take 2 (DOH!) Stombox guru's ~>Help!<~

[orbiter]

ok .. one more time..

my little orange friend died

I've got a phase 90 thats buggin out on me.

The signal passes thru the box fine ..

when I turn it on .. the signal stays .. but no effect.

I can hear the clipping and/or pulse of the phase faintly.. and it does change rate when the knob is turned ... but zero swoosh ...

suggestions?~>thanks

 

[Thames]

Re: take 2 (DOH!) Stombox guru's ~>Help!<~

Hmm... kinda hard to answer, but ive seen pedals doing the same thing, and having switch problems. Your switch might be wrong.

 

[orbiter]

Re: take 2 (DOH!) Stombox guru's ~>Help!<~

hmmmm... thanks for the input ... I'll look into that.

~G

 

[Kent S.]

Re: take 2 (DOH!) Stombox guru's ~>Help!<~

I just caught this, difficult to tell is right, sounds like you are getting the output from the phase shift circuit, but that it is getting no input ... I'd check the Fets (not sure what the RI use) in the phase shift stages, or the input to them after the first buffer ... if the Fets aren't biasing right it either won't work, or won't work correctly. Also, in the older ones there was a bias control for those, and there was a zener diode that feed into that line, I believe that those two things can cause the fets to do strange stuff. It may be as simple as a cap having gone open ... if you switch it to effect and get a vibrato with the rate maxed out, then the direct isn't feeding into the output, as at slower rates phase shift by itself isn't that noticeable.

 

[orbiter]

Re: take 2 (DOH!) Stombox guru's ~>Help!<~

thanks for the info kent. I appr. it !!

I can hear a change in tone when the pedal is on .. but it ,in no way , ads any vibrato .. it's even steven .. with just a pop pop pop of the speed/rate .. waay in the background .. fast or slow doesnt seem to matter tone-wise...

I def. seems like something (cap. fets.. etc..) went south on me .... all of a sudden ... funny .. it's one of the only pedals I still use .. I've been feeling kinda naked w/o it..

 

[Kent S.]

Re: take 2 (DOH!) Stombox guru's ~>Help!<~

Well get it fixed, and then do the univibe mod to it, you can add a small slide switch for that. (It changes one of the .047uF caps in the phase shift stage to a .1uF, and the other in the next stage to a .01uF cap, similar to the smallstone univibe mode). The mod was originally done on the Phase 45s, but you can do it on the 90's also, just two more stages. Unless you can trouble shoot the board yourself, toss it in the shop ... or if you want to see where the signal stops at, you can build an audio probe ... which is basically a probe connected to a cable, connected to a female phone jack with a cap in the tips path to bloack the DC bias from the effect, then you plug that into your amp on low, plug guitar into the effect, and strum the guitar while moving the probe around to different points in the circuit so you get to hear when the signal isn't making it thru at a certain point. To see how to buils one and more tips ... www.geofex.com .

 

[orbiter]

Re: take 2 (DOH!) Stombox guru's ~>Help!<~

thank you sir... great info!

I was gonna do the "script" mod ... is that the same as the one you mention .. cus it sounds like a different mod to me??

~G

 

[Kent S.]

Re: take 2 (DOH!) Stombox guru's ~>Help!<~

thank you sir... great info!

I was gonna do the "script" mod ... is that the same as the one you mention .. cus it sounds like a different mod to me??

~G

No, see the only thing the script mod does, it either cuts out or reduces the feedback line (also known as resonance in BOSS terms, regeneration in DOD/Digitech terms, colour in EH terms, intensity in still other companies' terms), I forget which it is, and the modern RI's have a pre-emphasis / de-emphasis circuit to control noise ... which it does, but many like it without like the originals. They may be a difference between script logo, and those shortly after that still were originals (not RI's) ... that I couldn't tell you about, there is also a gain mod.
Anyway, no, the univibe mod was made for the phase 45s , you can do it to the 90's also (also a smallstone or any other four stage phaser), although it was intended for two stages ... like the DOD 201 and MXR Phase 45.
You can shut the other to stages off, or use them stock, or switch them also ... a lot of variation within the mod itself. It revoices the center frequencies of the phase shift, and becomes a bit univibe like (without that annoying accidental tremolo and uneven sweep the the UV has/had).
Read this to get an idea of what's involved along with a small explanation referring the univibe thing ... Do a keyword search under this exact name ...
Custom analog guitar and bass effect DIY ... I've got the link stored, but I can't access the exact URL for some reason ... or just hit the internet with things like phase 45 / 90 mods ... that sorta stuff.

 

[rspst14]

Re: take 2 (DOH!) Stombox guru's ~>Help!<~

Is this a reissued Phase 90? If so, good luck with fixing it. They are much more difficult to work on than the originals. I've fixed a few of the originals, as they aren't too complex to work on. But the reissues use a completely different circuit, and the jacks and switches are soldered directly to the board.

The script mod won't actually make it exactly like a vintage script logo model, but it will make the pedal sound a little better. I had a reissue Phase 90 for a while, I ended up buying an original for $25 because it was broken. $10 worth of parts, and it was working good as new. I always recommend the originals, as the reissues are nowhere near the same circuit, which sort of defeats the purpose of a reissue. Those guys at Dunlop could screw up a free lunch.

Ryan

 

[Kent S.]

Re: take 2 (DOH!) Stombox guru's ~>Help!<~

Not sure of the circuit differences, I wasn't under the impression that they were totally different circuits (I assume an exaggeration to get the point across), but as I haven't mapped one out, I can't say ... stilll the feedback loop mod, should be easy to do, along with changing those caps. A big improvement no matter how you look at it.
BTW is it just me, or does the 90 RI try to be a *space phaser* ... man trim that feedback loop ... :saeek:

 

[LesStrat]

Re: take 2 (DOH!) Stombox guru's ~>Help!<~

Change the battery. Seriously.

A couple of years ago, my Dynacomp died (apparently). Bright LED, horrible sound. I changed the battery. No dice. I decided it was time to replace it. Fast forward a couple of days. I decide to try again before buying a new one. I changed the battery AGAIN. Voila! Apparently, the replacement battery was dead also.

Who knew?