Peavey Spectrum Analog Filter

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natek

Well-known member
Joined
Jul 5, 2008
Messages
224
Location
Eugene Oregon USA
So I picked up one of these on a trade with a friend who never used it and i thought it would be a nice piece to try out. I would be happy to post pics of the PCB and inside Guts for any interested parties,:green: I haven't been able to find a schematic for it yet but maybe someone else can help with that! I have ran some synth stuff through it and it can do some nice stuff for what it is, I didn't see any post's on this unit yet.
 
Inside guts would be nice - if it's not already known yet it could tell what kind of filter we're talking about here. OTA-based, Moog-style ladder etc
 
I need to borrow a better digital camera that will do close-ups cleaner than my iPhone can. I will post some links in the next few hours to some pics.

Nate
 
[quote author="natek"]Here are some pictures:

feed://picasaweb.google.com/data/feed/base/user/nate.kahle/albumid/5238560476226610657?kind=photo&alt=rss&hl=en_US[/quote]
I tried it, but sorry, how does that work ?
 
It works now.

I can't read any of the IC-type numbers, but because of what look to be discrete pairs & the four orange caps fully left in P1010010.JPG, my votes go out to a Moog-style four-pole ladder filter.

I wouldn't be sad about that :wink:

Bye,

Peter

edit: oops, later I realized I can also download those pics, can read all info now (& same conclusion :thumb: )
 
[quote author="clintrubber"]It works now.

I can't read any of the IC-type numbers, but because of what look to be discrete pairs & the four orange caps fully left in P1010010.JPG, my votes go out to a Moog-style four-pole ladder filter.

I wouldn't be sad about that :wink:

Bye,

Peter

edit: oops, later I realized I can also download those pics, can read all info now (& same conclusion :thumb: )[/quote]

Thats good! I am definitely not sad about it! :green: If anyone is interested in any more digging through this piece i am more than happy to do some more if you let me know!
 
[quote author="kazper"]I'd fix that leaky battery soon...[/quote]

:thumb: KUDO's Good spot! I have been doing a search on a replacement, found a them online but maybe you know a local place when i come up that way.

Also there is a burned spot on the PCB :shock: around the Motorola voltage reg. on the bottom right hand corner of that some picture , I uploaded a close-up of that to the photo album incase anyone wants to comment on that too. :thumb:
 
I'd say it looks like the 7805 got to hot.

Maybe place it on the side wall or give it a real heat-sink. I may have a couple lying around that will fit in their from my adventures at at Surplus gizmos. Looking at it if your holding on to if for a minute I'd add one to all. But definitely the 5V has a good load on it and is getting hot and or time/age.

Batteries plus? probably not

Not sure on the battery, It looks like the old style PC battery's. I'd say look at digikey/mouser and find what is close and modify to make it work. Depending on the values needed I see 60maH. I've replaced batteries in some of my synths and efex boxes. Most of the time I tried to get what was there, which has worked out fine for me. Only modification was in the sony 1/4 rack series which I replaced into a slip in type battery replacing a solder type.

It does look like it could handle replacement with a coin type cell, but you will need to look at the specs and PCB when it comes out.

http://www.mouser.com/catalog/635/2009.pdf is close to where you need. thats some coins and pcb holders.
 
I'm pretty sure that it's a Moog 4 pole type filter, I helped Steve with it just
before it was released, just writing lots of the "presets" that were in memory and
Beta testing it for him.
Various ADSR shapes and sweeps etc etc ( 99 different presets IIRC )

At the time, I created some basic synth waveform patches for the Peavey
SP sampler, that could be ran through the Spectrum Filter and this was a good
way to "Demo" it in stores, I was doing a lot of "in-store" and music fair work for
PV throughout the 90's.
It's a very cool unit and has that lovely FAT Moog sound, great also when running
drum loops through it, with the filter triggered by the loop "attack transient" points.

Marty.
 
I have one of these.
it's a really nice box.

pretty sure I remember the manual mentioning something about ladder filters, or moog, or some such.

very different from all the other filter boxes out there, as it also has a VCA and 2 separate ADSR generators... it's basically a synth without the oscillators.

mine's basically become a part of my TX-81z.


Though looking atyour pics, I think I should open it up.. just in case my battery is doing that too.
 
[quote author="no-fi"]I have one of these.
it's a really nice box.



Though looking atyour pics, I think I should open it up.. just in case my battery is doing that too.[/quote]

Wouldn't hurt to take a peek! I also noticed that one VR was heating up the PCB so i would be interested in knowing if yours has a similar issue. (take a look at my pictures should be the last pic zoomed in on the Motorola IC chip)

Also Marty,

do you think you could find the schematic for this? either from Steve, or maybe you had it from when you did that programming i dunno! Thanks for your coment's Always nice to have a story, and its cool you programmed the preset's I have been using too! :sam: :sam:

maybe you have some ideas on some new programs for this piece? feel free to email me! :green:
 
I don't have any documents for the Spectrum Filter, I think Steve gave me
one of the "prototypes" as it was different from the released version, sort
of plain Black finish and half finished graphics with generic PV mixer knobs !
The OS chip ended up as a final version though.

It's quite easy to program, being a "synth" without oscillators.

MM.
 
Not 100% sure but i think i downloaded the schematic for this a while back. probably from the electro-music forum (might be worthwhile to check there). Will check when i get back home tonight or tommorow.

greetings,

Thomas
 
[quote author="hobiesound"]Not 100% sure but i think i downloaded the schematic for this a while back. probably from the electro-music forum (might be worthwhile to check there). Will check when i get back home tonight or tommorow.

greetings,

Thomas[/quote]

Thanks Thomas!,:thumb: I will check that forum but if you do find it please forward it to my email (you can find it on my profile) or upload it to the group email!

Nate
 
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