Search found 1603 matches

by dave slagle
Wed Mar 06, 2024 1:28 pm
Forum: Your name here.
Topic: moe pics
Replies: 73
Views: 615152

Re: moe pics

hg
by dave slagle
Mon Mar 04, 2024 6:05 pm
Forum: Your name here.
Topic: moe pics
Replies: 73
Views: 615152

Re: moe pics

lkj;
by dave slagle
Fri Mar 01, 2024 2:28 pm
Forum: Your name here.
Topic: moe pics
Replies: 73
Views: 615152

Re: moe pics

jfgb
by dave slagle
Tue Jan 02, 2024 1:00 pm
Forum: Attenuators
Topic: Bias output stage via AVC
Replies: 1
Views: 1371

Re: Bias output stage via AVC

Hey, Your circuit will work fine as drawn and the DC offset is not a problem since as you mentioned, the current will be in the µA range. However introducing a switch to change levels to a situation with DC offset and an inductor (AVC) will open up the possibility of some audible transient "pop...
by dave slagle
Tue Jan 02, 2024 12:53 pm
Forum: Attenuators
Topic: How have the auoformers changed over the years
Replies: 4
Views: 5062

Re: How have the auoformers changed over the years

the 200Hy number is measured at 100Hz and will be the same at 20Hz.

dave
by dave slagle
Fri Dec 08, 2023 11:01 pm
Forum: Inductors
Topic: Series connection of inductors to cut down capacitance
Replies: 1
Views: 2801

Re: Series connection of inductors to cut down capacitance

in theory the capacitance of two identical discrete chokes connected in series should be half of a single choke which should net you an extra octave of top end. In practice I have come close to but never realized that behavior, primarily because the core if grounded to stop stray pickup prevents the...
by dave slagle
Tue Nov 07, 2023 3:51 am
Forum: Attenuators
Topic: How have the auoformers changed over the years
Replies: 4
Views: 5062

Re: How have the auoformers changed over the years

no changes... Inductance is in the 200Hy range.

dave
by dave slagle
Sun Oct 22, 2023 7:12 pm
Forum: Your name here.
Topic: moe pics
Replies: 73
Views: 615152

Re: moe pics

sd
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by dave slagle
Sat Oct 21, 2023 9:03 pm
Forum: Your name here.
Topic: moe pics
Replies: 73
Views: 615152

Re: moe pics

jk
by dave slagle
Fri Oct 13, 2023 9:26 pm
Forum: Phono
Topic: Loading and Frequency Response
Replies: 0
Views: 7723

Loading and Frequency Response

I was asked about how the load seen by the cartridge effects the frequency response so I made some quick crude measurements of a shelter 501 and a denon 103R. The test record was the CBS STR-120. The sound card was a Focusrite Scarlett 2i2. captures were made with audiotester. The tonearm cable fed ...
by dave slagle
Sun Oct 08, 2023 11:17 pm
Forum: Your name here.
Topic: moe pics
Replies: 73
Views: 615152

Re: moe pics

nn
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by dave slagle
Wed Sep 06, 2023 11:42 am
Forum: Phono
Topic: Step-up after LCR
Replies: 92
Views: 310058

Re: Step-up after LCR

Hey Daniel, The first thing that comes to mind is if the iRiaa filter you are using has the 50kHz time constant. Here is a LCR filter with the 50kHz Neuman time constant into a LCR filter with and without it. Screenshot 2023-09-06 at 7.27.40 AM.png I suspect if you add the resistor R6 you might be a...
by dave slagle
Sun Sep 03, 2023 12:41 pm
Forum: Phono
Topic: Step-up after LCR
Replies: 92
Views: 310058

Re: Step-up after LCR

V1 / V2 are voltage sources and serve as an easy way to set the tube bias. I have used LED's in this position and they work well. I simply put the expected voltage drop of the LED as a voltage source under the cathode rather than trying to find or model the exact LED I use.

dave
by dave slagle
Thu Aug 03, 2023 12:11 am
Forum: Phono
Topic: LCR parasitics
Replies: 2
Views: 3037

Re: LCR parasitics

no... I typically build the circuit, measure and then adjust the parasitics until spice matches the measured response.

dave
by dave slagle
Sat Jun 03, 2023 1:35 pm
Forum: Playing With Airgaps
Topic: Magnetized AVC?
Replies: 11
Views: 43574

Re: Magnetized AVC?

those numbers all look good.
by dave slagle
Sat Apr 29, 2023 2:14 pm
Forum: Inductors
Topic: RL high-pass at speaker level
Replies: 10
Views: 42972

Re: RL high-pass at speaker level

Actually.... since the device being high passed typically also needs attenuation the "Rf" can also be part of the pad and then a shunt inductor added as the filter element. Assuming around 6dB here is a LR compared to a typical capacitor + autoformer. The big difference between the two wil...
by dave slagle
Fri Apr 28, 2023 1:56 pm
Forum: Inductors
Topic: RL high-pass at speaker level
Replies: 10
Views: 42972

Re: RL high-pass at speaker level

Not that I can come up with for this situation. The RL filter requires a series resistance and a shunt inductor and the closest I can come is using the output impedance of the amplifier as the source Z and a shunt inductor but that will unduly load down the source at low frequencies. If say 6dB of H...
by dave slagle
Thu Apr 06, 2023 1:29 am
Forum: Inductors
Topic: RL high-pass at speaker level
Replies: 10
Views: 42972

Re: RL high-pass at speaker level

You would have to sim it but this should work... you may need a shunt resistor across the entire choke to get things stable since the impedance curve can get wonky with the stepup from the tapped choke.

dave
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by dave slagle
Sat Apr 01, 2023 11:56 am
Forum: Transformers
Topic: Autoformer for Klipsch crossover
Replies: 15
Views: 41548

Re: Autoformer for Klipsch crossover

This comes down to the applied voltage and crossover frequency. 80% nickel has a saturation of 1/2 that of the supplied 49% which is the difference between 500Hz and 1000Hz or 2W and 8W.

dave
by dave slagle
Sun Mar 19, 2023 9:33 pm
Forum: Your name here.
Topic: moe pics
Replies: 73
Views: 615152

Re: moe pics

pp
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by dave slagle
Sat Mar 18, 2023 12:51 am
Forum: Your name here.
Topic: moe pics
Replies: 73
Views: 615152

Re: moe pics

pj
Screen Shot 2023-03-17 at 8.48.32 PM.png
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by dave slagle
Sun Feb 26, 2023 2:47 pm
Forum: Your name here.
Topic: moe pics
Replies: 73
Views: 615152

Re: moe pics

mnb
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by dave slagle
Mon Feb 13, 2023 3:22 pm
Forum: Phono
Topic: Stereo to Mono
Replies: 11
Views: 13912

Re: Stereo to Mono

since these are simple input transformers the autoformer size would be fine. you should get 1:2 My first thought would be bifilar but I think the ground shift would "get you" at high frequencies.

dave
by dave slagle
Fri Jan 27, 2023 1:07 pm
Forum: Attenuators
Topic: Original AVC pcb and switch available seperately
Replies: 2
Views: 30473

Re: Original AVC pcb and switch available seperately

I do not follow.

The original $200 AVC's will not fit on the module PCB that has the integrated switches.

dave
by dave slagle
Tue Jan 17, 2023 9:46 pm
Forum: Your name here.
Topic: moe pics
Replies: 73
Views: 615152

Re: moe pics

tt
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by dave slagle
Sun Nov 27, 2022 2:40 pm
Forum: Playing With Airgaps
Topic: Magnetized AVC?
Replies: 11
Views: 43574

Re: Magnetized AVC?

I cannot think of anything within the AVC that could cause this.... The apparent short between 12 & 13 should not be there and it is highly unlikely that the problem is internal to the autoformer

dave
by dave slagle
Sat Nov 26, 2022 2:39 pm
Forum: Playing With Airgaps
Topic: Magnetized AVC?
Replies: 11
Views: 43574

Re: Magnetized AVC?

it sure seems somehow pins 12 & 13 are shorted to each other. carefully retrace your wiring looking for an error. I am assuming it was functioning properly and then "broke at some point"? The fact that it is happening the same in both channels points to some external cause since it is ...
by dave slagle
Thu Nov 24, 2022 1:17 pm
Forum: Playing With Airgaps
Topic: Magnetized AVC?
Replies: 11
Views: 43574

Re: Magnetized AVC?

can you re-check you numbers?

the source impedance (867,2354 ohms) number does not make sense unless it rounds down to 867Ω

the measurements between steps 12 & 13 are the same which should not be the case. what is the DCR between 12&13 (at the switch and at the autoformer.

dave
by dave slagle
Fri Nov 18, 2022 12:53 pm
Forum: Attenuators
Topic: $200 avc wiring diagram
Replies: 6
Views: 6404

Re: $200 avc wiring diagram

it is not possible to get a balanced output from a single ended circuit but two units per channel can attenuate a balanced to balanced line.


dave
by dave slagle
Fri Nov 18, 2022 12:51 pm
Forum: Playing With Airgaps
Topic: Magnetized AVC?
Replies: 11
Views: 43574

Re: Magnetized AVC?

Hey, There really isn't any possibility of the AVC to become magnetized or break. The two things that come to mind are a leaky cap putting DC on the core and a possible shorted turn (two pins shorted to each other). A DVM should help diagnose the first and a visual search might point to the second. ...