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- Sun Jun 12, 2022 1:23 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615202
Re: moe pics
ll
- Tue May 10, 2022 1:01 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615202
- Sat May 07, 2022 1:00 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615202
Re: moe pics
77
- Sat Apr 16, 2022 1:38 pm
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46924
Re: Klipsch woofer - tweeter crossover network.
well it took a year but I finally got the transformers done for this circuit and they work as expected. (apologies for the cell phone screen grabs... I am out of my element when it comes to working on a PC). Here is the spice simulation of the circuit that I started with. IMG_8203.jpeg This is the m...
- Fri Apr 01, 2022 11:52 am
- Forum: Attenuators
- Topic: TVC Driving a 600 Ohm Input Transformer
- Replies: 3
- Views: 4609
Re: TVC Driving a 600 Ohm Input Transformer
I do not think it is fair to comment on inductive volume controls as a whole since there are many design considerations and your best approach is to measure and listen to the specific case to determine suitability. In speaking about my autoformers, they do really well driving difficult loads but ult...
- Wed Mar 09, 2022 8:47 pm
- Forum: Attenuators
- Topic: TVC Driving a 600 Ohm Input Transformer
- Replies: 3
- Views: 4609
Re: TVC Driving a 600 Ohm Input Transformer
Hey, you answered all of your questions and the load the TVC will see is not 600Ω since the secondary is left open. The primary inductance will appear in parallel with the reflected load but at anything below unity that value will get very large since it will be multiplied by the turn ratio squared....
- Thu Oct 28, 2021 1:14 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615202
- Tue Oct 12, 2021 2:23 pm
- Forum: Transformers
- Topic: OPT options for a 10\50 SET
- Replies: 2
- Views: 5043
Re: OPT options for a 10\50 SET
Hello Merv, I will answer your questions inline below. 1. Ideally I would have liked to have both 8 and 4 ohm speaker outs as well as a headphone jack but after reading around, having more secondary outputs may not sound as good as sticking to one output? If this is the case then I'll stick with an ...
- Sun Oct 10, 2021 9:59 pm
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 310099
Re: Step-up after LCR
There are a couple of things going on here. When you terminate the "stock" LCR with both 600Ω and an inductance as is happening in this thread, the source Z driving it must also be 600Ω or things shift. The attached picture shows a stock tango driven from 150Ω (green) and 600Ω (blue) when ...
- Sat Oct 09, 2021 3:00 pm
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 310099
Re: Step-up after LCR
Taken out of context of the entire paper, it is unclear what docali is referring to in this statement. For a correct filter response both sides of the t-network must be "terminated" with 600 ohms In the amplitude realm if the output is terminated with 600Ω, a change from a input terminatio...
- Fri Sep 24, 2021 11:43 am
- Forum: Attenuators
- Topic: 28 vs 14 pin autoformers
- Replies: 6
- Views: 4499
Re: 28 vs 14 pin autoformers
replies.. 1) I don't have a picture handy but the 28 step is simply the 14 step with pins on both sides. It is no more or less difficult to solder but keeping track of the wires becomes the main issue. 3) the prewired modules have 3dB steps at the beginning and end and 2dB steps in the middle. dave
- Thu Sep 16, 2021 1:09 pm
- Forum: Transformers
- Topic: SE amps to drive ES panels.
- Replies: 20
- Views: 30732
Re: SE amps to drive ES panels.
You are indeed correct that the panels are driven by step-up transformers from the plates of the tubes. It always made little sense to me to step down the voltage 25X for a cable run to only step it up 270X to drive the panels. Asking two transformers to do this (amp output / quad input) and maintai...
- Wed Sep 15, 2021 12:37 pm
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 310099
Re: Step-up after LCR
If you consider the basics, the LCR has its irregularities in the middle of the audio band where transformers are flat so the two should not effect each other. Granted the Transformers will have bandwidth limiting issues but that is independent of the type of EQ used. I guess I am trying to say is t...
- Fri Sep 03, 2021 2:48 am
- Forum: Lurkers Lounge
- Topic: joining up.
- Replies: 0
- Views: 37353
joining up.
I'm getting 1000 new accounts created a day and several of them were making spam posts so I shut down all new activations. If you want to join, send me an email and i'll get you set up with an account.
dave
dave
- Fri Aug 27, 2021 12:04 pm
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 310099
Re: Step-up after LCR
When you start getting into higher impedance cartridges and SUT's the miller capacitance (and cable capacitance) of the input of your phono becomes an important consideration. In addition to the simple filter you speak of, the additional capacitance pushes the LC resonance down in frequency and depe...
- Tue Jul 27, 2021 11:34 am
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615202
- Sat Jul 17, 2021 2:44 pm
- Forum: Attenuators
- Topic: Damping factor.
- Replies: 1
- Views: 3223
Re: Damping factor.
Didn't have much time to ponder things since I already had a solution in hand.... Ditch the L-pad on the 2441 and replace it with an autoformer. Here is the big picture of the change showing the Lpad being replaced with an autoformer and the frequency domain plots clearly overlap. Screen Shot 2021-0...
- Sat Jul 17, 2021 1:56 pm
- Forum: Attenuators
- Topic: Damping factor.
- Replies: 1
- Views: 3223
Damping factor.
People go on and on about damping factor and I continue to be astounded how they only consider the ratio of the output impedance of the amp to the input impedance of the "speaker". In truth the load presented by the "speaker" is actually the impedance of the crossover and everyon...
- Sat Jul 17, 2021 1:40 pm
- Forum: Your name here.
- Topic: moe pics
- Replies: 73
- Views: 615202
- Tue Jun 29, 2021 11:33 am
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 310099
Re: Step-up after LCR
WE300B, I think the important factor here is to either drive the LCR with its characteristic impedance OR load it with its characteristic impedance and not both. If you choose to drive it with its characteristic Z then the output can (should) be left unterminated and if you load it with its internal...
- Mon Jun 28, 2021 1:41 pm
- Forum: Circuits
- Topic: wiring multiple inputs / outputs diagram
- Replies: 0
- Views: 7848
Re: wiring multiple inputs / outputs diagram
The attached picture is from the wiring the $200 autoformer FAQ . It is only for 14 positon s but it isn't hart to imagine another 14 taps. To add another input just use a 3 posiiton selector and wire another sent of RCAs. For parallel output simply wire in a second set of RCA's to the output. dave ...
- Sun Jun 27, 2021 8:50 pm
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 310099
Re: Step-up after LCR
The LCR network either needs to be driven by its characteristic impedance or loaded at its characteristic impedance. In either case you have a situation where Rsource=Rload which causes a 6dB loss of amplitude so there is really no difference in gain either way you go about it. This all started when...
- Thu Jun 24, 2021 12:09 am
- Forum: Transformers
- Topic: EL33 Headphone Amp OPTs
- Replies: 7
- Views: 4756
Re: EL33 Headphone Amp OPTs
everything looks right. the only concern is the inductance of the primary might be a bit low. worth a try though.
dave
dave
- Mon Jun 07, 2021 11:57 am
- Forum: Attenuators
- Topic: intro to Autoformers
- Replies: 0
- Views: 8019
Re: intro to Autoformers
I'll answer these question sin line. -what will be the ideal output impedance of the phono stage output(to go into the autoformers preamp)? The lower the better and typically under say 3kΩ but I have had people go as high as 6-8k and report great results. -what will be the ideal output impedance of...
- Sat Jun 05, 2021 12:39 am
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 310099
- Fri Jun 04, 2021 1:10 pm
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 310099
In the last schematic the EQ600 is not terminated with 600 ohm so load seen by input stage is higher this entire branch of the discussion was in response to your quoted text above. I believe the quoted text to be incorrect which is why I asked you to simply measure the input Z of the EQ-600 with 60...
- Thu Jun 03, 2021 9:24 pm
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 310099
Since you do not want to make the measurement I asked you for, I will tell you that the Z-in of a 600Ω LCR network above 1kHz is 600Ω independent of any terminating resistor. load it with 600Ω and the Z-in is 600Ω, load it with 1M5 and the Z-in is 600Ω. There is a small increase in Z below 100h...
- Thu Jun 03, 2021 9:11 pm
- Forum: Attenuators
- Topic: Dac user
- Replies: 23
- Views: 10810
- Thu Jun 03, 2021 5:51 pm
- Forum: Attenuators
- Topic: Dac user
- Replies: 23
- Views: 10810
- Thu Jun 03, 2021 1:00 pm
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 310099