Search found 12 matches

by XAUDIA
Thu Jun 24, 2010 4:37 pm
Forum: Test, Measurement and Repair
Topic: need a new scope...
Replies: 9
Views: 24055

Re: need a new scope...

many are pretty cheap. JR Indeed. In the past couple of years I pulled a working Tektronics storage scope out of a skip, and picked up another two channel scope for about £60 / $100. (Universities can be good hunting grounds!) The storage on the Tek is erratic, but I have a digital camera for that!
by XAUDIA
Thu Jul 03, 2008 3:43 am
Forum: Pro Audio Design
Topic: new shiny hammer- or Universal comp
Replies: 52
Views: 88107

Re: new shiny hammer- or Universal comp

I have a Nord Modular synth that uses MIDI to connect the core to PC for editing and it is quite the cool synth. Better to avoid legacy serial like RS232 and MIDI. (Slightly veering off topic - I have one of these too! They're great little synths and the software is cool. I had to buy a USB-midi ad...
by XAUDIA
Thu Jul 03, 2008 3:38 am
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 409061

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

Hi Roger,

I bought mine from the goldpoint website. They arrived this morning and feel really nice. I may have to use them on all my future projects!

My 1% resistors are here too so I can get started with the next build of these preamps tomorrow.

Cheers!
Stewart
by XAUDIA
Sat Jun 28, 2008 9:42 am
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 409061

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

That looks like a very useful spreadsheet, and for the record it works with the apple iWorks spreadsheet program too.
Thanks for sharing!
by XAUDIA
Sat Jun 28, 2008 8:53 am
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 409061

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

Hi Wayne, I haven't got past my very basic 1512 -> servo'd outpt (OP77) -> 1646 design. I had a hard drive crash this week which has cost me a lot of time, which is why I haven't been back to post. :evil: I did get to run the basic preamps last Sunday recording some stereo electric guitar tracks, us...
by XAUDIA
Sun Jun 22, 2008 4:29 am
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 409061

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

My basic preamps with output-servo'd 151x are up and running, and on a first listen seem pretty uncoloured. More serious tests today! Thought I'd post up the resistor table calculations I came up with. These are for the 1512 with 12 and 24 step switches. I'm just using a 12 position rotary for now. ...
by XAUDIA
Thu Jun 19, 2008 1:26 pm
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 409061

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

Thanks guys. I've had another look at the chip schematic in the datasheet & Mediatechnology's post, and that makes sense. The gain was relay controlled and I did not use Cgain. The only time I could see or hear the servo working was while changing gain. After the servo settled all was good AFAIK...
by XAUDIA
Thu Jun 19, 2008 11:11 am
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 409061

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

Absolutely! I've simply got it hooked up my a test rack with a simple +/-15V power supply. Once it's working (and if I like the sound), I'll get more ambitious.
by XAUDIA
Thu Jun 19, 2008 10:59 am
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 409061

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

Hi Wayne, Thanks for the clarification. Thought I'd get the iron out and start experimenting so I'm in the process of knocking together a pair of an extremely simple version of Wayne's circuit to see how the audio pathway sounds. I have a couple of nice new ribbon mics to play with too, and a fairly...
by XAUDIA
Wed Jun 18, 2008 8:20 am
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 409061

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

Hi! I too have been watching this with interest. I recently knocked together a minimum parts (no phantom power) 1512/1646 based preamp which did sound very clean and quiet, so I have high hopes for the design discussed here. I have a couple of thoughts / comments: Reading the THAT design note... htt...