Black Dog high pitch tone/noise (solved)

[John Kurzweg]

I have a black dog pre-2021 version that has developed a high-pitched tone like a sign wave (somewhere around 880 Hz or so— should’ve written it down a few weeks ago !) Every control & sound in the pedal works correctly except for this tone is  always there when I kick the pedal on – it gets louder as you turn the gain up — is this one of the BS 170s? – or a capacitor? — does anybody know what the voltage should read on the transistors? — I can do a little bit of probing and multimetering etc — any help or ideas are much appreciated!— thanks

[Billy]

It could be a few things causing it power supply etc if you’ve used sockets make sure your transistors are nice and securely locked in

You can put your finger on each transistor to see if the oscillation stops

 

 

 

[Playsforfun]

I agree with Billy and would usually guess that it is from the power supply. I tested my Black Dog and got the following: Input vdc 8.70. Q1 D 5.70, G 4.68, S 2.97. All were similar with no more than .1 volt diff.

[John Kurzweg]

Thanks for the replies Billy and PlaysforFun, and thanks PfF for checking the voltages, I’ll check those out— I have the transistors socketed, and the sockets suck(!) , probably won’t do that again, but I did try pushing them in  with a finger when this first came up and it didn’t change anything. So, if it is in the power supply , does that mean it’s a capacitor? I’m a nube , so just learning as I go along…thx

[Playsforfun]

For me, It’s in the walls. My last house was bad, this one is even worse power is very ‘dirty’. So the filtering provided by a wall wart power supply can’t cut it and some of my pedals whistle something fierce. Even off my pro monster power device. It can make testing pedals pretty interesting and frustrating. If I switch to a battery it goes away. That is provided that my transistors are seated right. Is your noise present even with a battery for power?

[John Kurzweg]

Wow, the battery test worked fine and i was able to isolate the problem,: – It’s this one power supply (by IK — came with their Capture Reamp)  that has no issues with other pedals , but makes the Black Dog whine……Thanks for suggesting that, I hadn’t tried other power supplies as that one was fine with 4 other pedals i tested…

So now i really feel like a NUBE , but am happy to know what’s going on!

One plus : i grabbed an Agile p90 les paul just now that i rarely play to test the pedal, and the BLack Dog sounds GREAT with it — nasty and raw , but great….though that tone stack in the Black Dog is a bit strange and i have to keep the treble pot set to OFF…..Did they change anything in the tone of  V2?  –

–Thanks again!

[John Kurzweg]

And on that note……If you were to darken the circuit tone of the Black Dog pre 2021 a little bit, how would you go about it?

[Playsforfun]

Glad we could help. Up front I’m not the best with tone circuits. The only change in V2 was to add a voltage protection diode. This tone circuit is very similar to famous amp circuits. It doesn’t and can’t add treble or bass. Only lose, as it is a passive circuit. The caps and pot resistances play off each other to a certain degree making the answer to your question complicated but the cap that most affects the highs is C12. It will also play with the upper mids is adjusted. The Tone Stack Calculator by Duncan is worth googling and playing with in an effort to a higher tonal education. Otherwise, as always, Socket and See. Don’t forget to report back.

[John Kurzweg]

Thanks  — will try out some different values in C12 (hopefully soon) and report back

 

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