ADA TFX4

[modsquad]

I have a 1982 ADA TFX4.  I have been reading with curiousity about the ADA Flanger.  I was wondering whether the circuit was similar in the rack unit that I have with just less adjustments available.  I do know after looking at the schematic for it (geez what a lot of stuff), that it seems the chorus and the flanger share some circuitry.  I never liked the echo and reverb on it, the chorus is okay.  Is there anything that could be done to get some more out of those effects.

Or should I part the whole thing out, mwahhhh, ha, ha.

[notchboy]

The TFX4's flanger section sounds good, but not as over the top and "wicked" sounding as the pedal version IMHO.

[modsquad]

That's kind of what I expected since it looks like the chorus and flanger share some of the circuit.  I wonder if there is some way of moding that part of the circuit to get more flexibility or sound out of both the chorus and flanger.  Have to put on my Dr. Frankenstein lab coat and see if I can figure out what's going on.

[RedHouse]

Hey, would you mind scanning and posting the schematic you have?

[modsquad]

Google is a wonderful thing...

http://www.adadepot.com/adagear/gearpages/effects/ADA-TFX4.htm

They have other schematics at the site for ADA stuff also.

[Mark Hammer]

Many or most of the schematics have been taken down and now need to be purchased.

You will note the following facts that can be gleaned from the specs which ARE posted.

1) A/DA Flanger - delay range = .33-14msec
2) TFX4 - flanger delay range = .21-4.3msec

The Flanger has a 42:1 sweep range.  The flanger in the TFX4 has a sweep range of roughly 20:1  (around the range of the Boss BF-2).  Generally, you'll want something like 30:1 to get really dramatic effects.  The TFX4 will sweep higher (which is nice) but not as low as the Flanger does.  It would be nice to think that the TFX4 contains an A/DA Flanger the way that the Ibanez UE-300 contains a Tube Screamer, but it doesn't.

[modsquad]

Mark, your so damn smart 

Did you glean that from the schematic?  If so is there a way to improve the flanger in it (other than replace it).  One cool thing it does have is a switch to "invert" the signal.   I have a 1984 version of  it and find the chorus okay, echo and reverb useless.

[Mark Hammer]

Not smart, just nosy and persistent.  I don't have the TFX4 schem with me here at work, but I think I have it at home (snagged it from the ADADEPOT before everything got compiled onto a CD for sale).  At this moment, I have no idea if or how the TFX4 and Flanger circuits may be different.  Chances are damn good they WILL be somewhat different, if only because the input-to-output companding in that unit will be implemented in a different way.  I may be wrong, but my guess is that the companding is not applied on a per-effect basis, but rather on a whole-rack basis.  That IS just a guess, mind you.  I'll let the schem tell the truth....or as much as it is able to tell.

Certainly one of the things that I imagine its design tries to anticipate is that if you are going to have that many clocks inside one package, the risks of noise and clock heterdyning are huge.  By running the flanger section at a faster overall clock rate, one of the things they can avoid is having the difference between the chorus and flanger clocks be audible.  In other words, the shorter overall delay time of the flanger may well have been a deliberate strategy to reduce risk of noise, in which case modding it to something approximating stompbox Flanger specs may not only require significant changes but may also be ill-advised.  The comparatively short delay times attainable from the TFX4, however, should provide a pleasingly dry-sounding (rather than boxey) flanger sound; something you can leave on for longer periods without growing weary of it.

[modsquad]

If my memory serves me the schematic shows that the chorus and the flanger share sections of the circuit (clock?).  Those scoundrels that must be a recent thing to take the schemos down because I just got it about a month ago.  I would be curious to know what the invert button is doing.  You know now that you mention it the flanger is pretty "mellow".  I find it great for Police stuff.   Its definitely easier than the digital one in my Digitech 2101 "Rocket Scientist Only" rack.

[Mark Hammer]

How many of the effects can you operate at once?

[modsquad]

One...that's one of the drawbacks.

[notchboy]

Yes, there's quite a bit of shared circuit between the sections.  It's halfway between being truly independent units, and one circuit with "presets" for flange, chorus, etc.

IIRC the doubler was the best part.

[Mark Hammer]

My wife just phoned a little while ago to inform me that all the shelves in my office/workspace had suddenly collapsed at home and I am awaiting armageddon when I get there.  I *may* be able to see if I can find and post a TFX4 schem this weekend, but that will depend on what I find when I get home and whether my equipment is even working.  She kind of waited a long time after I answered the phone to start speaking.  I don't take that as a good sign.  I had some heavier stuff on the highest shelves and plenty of breakables ling in harm's way just below where the shelves' contents would have fallen.  Piles of Vintage Guitar and Guitar Player magazines strewn all over with torn covers I can live with.  All my binders splayed out everywhere I can live with.  A 19" monitor with the top pushed in from a laptop or two raining from above, and all my installation CDs shattered I'm not so sure I can ignore.  It's gonna be a long weekend, folks.

[modsquad]

Ouch, sorry to hear about that.  It happened in my garage one time and I lost a 13 inch tv.  Hope it works out. 

[StephenGiles]

My wife just phoned a little while ago to inform me that all the shelves in my office/workspace had suddenly collapsed at home and I am awaiting armageddon when I get there.  I *may* be able to see if I can find and post a TFX4 schem this weekend, but that will depend on what I find when I get home and whether my equipment is even working.  She kind of waited a long time after I answered the phone to start speaking.  I don't take that as a good sign.  I had some heavier stuff on the highest shelves and plenty of breakables ling in harm's way just below where the shelves' contents would have fallen.  Piles of Vintage Guitar and Guitar Player magazines strewn all over with torn covers I can live with.  All my binders splayed out everywhere I can live with.  A 19" monitor with the top pushed in from a laptop or two raining from above, and all my installation CDs shattered I'm not so sure I can ignore.  It's gonna be a long weekend, folks.

Mark, just tell her you love her and that she has the sympathy of all our wives!

[analogguru]

Hey, hey, hey....unbelievable.....
Mark, this is not irresponsible, this is not incredible, this is a case for the court of human rights !
All the weekend without any drugs for schematic-addicts ?  This is imposible....
So let´s see what we´ve got here:

ADA TFX-4 schematic

enjoy,

analogguru