Golden Falk Treble Bleed Cap

[psychepool]

hello.
I made Golden Falk (Colombo Plexi Breed).
I also made Marble Drive, which has almost the same circuit as Golden Falk, but I was very satisfied because it didn't feel like there was a filter somewhere unique to Marble Drive.

The only disappointment is that the Treble Volume low gain setting produces a muffled sound when the gain boost is applied.
This is noticeable in high-pitched strings.

I got a hint from the fact that if I increase the treble volume, these symptoms will disappear.
When I lowered the 330pF connected between Treble Volume Pot 2/3 to 100pF like the marble drive, the symptoms completely disappeared.
However, of course, when using 100pF, the sparkle of the low gain and the tightness of the high gain are reduced.

Others who have made it ask if there were any symptoms like this, and if there is a way to solve the problem while maintaining the 330pF value.
I tested it by slowly lowering the value at 330pF, and even if it is about 150pF, the symptom occurs, and a value lower than this does not make a meaningful difference compared to 100pF.

Bias trimmer adjustment had no effect on this symptom.

 

[xefned]

Golden Falk is my favorite. So I tried to replicate your disappointment.

Am I understanding correctly? You're using the Tone knob rolled fully off and the Normal Channel Gain fully off.
And you're losing the high end on the top 3 strings when you crank the Bright Channel Gain?

 

[xefned]

If so, I can't replicate your problem with my properly built version. You should get super top boost with the bright channel low, but then the mids slightly overpower the highs when you crank it to 10. This is just playing a D chord on the highest 3 strings. Turning up the Volume brings your highs back, esp. if you switch to 1980's mode.

If not, it's safe to say yours has an error. I get plenty of brightness with the bright channel even with the tone knob down.

 

[psychepool]

It seems that the communication was not done properly due to lack of expressive power in English.

It's not that the treble is reduced, it's rather excessive, and the treble is strangely distorted.
It feels like a limiter is working, and it feels like a tube amp sag.

There is no problem when using it alone, but there is a problem when applying a gain boost.
If increase the treble gain, this phenomenon disappears. Perhaps it is because the ratio of treble has decreased relatively.

 

[Chuck D. Bones]

It is customary to include detailed photos of the board. Have you performed a thorough visual inspection of all components, wiring and solder joints? 99% of the time, the problem is caused by an error in workmanship. Please review some of the other troubleshooting posts in this form to see how we do it.

 

[psychepool]

It is customary to include detailed photos of the board. Have you performed a thorough visual inspection of all components, wiring and solder joints? 99% of the time, the problem is caused by an error in workmanship. Please review some of the other troubleshooting posts in this form to see how we do it.

I totally agree with what you said.
However, there are two reasons why I didn't post production photos.

First of all, I didn't build it using pedalpcb's board
I always want to make my pedals in Hammond 1590A size, so I make my own compressed layout and make it on perfboard.
Because of this, I thought that it would be difficult for the members to check the production conditions or errors when looking at my board.

Second, I wanted to first check if this was an issue in the circuit before checking if it was a manufacturing problem.
If it is an issue that other members are also experiencing, I can just accept it or find another alternative.
If it was an issue that the other members weren't experiencing, I was planning to check my production-related errors from then on.
Because if the issue already exists in the circuit, there is no need to check for manufacturing errors.

Seeing that no one has commented on the issue I raised yet, it is presumed to be a problem with my build status, which I am experiencing.

This is my build picture.
Unfortunately, I didn't take a picture of the soldering side, so I don't have it. In fact, even if I try to take a picture, it is difficult to take a picture of the soldered side properly because of the density of the pot wires.



In fact, I am satisfied with the current 100pF treble bleed cap.
Since there is an advantage that the tone is softer than when using 330pF, there is also a plan to use 100pF/330pF by switching.
Since the 1987X mode is unlikely to be used well, I am going to try using the DPDT on-off-on switch as a gain switch on one side and a 100pF/330pF switch on the other side.

Anyway, it may be a bit limited information, but if you can get a clue to confirm the problem, please comment.

 

[Laundryroom David]

I have nothing helpful to add, but wanted to compliment you on an impressive build!

 

[spi]

0R resistor FTW