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Non ADA Gear => Rack Gear => Topic started by: DrDckhol3 on January 25, 2014, 06:23:19 PM

Title: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 25, 2014, 06:23:19 PM
I've just acquired one of these, seems to be some love out there for them, but not from me....at least not yet. I can't get a good signal out of it. It's very , and I mean very, faint. Any suggestions? I hope it doesn't turn out to be a  :poop:
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 26, 2014, 12:44:24 PM
I've had a couple of these. I liked the all in one convenience of preamp and effects all in a shiny 1U case. The preamp tube gain was fairly mild though and you really had to wind the compressor right up to get any sort of lead tone, but then noise also increased lots. It was good as a clean / rhythm unit, but the single 12AX7 just did not seem to give enough 'ooomph' on its own. It's like it needed a 2 Tube mod! Never used the SS tones, which seemed to be based on the popular Digi stomp stuff and didn't appeal to me. That said, it was not a faint or weak sounding unit, so maybe you have something else going on in there with yours. Could try a factory reset, see if that improves things.
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 26, 2014, 02:48:56 PM
Did the factory reset when I got it. There is definitely something wrong with it. Checked the inputs and they are not suffering from any disconection from the board sooo..... :poop:
Title: Re: Any Love For The Digitech Valve FX?
Post by: rnolan on January 26, 2014, 10:19:52 PM
What are you running it into, could be inst/line level miss match?
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 27, 2014, 07:00:23 AM
Headphones as well as left and right outs all have only a faint hint of the signal coming through. :dunno:
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 27, 2014, 07:56:25 AM
Any signal coming through in bypass mode?
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 27, 2014, 08:38:41 AM
Any signal coming through in bypass mode?
.

Negative
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 27, 2014, 09:10:15 AM
And the front panel control stuff works as normal - buttons, LCD screen, LED display, selector knob?
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 27, 2014, 09:47:30 AM
Yes, everything works, I just hear a very faint top end hiss on distorted settings and that's it.
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 27, 2014, 10:31:09 AM
Ok, you will have to open the top of the case and check some low DC voltages, first either side of the +/- 12V regulators U6 and U7 with a multimeter. If you can post some high res pics of the board inside the case, I can tell you where to probe. Are you able to do this?
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 27, 2014, 12:24:31 PM
I will post them when I get off work tonight. I am somewhat of a newb although I did convert my Marshall from 6L6 to EL34 with no problem so I'm confident that I can change some components out if I need to. I appreciate your help.
Title: Re: Any Love For The Digitech Valve FX?
Post by: MarshallJMP on January 27, 2014, 02:02:33 PM
Do you have a schematic,maybe i can help too?
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 27, 2014, 04:04:50 PM
Ok, you will have to open the top of the case and check some low DC voltages, first either side of the +/- 12V regulators U6 and U7 with a multimeter. If you can post some high res pics of the board inside the case, I can tell you where to probe. Are you able to do this?

Here are some pics http://s34.photobucket.com/user/drdckhol3/library/Digitech%20Valve%20FX (http://s34.photobucket.com/user/drdckhol3/library/Digitech%20Valve%20FX)
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 27, 2014, 04:06:29 PM
Do you have a schematic,maybe i can help too?

I don't have scematics :facepalm:
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 27, 2014, 10:14:18 PM
Schematics and manual attached
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 27, 2014, 10:15:06 PM
Schematic
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 27, 2014, 10:26:27 PM
I have the manual, am I missing something in it though? The only thing I see that resembles a schematic was that block diagram. I've scoured the web for the full schem to no (Avail :metal:)
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 27, 2014, 10:29:03 PM
Plan is to check some PSU voltages first, then track a signal through in bypass mode. Back later (work   :(  )
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 27, 2014, 10:36:26 PM
Ok thanks, I'm in no hurry. Like I said before I'm a newb at electronics when it comes to identifying things and tracing the signal but I'm handy with the iron. So, with your eyes and my hand maybe we can get it going.  :thumb-up:
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 28, 2014, 01:10:25 PM
Ok, so quick PSU check, you need a multimeter for this -

With the unit powered up, set mutlmeter to DC volts, measure the DC voltage across BR1 Pin1 & Pin2, doesn't matter which way around. This is between two two eCaps. BR1 P1 is marked + and P2 is on the same side, but to the left in the photo. Guide pic attached.




Title: Re: Any Love For The Digitech Valve FX?
Post by: MarshallJMP on January 28, 2014, 02:26:36 PM
Next you can measure on pin 3 of U6,should be +12V,U7 pin 3 should be -12V and U1 pin 3 should be +5V.

If these are ok ,and from what i understand you have no sound in bypass either,it could be a bad opamp.If i look at the schematic it could be either U41 (LF353),U56 (LM833) or U32 (LF353).Or the switching circuit.(between bypass and effect).
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 28, 2014, 05:26:25 PM
Ok, so quick PSU check, you need a multimeter for this -

With the unit powered up, set mutlmeter to DC volts, measure the DC voltage across BR1 Pin1 & Pin2, doesn't matter which way around. This is between two two eCaps. BR1 P1 is marked + and P2 is on the same side, but to the left in the photo. Guide pic attached.


BR1 measured 32

Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 28, 2014, 05:30:04 PM
Next you can measure on pin 3 of U6,should be +12V,U7 pin 3 should be -12V and U1 pin 3 should be +5V.

If these are ok ,and from what i understand you have no sound in bypass either,it could be a bad opamp.If i look at the schematic it could be either U41 (LF353),U56 (LM833) or U32 (LF353).Or the switching circuit.(between bypass and effect).


All pins measured correctly
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 28, 2014, 11:33:23 PM
BR1 looks ok - was this with the tube pulled out?
Also, could you confirm that you don't get any sound in bypass mode with the tube pulled out.   :thumb-up:
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 29, 2014, 05:41:41 AM
The tube was in. Pulled the tube and no signal.
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 29, 2014, 08:54:03 AM
I'm trying to attach a 1kHz test tone in a ZIP file, but can't seem to upload it. The whole reply just disappears!! I'll try and PM it to you then get back with some more details. Basically you play it into the input of the ValveFX from a music player/pc/phone etc, and using your multimeter set to AC, trace how far the signal gets through the ccts.
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 29, 2014, 08:58:24 AM
Right on
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 29, 2014, 09:00:14 AM
Can't attach it in a PM either!!    :dunno:     Would be useful to have on the site though??   :thumb-up:

PM me an email address and I will send it there.

Cheers - Mike
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 29, 2014, 11:57:36 AM
Ok, I'm home and ready to trace the signal. What exactly am I looking for here? What components do I need to check?
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 29, 2014, 12:00:40 PM
I also forgot to ask....what setting to put my multimeter on on AC mode?
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 29, 2014, 02:12:58 PM
Now you have the test tone, you will need an MP3/music player, etc, to play the sine track into the ValveFX.
You will also need a lead and maybe a jack adaptor to connect these together.

Set the ValveFX to bypass mode
Play sine track into ValveFX front input (set to repeat/loop)
GND meter lead should be on the front jack socket GND (sleeve) for all measurements

Set meter to 2V AC and connect to the signal on the front jack socket tip connection.
Measure the input signal, adjust the MP3 player volume (or whatever)
to give a reading of around 1V AC on the meter.

Measure the signal on TP4 on the PCB by the input jack socket
Measure the signal on U56 pin1 and pin7
Measure the signal on U32 pin1 and pin7
Title: Re: Any Love For The Digitech Valve FX?
Post by: MarshallJMP on January 29, 2014, 02:37:38 PM
You have to be careful with using a 1khz tone,not all multimeters can handle 1 khz,most of them are made for 50 or 60 hz.Not that it will get damaged but you can get crazy readings especialy with cheap types.Just a tip.
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 29, 2014, 05:26:26 PM
Now you have the test tone, you will need an MP3/music player, etc, to play the sine track into the ValveFX.
You will also need a lead and maybe a jack adaptor to connect these together.

Set the ValveFX to bypass mode
Play sine track into ValveFX front input (set to repeat/loop)
GND meter lead should be on the front jack socket GND (sleeve) for all measurements

Set meter to 2V AC and connect to the signal on the front jack socket tip connection.
Measure the input signal, adjust the MP3 player volume (or whatever)
to give a reading of around 1V AC on the meter.

Measure the signal on TP4 on the PCB by the input jack socket
Measure the signal on U56 pin1 and pin7
Measure the signal on U32 pin1 and pin7


The closest I could get it to was .8 and that overloaded my Greenlee on 2V  so the measurment for TP4 is @ 20V
INPUT-.837
TP4-2.02

The U56 and U32, I was unable to find. The board has some listed beside them but others are beneath the opamps(I guess that is what those are?)

I have scoured the internet for a schematic but I guess I'm going to have to put this off until I get someone at Digitech to send me one, if that is possible.

 :poop:

Title: Re: Any Love For The Digitech Valve FX?
Post by: rnolan on January 29, 2014, 05:45:19 PM
Schematic
Didn't Sparker post the schematic here ?
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 29, 2014, 05:55:38 PM
Schematic
Didn't Sparker post the schematic here ?

I downloaded it and it was just the manual
Title: Re: Any Love For The Digitech Valve FX?
Post by: rnolan on January 29, 2014, 06:15:36 PM
Sparker did 2 posts, the first was the manual, the next was the schematics (which I was looking at yesterday), here it is again (now there are 2 :metal: )

Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 29, 2014, 06:23:51 PM
I totally overlooked the second one thinking it was the same. Thanks :thumb-up:
Title: Re: Any Love For The Digitech Valve FX?
Post by: rnolan on January 29, 2014, 06:29:31 PM
No Worries  :)
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on January 29, 2014, 07:06:57 PM
The U56 .860 and U32 .120 on AC 2V setting
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 29, 2014, 10:18:19 PM
Some whacky measurements there to start with (20V @ TP4), don't forget the meter should be AC. TP4 looks about right at 2V output with 0.8V input, U34 output looks low - can you check the ValveFX output level was turned to max when you measured U34 output?
Title: Re: Any Love For The Digitech Valve FX?
Post by: MarshallJMP on January 30, 2014, 04:37:45 AM
U56 pin 1 and pin 7 voltage should be around the same voltage as TP4 (in bypass mode).
Title: Re: Any Love For The Digitech Valve FX?
Post by: Sparker on January 30, 2014, 06:01:56 AM
.. and there is that as well. Could you put a little solder bridge, or short, across FET Q24, going from drain to source. Then, still in bypass mode, with the 2V AC signal at TP4, measure the AC signal at U56 pin 1. I'll try and get a pinout for Q24 in a bit.
Title: Re: Any Love For The Digitech Valve FX?
Post by: DrDckhol3 on February 03, 2014, 07:33:58 PM
I'm going to have to put this project on the back burner. Thanks fro every ones help. Hopefully I'll have some time to get back on it soon.  :facepalm:
Title: Re: Any Love For The Digitech Valve FX?
Post by: Achben on April 08, 2014, 10:56:45 AM
I have a valve fx that had a similar problem.
 Turns out the Output potentiometer was broken. These pots were made by a company called ALPS who had some trouble with curing the ink in these pots and were forced to overcook them in order to make the ink in the conductors cure. This made the inside of the pots brittle. Mine was in three pieces. Easy fix. You can buy them from a German fellow on ebay called Nocrotec for about 20USD.
 Another issue, the input gain is a bit weak. I was wondering if I could adjust P1 to let raise the input gain.

 Thank you.
 
Title: Re: Any Love For The Digitech Valve FX?
Post by: Chip Roberts on January 27, 2020, 02:30:51 PM
Resurrecting a dead post, but I just picked one of these up for its onboard whammy and also some good reviews about the effects.  My question is, some people say you can bypass the preamp and others say it cannot be bypassed.  If the former is true, then any information on that would be greatly appreciated.  If the latter is true, then I'm a dummy for buying it since the preamp sounds are effectively useless.
Title: Re: Any Love For The Digitech Valve FX?
Post by: rnolan on January 28, 2020, 12:06:57 AM
Hey Chip, it seems from the manual (simple block diagram) that you can bypass the distortion section (just after the compressor) thus feed in a signal (albeit at inst level) and then just apply effects to it.  The outputs will be line level so you will need to adjust for that.  So depends on how you patch it.  As the input is designed for a guitar, you'll have to be careful not to overload it but it should work.
Title: Re: Any Love For The Digitech Valve FX?
Post by: Chip Roberts on February 11, 2020, 09:54:04 AM
I haven't taken much time with this unit to dial anything in or rackmount it, so I'm just using it as a practice amp right now through the effects return of my Spider Valve.  It has some gnarly cleans, all way too overblown for what I need right now, so I'm mostly interested in dumbing it down a bit. 

I see that there are explicit instructions saying NOT to plug in a standard MIDI foot controller into one of the jacks because it'll blow up the unit or something, so I guess I need to search for the Control One if I actually want to use the whammy function.  Anyone know of a workaround?  An adapter, maybe?
Title: Re: Any Love For The Digitech Valve FX?
Post by: MarshallJMP on February 12, 2020, 01:28:59 AM
I just had a quick look at the manual and it does have midi in and out. You just have to be carefull not to plug in the midi controller into the footswitch connector since this input uses the same 5 pin connector as midi. So hooking up a midi pedal to the midi in is no problem. It does midi program and control change.
Title: Re: Any Love For The Digitech Valve FX?
Post by: Chip Roberts on June 02, 2020, 01:07:20 PM
Does anyone happen to know how to get my MIDI controller to talk to the whammy on this?  I routed every which way not too long ago and it wasn't liking anything I was sending to it.  I'm using An ART X15.
Title: Re: Any Love For The Digitech Valve FX?
Post by: rnolan on June 03, 2020, 01:18:28 AM
Hey Chip, try the manual MJMP posted, CC stuff starts page 48, you need to assign a MIDI CC expression pedal to the whammy parameter.  The pedal will have a CC number (with my ADA MXC moving the pedal shows its controller number when you are assigning it, IIRC 31 and 32) which can be changed (depending).  The parameter you want to change/effect must be something included in the selected patch, so you will need to include the whammy in the patch.
Title: Re: Any Love For The Digitech Valve FX?
Post by: Chip Roberts on August 17, 2020, 11:38:20 AM
I did a factory reset on the Valvefx and plugged in the X15 via the MIDI In, so it's at least able to switch between programs on a 1:1 ratio.  Now, the part I'm still stuck on is assigning the X15s Continuous Control to talk to the Valvefx.

I did the setup process on the X15 (holding mode and 1) and it showed that it was CC 4, which was what IntPedal on the ValveFx was assigned to.  (The ValveFx manual doesn't do a good job of specifying the difference between Internal and External Pedals, but I think the Internal refers to the proprietary Ground Control pedal, which I do not have). 

I then go to calibrate the CC pedal, pushing it forward is fine, but when it's time to push it back it reads "Calibrate error." 

I suppose I could just try and track down the Ground Control, but I feel like the X15 can already do all of the same thing, it just simply won't play nice. 
Title: Re: Any Love For The Digitech Valve FX?
Post by: rnolan on August 17, 2020, 09:49:20 PM
The CC stuff can do your head in a bit.  When I worked out the MB1 CC stuff it took a few reads of the manual to get my head around it, but it uses a "slots" kind of structure which is like another layer in between the controller/pedal and the patch parameter...  CC4 seems a low number for an expression pedal given the MXC assigns 31 and 32 to the expression pedal inputs.
Title: Re: Any Love For The Digitech Valve FX?
Post by: MarshallJMP on August 19, 2020, 02:08:47 PM
Found this in the manual of the X15

Pedal Test Mode

You may set up the X-15 to display visually the “value” of the expression pedals. Directly after power-up and before thedisplay shows Art, press simultaneously the BYPASS, 9 and 10 pads. You are now in pedal test mode. Moving either pedal will show the pedal’s hexadecimal value in the numeric display (00 to 7F). The first digit of the display will show either an "L" or “r” indicating which pedal has most recently moved, and its value. Exit by pressing the MODE button, When you are viewing the pedal value no MIDI information is being sent out the MIDI Out port. While you are in this mode, press any activator pad except the MODE pad and the software version will be displayed.
Title: Re: Any Love For The Digitech Valve FX?
Post by: rnolan on August 20, 2020, 01:42:04 AM
So this will show where (the hex value) the pedal is in it's sweep (from 00 to 7F or min to max) but you need the pedals CC assignment number so you can associate it with the Valve FX parameter.  For example, the first expression pedal socket in the ADA MXC pedal defaults to #31.  So in my MP2, I assign CC #31 to Stereo Master Volume but I could assign it to something else e.g. Wah.  Generally with these CC thingys you can set the CC number at both ends.  With the MP2, when you are assigning a CC button or pedal to a parameter, pressing the button or sweeping the pedal lets the MP2 detect what CC number the button or the pedal has been assigned.  But you can change the value to any valid CC number but you need to make sure it's the same as whatever has been assigned to the button or pedal in the MIDI (foot) controller. 
When the CC numbers are set the same in both send and receive device (in MXC and MP2 it's #31 for above example), you still need to get the pedal and device parameter to "Latch" (or it wont do anything).  To "Latch" you need to sweep the pedal past the value the receive parameter is currently set to.  So when I turn my MP2 on, I have to sweep the expression pedal past whatever the Stereo Master Volume is currently set to to get it to "Latch" and then start working.  So I just do a full sweep up and down to get it working.  I think I described this in more detail in the MB1 CC post I did ages ago.  It's also described in the MB1, MP2 manuals.When you do the calibration, it probably only needs to find the Max value so maybe you don't need to do the push back?
Title: Re: Any Love For The Digitech Valve FX?
Post by: MarshallJMP on August 20, 2020, 05:45:59 AM
Maybe the test is good for him to test if the pedals work. Also found in the manual that the left pedal is CC4 and the right CC11 unless it has been changed.
Title: Re: Any Love For The Digitech Valve FX?
Post by: Chip Roberts on August 21, 2020, 12:47:36 PM
Found this in the manual of the X15

Pedal Test Mode

You may set up the X-15 to display visually the “value” of the expression pedals. Directly after power-up and before thedisplay shows Art, press simultaneously the BYPASS, 9 and 10 pads. You are now in pedal test mode. Moving either pedal will show the pedal’s hexadecimal value in the numeric display (00 to 7F). The first digit of the display will show either an "L" or “r” indicating which pedal has most recently moved, and its value. Exit by pressing the MODE button, When you are viewing the pedal value no MIDI information is being sent out the MIDI Out port. While you are in this mode, press any activator pad except the MODE pad and the software version will be displayed.

I just tried this out and the display on the X15 is blank, unless I push any activator pad, which shows "-16"
Title: Re: Any Love For The Digitech Valve FX?
Post by: MarshallJMP on August 21, 2020, 09:49:47 PM
So it seems there is a problem with your pedals. I'll see if I can find a schematic.
Title: Re: Any Love For The Digitech Valve FX?
Post by: MarshallJMP on August 22, 2020, 01:54:41 PM
Well I found a really bad copy of the schematics and from what I can see the pedals don't work with a potentiometer but they are optical. So I looked around and found on YT a video about the strips used in the X15. https://www.youtube.com/watch?v=gFksy7imYLY

So my guess is that these work in similar way as an optical encoder. Maybe your stips are dirty or the optics (send/recieve) are dirty.

BTW anyone here have a scribd account, I found some schematics there but don't have an account.
Title: Re: Any Love For The Digitech Valve FX?
Post by: Chip Roberts on August 24, 2020, 02:49:53 PM
Well I found a really bad copy of the schematics and from what I can see the pedals don't work with a potentiometer but they are optical. So I looked around and found on YT a video about the strips used in the X15. https://www.youtube.com/watch?v=gFksy7imYLY

So my guess is that these work in similar way as an optical encoder. Maybe your stips are dirty or the optics (send/recieve) are dirty.

BTW anyone here have a scribd account, I found some schematics there but don't have an account.

So would you recommend going in there with some contact cleaner to see if that's the issue?
Title: Re: Any Love For The Digitech Valve FX?
Post by: MarshallJMP on August 25, 2020, 12:59:17 PM
Noooo no contact cleaner, that could ruin those strips. The thing is I don't know how it looks inside, I just had a look at the schematics and that YT video. But I'm sure it's optical with stripes on plastic strip and some send recieve leds I think (probably infra red) between the strip. So it could be the strip is dirty or the leds or one of the send/recieve leds. Actually the reciever is not a led but it looks like one. Maybe try to open it up and post some pics so I can have a look, or you can also mail them to me.