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

[it-goes-to-eleven]

Note: Your max dBu output will be reduced when running on reduced voltage input than 12V. i.e. lower headroom. But then again, you probably don't need +23dBu output whipping the inputs of your AD converter.

Curious what that might mean in terms of headroom when run on 9volts.

Any update on the headroom impact of running at 9v?   (maybe I missed the response)    Performance at 7-9volts is way more important to some of us than blinky LEDs.

[rePat]

  Another vote for a 1/8" stereo output.

As an R-09 user, I would vote for one too.  If I ever have to replace my SD MP-2, this would be tops on my list after watching its development.

Thanks again for including us!

Pat

[rastasean]

  Another vote for a 1/8" stereo output.

As an R-09 user, I would vote for one too.  If I ever have to replace my SD MP-2, this would be tops on my list after watching its development.

Thanks again for including us!

Pat

Keep me in mind when you are thinking about replacing the mixpre-2 

I don't think the lack of 1/8" input on this pre-amp is a bust just because there are dual XLR cables to 1/8" and there are AT least two people on this board that makes them. Just my opinion.
Since I have been interested in taping, electronics, photography, etc, I have noticed there is not just one device that is totally perfect but what fivefish is doing is damn near as much customization as possible. It is amazing seeing this idea and having it grow into a board and all the way into a nice looking metal case.
Great job to you, fivefish and +t for your great efforts

[fivefishdiy]

Just a quick update:

Haven't had time to breadboard the HP filter yet.

The addition of the HP filtering, pads, and relays will force me to redesign the motherboard and switchboard.   

Soooo I'm looking at other things to improve while I'm at it....

but first, had to test a few new things before committing them to the new PCB.

One thing for sure... current consumption will go up. New value will probably be between 150mA to 200mA (estimate).

[sygdwm]

dump the hpf. KISS.

[it-goes-to-eleven]

Do the relays end up being in the signal path?

[fivefishdiy]

Do the relays end up being in the signal path?

Will the signal go through the relay? Of course. Relays are just fancy switches.  Think of it as a movable piece of wire.

But instead of running low signal wires back and forth from the PCB to the front panel, the signal stays on the PCB & is switched remotely via relays... and only logic control signals run to the front panel switch.  i.e. the audio signal never left the PCB, i.e. shorter path = no noise pickup.

[H₂O]

Do the relays end up being in the signal path?

FWIW - I seem to remember that when the Mini-Pre came out one of Apogee's key design points was the removal of all Caps from the signal path and replacement with a network(s) of relays.  I don't know how they did  this, but may be worth noting.  I wouldn't think relays in the signal path should be a concern

[stevetoney]

I'm amazed how I've become such an expert preamp designer in the span of ONLY four weeks!  So many others too!!!

  

[ero3030]

any chance of this being made w/o the hpf to use up the parts u already have?  ed

[sanaka]

I wouldn't think relays in the signal path should be a concern

I agree. Whatever effect on the signal the relays have, and there will always be someone to argue that they do, it is the least effect that can be managed. i.e. 5fish is using the best methodology available, AFAIK.

It does feel a little tragic to make FF back up and have to remodel this. Are there in-line HPF doohickeys the same way there are in-line attenuators? Just wondering if there's other options for HPF that would keep things simpler and prevent FF having to go back several squares on this design.

One thing for sure... current consumption will go up. New value will probably be between 150mA to 200mA (estimate).

I don't think that's a problem. I really want an Edirol R44, and that burns like 1 whole amp! This is also why I like not having internal batteries for the TS-2, it's actually helpful in that any outboard power solution is likely to be so much better/higher capacity than anything that would fit inside. Bring on the pretty lights, man!

Peace,
Sanaka

[fivefishdiy]

any chance of this being made w/o the hpf to use up the parts u already have?  ed

Yes....will be cheaper too.

[fivefishdiy]

How about some video instead of pictures?

So hooked up my battery and 2 condenser mics to the pre... turn on power, turn on phantom for both channels, and recorded the VU meter "in action"...

Note: The audio in the video was recorded by the camera.

Youtube video here. (Make sure to watch in high quality mode.)


Enjoy!

[OOK]

How about some video instead of pictures?

So hooked up my battery and 2 condenser mics to the pre... turn on power, turn on phantom for both channels, and recorded the VU meter "in action"...

Note: The audio in the video was recorded by the camera.

Youtube video here. (Make sure to watch in high quality mode.)


Enjoy!

Its been a while since I 've checked in...but I have been following the progress...........Man is this going to be sweet!

OOK

[jerryfreak]

i dont need phantom or hpf. is there a bargain older rev board kit that would suit me? i know you had issues with phantom circuit and did the resistor workaround, but havent followed all the way thru to see if you actually rev'd the board since then