Help Troubleshooting volume loss PLEASE

[Khron]

the 1/4"-connector could be used as a "line-level" input and the XLR-connector could be used as a "mic-level" input. Although such a use would be possibly considered to be "rare", it is nonetheless.....a possibility to accomplish!!!

Not rare at all - in fact, apart from most MOTU gear (with specifically designated inputs such as the Ultralite the OP has), and certain TC Electronic products, damn near ALL audio interfaces with XLR-combo input connectors have the XLR dedicated to mic-level and the TRS to line-level (going into the mic preamp via a resistive pad). Combo inputs that can also act as instrument inputs as well, have that side of things switchable (either physically or via respective the control software).

That's the case at least with Focusrite, Presonus, M-Audio, Alesis etc.

 

[sonolink]

Not rare at all - in fact, apart from most MOTU gear (with specifically designated inputs such as the Ultralite the OP has), and certain TC Electronic products, damn near ALL audio interfaces with XLR-combo input connectors have the XLR dedicated to mic-level and the TRS to line-level (going into the mic preamp via a resistive pad). Combo inputs that can also act as instrument inputs as well, have that side of things switchable (either physically or via respective the control software).

That's the case at least with Focusrite, Presonus, M-Audio, Alesis etc.

Absolutely, and that's probably why I assumed the MOTU was like that (although it was clearly labelled on the front panel

Khron, do you think it's worth having the balanced output on this pedal, considering that the idea behind it, is to avoid carrying an amp for a recording or a gig, and being able to plug directly into a mixer or soundcard?

Cheers
Sono

 

[Khron]

Khron, do you think it's worth having the balanced output on this pedal, considering that the idea behind it, is to avoid carrying an amp for a recording or a gig, and being able to plug directly into a mixer or soundcard?

Why wouldn't it be? Should be great fun to hear just how much more noise you'd get and how huge a (possible) ground loop could form, with the pedal on stage, and a single-ended cable going at the very least 40-50ft / 10-15m or so, all the way back to the mixer...

Just keep in mind to add a ground-lift switch for the output XLR.

 

[sonolink]

Why wouldn't it be? Should be great fun to hear just how much more noise you'd get and how huge a (possible) ground loop could form, with the pedal on stage, and a single-ended cable going at the very least 40-50ft / 10-15m or so, all the way back to the mixer...

Just keep in mind to add a ground-lift switch for the output XLR.

I'm not sure I explained myself well. What I meant to ask was if you reckon it's a good idea to have an inbuilt DI box output in the pedal or it's not worth it since an external DI box can be used.

This build is quite tight in a Hammond 1590BB but I don't want to use a bigger enclosure and at the same time I'm trying to cut on everything I can to gain space.

For instance I have to check how useful the Cab Volume pot is, considering there's also a Gain and a Master pot. If it's not really useful I'd rather put a fixed resistor or directly eliminate the pot to gain space inside the enclosure.

Initially I would have used a transformer for the DI out, something like a 13k:600 but it's also bulky and more expensive.

The DI out can be done with a TRS connector but ideally you would use an XLR, again meaning a more bulky connector.

So I'm trying to get around all these considerations and was just asking fpr advice and opinions. Sorry if it sounded like a dumb question.

Cheers

Sono

 

[MidnightArrakis]

I don't want to use a bigger enclosure and at the same time I'm trying to cut on everything I can to gain space.

[I don't want to use a bigger enclosure and at the same time I'm trying to cut on everything I can to gain space] -- This might come across as being a -- bummer -- for you to read, but.....your reasoning is one of the reasons why things are being designed with "Surface-Mount" components. Whatever circuitry that you have, minus the "electro-mechanical" components (most switches, transformers, connectors, etc.) can all be designed onto a PCB significantly smaller than anything you could come up with using "Thru-Hole" components. Just sayin'.....

/

 

[sonolink]

Thanks for pointing that out

 

[MidnightArrakis]

At the same time, use crocodile-clips from your multimeter to monitor the HV DC supply.

[use crocodile-clips from your multimeter] -- "Alligator-clips" are friendlier!!! More widely available, too!!!

/

 

[MidnightArrakis]

This build is quite tight in a Hammond 1590BB but I don't want to use a bigger enclosure and at the same time I'm trying to cut on everything I can to gain space.

>> Just for your reference:




And.....you built THIS ↓↓↓↓ schematic into THIS enclosure ↑↑↑↑, right???



Just my personal opinion here, OK???.....But, from what I see here looks like some rather -- iffy -- solder-joints:




And.....I'm also guessing that this is some purchased PCB from either a member of this forum or from some other DIY website. Regardless, in either case, the -- annular ring -- of these pads are what I would consider to be "too small" for being hand-soldered. Wave-soldered??? No problem. But, "hand-soldered"??? The "annular rings" should be a bit larger, while also being soldered with a bit more "finesse"!!! The general appearance of these solder joints looks to be a bit "rough", which could also possibly be an underlying cause of some of your "difficult to locate" noise problems. As an example, the solder joint of the anode on the bottom diode looks a bit "iffy" to me. While it could actually be perfectly fine in reality, I would still go ahead and touch it up some.

The three connections shown above of the pot solder joints also all look rather dubious at best. They all could possibly use some "warming up" just to make sure everything is all connected nice and snug!!! A possible "cold solder joint" on one of those connections could be causing some of your "scratchiness" by an ever-so-minute (pronounced: meye - noot, in this case) rapidly intermittent connection as you rotate the control. I once actually encountered this with a brand-new $2,500 compressor from a well-known brand-name. All it took was for me to first track-down the source of my problem and then all of a few seconds to reheat the solder joint on the pot having an issue. PROBLEM SOLVED!!!

/

 

[sonolink]

And.....you built THIS ↓↓↓↓ schematic into THIS enclosure ↑↑↑↑, right???

View attachment 127715

That's right, yes.

And.....I'm also guessing that this is some purchased PCB from either a member of this forum or from some other DIY website.

Actually no. I did the layout and got the board from JLCPCB

Regardless, in either case, the -- annular ring -- of these pads are what I would consider to be "too small" for being hand-soldered. Wave-soldered??? No problem. But, "hand-soldered"??? The "annular rings" should be a bit larger, while also being soldered with a bit more "finesse"!!! The general appearance of these solder joints looks to be a bit "rough", which could also possibly be an underlying cause of some of your "difficult to locate" noise problems. As an example, the solder joint of the anode on the bottom diode looks a bit "iffy" to me. While it could actually be perfectly fine in reality, I would still go ahead and touch it up some.

The three connections shown above of the pot solder joints also all look rather dubious at best. They all could possibly use some "warming up" just to make sure everything is all connected nice and snug!!! A possible "cold solder joint" on one of those connections could be causing some of your "scratchiness" by an ever-so-minute (pronounced: meye - noot, in this case) rapidly intermittent connection as you rotate the control. I once actually encountered this with a brand-new $2,500 compressor from a well-known brand-name. All it took was for me to first track-down the source of my problem and then all of a few seconds to reheat the solder joint on the pot having an issue. PROBLEM SOLVED!!!

/

You're right. When I did the second board I took care of soldering every spot carefully and the noise was gone. So probably that was the cause.