Search found 1603 matches
- Wed Mar 06, 2024 1:28 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615189
Re: moe pics
hg
- Mon Mar 04, 2024 6:05 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615189
Re: moe pics
lkj;
- Fri Mar 01, 2024 2:28 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615189
Re: moe pics
jfgb
- Tue Jan 02, 2024 1:00 pm
- Forum: Attenuators
- Topic: Bias output stage via AVC
- Replies: 1
- Views: 1375
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...
- Tue Jan 02, 2024 12:53 pm
- Forum: Attenuators
- Topic: How have the auoformers changed over the years
- Replies: 4
- Views: 5070
Re: How have the auoformers changed over the years
the 200Hy number is measured at 100Hz and will be the same at 20Hz.
dave
dave
- Fri Dec 08, 2023 11:01 pm
- Forum: Inductors
- Topic: Series connection of inductors to cut down capacitance
- Replies: 1
- Views: 2805
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...
- Tue Nov 07, 2023 3:51 am
- Forum: Attenuators
- Topic: How have the auoformers changed over the years
- Replies: 4
- Views: 5070
Re: How have the auoformers changed over the years
no changes... Inductance is in the 200Hy range.
dave
dave
- Sun Oct 22, 2023 7:12 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615189
Re: moe pics
sd
- Sat Oct 21, 2023 9:03 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615189
Re: moe pics
jk
- Fri Oct 13, 2023 9:26 pm
- Forum: Phono
- Topic: Loading and Frequency Response
- Replies: 0
- Views: 7729
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 ...
- Sun Oct 08, 2023 11:17 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615189
Re: moe pics
nn
- Wed Sep 06, 2023 11:42 am
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 310093
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...
- Sun Sep 03, 2023 12:41 pm
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 310093
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
dave
- 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
dave
- Sat Jun 03, 2023 1:35 pm
- Forum: Playing With Airgaps
- Topic: Magnetized AVC?
- Replies: 11
- Views: 43596
Re: Magnetized AVC?
those numbers all look good.
- Sat Apr 29, 2023 2:14 pm
- Forum: Inductors
- Topic: RL high-pass at speaker level
- Replies: 10
- Views: 42980
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...
- Fri Apr 28, 2023 1:56 pm
- Forum: Inductors
- Topic: RL high-pass at speaker level
- Replies: 10
- Views: 42980
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...
- Thu Apr 06, 2023 1:29 am
- Forum: Inductors
- Topic: RL high-pass at speaker level
- Replies: 10
- Views: 42980
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
dave
- Sat Apr 01, 2023 11:56 am
- Forum: Transformers
- Topic: Autoformer for Klipsch crossover
- Replies: 15
- Views: 41564
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
dave
- Sun Mar 19, 2023 9:33 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615189
Re: moe pics
pp
- Sat Mar 18, 2023 12:51 am
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615189
Re: moe pics
pj
- Sun Feb 26, 2023 2:47 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615189
Re: moe pics
mnb
- Mon Feb 13, 2023 3:22 pm
- Forum: Phono
- Topic: Stereo to Mono
- Replies: 11
- Views: 13921
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
dave
- Fri Jan 27, 2023 1:07 pm
- Forum: Attenuators
- Topic: Original AVC pcb and switch available seperately
- Replies: 2
- Views: 30486
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
The original $200 AVC's will not fit on the module PCB that has the integrated switches.
dave
- Tue Jan 17, 2023 9:46 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615189
Re: moe pics
tt
- Sun Nov 27, 2022 2:40 pm
- Forum: Playing With Airgaps
- Topic: Magnetized AVC?
- Replies: 11
- Views: 43596
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
dave
- Sat Nov 26, 2022 2:39 pm
- Forum: Playing With Airgaps
- Topic: Magnetized AVC?
- Replies: 11
- Views: 43596
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 ...
- Thu Nov 24, 2022 1:17 pm
- Forum: Playing With Airgaps
- Topic: Magnetized AVC?
- Replies: 11
- Views: 43596
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
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
- Fri Nov 18, 2022 12:53 pm
- Forum: Attenuators
- Topic: $200 avc wiring diagram
- Replies: 6
- Views: 6415
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
dave
- Fri Nov 18, 2022 12:51 pm
- Forum: Playing With Airgaps
- Topic: Magnetized AVC?
- Replies: 11
- Views: 43596
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. ...