This TubeScreamer screams a little too loud

[Diamondj421]

Greetings all!
Noob here! I've built a good amount of gear over the past few years (rack mount compressors, EQs, preamps) but this is my first pedal. I'm building an Aion Stratus for my singer/guitarist who knows very little about gear. I've only used a barely functional SoundTank TS5 and the multiple plugin versions of the TubeScreamer so I'm not exactly sure how a proper TS9 should be functioning. The volume with the pedal bypassed is considerably quieter than when the pedal is engaged. I have to set the volume pot to about 9 o'clock for the levels to be about the same. Again, I'm a noob but this doesn't seem right. I followed the provided schematics and just went through double checking component values which all seem right. Any idea what it could be? If this is functioning as it should, what can I do to bring the level down?
Thanks!

https://aionfx.com/app/files/docs/stratus_documentation.pdf

[antonis]

I have to set the volume pot to about 9 o'clock for the levels to be about the same.

Volume levels when bypassed & engaged should be equal for volume setting when pedal engaged..
(in the mean of no audible difference either effect been on or off..)

So, if Vol pot setting at 9 o'clock is what setting you use, things are fine..
If you use higher Vol pot setting, raise R15 (10k) resistor according to your taste..
(always depending on following effect input impedance..)

[Kevin Mitchell]

Just an overdrive doing it's best!
Raise R14 and lower R15 to taste.

[Kevin Mitchell]

If you use higher Vol pot setting, raise R15 (10k) resistor according to your taste..

[antonis]

@Kevin: 

OP said he experienced a level DROP..!!
(regarding to 12 o'clock -midpoint pot set)

P.S.
@Diamondj421: do you mean you'd like to have equal modes level for Vol pot FCCW..??

[Diamondj421]

Volume levels when bypassed & engaged should be equal for volume setting when pedal engaged..
(in the mean of no audible difference either effect been on or off..)

So, if Vol pot setting at 9 o'clock is what setting you use, things are fine..

Ahhhh gotcha. I just looked over the schematic and correct me if I'm wrong, but the signal hits the clipping circuit prior to the level. I had been thinking of the level knob boosted the input, not an output.

@Diamondj421: do you mean you'd like to have equal modes level for Vol pot FCCW..??

I'd just like a little less headroom. Being able to turn up to 12 o'clock without it ripping my head off would be nice.

P.S. Does this forum really not like people posting on it? Having to do a Captcha and then answer 5 questions (some of which I have to Google the answers to) really makes me think twice. lol.

[Kevin Mitchell]

@Kevin: 

OP said he experienced a level DROP..!!
(regarding to 12 o'clock -midpoint pot set)

I read the opposite. 
Which is why I suggest increasing the output resistor and lowering the pull-down resistor.

[antonis]

I just looked over the schematic and correct me if I'm wrong, but the signal hits the clipping circuit prior to the level. I had been thinking of the level knob boosted the input, not an output.

Quite common wrong impression..
(for any high gain distortion circuit, power supply headroom, hence signal voltage amplitude is already overlied before output Volume/Level setting..)

I'd just like a little less headroom. Being able to turn up to 12 o'clock without it ripping my head off would be nice.

IMHO. it's not a "headroom" matter but an output voltage one..
So, proceed with modding R14/R15 ratio..
(be aware of it shouldn't work the same for a 100k and a 1M next effect input impedance..)

Does this forum really not like people posting on it?

It stronly depends on THE kind of people..!!

[antonis]

I read the opposite. 
Which is why I suggest increasing the output resistor and lowering the pull-down resistor.

To be honest, I'm not sure who of us (if anyone) have read OP's query correctly..

[Diamondj421]

IMHO. it's not a "headroom" matter but an output voltage one..
So, proceed with modding R14/R15 ratio..
(be aware of it shouldn't work the same for a 100k and a 1M next effect input impedance..)

Could you repeat this like I'm a 5-year old? lol

[antonis]

 

What comes out of Q2 Emitter is set by Level pot setting
(considering Q2 Emitter follower of unity voltage gain..)

That "what" further exhibits a voltage dividing effect due to R14/R15 divider..
(considering next effect infinite input impedance..)

So, final output voltage amplitude is R15/(R14+R15) of what comes out of Q2 Emtiter for any given Level pot setting..
So far so good..
(candy for 5 years old kid..)

In real world (no candies anymore..), next effect exhibits "some" input impedance..
This impedance is effectively set in parallel with R15 dominating equivalent resistance and further dominating actual voltage output level..

So, if you wish a lower output level (Volume), raise R14/R15 ratio - and vice versa..
(C9/R15 HPF wouldn't stamp its feet as long as you pass your candy to it..)

[ElectricDruid]

The volume with the pedal bypassed is considerably quieter than when the pedal is engaged. I have to set the volume pot to about 9 o'clock for the levels to be about the same.

This sounds right to me. An overdrive should be loud, so you can overdrive the front end of an amp with it if you want to. After all, you can always turn it down.

Where the exact point that the bypassed and engaged levels are audibly "the same" depends a lot on how loud the signal coming from the guitar is, and that's a very variable thing depending on model, pickup choice, etc etc.

If 9 o'clock works for you, use 9 o'clock. If you plug a quieter guitar in, you'll find you need to go higher, but at least you'll have lots of room to do so.

HTH

[Diamondj421]

On the BOM, R14/R15 have these notes next to them on the spreadsheet:



If I'm doing this correctly, the TS-808 would come out to .01 and the TS-9 would be .0047 meaning the TS-9 would be even louder that what I have now, correct?

[PRR]

"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

Happy birthday!

[antonis]

"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

Happy birthday!