Mpp

[Joachim Gerhard]

i forgot the inductors in the equivalent circuit. i h..... inductors really they are a pain in the but

[anatech]

Hi Joachim,
My scanner just stopped working properly. I'll see what I can do if there are electronic copies around still.

The buffers I tend to use are very simple, basic. However, there are some members here that have done a wonderful job with their buffer designs. Let me see if I can find their names for you. PMA comes to mind for one.

Best, Chris

[Joachim Gerhard]

for "emergency" cases i simply use "Paint" from the windows toolbox to draw circuits but anyhow thanks for the eford

[Salas]

Originally Posted by Joachim Gerhard

the lumped parameters...

Since there is discussion about minimal frequency response deviations for different enough MC loading, hence contradiction between the amplitude domain and the too commonly reported substantial subjective difference perceived, almost a traditional ''fact'' between TT owners, I was leaning towards the idea that it can be possibly researched as a matter of correct termination of a complex conduit of interacting parameters standing between the cartridge output pins with its generator characteristics, and chosen load. I.e. cabling, phono input charactristics. So, maybe proper loading could be about terminating the transmission well, avoiding reflections. Is that too wild a guess in your experience?

[Joachim Gerhard]

well, why not. i have seen newest research on transmission lines and the conclusion was that reflexions ARE relevant in audio frequencies i look if can find the literature
what amases me is that nobody is talking about terminating an mc cartridge with a resistor
AND a capacitor to compensate the substantial rise in the treble that they all have to a certain degree with circuits like the MPP i had success with a 10nF in parallel

[Salas]

I have used a trap circuit in the past so to catch tip mass on vinyl resonance in the last octave. While the bode flattened out, mid to upper range dynamics suffered. Did you tame the last octave fully with 10nF? Here is what I have with DL103R and about 450pF (cable and one fet input Miller), res 1/48 oct. Telarc OmniDisc pink noise L+R band 13/side 2. 150R load resistor. Look to that Lyra test too. Werner has some FFTs and some interesting opinion above the first graph he shows. I think you mentioned having familiarity with Lyra models.

[Joachim Gerhard]

the combination of the 5.5 ohm 0.0005mH titan and 10nF with the 25 Ohm input impedance of the MPP is only 3dB down at 3.5 Meg Hz my simulation shows nevertheless the sound got more "natural" without any spittyness to be honest i just listened to various combinations and it sounds crazy good for my taste a lot of dynamic slamm and big-focussed soundstage with tremendoes height and projection people are quite shocked that hear the system because it is so emotional
maybe i also have to measure inductance of my wire but it should not be much

[Salas]

I thought you meant response manipulation when I read ''to compensate the substantial rise''. Sorry. So you don't talk about ironing out its 10-20kHz on its bode plot on test disc FFT, but about softening the subjectively perceived HF edginess? Hmm, hints to the time domain. Impulse response.

[Joachim Gerhard]

yes exactly we should do some simulation with step response, etc and waterfall

[Joachim Gerhard]

and of cause measurements did you know for example that in the inner groove of a record the treble drops a lot ? that means that when you record the frequency response of the cartridge in the outer, middle and inner groove you get different results
the treble flattens out in the direction of the inner groove so a rising response can compensate for that effect