Falcon 030: Doing the C-Lab Audio Mod!

[TPAU65]

Planned for a long time and finally I did it: The Audio modifications C-Lab did on their Falcons to get line-level in/output and remove Bassboost!

Some SMD soldering skills with small components (resistors and caps) are needed. But as I already did a LED mod for my Amiga 1200 and got some better equipment since then, I was quite confident I could make the necessary SMD mods on the Falcon. 😉

The modification is based on this article, which is basically the same as described in the Cubase Audio manual.

 

Problem with both sources: They are not complete!

At least the changed capacitors C26 and C79 are not mentioned there, not even in the latest Rev. L shematics from Atari (which contains, apart from this, all changes for this mod!)

You can only see the changes on these two caps on photos of C-Lab Falcons.

Changes to R124 and R131 were also not mentioned in the article (or Cubase Audio manual) but can be found in the Rev. L shematics.

 

There are eleven additional ceramic caps, which somehow deal with noise filtering. The exact positioning of them, a complete PDF of the SMD changes and some photos of the mod can be found in the attached zip!

 

What I did not do is changing the old filter components to some ferrite type coils seen in most C-Lab Falcons (the green and red wires near the audio connectors) like here:

 

Although these ferrites are in the schematics, I couldn't find any detailed information on these, so I left this part untouched.

This modification seems not to be really neccessary as you can see in this photo of a C-Lab MK1 Falcon.

 

Here's the backside of my modified Falcon:

 

And the front with more filter ceramics:

 

Here a video of the modification (german!): 

 

 

And finally a sample test video with the new Line-In:

 

Falcon Audio-Mod.zip

Edited February 5, 2023 by TPAU65

[JamesWD]

Superb closeup clarity of the Falcon motherboard in your youtube video although I have no idea what you are saying I have bookmarked it for when i re-cap and modify my Falcon in the near future, very good reference so thank-you. 👍

[mikro]

@TPAU65 thanks for sharing! Can I ask, as a total audio ignorant, what is the practical outcome of this mod? I mean, I have my (non-CLAB) Falcon, it sounds ok, don't hear anything which would make me think "I wish I had a mod to change this".

 

Is it related to Cubase/Notator kind of stuff?

Edited February 10, 2023 by mikro

[Atari74user]

This is very useful, well done and thanks!

 

@mikro Not to steal TPAU65's thunder, but essentially the mods are for a cleaner audio signal path, or in layman terms removing bass boost as well as headphone amplification has the net result of reducing any potential distortion or even unwanted noise.  Useful for recording in particular, but not exclusive to Cubase Audio.  I have speculated whether to do this to my Falcon, however having a small home studio, means I have a few mixers, and one small 'sub mixer' specifically for my Ataris, meaning I can control as I see fit and roll off any bass / distortion should I wish.  There was a company called Intrinsic Technology out of the UK that did a Falcon specific MixIT sub mixer for the Falcon for this purpose, and negate the mods, but I admit I have never seen one so don't what was special about it.

 

The way I see it, the mod is very useful for a cleaner sound, if you have a mixer, perhaps not essential, however it is arguable it is better to add harmonics, as opposed to removing from a potential already less clean signal.

Edited February 10, 2023 by Atari74user

[TPAU65]

@JamesWDyou can activate subtitles with english translation, which mostly are quite suitable. 😉

 

@Atari74usersums it up very good!

 

The major difference of course is the input level. No need for using resistor circuitry anymore, to connect line level devices like CD-players etc.

 

Concerning the output I must admit that I'm a little bit disappointed with the result of the mod. But I only did a before/after test with one specific ACE-Tracker music.

With this I think the pure headphone output with Bass-Boost has slightly more "punch" (veeery little!) in bass, resulting in a overall better sound than with the mod.

But it's barely recognizable and there might be other music where the mod may sound better! 🤔

 

But judge for yourselves...

 

Pure Headphone output, sound CPX module set to 15 (vertical volume) and 0 (horizontal input? "whatever" volume):

 

With modified line-level output, no Bass-Boost, same CPX settings, roughly same volume level in OBS-Studio on PC (did some Falcon captures between these two videos, so it's not exactly the same):

 

Edited February 10, 2023 by TPAU65