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
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Sunday, 10 February 2013
Hexe Night Train
Hexe Guitar Electronics' Night Train overdrive. Nothing too ordinary here. Original Hexe demo and layout feature the 3 knob version of the design. NPN/PNP pair should be low gain and matched to approx same hFE/beta.
I'm building this right now, just checking it against the schematic (http://www.hexeguitar.com/schem/NTv2.gif). The C4 10uF capacitor on the bias trimmer has been omitted. I don't know if this is important or not. Will let you know when I fire it up as to verified. Thanks.
Well I have it working, seemed to work without 10uF cap. I added it again anyway. Had to snake cap around to add it in. I had no trouble biasing Q2 collector to 4.5v, adjusting trimmer did vary the voltage. Gain control also works. Distortion is mild but good. I replaced 47k with jumper for more drive. I used 2n5088 instead of 2n5089 and 2n2907a instead of the 2n3906 PNP. Have not tried the 220a swap. Will give it a try and report back
220k resistor is correct. 220 ohm stops it working! I used a few different opamps. Doesn't make any difference to my ears. So yes verified. A good general overdrive sounds great for TRex and ACDC rhythm riffs.
So I just spent another 3 hours on this. Built another circuit which is hole by hole exactly like the layout. Doesn't work. I get just barely audible signal coming through. When I turn the trimmer, at one point the signal kind of kicks in for a split second and drops instantly down to almost nothing. I don't know what's wrong. I've gone over the whole thing at least ten times now and I cannot see anything wrong with the board.
I've had a few builds that I diagnosed with an audioprobe that I'd need plain dumb luck to troubleshoot otherwise.
I realize that you've built more boxes than I probably ever will but you really ought to make yourself an audioprobe. I don't even have one per se, I just make one when I need it. One cap and two wires with alligator clips on both ends is all it takes and it takes troubleshooting to a whole another level. It lets you pinpoint exactly where your signal goes missing/bad and I can't praise it enough, especially for how simple it is.
How do you normally check for trimmer or IC faults?
I think I should do that. I'm getting fed up with this circuit hah!
Checking a trimmer is easy, just measure and see if the value changes when you turn it. I'm not sure about ICs other than just socket them and swap to see if there's any change.
Then you are a prime candidate for an audioprobe, man! :)
Say if your signal goes through the wiper and the wiper is somehow grounded, you'd still lose all signal even though the measured value is changing, right?
As for ICs, pinouts are all over the interwebz and it's a piece of cake to see if anything is coming in or out of the say an opamp...
Hi, sorry to bother you, I recently got intrested in this pedal, so I built one. But unfortunately didn't have access to 2N5088-9 transistors, so I used a BC550 instead as buffer, but the rest is just like 2009 version schematic: link: http://www.hexeguitar.com/schem/NTv2.gif Now it's finished but doesn't work at all! I messured the voltage at 3904's collector and it is almost around .05 V, even when I twist the 22K trimpot. can you help me troubleshoot it? plz help me, I'm very intrested in its sound! and sorry for terrible English!
my voltage readings in volts: +V: 8.61 Ub: 4.62 Uc: 0.05 Tp1: 0.04
Thank you mirosl, I think my problm is the schem! yep, as I thought this board layout is okay and something's wrong with the schem that I was using. I don't have this kind of boards, so I used the original schem for my perfboard and in that stupid schem the Uc goes nowhere!! I'll fix that and I'll report the result...
Yes, I connected Uc to positive lead of the diode and now 3904's collector is on about 4.3 volts, but no, still doesn't work! when I probed the signal path with an audio probe, the signal exists at BC550's emitter but it disapears after 33n cap. can this cap be dead or something? and how can I test it? thanks
I'm building this right now, just checking it against the schematic (http://www.hexeguitar.com/schem/NTv2.gif). The C4 10uF capacitor on the bias trimmer has been omitted. I don't know if this is important or not. Will let you know when I fire it up as to verified. Thanks.
ReplyDeleteThat could be making a difference.. I think Geiri didn't get this working, but he had other issues with biasing the transistor pair too..
DeleteLet me know. That should act as a ripple filter for bias voltage divider - so it basically should work ok without it...
+m
Yeah mine still isn't working properly. So should I try just removing that 10uF cap?
DeleteThe drive was working but the gain knob didn't do anything at all so let me know if it works for you!
No. There's one 10ยต cap missing from the trimmer pin 2 to ground. But i recall you had some weird voltages for bias..
Delete+m
Yeah turning the trimmer didn't work normally. The voltage didn't go from either nothing to max, just lingered around 5-6v
DeleteLooking at the schem last night, i started to wonder if that 220K resistor is really 220K..
DeleteI'd really like to hear how this goes for James. Fingers crossed and a lucky hat on!
+m
Yeah I wanna get mine working! I could try swapping out the 220K for a 220R and see what happens?
DeleteYou could try different values there.. I would probably start with 100K or 56K and go lower from there if the collector voltages do not go down.
Delete+m
Well I have it working, seemed to work without 10uF cap. I added it again anyway. Had to snake cap around to add it in. I had no trouble biasing Q2 collector to 4.5v, adjusting trimmer did vary the voltage. Gain control also works. Distortion is mild but good. I replaced 47k with jumper for more drive. I used 2n5088 instead of 2n5089 and 2n2907a instead of the 2n3906 PNP. Have not tried the 220a swap. Will give it a try and report back
ReplyDeleteThat means it's verified and that I need to have a look at my circuit. Thanks for clarifying!
DeleteCool! Thanks James!
DeleteI'll tag it and try to remember to jig it a bit to fit that filter cap in there..
+m
499 :o)
Delete220k resistor is correct. 220 ohm stops it working! I used a few different opamps. Doesn't make any difference to my ears. So yes verified. A good general overdrive sounds great for TRex and ACDC rhythm riffs.
ReplyDeleteSo I just spent another 3 hours on this. Built another circuit which is hole by hole exactly like the layout. Doesn't work. I get just barely audible signal coming through. When I turn the trimmer, at one point the signal kind of kicks in for a split second and drops instantly down to almost nothing. I don't know what's wrong. I've gone over the whole thing at least ten times now and I cannot see anything wrong with the board.
ReplyDeleteDo you have an audioprobe to find out where your signal gets grounded?
DeleteNo I've never had one of those. I've checked, all the connections are spot on. I use a hacksaw between all the tracks which completely clears them.
Delete
DeleteI've had a few builds that I diagnosed with an audioprobe that I'd need plain dumb luck to troubleshoot otherwise.
I realize that you've built more boxes than I probably ever will but you really ought to make yourself an audioprobe. I don't even have one per se, I just make one when I need it. One cap and two wires with alligator clips on both ends is all it takes and it takes troubleshooting to a whole another level. It lets you pinpoint exactly where your signal goes missing/bad and I can't praise it enough, especially for how simple it is.
How do you normally check for trimmer or IC faults?
I think I should do that. I'm getting fed up with this circuit hah!
DeleteChecking a trimmer is easy, just measure and see if the value changes when you turn it. I'm not sure about ICs other than just socket them and swap to see if there's any change.
Then you are a prime candidate for an audioprobe, man! :)
DeleteSay if your signal goes through the wiper and the wiper is somehow grounded, you'd still lose all signal even though the measured value is changing, right?
As for ICs, pinouts are all over the interwebz and it's a piece of cake to see if anything is coming in or out of the say an opamp...
Such a simple contraption, yet so useful...
Hi, sorry to bother you, I recently got intrested in this pedal, so I built one. But unfortunately didn't have access to 2N5088-9 transistors, so I used a BC550 instead as buffer, but the rest is just like 2009 version schematic:
ReplyDeletelink: http://www.hexeguitar.com/schem/NTv2.gif
Now it's finished but doesn't work at all! I messured the voltage at 3904's collector and it is almost around .05 V, even when I twist the 22K trimpot. can you help me troubleshoot it? plz help me, I'm very intrested in its sound! and sorry for terrible English!
my voltage readings in volts:
+V: 8.61
Ub: 4.62
Uc: 0.05
Tp1: 0.04
2N3904 and 2N3906 need to be hFE matched for the circuit to work. Input buffer transistor shouldn't matter at all as long as the pinout is correct.
Delete+m
Thank you mirosl, I think my problm is the schem!
Deleteyep, as I thought this board layout is okay and something's wrong with the schem that I was using.
I don't have this kind of boards, so I used the original schem for my perfboard and in that stupid schem the Uc goes nowhere!!
I'll fix that and I'll report the result...
Yes, I connected Uc to positive lead of the diode and now 3904's collector is on about 4.3 volts, but no, still doesn't work!
Deletewhen I probed the signal path with an audio probe, the signal exists at BC550's emitter but it disapears after 33n cap. can this cap be dead or something? and how can I test it?
thanks
Yes it worked! my problem was the pair of 3904 & 3906, I replaced them with another pair and it worked, sounds great!
ReplyDeletethank you all