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Old 26th December 2010, 11:55 AM   #5521
Salas is offline Salas  Greece
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Quote:
Originally Posted by merlin el mago View Post
Using the calc. for an input impedance of 10K 1uF cutoff/corner frecuency 15.92Hz time constant 9.997us & 1.5uF cutoff/corner frecuency 10.61Hz time constant 15.000us, are my calculations right? what about the phase it's right?
That calc is right by all means. About phase, we are not dealing with rumble free USB servers here to go flat to DC without nasties, so the general idea is to keep the corner frequency as low as no gross over excursions occur with a given TT set up and speakers, helping to keep the phase as linear in the audio band's low region as it can be. 2nd or third order filtering I would not prefer though, unless there is strong need.
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Old 26th December 2010, 12:21 PM   #5522
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Originally Posted by RCruz View Post
Please explain what do you mean by turning the phase early.

I know that we are wasting precious power just moving the woofer without producing any sounds but I know little about phase issues.
So using smaller output caps turns phase earlier.... there must be a sweet point if I get the general idea right ?
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Old 26th December 2010, 12:55 PM   #5523
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The 'sweet spot' in any system is to battle best what does the most damage first IMHO. If there is problem with rumble, say because the arm resonance is low and average disc is slightly warped, you fix that first by filtering if not to change cart. If you have closed box stiff suspension bass system and big amp, maybe not, depends. The recommended 2.2uF output cap is to make sure that the phono can relay bass well even when hooked up on an LSPD DCB1 or alike low impedance preamps. If you are sure a build will never be interfaced under 20K line input, you can use 1uF for instance. If there is no problem with excursions in given systems (as it seems the norm to be from all those applications reported here) prefer the 2.2uF. With 6u8, 47k, and underdamped reflex speakers, it surely went looking for trouble.
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Old 26th December 2010, 01:40 PM   #5524
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Chinese on Epay!!!!! I wanted the French but they were BIG bucks to get them here and I don't read/or speak Fench very well so their web site was a bit difficult. Before I committed to the R-core I wanted to try the cheaper ones first.
In reality they are right on spec for the size, just smaller than than the ones you are using. They are 2x18v secondaries and 30VA. When driving two channels it did fine but just was a little short of the voltage I wanted. With a single channel they were spot on.

I don't plan on putting it in a single box anymore. None the less I will run shielded mains and secondary wires. I put ferrite rings on the mains right at the trany as well. You can see them in the first picture of post 5509.
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Old 26th December 2010, 01:47 PM   #5525
Salas is offline Salas  Greece
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OK. Only thing remaining to see is how 1.2R will translate in your system then. And then you can visit back the Teac to re arrange the rows thing.
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Old 26th December 2010, 01:57 PM   #5526
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I look forward to visiting back. I will also demo it at TTweights with Larry.
IMHO, with the removal of the Carbon Comp Resistor, It allready adressed the row issue;-) As I said in the earlier post, it is like being on stage with certain recordings.
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Old 26th December 2010, 02:09 PM   #5527
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Not bad for your $25 MM 5mV cart and junk TT. Well done.
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Old 26th December 2010, 04:07 PM   #5528
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Originally Posted by SGregory View Post
I like this time of year as I get a little down time from work and can focus. Starting to complete a few of the project lists I have for the simplistic.
Attached are photo's of the new power supply and V1.2R for my simplistic. After a brief break to play with some of my kids gifts, I am going to breadboard it and fire it up.
Hi Sgregory

Really like your psu.

Are the Nichicon 3300u after the nippon caps ?

Would you post a schematic ? I am majoring in psu voicing and this info is very important.

What is the values of the Nippon caps ?

Ricardo
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Old 26th December 2010, 04:43 PM   #5529
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I will post a schematic shortly. Right now I am majoring in trouble shooting as I can't seem to get the V1.2R to light up properly. It seems that Q5 is full on dropping the rail to 1 volt.

The caps are slightly mixed. It is a R1 C1 L1 C2 L2 C3 filter.

R1 = 2R2
C1 = Nippon 6800uF + 3300 Nichicon
L1 = 1.5mH Hash Choke (ferrite Core)
C2 = 1000pF Mica
L2 = 1.5 mH Hash Choke (ferrite Core)
C3 = Nippon 12000uF + 2x 3300uF Nichicon.

I will replace L2 at some point with an iron core of higher value. I left room on the board for that. I do like the hash filter that Eli Dutman has been pushing.

I am considering to make a seperate rectifier board that RC bypasses the diodes.
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Old 26th December 2010, 05:32 PM   #5530
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Trouble Shooting Complete. I have no idea how the error checking routine in eagle allowed me to have a trace error, but it did. Once I corrected it in the software it wouldn't let me redo it? Go figure. My error. Anyhow after a little cosmetic surgery on the board, I now have two V1.2R's up and ready for install.
They hold voltage very well and have no hint of oscilation under resistive simulated load.

Now to install them....
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