EHX - Holy Stain  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
User avatar
wildschwein
Breadboard Brother
Information
Posts: 76
Joined: 31 Jul 2008, 11:38
Has thanked: 15 times
Been thanked: 2 times

Post by wildschwein »

Ice-9 wrote:
wildschwein wrote:
Ice-9 wrote:
wildschwein wrote:I've just done the switch and the pot mod as shown in this thread. Followed it as best I could to the letter. Used a 50k linear pot. I have the extra effects (pitch shifter, flanger and chorus) when the switch is engaged but there is no reverb or echo on them that I can discern -- they're dry. The new pot does change the rate so that seems to be working. In the regular mode it seems that the reverb effects are not as deep as they used to be before the mod and the pitch shift effect there has changed too -- I used to be able to get a unison/slap effect which is no longer there. I'm wondering if I have done something wrong -- maybe there is a solder bridge across one of the chips' pins that is not meant to be there.
I would suggest you have done something not quite right as all the original effect should work exactly as they did before but with the extra pot used to separately control one of the parameters that previously controlled a mixture of two parameters.
Yeah; I killed it. It's dead. Ended breaking the pins off the chip trying to trouble shoot the problem. I have a glorified fuzz box now. It's always a gamble with smd modding.
Have you damaged the PCB, if not it should be an easy repair. I'm in the UK and if you need a repair done.
Thanks for the offer -- I'm in Australia so I don't know how feasible it is to send to the UK. I damaged the chip itself. I was stupid -- should have left it alone. I have a bad track record with smd stuff.

User avatar
Ice-9
Degoop Doctor
Information
Posts: 1094
Joined: 31 Mar 2009, 15:29
my favorite amplifier: Marshall
Completed builds: Far to many to afford the enclosures for them all. :)
Has thanked: 134 times
Been thanked: 359 times
Contact:

Post by Ice-9 »

wildschwein wrote:
Ice-9 wrote:
wildschwein wrote:
Ice-9 wrote:
wildschwein wrote:I've just done the switch and the pot mod as shown in this thread. Followed it as best I could to the letter. Used a 50k linear pot. I have the extra effects (pitch shifter, flanger and chorus) when the switch is engaged but there is no reverb or echo on them that I can discern -- they're dry. The new pot does change the rate so that seems to be working. In the regular mode it seems that the reverb effects are not as deep as they used to be before the mod and the pitch shift effect there has changed too -- I used to be able to get a unison/slap effect which is no longer there. I'm wondering if I have done something wrong -- maybe there is a solder bridge across one of the chips' pins that is not meant to be there.
I would suggest you have done something not quite right as all the original effect should work exactly as they did before but with the extra pot used to separately control one of the parameters that previously controlled a mixture of two parameters.
Yeah; I killed it. It's dead. Ended breaking the pins off the chip trying to trouble shoot the problem. I have a glorified fuzz box now. It's always a gamble with smd modding.
Have you damaged the PCB, if not it should be an easy repair. I'm in the UK and if you need a repair done.
Thanks for the offer -- I'm in Australia so I don't know how feasible it is to send to the UK. I damaged the chip itself. I was stupid -- should have left it alone. I have a bad track record with smd stuff.
The chip is available to buy but I am unsure about who supplies in Australia. If you have just broken a leg off the chip, an easy but messy fix is to use a dremel to carefully grind the plastic package over the broken pin. This will uncover the connection to the pin and you can solder a wire directly to it. (this was a hack many used to use on modding the Wii games console chip that had no connection to a certain pin on the chip.) I can find a picture to post if this makes it clearer on what I mean.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

User avatar
wildschwein
Breadboard Brother
Information
Posts: 76
Joined: 31 Jul 2008, 11:38
Has thanked: 15 times
Been thanked: 2 times

Post by wildschwein »

Ice-9 wrote:
wildschwein wrote:
Ice-9 wrote:
wildschwein wrote:
Ice-9 wrote:
wildschwein wrote:I've just done the switch and the pot mod as shown in this thread. Followed it as best I could to the letter. Used a 50k linear pot. I have the extra effects (pitch shifter, flanger and chorus) when the switch is engaged but there is no reverb or echo on them that I can discern -- they're dry. The new pot does change the rate so that seems to be working. In the regular mode it seems that the reverb effects are not as deep as they used to be before the mod and the pitch shift effect there has changed too -- I used to be able to get a unison/slap effect which is no longer there. I'm wondering if I have done something wrong -- maybe there is a solder bridge across one of the chips' pins that is not meant to be there.
I would suggest you have done something not quite right as all the original effect should work exactly as they did before but with the extra pot used to separately control one of the parameters that previously controlled a mixture of two parameters.
Yeah; I killed it. It's dead. Ended breaking the pins off the chip trying to trouble shoot the problem. I have a glorified fuzz box now. It's always a gamble with smd modding.
Have you damaged the PCB, if not it should be an easy repair. I'm in the UK and if you need a repair done.
Thanks for the offer -- I'm in Australia so I don't know how feasible it is to send to the UK. I damaged the chip itself. I was stupid -- should have left it alone. I have a bad track record with smd stuff.
The chip is available to buy but I am unsure about who supplies in Australia. If you have just broken a leg off the chip, an easy but messy fix is to use a dremel to carefully grind the plastic package over the broken pin. This will uncover the connection to the pin and you can solder a wire directly to it. (this was a hack many used to use on modding the Wii games console chip that had no connection to a certain pin on the chip.) I can find a picture to post if this makes it clearer on what I mean.
Cheers for all the advice mate. I did actually grind away some small areas of the chip (read about it on the Internet) and managed to solder very fine wire to the the two respective broken pins but when it's all hooked up all I get sound-wise is a lot aggressive and extremely loud digital whining noises from that side of the pedal--so the chip is definitely fried now. Probably there is short or it was overheated.

I won't be pursuing it but it appears that putting a new chip in would be a very delicate task with so many pins. Just out of curiosity would the sound presets also need to loaded onto the new chip through external means?

User avatar
Ice-9
Degoop Doctor
Information
Posts: 1094
Joined: 31 Mar 2009, 15:29
my favorite amplifier: Marshall
Completed builds: Far to many to afford the enclosures for them all. :)
Has thanked: 134 times
Been thanked: 359 times
Contact:

Post by Ice-9 »

The sounds will be already on the new chip, it is an easy replacement with a little practice. I'm sorry this has been a bad experience for you, I did make a video of how to easily remove an SMD 28 pin chip same as the FV-1 a little while ago. I will se if I can find it and post the info.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

User avatar
wildschwein
Breadboard Brother
Information
Posts: 76
Joined: 31 Jul 2008, 11:38
Has thanked: 15 times
Been thanked: 2 times

Post by wildschwein »

Ice-9 wrote:The sounds will be already on the new chip, it is an easy replacement with a little practice. I'm sorry this has been a bad experience for you, I did make a video of how to easily remove an SMD 28 pin chip same as the FV-1 a little while ago. I will se if I can find it and post the info.
That's okay -- I accept the responsibility for attempting it -- sometimes these things come off and other times they don't. That would be cool if you put the video up. I will have one last go at it. I did like the pedal stock so would be good to have it back working again.

User avatar
Ice-9
Degoop Doctor
Information
Posts: 1094
Joined: 31 Mar 2009, 15:29
my favorite amplifier: Marshall
Completed builds: Far to many to afford the enclosures for them all. :)
Has thanked: 134 times
Been thanked: 359 times
Contact:

Post by Ice-9 »

wildschwein wrote:
Ice-9 wrote:The sounds will be already on the new chip, it is an easy replacement with a little practice. I'm sorry this has been a bad experience for you, I did make a video of how to easily remove an SMD 28 pin chip same as the FV-1 a little while ago. I will se if I can find it and post the info.
That's okay -- I accept the responsibility for attempting it -- sometimes these things come off and other times they don't. That would be cool if you put the video up. I will have one last go at it. I did like the pedal stock so would be good to have it back working again.
The video of removing the smd chip is on the other forum .
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

User avatar
wildschwein
Breadboard Brother
Information
Posts: 76
Joined: 31 Jul 2008, 11:38
Has thanked: 15 times
Been thanked: 2 times

Post by wildschwein »

Ice-9 wrote:
wildschwein wrote:
Ice-9 wrote:The sounds will be already on the new chip, it is an easy replacement with a little practice. I'm sorry this has been a bad experience for you, I did make a video of how to easily remove an SMD 28 pin chip same as the FV-1 a little while ago. I will se if I can find it and post the info.
That's okay -- I accept the responsibility for attempting it -- sometimes these things come off and other times they don't. That would be cool if you put the video up. I will have one last go at it. I did like the pedal stock so would be good to have it back working again.
The video of removing the smd chip is on the other forum .
Sorry if it is obvious but what is the other forum? Cheers in advance.

User avatar
El Luz
Information
Posts: 5
Joined: 26 Feb 2016, 22:53
Has thanked: 1 time

Post by El Luz »

Diggin in the past...

I want to mod my Stain and bought most the stuff i need. I don't know how to adjust the amount of Fuzziness of the analog stage. This is my main problem - the fuzziness is a smash in the face... Can you adjust the 'Fuzziness' or mix it with the Clean channel? Any Ideas to minimize the Effekt for a more vintage, smooth effekt?

Maybe one of the Pros are still in the house...

(Greetings from Rockinger/Duesenberg Hometown Hanover)

User avatar
Ice-9
Degoop Doctor
Information
Posts: 1094
Joined: 31 Mar 2009, 15:29
my favorite amplifier: Marshall
Completed builds: Far to many to afford the enclosures for them all. :)
Has thanked: 134 times
Been thanked: 359 times
Contact:

Post by Ice-9 »

El Luz wrote:Diggin in the past...

I want to mod my Stain and bought most the stuff i need. I don't know how to adjust the amount of Fuzziness of the analog stage. This is my main problem - the fuzziness is a smash in the face... Can you adjust the 'Fuzziness' or mix it with the Clean channel? Any Ideas to minimize the Effekt for a more vintage, smooth effekt?

Maybe one of the Pros are still in the house...

(Greetings from Rockinger/Duesenberg Hometown Hanover)
Sorry I can't really help you with the fuzz on this as I only traced the Digital side, I also don't have this pedal anymore but if you have any general questions on modding the digital side I should be able to help. Somewhere in the thread another member here added the fuzz section so some clues to modding it should be around.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

User avatar
mirosol
Resistor Ronker
Information
Posts: 292
Joined: 11 Mar 2012, 16:15
my favorite amplifier: Been on Bogner for quite some time now.
Completed builds: Over 1000 and counting.
Location: TKU, FI
Has thanked: 192 times
Been thanked: 449 times

Post by mirosol »

On previous page, there is a schematic of the fuzz/clean circuit. One solution could be to change R5 and C2 to match the standard fuzz face gain control. Remove R5, take Q2 emitter + R2 to C1K pot's lug 3. Positive lead of C2 to lug 2 and lug 1 to where C2's negative lead is.

Or, one could remove SW2B (the latter part of fuzz/drive/clean switch) and wire a B500K pot to replace that half. C34 to lug 1, R7 to lug 3 and lug 2 to R11/VD1/C29/volume pot's lug 3.

Added a crude mspaint modded schem for these mods.

Both should be a nice option as well.
+m
Attachments
HolyStain1.JPG
http://tagboardeffects.blogspot.com/
http://mirosol.kapsi.fi/
"No such thing as innocence" -Iron Chic

User avatar
El Luz
Information
Posts: 5
Joined: 26 Feb 2016, 22:53
Has thanked: 1 time

Post by El Luz »

Sounds good! Thanks a lot. I will try the Fuzz Control MOD. Maybe i will Mess with the clean Switch later to try something footswitchable... But it will take some time - my son just born :applause:

User avatar
El Luz
Information
Posts: 5
Joined: 26 Feb 2016, 22:53
Has thanked: 1 time

Post by El Luz »

Today i found some time to mod the holystain. I tried the FUZZ-Control mod it did'nt work like I hoped. Clean is everything fine. in Fuzz mode the new Pot works like this: on min total silence, then after some degree real bad distorsion/fuzz popps in and don't change the rest of the travel.
I tried a 500K: really bad
and a 5k: a little better

- that's all I could buy at my local store.

Will it work with 1k? I thought a 5k should work somehow...

Or did i something really wrong?

Thank you very much!
Attachments
IMG_4595_web.jpg
IMG_4596_web.jpg

User avatar
El Luz
Information
Posts: 5
Joined: 26 Feb 2016, 22:53
Has thanked: 1 time

Post by El Luz »

I bought yesterday a 1k Pot and try this but it was a simular effekt. So I reverse the mod and startet the other mods - Bank2 switch and level the drive outputs to the clean one. (10k).

Maybe I try the blend mod this weekend.

User avatar
mirosol
Resistor Ronker
Information
Posts: 292
Joined: 11 Mar 2012, 16:15
my favorite amplifier: Been on Bogner for quite some time now.
Completed builds: Over 1000 and counting.
Location: TKU, FI
Has thanked: 192 times
Been thanked: 449 times

Post by mirosol »

1K should have worked in a decent manner. As you see, the fuzz is pretty much 1:1 with fuzz face. The 5K here is big. When the resistance from that transistor's emitter to ground is too big, there won't be any signal passing at all due to bias of that transistor being completely off - exactly as you experienced with 500K pot. Many people like their Fuzz Face gain pots as reverse log taper to give them better control. For me, i've mainly used 500R pot for this purpose.
http://tagboardeffects.blogspot.com/
http://mirosol.kapsi.fi/
"No such thing as innocence" -Iron Chic

User avatar
El Luz
Information
Posts: 5
Joined: 26 Feb 2016, 22:53
Has thanked: 1 time

Post by El Luz »

I made the blend mod now and had to reverse the 'FUZZ-Level-Mod' because the main Volume dropped in the the midrange of the blend pot very hard. I made the second control pot-mod and the bank2 mod also and put everything in place. I think I will have to play around some time to get a feeling for the possibilties and usefull settings. Thank you for all your help!

Maybe I will try some custom sounds for the FV-1 someday...

User avatar
jerfo
Information
Posts: 1
Joined: 24 Jun 2019, 20:18
Been thanked: 3 times

Post by jerfo »

Ice-9 wrote:I don't have my Holy Stain anymore but I have just had a look at the pictures I posted and U4 is just a dual opamp, anything will do for example a TL072.Maybe someone that still has there pedal could give you the exact opamp markings but i would just throw in a TL072 or similar opamp.
I apologize for the extreme necropost here, but I ran into the same issue with U4 and figured that this information might be helpful to someone else on the interwebs. Based upon the statement above, I attempted to swap in a TL072 and it did not work as a drop-in replacement; there was sound, but it was extremely faint. The correct opamp is a TLC2262CD or TLC2262CDR (same part, different packaging). I dropped one in and my Holy Stain came right back to life.

- Jeff

User avatar
wildschwein
Breadboard Brother
Information
Posts: 76
Joined: 31 Jul 2008, 11:38
Has thanked: 15 times
Been thanked: 2 times

Post by wildschwein »

wildschwein wrote: 17 Jul 2015, 12:43
Ice-9 wrote:
wildschwein wrote:
Ice-9 wrote:The sounds will be already on the new chip, it is an easy replacement with a little practice. I'm sorry this has been a bad experience for you, I did make a video of how to easily remove an SMD 28 pin chip same as the FV-1 a little while ago. I will se if I can find it and post the info.
That's okay -- I accept the responsibility for attempting it -- sometimes these things come off and other times they don't. That would be cool if you put the video up. I will have one last go at it. I did like the pedal stock so would be good to have it back working again.
The video of removing the smd chip is on the other forum .
Sorry if it is obvious but what is the other forum? Cheers in advance.
Finally bought another Holy Stain this year to replace the one I ruined. Won't be modding this one:)

User avatar
[Gringo]
Information
Posts: 3
Joined: 05 Jul 2017, 14:51
Has thanked: 22 times
Been thanked: 1 time

Post by [Gringo] »

Hi, i got one of these in for repair, maybe someone has saved the schematic? Thanks!

User avatar
howmuch
Breadboard Brother
Information
Posts: 68
Joined: 09 Nov 2014, 18:31
Has thanked: 21 times
Been thanked: 58 times

Post by howmuch »

Ice-9 wrote: 18 Jan 2011, 12:03 Here is an updated schematic, the only bits that need adding now are the fuzz effect, the 3pdt wiring and the program scroll switch.

Image
Could you upload this schematic again please?
Or anyone else who has it.

Thanks.
R.I.P. Burke Shelley, from one of my favourite (and much underrated) bands - Budgie
Their songs have been covered by Van Halen, Iron Maiden, Soundgarden, Metallica and more.
If you don't know how HEAVY this band was in the 70s, check Breadfan out.

User avatar
Ice-9
Degoop Doctor
Information
Posts: 1094
Joined: 31 Mar 2009, 15:29
my favorite amplifier: Marshall
Completed builds: Far to many to afford the enclosures for them all. :)
Has thanked: 134 times
Been thanked: 359 times
Contact:

Post by Ice-9 »

howmuch wrote: 20 Jul 2022, 21:49
Ice-9 wrote: 18 Jan 2011, 12:03 Here is an updated schematic, the only bits that need adding now are the fuzz effect, the 3pdt wiring and the program scroll switch.

Image
Could you upload this schematic again please?
Or anyone else who has it.

Thanks.
I'm very sorry as it is a file I no longer have, when photobucket deleted peoples files due to forcing a charge I lost loads of files that I had not saved on a local hard drive. If you have any specific question on that pedal I may be able to remember what you need although I only bothered with the digital side o the pedal I do remember it was quite simple.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

Post Reply