Grandlaugh D-Booster

JHS · Post by **JHS** » 10 Aug 2007, 10:15

~~s206.photobucket.com/albums/bb41/JHSNRW/?action=view&current=LG_DB_JHS_CUSTOM.jpg~~

I didn't like the socket I-cap, I think it's easier to go with 3 inputs.
Tone control is custom, original has a 100k R.

Original has CC Rs and an yellow AVX MF as I-cap.

JHS

bajaman · Post by **bajaman** » 10 Aug 2007, 11:21

....and it has the crackle mojo control too
bajaman

markm · Post by **markm** » 10 Aug 2007, 12:19

What's the deal with the 3 inputs?

invictus · Post by **invictus** » 10 Aug 2007, 13:19

.

there are 3 inputs so you can share it with your friends....

.

JHS · Post by **JHS** » 10 Aug 2007, 14:34

Switching a guitar cable into another jack is easier than changing caps in a circuit. (the 100n GL DB I-cap is monted in a socket and a 150n was delivered with the booster for a cap change.

I didn't want to use an on/on/on switch and 1 input jack, cause a switch always cause some tone loss.
JHS

analogguru · Post by **analogguru** » 10 Aug 2007, 14:37

Hmmm....I can´t imagine a big sound-difference between the 3 input-caps. And I can´t follow which influence the tone poti should have..... we have 11,5 µ output-coupling capacitor followed by a resistor of 50k to 100k. This neither influences the bass response nor the treble response

Did Grandslaugh clone from zvex ? Or Zvex from grandslaugh ? or both from fuelbone ?

analogguru

briggs · Post by **briggs** » 10 Aug 2007, 15:09

Now their cloning each other

markm · Post by **markm** » 10 Aug 2007, 15:28

JHS wrote:Switching a guitar cable into another jack is easier than changing caps in a circuit. (the 100n GL DB I-cap is monted in a socket and a 150n was delivered with the booster for a cap change.

I didn't want to use an on/on/on switch and 1 input jack, cause a switch always cause some tone loss.
JHS

Oh yes.
Okay, I get it now.
Which sounded "best" to you?

kagaxdx · Post by **kagaxdx** » 10 Aug 2007, 15:46

Hmmm....I can´t imagine a big sound-difference between the 3 input-caps. And I can´t follow which influence the tone poti should have..... we have 11,5 µ output-coupling capacitor followed by a resistor of 50k to 100k. This neither influences the bass response nor the treble response

I agree and I can't see how it's influencing anithing there, well the "tone" pot would influence the output load and then cause any difference? Can't figure it would make an audible change......

JHS · Post by **JHS** » 10 Aug 2007, 15:57

The tone-cut works very subtle, it softens the highend a bit when the pot is closed, I use this often with my vintage maple neck Strat.

All 3 cap values are useful, depending on the guitar and the amp, the booster acts with values less than 100n more as a treble booster. IMHO 180n is to much, the bass is mushy and undefined.

100n sound neutral, 150n is more middy, 120 is somewhere in-between.

The 1,5uF MKT adds definition to the highs (switchable on mine) and compensate the treble loss of the electrolytic cap.

JHS

MoreCowbell · Post by **MoreCowbell** » 10 Aug 2007, 16:14

That "treble cut", IIRC, is similar to the "tone" control on the Sam Ash Fuzz...though I believe that the SAF uses a much lower value resistor. I'm just going by memory though, so I may be mistaken.

analogguru · Post by **analogguru** » 10 Aug 2007, 16:57

That "treble cut", IIRC, is similar to the "tone" control on the Sam Ash Fuzz...though I believe that the SAF uses a much lower value resistor. I'm just going by memory though, so I may be mistaken.

Yes....the memory....
Sam Ash Fuzz Tone-control doesn´t act as a treble-cut it acts as a bass-cut.

we have a coupling capacitor of 50nF and a resistor to ground beetween 1k8 and 11k8 in parallel with the volume-control of 10k. thzis gives an effective load between 5k4 and 1k5 causing a low frequency roll-off between 2kHz and 10kHz.

As far as I remember a (strat)-tone-control has an additional capacitor to ground and also a higher output impedance than a SHO.

So I assume in this config the tone-change must me very subtle - maybe inaudible ?

analogguru

JHS · Post by **JHS** » 10 Aug 2007, 17:01

To tell the truth , I've copied the principle from the Sam Ash fuzz.

50k in the output is the lowest value I can recommend, with lower values the bass gets mushy and the sound loose the definition (same in OD-circuits).

A 10k Vol-pot is good for a Si-Fuzzface-mod, if you want it really smooth.

JHS

analogguru · Post by **analogguru** » 10 Aug 2007, 17:21

10µ in parallel with 1µ5 gives 11µ5 output coupling capacitance. With 100k load, the lower corner frequency will be about 0,38 Hz and with 50k load it will be at 0,76 Hz.....

analogguru

JHS · Post by **JHS** » 10 Aug 2007, 19:53

The input of a tube amp is loaded down much more with a 47k as with 100k and in parallel with this 47k is the capacity (app. 2-3n) of the guitar cord, the result is less treble response compared to the 100k.

The effect of this tone-control is not dramatic but it is able to kill the icy peaks in the sound.

The new OCD has a 500k Vol-pot (100k in the first version). With the 500k pot the highs are much clearer and the tone is more dynamic, same thing here.

JHS