Search found 5468 matches
- Fri May 01, 2009 7:27 am
- Forum: Build
- Topic: 1510 -- servo, or not ?
- Replies: 24
- Views: 75149
Re: 1510 -- servo, or not ?
So I'll be OK using the two 3.3k resistors and 22k for the center resistor? Yes, to make my rather long story short that should work fine. :ugeek: Without coupling caps however that extra resistor doesn't bring much to the party. Have you considered using a 1512? It would drop in the same socket an...
- Thu Apr 30, 2009 7:29 pm
- Forum: Build
- Topic: 1510 -- servo, or not ?
- Replies: 24
- Views: 75149
Re: 1510 -- servo, or not ?
Using the T-bias scheme, what impedance will a mic see? I'm concerned about loading dynamic and ribbon mics. I have built a preamp around the 1510 using two 3.3k resistors to ground using the rule of thumb that the input impedance should be 10x the mic impedance (I do have a 600-ohm mic, AT804, and...
- Mon Apr 27, 2009 9:00 pm
- Forum: Pro Audio Design
- Topic: THAT1646 Operation From A Single Supply Voltage
- Replies: 6
- Views: 15724
THAT1646 Operation From A Single Supply Voltage
Here's one way to operate and bias a THAT1646 for single supply operation: https://www.ka-electronics.com/images/jpg/THAT1646_Single_Supply.jpg Image courtesy of THAT Corporation If the input is at or near the same DC potential as Vref (the one-half Vcc potential at the output of U2A) then C2 and R1...
- Mon Apr 27, 2009 6:13 am
- Forum: Pro Audio Design
- Topic: Using the THAT1646 As A Transistor Pre-Driver/Headphone Amp
- Replies: 80
- Views: 353870
Re: Using the THAT1646 As A Transistor Pre-Driver/Headphone Amp
They are an insulated TO-126 on a 2.28 mm pitch. 0.1" may be close enough.raf wrote:I need to re-pitch the output device pads... I used 0.1" thinking they were TO220, they are, what TO126?
Thanks Roger and Doug.
- Sun Apr 26, 2009 9:27 pm
- Forum: Pro Audio Design
- Topic: Using the THAT1646 As A Transistor Pre-Driver/Headphone Amp
- Replies: 80
- Views: 353870
Re: Using the THAT1646 As A Transistor Pre-Driver/Headphone Amp
I had a chance to check the PC board a few weeks ago and run a few measurements. The output Vos was <5mV. The orginal slew rate was thought to be ~4V/us but when re-measured turned out to be ~8V/us. This is consistent with the THAT1646 when driven in the "common mode" configuration. The RM...
- Fri Apr 24, 2009 8:25 pm
- Forum: Build
- Topic: Hum differences in toroidal power transformers...
- Replies: 2
- Views: 14680
Re: Hum differences in toroidal power transformers...
What was the harmonic content of the fields? Could it be an issue of core saturation?
- Fri Apr 24, 2009 11:46 am
- Forum: Document
- Topic: Phono Preamps
- Replies: 49
- Views: 203710
Re: Phono Preamps
Check out the Archiver USB preamp. This thing is full of 2SK389s.
http://www.hagtech.com/pdf/archiverman.pdf
The schematics are on page 7.
http://www.hagtech.com/pdf/archiverman.pdf#page=7
Cute the way the FETS are drawn as triodes.
http://www.hagtech.com/pdf/archiverman.pdf
The schematics are on page 7.
http://www.hagtech.com/pdf/archiverman.pdf#page=7
Cute the way the FETS are drawn as triodes.
- Tue Apr 21, 2009 8:27 pm
- Forum: Pro Audio Design
- Topic: NE570-based NR compander (P-522) by JR
- Replies: 34
- Views: 71128
Re: NR compander (P-522)
That particular node (Rgain) is not the best place to do stuff in series or parallel. In the 1510 (and most CFB mic preamps of similar topology) even a small amount of stray capacitance to ground ~1-2 pF is going to create issues. In series, a few thousand uF are required to make changes. I agree wi...
- Mon Apr 20, 2009 8:58 pm
- Forum: Pro Audio Design
- Topic: NE570-based NR compander (P-522) by JR
- Replies: 34
- Views: 71128
Re: NR compander (P-522)
I got to play with this a little this weekend by scabbing into an eq. Not really needed as the opamp I used recovers quite nicely on its own. It does make for a nice effect when abused (!) I 'nested' a few sets across the feedback path and could get a nice and smooth limiting effect. I want to try ...
- Mon Apr 20, 2009 8:38 pm
- Forum: The Peabody Lounge
- Topic: Another reason not to buy used appliances from Crusty...
- Replies: 11
- Views: 22958
Re: Another reason not to buy used appliances from Crusty...
Those Elco shafts are pretty hard aren't they? Stainless steel IIRC?