and are guaranteed to meet that spec, I just stay away from them now.
Yep -- it was Q3. I put a 2N5088 in it just to see what would happen and it almost blew my head off! :D
DeleteThink I'll go with an OC140.
Thanks for the help!
Yep -- it was Q3. I put a 2N5088 in it just to see what would happen and it almost blew my head off! :D
DeleteThink I'll go with an OC140.
Thanks for the help!
Do you reckon you could use a very low gain silicon transistor in Q3? All my npn germaniums are either around 10 hfe, low leakage or 150 hfe with high leakage. Just a thought......
ReplyDeleteI did order some new ones from russia but they never made it to Oz. Must have had a stopover at Germania (ok, that was BAD!!), hehheh.
Cheers for any help at all.
This comment has been removed by the author.
ReplyDeleteI just put one together, but at the moment the output is below unity gain. If anyone were able to post voltages from a working board, I would be grateful. I've been over the board several times. All the joints are good, no bridges, etc... I'm guessing it might be an issue with one of the transistors.
ReplyDeleteI have it sorted at this point. Thanks.
DeleteWhat was causing the problem with your pedal? I am facing the same thing now. Volume is below unity. I have tried 4 ac127 but there is no difference. Thanks
DeleteIs the brilliance knob known to cause a volume change across its sweep? My pedal's volume is very low at the lowest brilliance setting and increases significantly as I turn it to max brilliance. I leave it at max now but its not very useful at other positions.
ReplyDeleteHow would I sub the germanium for a silcon NPN transitor. Or do you have a layout of a great cranked tweed style od that is nice and saggy but it can't use a jfet. I don't have any j201 or equivalents right now. Tons of mosfets and npn transistors
ReplyDeleteAC127 (the germanium transistor) is NPN so you could just pop in a NPN silicon transistor. Just check the pinout of your transistor and follow the CBE labels on the layout.
ReplyDeleteYou might shoot for a relatively low hfe to approximate the performance of the AC127
It's definitely worth buying some JFETs and germanium transistors in the future
Hi , Apart from the Cry Baby is there a pedal circuit that can be made to reproduce the Orca/seagull sounds in PINK FLOUYD ECHOS Album. I would really love to make a pedal that can produce this sound . Any ideas.
ReplyDeleteIm no expert, but I believe you just made an excellent point. You certainly fully understand what youre speaking about, and I can truly get behind that. Cordless Screwdrivers Review
ReplyDeleteGreat things put in this blog, thank you so much for sharing with us this informative blog. Visit Ogen Infosystem to get creative and responsive website designing services.
ReplyDeletePPC Company in Delhi
Amazing blog, thank you so much for sharing with us. Get the best Shipping Services by Y&H Cargo India.
ReplyDeleteShipping Company in India
Nice Information presented you by this blog, thank you so much for sharing this informative blog. Visit for Mutual Find Schemes and Advisors.
ReplyDeleteBest Performing Mutual Fund
Nice Blog, Visit for the daily lifestyle activities and about Health, Wealth and Lifestyle Events by Lifestyle Magazine in India.
ReplyDeleteLifestyle Magazine India
Search our best SEO Services in India. Provide professional SEO Services increase Visibility of your Website on the Search Engine. CSS is a top Rated SEO Company in India.
ReplyDeleteDigital Marketing Company in India
Website Designing Company in India
Lead Generation Services in India
Website Development Services in India