Search found 58 matches
- Thu Oct 07, 2021 8:41 am
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 311157
Re: Step-up after LCR
What you state here is mathematically not correct. For a correct filter response both sides of the t-network must be "terminated" with 600 ohms. I showed the effect of different driving impedance in my wp. Everything else than a driving impedance of 600 ohms is less correct. Then we come t...
- Sun Jun 06, 2021 9:34 am
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 311157
- Thu Feb 18, 2021 5:51 am
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 311157
- Wed Jan 20, 2021 7:43 pm
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 311157
- Sat Jan 16, 2021 3:38 pm
- Forum: Phono
- Topic: Step-up after LCR
- Replies: 92
- Views: 311157
- Fri Jan 15, 2021 9:06 pm
- Forum: Phono
- Topic: New Phono Project
- Replies: 4
- Views: 5238
- Thu Aug 06, 2020 7:27 pm
- Forum: Sim City
- Topic: DHT filament modeling
- Replies: 0
- Views: 8554
DHT filament modeling
Hi, it seems that Stephie is active again ;-) Maybe we might continue our discussion about filament modelling we did some years ago about ER300B. I recently got new tube EML12B and tried to re-work the approach for this tube. Unfortunately I do not have enough experimental data. Only what Jac publis...
- Mon Jun 19, 2017 7:46 pm
- Forum: Attenuators
- Topic: How to HF boost an compression driver behind an autoformer?
- Replies: 8
- Views: 6507
How to HF boost an compression driver behind an autoformer?
Hello Dave! Maybe you have an idea to this issue. I have a compression driver that slighty falls off after 10 kHz in the used CD-horn. The current solution to overcome this in the cross-over is to use an series resistor which levels down the efficiency to adapt the compression driver to the woofers ...
- Mon Dec 21, 2015 4:40 pm
- Forum: Attenuators
- Topic: Problem with Autoformer Modules
- Replies: 4
- Views: 6958
You should read here about this issues:
[url]http://www.intactaudio.com/forum/viewtopic.php?t=40[/url]
[url]http://www.intactaudio.com/forum/viewtopic.php?t=40[/url]
- Mon Dec 21, 2015 4:31 pm
- Forum: Attenuators
- Topic: Problem with Autoformer Modules
- Replies: 4
- Views: 6958
- Thu Nov 19, 2015 7:41 am
- Forum: Attenuators
- Topic: AVC measurements?
- Replies: 39
- Views: 84521
Hello Dirk! You state that the source impedance of the oscillator is about 600 Ohms. In this case it is no wonder that there is less ringing. The 600 Ohms damps the TVC quite good. But what when you drive it with abot 200 Ohms or even 50 Ohms? Then you see the truth :wink: You can do this while driv...
- Mon Oct 26, 2015 7:25 am
- Forum: Attenuators
- Topic: AVC measurements?
- Replies: 39
- Views: 84521
- Fri Sep 05, 2014 4:33 pm
- Forum: Sim City
- Topic: Grid Bypass NOT Cathode Bypass!
- Replies: 0
- Views: 10603
Grid Bypass NOT Cathode Bypass!
Hello! I was thinking already a long time about replacing the big cathode bypass capacitor in single ended stages. Ultra path might be a way. But one big disadvantage is that you need a really large capacitor to avoid the output impedance raise for low frequencies. I observed this for the GCA and UP...
- Tue Aug 19, 2014 12:49 pm
- Forum: Phono
- Topic: Phono RC RIAA to LCR RIAA
- Replies: 2
- Views: 8635
- Sat May 11, 2013 11:11 pm
- Forum: Phono
- Topic: 4th time constant for LCR RIAA
- Replies: 10
- Views: 16028
Hello Claus, thanks for your explanation! From my testings I found that you can get a similar error by leaving RL2A out and reducing C2 slightly and adjusting the other values around it. But, and this seems to be the important point, which was not clear to before: you loose the contstant impedance o...
- Fri May 10, 2013 8:41 am
- Forum: Phono
- Topic: 4th time constant for LCR RIAA
- Replies: 10
- Views: 16028
- Thu May 09, 2013 11:46 am
- Forum: Phono
- Topic: 4th time constant for LCR RIAA
- Replies: 10
- Views: 16028
Thank you very much, Claus, for sharing this with us! It must have been an huge amount of work! What I do not fully understand actually are the resitors RL1A and RL2A. I suppose that these have to soldered in series to the inductors as additional external resistor? Is there any chance to change the ...
- Tue Apr 09, 2013 4:18 am
- Forum: Phono
- Topic: 4th time constant for LCR RIAA
- Replies: 10
- Views: 16028
- Wed Aug 01, 2012 6:30 am
- Forum: Phono
- Topic: Differential amplifier to feed an lowZ LCR or LR
- Replies: 15
- Views: 21662
Impedance by frequency
Hi, I did some interesting simulations to show you the difference of LCR and LR. The input impedance of the LCR-RIAA is really very stable and nearly the same over the whole audio frequency range while the LR-RIAA has 10 times more deviations. Maybe this is the what makes the magic of the sound of a...
- Mon Jul 30, 2012 7:38 pm
- Forum: Phono
- Topic: Differential amplifier to feed an lowZ LCR or LR
- Replies: 15
- Views: 21662
Hi, if you take a look at my LR-RIAA the phase shift is only about 1-2 degress at 20 KHz. This looks fastastic in my eyes. The high frequencies should be more important here. If someone has time it would also be interesting to see the difference of the impedance with frequency compared for LR and LC...
- Mon Jul 30, 2012 8:09 am
- Forum: Phono
- Topic: Differential amplifier to feed an lowZ LCR or LR
- Replies: 15
- Views: 21662
Hi, so far as I know there was no standard what inverse RIAA was used. I think long time ago they used indeed inductive components but in newer times capacitors only. The phase shift should be different with different inverse RIAA. What sems more important for us is what load sees the source tube by...
- Sun Jul 29, 2012 6:03 pm
- Forum: Phono
- Topic: Differential amplifier to feed an lowZ LCR or LR
- Replies: 15
- Views: 21662
Hi, there is a nice script from Dmitry Nizhegorodov which extracts the values for PtPlot from the spice output. Yes, NoC area ;-) But many people say you should use an LCR because it is constant T-network which presents a nearly constant load independent from frequency to the source. I do not know i...
- Sat Jul 28, 2012 11:46 pm
- Forum: Phono
- Topic: Differential amplifier to feed an lowZ LCR or LR
- Replies: 15
- Views: 21662
- Thu Jun 14, 2012 12:00 pm
- Forum: Phono
- Topic: Differential amplifier to feed an lowZ LCR or LR
- Replies: 15
- Views: 21662
LCR Differential
Hello,
here you see an example of an fully differential LCR that works quite well with the class A push pull differential D3a stage.
Best regards,
docali
here you see an example of an fully differential LCR that works quite well with the class A push pull differential D3a stage.
Best regards,
docali
- Tue Jun 12, 2012 3:17 pm
- Forum: Phono
- Topic: 4th time constant for LCR RIAA
- Replies: 10
- Views: 16028
4th time constant for LCR RIAA
Hello,
does anyone know the correct mathematics how to calculate or incorporate the 4th time constant to an LCR? I did some simulations by trial and error (see attachement).
But there must be a way to calculate these values including the real series resistors of the inductors.
Best regards,
docali
does anyone know the correct mathematics how to calculate or incorporate the 4th time constant to an LCR? I did some simulations by trial and error (see attachement).
But there must be a way to calculate these values including the real series resistors of the inductors.
Best regards,
docali
- Fri Mar 30, 2012 1:44 pm
- Forum: Phono
- Topic: Differential amplifier to feed an lowZ LCR or LR
- Replies: 15
- Views: 21662
Effect of amount of unbalanced inputs
Hi, I would like to show the effect of unbalancing the inputs for a fixed load of 600 Ohms parallel with 1nF. The sum of both resistors always equals 47k. if r1=22k then r2 is 25k. As you can see from the graph the 3rd order distortion is quite the same ofr all scenarios but second order can be trim...
- Sat Feb 25, 2012 2:02 pm
- Forum: Phono
- Topic: Differential amplifier to feed an lowZ LCR or LR
- Replies: 15
- Views: 21662
Forced unbalanced feeded differential amplifier
Hello, but I found that you can use a trick which was inspired by Linn Olson and Stephie. Just shunt the middle of the output transformer to the cathodes and feed the amplifer with a slight unbalanced signal. The capacitor only comes into the game if the output signal is not symmetric. In this confi...
- Sat Feb 25, 2012 1:52 pm
- Forum: Phono
- Topic: Differential amplifier to feed an lowZ LCR or LR
- Replies: 15
- Views: 21662
Differential amplifier to feed an lowZ LCR or LR
Hello, during my studies concerning the usage of the differential amplifier for LR or LCR RIAA I want to present some results to you. The results based on an D3a differential amplifier which was designed totally balanced so that both tubes are in series with respect to the signal. So they are forced...