Build Your Own Clone Message Board

Hi All,
I have been using my DI pedal for about 2 years without a problem.
For no apparent reason the volume is now much more quiet in bypass.
Both the effect and aux outputs have the same problem.
I have reflowed the solder,and replaced the foot switch.

So I was trying the pedal out this weekend.
Should the output volume be the same in bypass with power or no power?
Is it possible that the main output and aux output with the effect engaged would be louder than in bypass with no power?

Sorry your post slipped through the cracks a bit here!


Yes. Since the pedal is true bypass, you should get the same signal in bypass whether or not the pedal is being powered. Are you getting something different than that?


You should not get any sound from the main and aux outputs in effect mode when the pedal is not powered. Are you getting signal in effect mode with no power?

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MasterDelayer/Reverbrador/Ampaholic/TopJacker

Hi Morgan,
With no power I am not getting signal when in effect mode.
With the switch in bypass I am getting signal.It is the same volume as when the effect is removed from the chain.

With power:
Out of Aux there is a louder signal with effect engaged
Out of Main there is a significant volume increase with the effect engaged.

Weird.
Any ideas?
I checked the voltage on the I.C.s Everything checked out fine.

Am I correct in thinking that when the pedal was previously working, you did not have this volume boost with the effect engaged?

Has anything in your signal chain changed? Have you tried just instrument > short cable > pedal > short cable > amp to eliminate possible impedance interactions?

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MasterDelayer/Reverbrador/Ampaholic/TopJacker

You are correct.
The pedal was working for over a year in my set up.
Then one day I clicked it on and the effect was accompanied by a pretty huge volume jump.
As I have been trying different repairs (reflow solder, install new switch, reseat ICs, rereflow solder)
I have tested it with nothing else in the chain.

I guess it's time to start pulling individual components and testing them.

I have a signal tester on order.

Thanks for your help!

Okay, great. A signal tester will be a lot of help.

Since the volume boosting issue is there on both the aux and effect outputs, you want to focus on the aux output first, since there is much less circuit to troubleshoot.

A volume boost from the aux output should be limited to the area of the circuit associated with IC1. The aux signal path is as follows:

C1 > R1 > IC1 pin 5 > IC1 pin 7 > C13 > R37 > tip of the Aux output jack

You'll want to probe the signal path in that order (in effect mode) and note where the signal gets boosted.

Also, R2-R4 and C3-C4 work together to set the gain of IC1. You want to check out all of those components and their solder joints.

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MasterDelayer/Reverbrador/Ampaholic/TopJacker

I have been having a hard time testing the circuit.
When I have been testing I use my iPhone output and the issues aren't as apparent as when I use my guitar.
I'm sure it has to do with impedance matching or output.
Does anybody have a trick for passing signal whilst testing, aside from having my 8 year old play guitar while testing?
He gets bored too fast.
Maybe the 5 year old...

Set everything up, plug your guitar into the input, signal tester into amp, probe in left hand, strum open strings with right hand. Strum & probe, strum & probe. You'll get the hang of it.

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MasterDelayer/Reverbrador/Ampaholic/TopJacker

Yup, that's how I do it, too.

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“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Huge volume increase between IC1:5 and IC1:7
I swapped 2 ICs and they performed the same. I guess it's supposed to be that way?


Sent from my iPhone using Tapatalk

Ditto looper is so handy for these occasions.


Sent from my iPhone using Tapatalk

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Pedal building is like the opposite of sex. All the fun stuff happens before you get in the box.

Apologies, I lead you astray a bit. Ic1 should be boosting the signal. The signal gets reduced over at R37 & R38. Test signal at both sides of R37 and see if one side is more quiet.

The regular output also has a voltage divider attenuator (sort of a fixed volume control) at R16 and R17. Check both sides of R16 too.

I'm starting to think it something shorted past these voltage dividers.

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MasterDelayer/Reverbrador/Ampaholic/TopJacker

I did some testing on the subject last night.

All my direction references are based on pots on top and switches on the bottom.

bottom of R37 is the louder side
top of R16 is the louder side
top of R3 is the louder side
top of R2 passes signal, not the bottom
top of R4 passes signal, not the bottom
no signal at C4
C3 similar to R3

I'm still floundering.
I can't give up, but I am out of my depth.

The quieter sides of these two resistors is what connects to the outputs (aux for R37, normal for R16). Is the quieter side of these resistors still a lot louder than the bypass level?

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MasterDelayer/Reverbrador/Ampaholic/TopJacker

I am away the board.
I would say the quieter side of the resistors is not much louder than the bypass volume.

The quiet side of R37 is the same as the aux output. In bypass I get no sound from R37.
R16 has a very different tone from the normal output. In bypass I get nothing from R16.


Sent from my iPhone using Tapatalk

We're trying to chase down where you are getting this volume boost in effect mode. These resistors are right at the end of the circuit. I need to know if the volume boost you are hearing is present here as well.

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MasterDelayer/Reverbrador/Ampaholic/TopJacker