Boss PH-2 volume drop

stevenrb718
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Boss PH-2 volume drop

Post by stevenrb718 » Fri Mar 31, 2023 8:55 pm

Does the Boss PH-2 inherently have a bad volume drop when effect is on or is there something wrong with my pedal? I've already replaced a couple leaky capacitors but all the others are tested good.

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Pepe
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Re: Boss PH-2 volume drop

Post by Pepe » Fri Mar 31, 2023 9:19 pm

Welcome to the forum! When I had a PH-2 I only noticed a slight volume boost in some settings in Mode II, as you can hear in my demo video where I used a Japanese Fender Stratocaster. I don't know if there might be a volume drop if you use hot or active pickups. What kind of guitar do you use and what else is in the signal path before the PH-2?
Pepe at YouTube and Instagram

stevenrb718
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Re: Boss PH-2 volume drop

Post by stevenrb718 » Sat Apr 01, 2023 2:41 pm

PH-2 is the only pedal in the chain, and the guitar has swapped and hasn't made a difference. Also, the bypass effect is at a normal volume level.

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laurie
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Re: Boss PH-2 volume drop

Post by laurie » Sat Apr 01, 2023 4:24 pm

I don't currently have a PH-2 so can't experiment/confirm the issue.

If the pedal is basically OK and the output is just "low to your taste", the effected output can be increased by increasing R77.

stevenrb718
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Re: Boss PH-2 volume drop

Post by stevenrb718 » Mon Apr 03, 2023 4:32 pm

laurie wrote:
Sat Apr 01, 2023 4:24 pm
I don't currently have a PH-2 so can't experiment/confirm the issue.

If the pedal is basically OK and the output is just "low to your taste", the effected output can be increased by increasing R77.
Increasing the R77 resistance at IC5? That didn't change the effect at all.

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laurie
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Re: Boss PH-2 volume drop

Post by laurie » Mon Apr 03, 2023 6:27 pm

stevenrb718 wrote:
Mon Apr 03, 2023 4:32 pm
laurie wrote:
Sat Apr 01, 2023 4:24 pm
I don't currently have a PH-2 so can't experiment/confirm the issue.

If the pedal is basically OK and the output is just "low to your taste", the effected output can be increased by increasing R77.
Increasing the R77 resistance at IC5? That didn't change the effect at all.
My bad (should have looked at the schematic closer!). That will only work on Mode II, and probably not well even then.

Try lowering R79 - that will increase the level in the output drive done by IC1B.

stevenrb718
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Re: Boss PH-2 volume drop

Post by stevenrb718 » Tue Apr 04, 2023 6:22 pm

I wondered why that was a suggested idea, haha. Didn't make any sense to me looking at the schematic, but now I see why. I lowered the resistance at R79, but sadly it added a fair amount of hiss to the signal. Jumping the resistor altogether actually increased the volume close to the bypass volume, but the added noise is just too much. I'll pay with the resistors to find a happy medium. I wonder if there is a different fault in my pedal or "just how it is."

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laurie
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Re: Boss PH-2 volume drop

Post by laurie » Tue Apr 04, 2023 7:50 pm

It does sound like it has a fault. Do you have access to test equipment? An oscilloscope, maybe?

Where are you located? If by pure chance you are in Calgary, Canada, I can help hands-on.

stevenrb718
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Re: Boss PH-2 volume drop

Post by stevenrb718 » Wed Apr 05, 2023 4:30 am

Note quite, I'm about 2100 miles ESE of Calgary, haha. Unfortunately no oscilloscope, but I am an electronics repair tech, so I know my way around for the most part. I've already swapped leaking capacitors, but wanted to know if the volume drop was normal or not before going further by swapping something like the 571.

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laurie
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Re: Boss PH-2 volume drop

Post by laurie » Wed Apr 05, 2023 11:37 am

No - what you describe is not normal.

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