My pulsar is too weak..help

[dschwartz]

Hi all, i built tonepad´s pulsar tremolo..it started working right away, but the effect is too subtle, even with the depth control at max..

my peers at www.plexilandia.cl told me that the effect is rather notorious, so maybe i have something wrong....in triangle setting the tremolo is barely noticeable.

i used all  2n3904 and replaced all 30kOhm for 33kohm, and 200kohm for 220kohm..
caps values i used:
c2 220uF
c3 10uF

maybe the 3904's are too low gain for the job?
would help if i change the 100k depth pot for a 1M pot?

[blanik]

did you correct the error, go read about in in Tonepads comments of the Pulsar, someone posted a mistake he found on the layout...

the effect is VERY obvious when working correctly

i finished my Pulsar 2 weeks ago and i'm dissapointed with it... it's very noisy and unatural... i wanted more something like my twin... (i might try the EA soon, from what i read it's more what i'm looking for...)


R.

[dschwartz]

the fix mentioned in the build reports is related with the rate pot and the popping sound.. there´s nothing about too subtle operation...

besides the depth control, wich component sets the depth of the effect? any body?

[bioroids]

Well there could be trouble with Q1 which is the transistor that provides the modulation, or resistors R12/R13 which carry the control signal to Q1. Or maybe you have a mistake in the LFO that causes a low amplitude waveform to be created in the first place. As a matter of fact, almost every component in this pedal can play a part for setting the correct depth, for example R2 and R3 that carry the input signal to both opamop inputs.

Besides the depth problem, the guitar sounds ok and everything else seems to be right?

Luck

Miguel

[dschwartz]

yes, everything seems rioght, guitar sounds good, the speed and depth pots work correctly..all OK...the depth issue is the only problem..

[bioroids]

Can you measure the LFO amplitude at the join of R13 and C9? Set it to the slowest speed and measure the max and min voltage with a DMM at that point. Though I'm not sure, I think they should be somewhat close to the railis.

Luck

Miguel

[momiel]

In the past I experienced some weird problem with the tonepad pulsar board. All I can say is: clean your board, the solder side.

[mydementia]

Check out this thread for the correction to the TP board (first post).  I made the change and it worked great...
http://www.diystompboxes.com/smfforum/index.php?topic=52531.msg397020#msg397020