Author Topic: EHX Small Clone mods? (Read 3521 times)

zachlovescoffee · « **Reply #20 on:** October 23, 2021, 07:51:56 PM »

Quote from: idy on October 23, 2021, 07:31:57 PM

Quote
the side of the 4.7k that went to pin one of the 358 goes to pot pin 3 (your "hot" lfo signal).

Are you sure you have right end? I cold have sworn I could see in previous photo that the end near the 358 was connected to pin 1, and that big cap there...no?

If I have the right end Or not I’m not sure. I’ve added some
More detailed photos of the front and back of the board. What do you think? Pin 2 is actually connected via trace to that cap and the 4k7 by my look.

idy · « **Reply #21 on:** October 23, 2021, 08:14:00 PM »

Do you have a meter? Use it to determine which end is attached to 358 pin1. No meter. Brother, get a cheapie! If you have eyes, you can probably make out if the end near the 358 is attached. Can't you see the traces under the board, even through the board?

zachlovescoffee · « **Reply #22 on:** October 23, 2021, 08:24:16 PM »

Quote from: idy on October 23, 2021, 08:14:00 PM

Do you have a meter? Use it to determine which end is attached to 358 pin1. No meter. Brother, get a cheapie! If you have eyes, you can probably make out if the end near the 358 is attached. Can't you see the traces under the board, even through the board?

According to my meter in continuity mode both ends of 4k7 are attached to pin 1 of the 385. For 2k7 only the right-most, closest to the 1M pot is connected to pin 1. Provided I used it correctly. When I touched either end of 4k7 my meter beeped and provided a voltage reading. It was silent on the left side of 2k7 but beeped on the right side.

idy · « **Reply #23 on:** October 23, 2021, 08:32:31 PM »

Pretty sure you are confused about Both ends of the R going to the 358. *Can't* be.

idy · « **Reply #24 on:** October 23, 2021, 08:38:08 PM »

In continuity setting your meter will beep, but will not show a voltage reading! It may show resistance...

I think you know the circuit is powered down when you go poking for continuity or resistance.

No component functions when both ends are shorted together!

And can't you see the trace connecting the near side of the R to the big cap and 358 pin?

zachlovescoffee · « **Reply #25 on:** October 23, 2021, 08:52:54 PM »

Quote from: idy on October 23, 2021, 08:38:08 PM

In continuity setting your meter will beep, but will not show a voltage reading! It may show resistance...

I think you know the circuit is powered down when you go poking for continuity or resistance.

No component functions when both ends are shorted together!

And can't you see the trace connecting the near side of the R to the big cap and 358 pin?

The Trace is hard to see but I think the problem is two things: 1) that I wasn’t making good contact with the pads, 2) I had the green and white wires connected through the pot.

When I pull both wires out and test again the far side produces no sound but the near side of the 4k7 sounds out! So I think that’s the gem. What’s next?!

idy · « **Reply #26 on:** October 23, 2021, 09:05:10 PM »

I was going to post: Oh, maybe since you have already soldered the pot in (the wrong way) you may be seeing a short there! remove the pot. Then check for which side to the R goes to 359 pin 1.

But now: good. You have confirmed that the near side of the 4.7k goes to Pin one of the 358. That's where pot 3 goes. The wiper goes in the other hole. OK?

zachlovescoffee · « **Reply #27 on:** October 23, 2021, 09:07:03 PM »

Quote from: idy on October 23, 2021, 09:05:10 PM

Oh, maybe since you have already soldered the pot in (the wrong way) you may be seeing a short there! remove the pot. Then check for which side to the R goes to 359 pin 1.

Yep I pulled the white and green and pot out. Now only the near side of 2k7 buzzes when connected to pin 1

idy · « **Reply #28 on:** October 23, 2021, 09:09:50 PM »

we don't care about the 2.7k do we? unless you are trying to determine which side of that goes to the connection of the 4.7, pin 1 of the 358 and the cap. The other side of the 2.7 should go to ground, a handy place to attach pin 1 of the pot.

zachlovescoffee · « **Reply #29 on:** October 23, 2021, 09:14:03 PM »

Quote from: idy on October 23, 2021, 09:09:50 PM

we don't care about the 2.7k do we? unless you are trying to determine which side of that goes to the connection of the 4.7, pin 1 of the 358 and the cap. The other side of the 2.7 should go to ground, a handy place to attach pin 1 of the pot.

So sorry I mistyped. I meant near side of the 4k7 buzzes when touching pin 1. So lug 3 of the pot there? And lug two of the pot on the far side or vice verse?

idy · « **Reply #30 on:** October 23, 2021, 09:32:55 PM »

Quote

But now: good. You have confirmed that the near side of the 4.7k goes to Pin one of the 358. That's where pot 3 goes. The wiper goes in the other hole. OK?

should I say it so it rhymes? maybe set it to music...

zachlovescoffee · « **Reply #31 on:** October 23, 2021, 09:38:41 PM »

Quote from: idy on October 23, 2021, 09:32:55 PM

Quote
But now: good. You have confirmed that the near side of the 4.7k goes to Pin one of the 358. That's where pot 3 goes. The wiper goes in the other hole. OK?

should I say it so it rhymes? maybe set it to music...

Nailed it! I’ll solder them all on tomorrow. I’m taking notes so I can reproduce this mod in the future and help other folks.

Now how about that 2k7 and the grounding lug? Throw a 1k resistor on there and call it a day or something a little more tricky?

idy · « **Reply #32 on:** October 23, 2021, 09:51:59 PM »

Did you figure which hole from the 2.7k goes to ground? That one. It's ground. The pot pin 1 goes to ground. There.
If you want to put a 1k between there and the pot, do it. Better to first put the wire in, confirm it works....,

....then cut the wire and splice in a 1k (or other small value.) Having the R soldered in at one end and free to wiggle is bad housekeeping. Having the R soldered at Bothe ends to the wire and somehow shrink tubed or looped around to strain relief is smarter.

idy · « **Reply #33 on:** October 23, 2021, 09:55:58 PM »

Pretty sure the 2.7k has the right side connected to the + side of the big cap next to it. Can you see that? that side must not be ground. Which side do you think is ground, Mr Holmes?

idy · « **Reply #34 on:** October 24, 2021, 02:23:52 AM »

Actually, neither side of the 2.7k goes to ground since the switch is removed. You need to find where the depth switch went and test to see which side went to ground.

zachlovescoffee · « **Reply #35 on:** October 24, 2021, 09:26:50 AM »

Quote from: idy on October 24, 2021, 02:23:52 AM

Actually, neither side of the 2.7k goes to ground since the switch is removed. You need to find where the depth switch went and test to see which side went to ground.

From what I can tell looking at the Trace the left side of the 2k7 is ground. It doesn’t go anywhere. On the right hand side it’s connected via Trace off of the left hand side of the 39k as connected through a 10uf cap. There was an orange wire that went to one lug on the depth switch. The other side of the depth switch was a white wire that is wired into the left hand side of a 47R resistor (r37).

In the photo below I show a the path and a mock orange wire but you can see how they are connected.

This is a schematic I found that sort of supports what I found by visual inspection (https://sites.google.com/site/electroconducive/EHXSmallCloneSAD1024AMN3007-FactoryE.pdf). Also, any pictures online the boards and wiring look different than mine. Mine is a 2020 model and it has ribbon cables and pretty much all metal film resistors. Most of what I see online has point to point from switches and carbon film resistors.

Picture #2 below shows an orange/yellow depth switch connection. Mine was white and orange.

idy · « **Reply #36 on:** October 24, 2021, 12:26:43 PM »

The schematic you shared does not bear out what you say. It is identical as to depth switch with the other I posted. Pretty sure you are confused.

Schematic shows 2.7k to depth switch (the circle over the trace in the schema. is a sign for off board wire) and then to the switch, other side of switch (through off-board wire) to ground. Do you see something different on your schematic or mine?

The 47ohm is connected to the 9v power "rail". it is a part of the power supply, a decoupling R part of the power filtering. It goes from the power jack to the place everything else gets 9v. The depth switch I bet does not go there!

I do see where the wires for the switch on that other pedal go. They have nice neat pads marked s2 1 and s2 2, right near the 2.7k. You have not shown me where the wires for the switch on yourpedal go.

zachlovescoffee · « **Reply #37 on:** October 24, 2021, 12:51:54 PM »

Quote from: idy on October 24, 2021, 12:26:43 PM

The schematic you shared does not bear out what you say. It is identical as to depth switch with the other I posted. Pretty sure you are confused.

Schematic shows 2.7k to depth switch (the circle over the trace in the schema. is a sign for off board wire) and then to the switch, other side of switch (through off-board wire) to ground. Do you see something different on your schematic or mine?

The 47ohm is connected to the 9v power "rail". it is a part of the power supply, a decoupling R part of the power filtering. It goes from the power jack to the place everything else gets 9v. The depth switch I bet does not go there!

I do see where the wires for the switch on that other pedal go. They have nice neat pads marked s2 1 and s2 2, right near the 2.7k. You have not shown me where the wires for the switch on yourpedal go.

Sorry I am new just trying to figure it out. Here is how mine was hooked up — I think! I removed the depth switch when the pedal was still together so I’m not certain any more.

See attached pic.

zachlovescoffee · « **Reply #38 on:** October 24, 2021, 01:16:55 PM »

Quote from: zachlovescoffee on October 24, 2021, 12:51:54 PM

Quote from: idy on October 24, 2021, 12:26:43 PM
The schematic you shared does not bear out what you say. It is identical as to depth switch with the other I posted. Pretty sure you are confused.

Schematic shows 2.7k to depth switch (the circle over the trace in the schema. is a sign for off board wire) and then to the switch, other side of switch (through off-board wire) to ground. Do you see something different on your schematic or mine?

The 47ohm is connected to the 9v power "rail". it is a part of the power supply, a decoupling R part of the power filtering. It goes from the power jack to the place everything else gets 9v. The depth switch I bet does not go there!

I do see where the wires for the switch on that other pedal go. They have nice neat pads marked s2 1 and s2 2, right near the 2.7k. You have not shown me where the wires for the switch on yourpedal go.

Sorry I am new just trying to figure it out. Here is how mine was hooked up — I think! I removed the depth switch when the pedal was still together so I’m not certain any more. Maybe it was connected to the output mono jack?

See attached pic.

idy · « **Reply #39 on:** October 24, 2021, 01:52:34 PM »

The attached picture looks to be posed to mislead and confuse... it almost looks like the wires "went" where you are holding them, but that's just a "guess" on your part.

Can you see those two pads are labeled? Can you read what the labels say? Can you guess what those labels mean?

Hint: you're probably right in thinking that one leg of the switch went to the ground somewhere like the input jack.

News:

Author Topic: EHX Small Clone mods? (Read 3521 times)