[Seamless Sounds]

 
What do you have R3, R4, Rbb, and Cbb set to? For me, at a gain of 5 I have R3 and R4 set to 2.55KΩ and 10.2KΩ respectively. Rbb is 50KΩ for the Alps RK27. And Cbb is ??
My current headphones is in my sig. I'm just curious that's all. I'm going to tinker with an EQ for a bit, but I want to hear yours.
 
Here's an interesting chart http://www.independentrecording.net/irn/resources/freqchart/main_display.htm

 

[FallenAngel]

Well, as you use a 50K pot for bass boost, it's adjustable so R3 and R4 values aren't a big deal, just set Cbb to how much of a curve you want.  I generally stick to 0.22uF but as I think the K701 sound thin, perhaps 0.1 - 0.15 would give some more boost.

 

[Seamless Sounds]

 
I can't decide between .1uF and .068uF. I might as well order both and experiment!
Edit: I wonder if it's possible to build a switch that can toggle between .1uF and .068uF for the left and right Cbb

 

[t0wer]

Quote:

Edit: I wonder if it's possible to build a switch that can toggle between .1uF and .068uF for the left and right Cbb

It's DIY, everything is possible,
 
If I were going got do that, I'd get 2 dpdt switches or one 4pdt switch and wire the center poles to the board and put the capacitors on each side.

 

[Fred_fred2004]

Why not just use sockets until you've settled on the right mix
 
cheers
FRED

 

[Seamless Sounds]

Quote:

It's DIY, everything is possible,
 
If I were going got do that, I'd get 2 dpdt switches or one 4pdt switch and wire the center poles to the board and put the capacitors on each side.

So say I have 0.22, 0.15, 0.1, and 0.068 for both CbbR and CbbL. I want to use a single knob to select different values for CbbR and CbbL instead of two knobs for each Cbb. Can you illustrate it as a diagram? I understand things better visually.

 

[amb]

I suggest not to switch multiple caps.  It's undesirable to add complicated wiring in the negative feedback loop of the amp.  The bass boost is already variable (pot adjusted), so just choose a good Cbb value, along with R4 and R3, and be done with it.  Use the "Bass boost calculator" at the M³ website to see what the max boost curve would look like.

 

[Seamless Sounds]

 
Really? aw... Just when I was going to label it as "sub-bass," "lower bass," "upper bass," and "bass-head" on a 4-way knob switch (.22uF, .15uF, .1uF, and .068uF respectively) depending on the music. I came to that conclusion using the BB calculator. I'll still order all four for experimentation, but I don't like the idea of putting the other 3 caps to waste.
 
Besides the "complicated wiring," what problems will there be should it be attempted? Will the sound quality degrade?

 

[amb]

The extra wires to the switch (and offboard parts) could cause the amp to become unstable and/or pick up noise and interference.
 

 

[Seamless Sounds]

Quote:

The extra wires to the switch (and offboard parts) could cause the amp to become unstable and/or pick up noise and interference.
 

okay. Well I guess I'll have to compromise then. I'm going to remove .22 and .15 off the list since it doesn't help K701's bass punch much. Back to square one, .1 or .068. I used an FFT filter to simulate the frequency graph results I got from the BB calculator. I wish I can swap them easily without hassle...


 
Quote:

Why not just use sockets until you've settled on the right mix
 
cheers
FRED

What sockets? There's sockets for caps?

 

[Fred_fred2004]

I use these all the time
 
when mucking about with ideas
 

 
off ebay
 
cheers
FRED

 

[Seamless Sounds]

I don't see any caps in your pic. How will those sockets secure caps in its place?

 

[amb]

Quote:

I don't see any caps in your pic. How will those sockets secure caps in its place?

By friction only.  Of course, it assumes that the cap leads are the correct diameter to work.  You could use these sockets (they're called "break-apart SIP sockets" and available from the usual vendors) to experiment with different caps, but I recommend soldering in the caps afterwards.  You don't want those caps to fall out accidentally.

 

[Seamless Sounds]

 
just wondering, would the amp go haywire if I omit the Cbb pads?

 

[MisterX]

You planning on cutting them off the PCB?