It is currently Thu Dec 13, 2018 5:07 pm

Post new topic Reply to topic  [ 13 posts ]  Go to page Previous  1, 2
 9710 VCA Hum 
Author Message
User avatar

Joined: Sun Nov 09, 2008 2:49 pm
Posts: 733
Post Re: 9710 VCA Hum
Here's to a speedy recovery!

The 'insert' filtering is best since it's back nearest the origin of the DC supplies.

A modified 9770R-15 mounted in the end of the FR-7 chassis, behind one of the FR-PWP would work to provide cleaner power too; however, since we only have the 12vac wall-mounted transformers for these now, there aren't enough mA for the P9700S. Substituting a bigger transformer would do, but they aren't so readily available (the 9770 series originally had a 14vac, 400mA and for powering a P9700S it would be best at 14vac with 700mA or more). A new power supply is planned for the FR-7 chassis (contains the P9700S) and maybe we can work out a way to make it work in the ear space, if not at the left end, the right end.

Scott Lee

Wed Sep 07, 2011 3:00 pm

Joined: Mon Sep 14, 2009 7:43 pm
Posts: 80
Post Re: 9710 VCA Hum
Hi Scott, I missed this reply. Thanks for the good wishes!

The "new," upgraded power supply, is what is powering my mix of PAiA and Blacet modules and seems very up to the task. Clean power and no noise/hum from any of the modules. For my next frac rack of modules I am thinking about using the Blacet PS (sorry). The advantage to it is that it is mounted on the back of the frac and takes up no module space and is highly rated to run different manufacturers modules which, I believe, is the real purpose between using a frac rac or Euro style case to begin with: mixing and matching various modules. I'm surprised that no one uses the 500 series frames. You could standardize the power, back plane and mixer/interface/MIDI>CV and have plenty of room for 500 series modules. I'm sure it would be pricey.

Getting back to the PAiA power supply, the real problem is with the "juice" coming out of the wall wart, right? Wall warts are cheaper than free dirt but maybe having a regulated power module, complete with toroidal transformer, be a somewhat economical solution? Kinda like the 4700 series regulated power supply along with a power connector strip that could accommodate the different power plugs used by various frac module manufacturers?

One other thought regarding space. There's never enough. Have you guys thought about a redesign of the the original 9700 modules that could take advantage of over all lower component prices as well as partial and full assembly? I would think with a re-layout of the boards with SM technology, the topography would shrink per module and more add on 9700 modules could be sold. Nothing is worse than a synth case with empty space.

Another idea to gain space is using as side wings "passive modules" such as
patch bays, splitters and passive mixers or attenuators.

I guess all it takes is time and money, eh?

Brian Folkes

Wed Sep 14, 2011 4:15 pm

Joined: Mon Sep 14, 2009 7:43 pm
Posts: 80
Post Re: 9710 VCA Hum
Heya Scott!

Sorry it has taken so long to get back in my studio to install the PS ripple remover, let alone test it. I had no idea I would be so zapped of energy from the knee replacement surgery. It seems I've turned a corner and, as long as I don't over do it, I'm able to get around, drive by myself, get into the office for a few hours a day and maybe look into the studio wishing I could spend all this downtime working on music!

Anyway...enuf about me and my recovery. On to the 9710 hum from the "A" output problem!

Your concoction worked perfectly! The is no noise let alone a low frequency hum. I ran the gain all the way up on my main mixer and the sub mixer that the 9700 goes into along with the rest of my analog menagerie. There was no difference in the noise floor with the 9700 channel all the way up or totally off.

So, PAiA Phans, if you are experiencing noise/hum from your 9700, build yourselves one of these handy-dandy ripple killers. It will improve your sound immensely!


Brian Folkes

Sun Oct 09, 2011 6:34 pm
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 13 posts ]  Go to page Previous  1, 2

Who is online

Users browsing this forum: Google [Bot] and 2 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © phpBB Group.
Theme designed by Vjacheslav Trushkin , adapted for PAIA by Illumimedia Design Studios
./cache/ is NOT writable.