The "capacitor trick" on a Superblock US: 3 values compared (with audio)

**sgosnell** · 03-13-2023, 02:26 PM

Originally Posted by jzucker

link still broken. Did mouser to under?

That link works for me. Mouser is still in business, has been for as long as I can remember.

**jzucker** · 03-13-2023, 06:43 PM

Originally Posted by sgosnell

That link works for me. Mouser is still in business, has been for as long as I can remember.

doesn't work here. Tried it on a couple browsers and also my cell network. "Site is unavailable"

**nevershouldhavesoldit** · 03-13-2023, 07:19 PM

Originally Posted by jzucker

doesn't work here. Tried it on a couple browsers and also my cell network. "Site is unavailable"

You want either the 220 (black) or the 225 (red) 90 degree screw terminal plug, Jack. You can buy directly from the Switchcraft website (switchcraft.com). But you'll have to use smaller caps than the 400V ones I used in that comparison. A guitar signal is less than half a volt, so you don't need anything bigger than that.

I settled on 0.22 uF for my Superblock through my Toob Metro and 0.15 for my 10" Toob.

**jzucker** · 03-13-2023, 07:19 PM

Originally Posted by nevershouldhavesoldit

You want either the 220 (black) or the 225 (red) 90 degree screw terminal plug, Jack. You can buy directly from the Switchcraft website (switchcraft.com). But you'll have to use smaller caps than the 400V ones I used in that comparison. A guitar signal is less than half a volt, so you don't need anything bigger than that.

I settled on 0.22 uF for my Superblock through my Toob Metro and 0.015 for my 10" Toob.

thanks!

**nevershouldhavesoldit** · 03-13-2023, 07:21 PM

Originally Posted by jzucker

thanks!

You posted a response before I caught my error - it's edited corectly now. I use a 0.22 uF for the Metro and a 0.15 for the 10". YMMV.

**Rograt** · 03-14-2023, 01:40 AM

Thanks for taking the time to do this. Having established that the loop is a good place for the low pass filter I would probably get something like a Source Audio EQ2 and put that in the loop for some wild adjustment. I have one in front of my amp. I will try it in the loop!

**Little Jay** · 03-15-2023, 06:26 AM

Thanks for this!

I am very happy with my Superblock US, done a couple of studio sessions with it already (check here: (124) Shepperd Street Sessions - YouTube

) but yes, there is some brightness I'd like to control.

I should have enough caps and jack plugs laying around so I'll definitely try this!

**nevershouldhavesoldit** · 03-15-2023, 07:49 AM

Originally Posted by Rograt

Thanks for taking the time to do this. Having established that the loop is a good place for the low pass filter I would probably get something like a Source Audio EQ2 and put that in the loop for some wild adjustment. I have one in front of my amp. I will try it in the loop!

Your EQ pedal will affect tone differently when inserted into the loop (which may be good or bad, depending on what you want and like). At the input, your EQ will affect the signal through all preamp stages. There's a lot of adjustable coloration in the front end of a Superblock, and your EQ pedal will affect all of it at the input. The signal goes through the voice circuitry, adjustable gain stage, and the Superblock's EQ before it reaches the loop. At the input, you'll already have applied EQ to it before it reaches them. This will probably change the 3 voices in different ways. But if you insert it into the loop, those functions will already have been applied before EQ - so you may be "undoing" or otherwise altering them. The general recommendation for EQ pedals is to use them at the input of any amp because of the above. It won't hurt to try it, but I suspect the voicings will be a bit different - so you'll have to see which you prefer.

Capacitors are inherently high pass filters. Bridging the signal to ground through a cap bleeds highs out of the signal. By removing highs from the signal, the effect is as though a low pass filter had been inserted into the signal path. The frequency at which flow through a capacitor begins goes down as the capacitance value goes up. So tone gets darker as the bypass cap gets bigger. If you insert a capacitor into the signal lead, tone will get brighter because it will block lows. The capacitance in a cable is also a bridge to ground because it's between the signal lead at the center and the grounded shield wrapped around it. This is why long standard cables darken tone.

**monkmiles** · 04-30-2023, 09:32 PM

Thank you for the awesome information in this thread to those who have posted. While I really like the SBUS, you can count me in that it's bright. I set my treble knob at 9:00 while also boosting both the mid and bass knobs a bit. Might give this a try. I leaned towards the 0.33mf clip myself. To those who do this, do you find you can set your SBUS treble knob up a bit more than before?

**jzucker** · 04-30-2023, 10:01 PM

what is sbus?

**ccroft** · 05-01-2023, 01:07 AM

Super Block United States. Compare to Super Block United Kingdom. SBUK

I don't have one but I use the capacitor in my ToneBlock 202, and I do have the treble up higher than I used to.

**nevershouldhavesoldit** · 05-01-2023, 08:17 AM

Originally Posted by monkmiles

Thank you for the awesome information in this thread to those who have posted. While I really like the SBUS, you can count me in that it's bright. I set my treble knob at 9:00 while also boosting both the mid and bass knobs a bit. Might give this a try. I leaned towards the 0.33mf clip myself. To those who do this, do you find you can set your SBUS treble knob up a bit more than before?

I do not. I’ve been using the 0.33 uF since the OP and am very happy with the sound of both my archtops and solids through it into my Toobs. For jazz, I leave treble & mid flat with bass flat through he RevSound 8, bass @ 1 o’clock through the Metro and bass @ 11 through the RE 10.

**JCat** · 05-03-2023, 04:59 AM

Those SS mini-heads are clever for light travel and studio work or as a low noise back-up solution that accepts both 8 and 16 ohms guitar speakers. Great.
There's a variety of brands and models and they always come with a headphone jack for silent practicing...

-What's the general verdict on the Superblock headphone out?

(Hypothetically, the headphone jack could also connect to desktop computer monitors or line out to a mixer or a sound card/recording device. This may or may not be a good idea depending on the implementation of the headphone interface and its speaker simulation and EQ.

A headphone out jack is not a neutral "line-out", it's equalized to sound "good" through headphones. As "good" in this context is subjective it's crucial that the tone shaping controls of the amp are in full control also of the headphone signal. For example; If the headphone out jack implementation got a deep hi-fi oriented mid scoop, it may not be possible to recover those mids by tweaking the amp controls and the guitar tone comes out thin, which is often perceived by the user as too bright...

It should be noted that some users don't even own a guitar cab and that it's possible to make a Youtube "demo" by lining out from the headphone jack...

We can change the sound of the rig by plugging in different guitar speakers, but the basic headphone signal can't be changed, It is what it is by design, unlike a modeler that got a selection of cab simulations. If someone is using a proper guitar cab but still finds there's too much treble that can't be tamed by using the controls of the guitar and amp, then I think the standard recipe would be to first try a longer, high capacitance instrument cable.)

**nevershouldhavesoldit** · 05-03-2023, 07:40 AM

Originally Posted by JCat

What's the general verdict on the Superblock headphone out?

(Hypothetically, the headphone jack could also connect to desktop computer monitors or line out to a mixer or a sound card/recording device. This may or may not be a good idea depending on the implementation of the headphone interface and its speaker simulation and EQ.

A headphone out jack is not a neutral "line-out", it's equalized to sound "good" through headphones. As "good" in this context is subjective it's crucial that the tone shaping controls of the amp are in full control also of the headphone signal. For example; If the headphone out jack implementation got a deep hi-fi oriented mid scoop, it may not be possible to recover those mids by tweaking the amp controls and the guitar tone comes out thin, which is often perceived by the user as too bright.

The SB’s “headphone” output is more than that - it’s an unbalanced line out with enough voltage to drive most headphones. It won’t drive true low impedance ‘phones, but it’s enough for my 62 Ohm AKG Q701s. It’s after the master volume and the cab sim switch as well as all other controls. It’s not “equalized to sound good through headphones”. It gets the same signal that comes out of the XLR line out - the only difference is in the electrical parameters of that signal, which are optimized for driving unbalanced headphones and balanced line inputs.

The headphone jack sounds great through my AKGs and my Sony MDRs. On FRFR, it’s flat and uncolored, aka “hifi”, which is good for most acoustic guitars but not for electric jazz tones from archtops. All controls are functional to shape the sound. I haven’t tried recording from it because my recording setup has XLR inputs.

**JCat** · 05-03-2023, 08:19 AM

Originally Posted by nevershouldhavesoldit

The SB’s “headphone” output is more than that - it’s an unbalanced line out with enough voltage to drive most headphones. It won’t drive true low impedance ‘phones, but it’s enough for my 62 Ohm AKG Q701s. It’s after the master volume and the cab sim switch as well as all other controls. It’s not “equalized to sound good through headphones”. It gets the same signal that comes out of the XLR line out - the only difference is in the electrical parameters of that signal, which are optimized for driving unbalanced headphones and balanced line inputs.

The headphone jack sounds great through my AKGs and my Sony MDRs. On FRFR, it’s flat and uncolored, aka “hifi”, which is good for most acoustic guitars but not for electric jazz tones from archtops. All controls are functional to shape the sound. I haven’t tried recording from it because my recording setup has XLR inputs.

OK, thanks,

So the Superblock actually got a cab simulation switch....
-Is this feature only enabled when there's no guitar speaker plugged in? If so, it wouldn't be a regular bright-switch (Brt/Norm) but rather a simulation of a bright and a less bright speaker?

-What speaker is it supposed to simulate? a generic Jensen in a closed (norm) or open cab (Brt)?

**jzucker** · 05-03-2023, 08:22 AM

Originally Posted by JCat

OK, thanks,

So the Superblock actually got a cab simulation switch....
-Is this feature only enabled when there's no guitar speaker plugged in? If so, it wouldn't be a regular bright-switch (Brt/Norm) but rather a simulation of a bright and a less bright speaker?

-What speaker is it supposed to simulate? a generic Jensen in a closed (norm) or open cab (Brt)?

It's not an impulse response. My understanding is that it's more of a low pass eq

**nevershouldhavesoldit** · 05-03-2023, 08:26 AM

Originally Posted by JCat

OK, thanks,

So the Superblock actually got a cab simulation switch....
-Is this feature only enabled when there's no guitar speaker plugged in? If so, it wouldn't be a regular bright-switch (Brt/Norm) but rather a simulation of a bright and a less bright speaker?

-What speaker is it supposed to simulate? a generic Jensen in a closed (norm) or open cab (Brt)?

The manual is on the Quilter site (here). The cab sim switch only affects the two line outs and is independent of speaker use. It’s not just a normal-bright switch (I.e. simple EQ), but the sonic effect includes a brighter sound.

**JCat** · 05-03-2023, 09:00 AM

Originally Posted by nevershouldhavesoldit

The manual is on the Quilter site (here). The cab sim switch only affects the two line outs and is independent of speaker use. It’s not just a normal-bright switch (I.e. simple EQ), but the sonic effect includes a brighter sound.

Thanks,

The manual says "norm" = 12" speaker and "Brt" = smaller speaker. So appearantly they did something to the headphone signal to make it "sound good".
I have not had the opportunity to plug into a Superblock, but I have experience with other mini heads and modelers that got too much bass in the headphones out, resulting in a scooped, thin tone. (I mostly use AKG open backs).

**nevershouldhavesoldit** · 05-03-2023, 10:16 AM

Originally Posted by JCat

Thanks,

The manual says "norm" = 12" speaker and "Brt" = smaller speaker. So appearantly they did something to the headphone signal to make it "sound good".
I have not had the opportunity to plug into a Superblock, but I have experience with other mini heads and modelers that got too much bass in the headphones out, resulting in a scooped, thin tone. (I mostly use AKG open backs).

That’s not my experience with the SBUS through my AKG Q701s. With the cab switch on normal, my archtops sound fantastic. My jumbo flattop with piezo sounds like itself with cab on bright, more so on FRFR, and more dreadnought-y on normal.