Topic: New TS-2 Preamp ... under development (part II)

[fivefishdiy]

The resistor/phantom power workaround was only necessary if input transformers are installed on this PCB revision.

If input transformers are not used, this current board works just fine without any workaround fixes.

I'll try to build a few units (i.e. without input transformers).

[Mr.Fantasy]

I want the full boat!!!!

Product number 001...or 420... he he.

[fivefishdiy]

UPDATE:

Start doing prototype of the case... get dimensions of holes and stuff... drill manually, make corrections, keep notes... do some filing to fix the screwups.

Some notes:

The Motherboard, Switchboard and VU meter PCBs... crammed in a 2-inch high, 6" width case. As you can see, it is tight... the switches and capacitors have literally millimeter clearances from hitting the ceiling and bottom of the internal case.  The distance between the motherboard and switchboard perfectly aligns with the PCB slot of the case. 



Attach the front panel to the PCBs. Check out the input transformer peeking from the side.


Photo of the blue anodized case with the black anodized rack handles temporarily attached.


The switch toggle handles peek out just enough... No accidental flipping of switches. It takes some effort to consciously flip it. Using your thumb and fingernails seems to be the easiest way to toggle it. I need to make the switch toggle openings narrower but longer, instead of round.

The blue anodized finish of the case gives it a weird effect when photographed... kinda like a soft glow coming from the surface of the case.

Forgive the crooked holes for the VU meters, and too large holes for the switches.   These were manually drilled.

I'm going to finalize the dimensions, and have a prototype shop do a sample panel for me using CNC.

[digifish_music]

UPDATE:

Very nice. Can you remind me what the two knobs / channel are for, preamp gain and? I am having a blank on that one

digifish

[sanaka]

what the two knobs / channel are for

IIUC: Gain (6dB stepped) & Trim (the 6 dB in between each step).

[sanaka]

Looking sweet FF!

I thought you had your own CNC machine? Thought it was in some pics you posted before.

Peace,
Sanaka

[digifish_music]

what the two knobs / channel are for

IIUC: Gain (6dB stepped) & Trim (the 6 dB in between each step).

...that's nice. Interestingly I have been using an R44 for a couple of months now and the 6 dB steps are OK on their own. Still, the option for sub-trim is welcome.

digifish

[fivefishdiy]

I thought you had your own CNC machine? Thought it was in some pics you posted before.

I do... but I need more tighter tolerances for these front panels. Plus looking forward to someone else mass producing and laser etching these for me.

[TNJazz]

I've been following this thread with interest for a while now and I've got to say it's looking good!

Hopefully you'll crank out an 8-banger next.  That I could really put to good use...

[Chuck]

This might sound strange, but let me suggest that you test this pre-amp close to bass bins in a high SPL environment. See if it can tolerate the bass thump. Some pieces of gear don't tolerate that type of environment very well. Also, the fact that the pre-amp has relays in the signal path. If the relays are mechanical the rattling in a high SPL environment may cause them to fail.

I love projects like this.

Is it too late to request a high quality A/D converter be incorporated  

...just joking, of course.

[fivefishdiy]

See if it can tolerate the bass thump.

How about a close-mic'd drum?... with the mic inside the kick drum? and another mic right in the vent hole?

http://www.fivefishstudios.com/audio/SC1demo-drum_mix.mp3

The kick was recorded with a AKG D-112 inside and a Shure Beta 52 in the vent hole.
The snare was recorded with a Shure SM57 on top and an Octava MK-012 on the bottom.
The toms were recorded through Sennheiser E504's.
The overheads are Shure SM81's in an XY pattern.
... my preamps used on everything.

Also, the fact that the pre-amp has relays in the signal path. If the relays are mechanical the rattling in a high SPL environment may cause them to fail.

I'm not using old style relays (i.e. the big bulky relays where you can see through the mechanical workings). No siree.

I don't think this mechanical rattling is an issue you have to be worried about. I checked the specs on the relay and they are rated at 500 m/s^2 for misoperation, and endurance of 1,000 m/s^2.  ... and the force of gravity is what?.... 9.8 m/s^2?

[Gutbucket]

I think Chuck's suggestion is more about to testing the effects of vibration on the unit - perhaps by putting the preamp inside the kick drum. 

Unlike taping from the 'section' back by the soundboard, another approach used for concert recording is referred to as 'stack taping'.  Stack taping means getting as close as possible to one of the FOH stacks in an effort to increase the ratio of direct to reverberant (& crowd noise) sound.  That often means being directly in front of big sub woofer bins that vibrate everything, strongly.  Most users probably won't use this unit that way very often but still..

[fivefishdiy]

Ahhhh I see... I'll think of something

[Unitmonster]

Ahhhh I see... I'll think of something

Maybe run it on top of a clothes dryer!

[willndmb]

looking good
the video is nice with the pop up too, never saw that before