Dunlop Crybaby
- Thread starter TonyBar3
- Start date
shredaholic
New member
Re: Dunlop Crybaby
the only mods i know of are the ones from indyguitarist in my signature
(http://212150kc2wd-4516wbq16n1guz.hop.clickbank.net/?tid=FORUM)
the only mods i know of are the ones from indyguitarist in my signature
(http://212150kc2wd-4516wbq16n1guz.hop.clickbank.net/?tid=FORUM)
Last edited:
Spark
New member
Re: Dunlop Crybaby
Phase 90 stuff
from Dunlop:
You can remove the feedback resistor, R28, 24K. This will make it more like the classic script version and pretty much eliminate the distortion. If this is not enough, then remove C11 and C12, this mod will remove the pre and de-emphasis (noise filtering).Doing this modification will VOID your warranty. Were are not responsible for anything that will happen to your pedal.
Jayson Ocampo
Tech Support
from the internet:
The Phase 90 needs a few simple mods to sound its best.
1) Removing the Pre and De-emphasis will result in a slightly higher noise
floor while raising the headroom at 1.3Khz +3dB and 7.2Khz +12dB. Procedure:
Remove C11 (.01MF) and C12 (680PF).
2) Removing the feedback around the Phaser circuit will diminish
regeneration. This will result in a mellower effect, reduce the midrange
frequency response, and sound more like the earlier SCRIPT MXR Phase 90s.
Procedure: Remove R28 (24K).
3) For lowering the overall effect output change R7 from 150K to a 100K
or -3dB reduction, R7 150K to a for -2dB reduction. This modification
should only be done in conjunction with modification #1.
Modifications #1 and #2 can be done separately or together.
more block vs. script logo technical details:
There are a lot of small difference between script circuit and later circuit...
First, the phase shift sections ,4 of them, use .05 caps on the script while the later block circuit uses .01, also the same phse shift sections, the scipt uses four 22K as opposed to 24K resistors.... The R28 feedback resistor 24K is not in the script circuit...
The key difference is in drive at the op-amp input circuit...The script uses the input satge as a buffer "follower"....ie..no gain.
The later circuit uses that op-amp with some gain since it uses a 10K in the feedback with a 2.2K to ground through a .01 cap...You need to remove the 2.2K and cap and then use a bypas wire for the 10K to convert that stage to a buffer..
Also the script circuit uses a 470K resistor input load resistor, after the 10K series resistor, while the block circuit uses a 1Meg instead of 470K...
Also..the output stage transistor, 2N4126, on the block ciruict uses a fedback network of 150K and 680pF from collector to base...the script ciruit does not use the 680pF but does use the 150K..
The last section to change is the DC BIAS control pot...The script circuit used a 200K trimpot with 24K to ground on one leg and 27K on the other leg that goes to B+ rail....The resistor for the center wiper on the script is 1Meg....
The later block logo used 25K trim-pot with 56K on one leg and 68K on the other leg with 750K for the center wiper...
The script circuit used 6 OP-AMPS all are single op-amps... The block logo uses DUAL OP-AMPS and therefore uses only 3 OP-AMPS...
Phase 90 stuff
from Dunlop:
You can remove the feedback resistor, R28, 24K. This will make it more like the classic script version and pretty much eliminate the distortion. If this is not enough, then remove C11 and C12, this mod will remove the pre and de-emphasis (noise filtering).Doing this modification will VOID your warranty. Were are not responsible for anything that will happen to your pedal.
Jayson Ocampo
Tech Support
from the internet:
The Phase 90 needs a few simple mods to sound its best.
1) Removing the Pre and De-emphasis will result in a slightly higher noise
floor while raising the headroom at 1.3Khz +3dB and 7.2Khz +12dB. Procedure:
Remove C11 (.01MF) and C12 (680PF).
2) Removing the feedback around the Phaser circuit will diminish
regeneration. This will result in a mellower effect, reduce the midrange
frequency response, and sound more like the earlier SCRIPT MXR Phase 90s.
Procedure: Remove R28 (24K).
3) For lowering the overall effect output change R7 from 150K to a 100K
or -3dB reduction, R7 150K to a for -2dB reduction. This modification
should only be done in conjunction with modification #1.
Modifications #1 and #2 can be done separately or together.
more block vs. script logo technical details:
There are a lot of small difference between script circuit and later circuit...
First, the phase shift sections ,4 of them, use .05 caps on the script while the later block circuit uses .01, also the same phse shift sections, the scipt uses four 22K as opposed to 24K resistors.... The R28 feedback resistor 24K is not in the script circuit...
The key difference is in drive at the op-amp input circuit...The script uses the input satge as a buffer "follower"....ie..no gain.
The later circuit uses that op-amp with some gain since it uses a 10K in the feedback with a 2.2K to ground through a .01 cap...You need to remove the 2.2K and cap and then use a bypas wire for the 10K to convert that stage to a buffer..
Also the script circuit uses a 470K resistor input load resistor, after the 10K series resistor, while the block circuit uses a 1Meg instead of 470K...
Also..the output stage transistor, 2N4126, on the block ciruict uses a fedback network of 150K and 680pF from collector to base...the script ciruit does not use the 680pF but does use the 150K..
The last section to change is the DC BIAS control pot...The script circuit used a 200K trimpot with 24K to ground on one leg and 27K on the other leg that goes to B+ rail....The resistor for the center wiper on the script is 1Meg....
The later block logo used 25K trim-pot with 56K on one leg and 68K on the other leg with 750K for the center wiper...
The script circuit used 6 OP-AMPS all are single op-amps... The block logo uses DUAL OP-AMPS and therefore uses only 3 OP-AMPS...