Search found 2802 matches

by mediatechnology
Sun Jan 21, 2018 4:19 pm
Forum: Build
Topic: Phono Transfer System
Replies: 89
Views: 48741

Re: Phono Transfer System

I've been telling myself the sights I'll see by not HPF everything in analog may not be pretty and it's probably mostly an irrational goal I'll soon regret after trying dc coupled. I'm usually the most freaked out about the LF wiggles when I'm looking at X-Y on the 'scope and I see LF Side vectors....
by mediatechnology
Sun Jan 21, 2018 11:45 am
Forum: Build
Topic: Phono Transfer System
Replies: 89
Views: 48741

Re: Phono Transfer System

The sole reason for DC-coupling the low impedance outputs of the flat preamp is to eliminate electrolytics in the potentially-long balanced low-impedance lines from the remote preamp to the EQ box. Maintaining common mode rejection to DC in the balanced preamp stages eliminates the need for matched ...
by mediatechnology
Sun Jan 21, 2018 5:57 am
Forum: Build
Topic: Phono Transfer System
Replies: 89
Views: 48741

Re: Phono Transfer System

Very nice Kevin!

Sawing that heatsink on the table saw was definitely an adventure. You made it all fit!

The one thing you did that I would change is shield the twisted pair lines for the phono inputs. Event though its in an enclosed box I think it will be quieter.
by mediatechnology
Sat Jan 20, 2018 1:30 pm
Forum: Document
Topic: THAT 6261, 6262, 6266 Dual Mic Preamp plus A/D Driver
Replies: 0
Views: 32

THAT 6261, 6262, 6266 Dual Mic Preamp plus A/D Driver

The THAT 626x is a family of two-channel “all-in-one” digitally controlled preamplifiers with integrated ADC drivers. Gain is programmable from -8 to +34 dB. The low-power (60 mW) devices can be powered from unipolar (+10 V and +5 V) or bipolar (±5 V) supplies. The 626x family includes three produc...
by mediatechnology
Sat Jan 20, 2018 1:24 pm
Forum: Pro Audio Design
Topic: Low noise grounding tips in mic preamp
Replies: 11
Views: 133

Re: Low noise grounding tips in mic preamp

Oh, OK these are not "active" input preamps. I can see how your first fix, moving the op amp inverting input reference to the transformer secondary worked. If it had been an active preamp, e.g. a THAT1510, then I would have suggested referencing the differential amp to the input for the same reason....
by mediatechnology
Sat Jan 20, 2018 12:14 pm
Forum: Pro Audio Design
Topic: Low noise grounding tips in mic preamp
Replies: 11
Views: 133

Re: Low noise grounding tips in mic preamp

The output stage gets connected to the PSU output ground point which is the main filtering cap right after the diode bridge. This statement raises a lot of questions. What do you mean by the output stage gets connected to the PSU output ground? Where does the preamp's common mode rejection stage re...
by mediatechnology
Fri Jan 19, 2018 9:48 am
Forum: Document
Topic: "Some Tips on Stabilizing Operational Amplifiers" Deane Jensen
Replies: 1
Views: 34

"Some Tips on Stabilizing Operational Amplifiers" Deane Jensen

"Some Tips on Stabilizing Operational Amplifiers" Deane Jensen JR sent me this years ago and I never scanned it due to it being available at Jensen. After revisiting it I realized that this version has Deane's original hand drawings and might be of historical interest. This article originally appea...
by mediatechnology
Fri Jan 19, 2018 6:14 am
Forum: The Peabody Lounge
Topic: Links in topic reply notifications
Replies: 1
Views: 24

Re: Links in topic reply notifications

Mine come in as html.
What email client do you use?
by mediatechnology
Fri Jan 19, 2018 5:39 am
Forum: Pro Audio Design
Topic: Low noise grounding tips in mic preamp
Replies: 11
Views: 133

Re: Low noise grounding tips in mic preamp

I agree with JR: You need to find the vector first.
Electrostatic, magnetic or conducted?
by mediatechnology
Thu Jan 18, 2018 5:54 pm
Forum: Pro Audio Design
Topic: Super Low Distortion Ultra Pure Audio Oscillators Revisited
Replies: 33
Views: 7825

Re: Super Low Distortion Ultra Pure Audio Oscillators Revisited

I think the ambitious part of building the Cordell Analyzer are obtaining and wiring the multipole switches.