I think that the output impedance in the parallel SE drive configuration is 12.5 Ohms. So pretty darn low and essentially no buildout. Glad this worked out.emrr wrote:I don't see any need to use build-out R between 1646 and filter at all.
Search found 5449 matches
- Fri Sep 24, 2010 4:28 pm
- Forum: Pro Audio Design
- Topic: THAT1646 Current Booster and Transformer Driver
- Replies: 45
- Views: 128224
Re: THAT1646 Current Booster and Transformer Driver
- Fri Sep 24, 2010 4:11 pm
- Forum: Pro Audio Design
- Topic: console grounding
- Replies: 12
- Views: 20461
Re: console grounding
On a protoboard it's easy to have pin 3 telescope. Let me add the words "and it oscillate." to the end of that sentence. One distinction that can be made to reduce confusion - and JR was able to define the two elegantly - is that there's ground and "zero signal reference." BTW l...
- Fri Sep 24, 2010 3:51 pm
- Forum: The Peabody Lounge
- Topic: PSU Enfuego: Exploding Power Supply Story in EE Life
- Replies: 1
- Views: 5315
PSU Enfuego: Exploding Power Supply Story in EE Life
This made it to my inbox and I'm reminded of a similar story once told to me involving an SSL Pipe Organ system. "Excuse me sir, but is the power supply supposed to be on fire?" http://www.eetimes.com/electronics-blogs/other/4208755/analogue-computers-to-the-rescue I'm sure Roger can relat...
- Mon Sep 20, 2010 11:01 am
- Forum: Document
- Topic: dBx 3BX Three Band Dynamic Range Expander
- Replies: 8
- Views: 18811
dBx 3BX Three Band Dynamic Range Expander
Schematics for the dBx 3BX dynamic range expander. One of the first applications I saw using the non-linear capacitor. https://www.proaudiodesignforum.com/Images/jpg/3BX_small.JPG dBx 3BX Schematic Large format: https://www.proaudiodesignforum.com/Images/jpg/3BX.JPG (4.4 MB) When I had a 3BX I had t...
- Fri Sep 03, 2010 8:16 am
- Forum: Pro Audio Design
- Topic: THAT 1570 1510 and 1512 Input/Output Circuits
- Replies: 22
- Views: 54839
Re: THAT 1570 1510 and 1512 Input/Output Circuits
Thanks MIQ. Yes, the 1G gate resistor should be lowered by many orders of magnitude. In your original post you mentioned the 1512 and I responded with a 1570. Sorry wasn't paying attention. Since you're using a 1512, you will definitely want to AC-couple the FET source and drain loads to the 1512 in...
- Thu Sep 02, 2010 6:45 pm
- Forum: Pro Audio Design
- Topic: THAT 1570 1510 and 1512 Input/Output Circuits
- Replies: 22
- Views: 54839
Re: THAT 1570 1510 and 1512 Input/Output Circuits
What about using a FET buffer (LSK170?) with say 2K source and drain loads and also use those loads as the 1570's bias resistors? The +/- inputs of the 1570 can be treated as independant "halves." I'm wondering if you AC couple the Rgain line (or 1570 outputs) if you can overcome the Vgs t...
- Fri Aug 20, 2010 12:39 pm
- Forum: Pro Audio Design
- Topic: Mid Side M-S Matrix Uses No Precision Resistors
- Replies: 271
- Views: 620668
Re: Mid Side M-S Matrix Uses No Precision Resistors
True about the drop-out beween positions. In the mic preamp the gain drops to unity for a few ms between steps but it wasn't too audible. Your mastering situation however would require seemless switching. I think that was the motivation for bruno2000 (live) to use pots in his preamp build.
- Fri Aug 20, 2010 12:30 pm
- Forum: Pro Audio Design
- Topic: Mid Side M-S Matrix Uses No Precision Resistors
- Replies: 271
- Views: 620668
Re: Mid Side M-S Matrix Uses No Precision Resistors
OK, got it. Absence of serial errors is the key IMHO.
I wished I had some of the old Kay Elemetrics attenuators...
I wished I had some of the old Kay Elemetrics attenuators...
- Fri Aug 20, 2010 11:45 am
- Forum: Pro Audio Design
- Topic: Mid Side M-S Matrix Uses No Precision Resistors
- Replies: 271
- Views: 620668
Re: Mid Side M-S Matrix Uses No Precision Resistors
+1 what JR. said.
The predecessor to the iPad was the hPad. Both trace their origins to garages.
http://www.amazon.com/Hewlett-Packard-F ... 654&sr=8-1
The predecessor to the iPad was the hPad. Both trace their origins to garages.
http://www.amazon.com/Hewlett-Packard-F ... 654&sr=8-1
- Fri Aug 20, 2010 7:09 am
- Forum: Pro Audio Design
- Topic: Mid Side M-S Matrix Uses No Precision Resistors
- Replies: 271
- Views: 620668
Re: Mid Side M-S Matrix Uses No Precision Resistors
I did the calculations for the potentiometer style attenuator. I even learned Reverse Polish Notaion to do it. Thanks iPAD! I ordered the resistors and did a mock up. The good news is that I basically got it right. The bad news is that even with .1% resistors the accuracy varies more than 0.2dB per...