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| Romy the Cat's
personal site dedicated to advanced audio and evolved music reproduction
techniques
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Looks like I've found a solution but I don't understand it:
1) Lifting the phono ground from the PP with a cheater plug and connecting the phono case to the SAME PP ground with a separate cable not only does not bri...
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Adrian, I'm not yet convinced the PP is to blame. Also PP Richard is helping a lot to understand the issue (thank you Richard!). Now this f@#$%@%$ 100Hz noise stepped on my male ego - want ot understand where it comes from.
I qu...
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Paul, ground is ground, neutral is neutral. Where they are connected I have no idea, for sure not in my equipment. The case of my phono is connected to the safety ground not to the neutral. The reasons why I'm onto this and has not listened to th...
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- The noise has two phases - large noise and steady state noise. Large one ocures when the PP is switched offline and then switched on. This noise depends on the input (SUT or MM) and the orientation Signal enclosure vs power supply
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My exorcisms to eliminate 100Hz PP induced noise in the EndOfLife phono gave no results so far.
- I took GND from the PP socket and tried connecting it to various GND points I could access (the signal GND plane, input sockets GN...
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The GND noise enters somewhere past the input RCA's. And this GND noise is not the PP RFI/EMF.
RFI/EMF of PP looks like this:
This one is caught by my Decca cart (phono GND lift...
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Thank you very much for all the help/advise. I'm still to investigate the problem. The working hypothesis is that my phono has some GND routing problem. Will examine it with the scope and shortening method to see if that's the case.
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Anthony, I didn't realize the potential of your remark, thank you. The chassis has been tied to the signal GND already at the birth as otherwise the phono would develop noise even off the wall. I have to go throroughly with a scope to see where the n...
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...in my case the problem seems to be a GND loop *inside* my End of Life phono. Thanks to the continous help of PP Richard, I started to suspect the terrible noise I'm getting actually may be the charging voltage of the PP el caps (indeed it is 100Hz...
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From my short encounter so far, when it works, it works great. When it does not, it's a hell. I'm waiting for reply from PP, perhaps I'm overlooking something (not cables and not ground loops). ...
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Steverino, I've asked same question to PurePower who kindly contacted me: If a moving around battery could have caused the issue? Waiting for the answer. My quick visual inspection did not show any obvious irregularities though.
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I followed exactly Romy's advice. I disconnected EVERYTHING from PP1500 apart from the Endoflife phono. The phono output was monitored via RTA software on a battery powered laptop. There was only phono connected to the PP. [I don't have GND loop...
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Romy, do you power your End of Life phono from the PP??
I have the same phono, with choke input PS for both the heating and the HV.
1) If I plug the phono just to the wall, the noise just normal wi...
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Adrian, was your PP1500 noise present ONLY in the phono section or across the sources/components? My tuner and digital work like a wonder, only phono picks the noise. I read your earlier description and my noise is not high pitched but rather upper b...
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Thank you for the feedback guys!
- Bill and drdna below is the actual physical situation. The distance to the Decca is 110cm, to Phono 140cm (the noise is present even if I switch to a shorted MM input and the PP is on batteries...
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I finally got a PP unit. It is 1500W model as this is enough for now. It is the actual Golden version (Plus not available anymore) but the PP factory claims it's identical electrically just in a new aluminium case and some extras added. I managed...
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...the problem starts outside North America - eventual shipping a faulty unit there and back, paying each time the cargo (20-40kg), customs, taxes, can be quite costly.
Romy, reading the beginning of the thread there seemed to b...
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...in learning what is the reliability of the current production PurePower units. I'm considering investing in PP+1500 to power:
- A clone of Romy's phono (choke input filters)
- Headphone amp (180W...
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[quote user="N-set"]
Other changes to come:
- looking for Amperex 0A2 with mesh plates
- will rewire MM input in silver with silver WBT RCA's - it now welcomes my top cart, Decca London Reference with silver AQ Leopard ph...
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Romy, that's sort of a feedback I was hoping for, thanks. Ok, I see the point, with the feedback and R3 resistors. The last loads the loop. I have now there 1W Dale RN65D, guess Z-foils with their 0.25W dissipation won't work.
A...
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I'm wondering if Romy experimented with the feedback resistor quality. His ingenious contribution to the design was to use the purest caps possible as in the feedback loop every imperfection gets amplified. So the next logical step after caps wou...
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[quote user="N-set"]
- considering another red tip 12AX7 for the output but given the change was not big at the input it's more of an itch...a costly one at $275
[/quote]After a second thought actually the output tube is obviously in the feedback...
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Alex, as I wrote I use Z-foils at the primaries of mu SUT's. I'm not sure if colder is the world *I* would use. I'm after immediacy and transparency and this is what they gave me. Also widening tonal discrimination, hearable esp with solo piano. ...
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I think industrial grade Arcotronics KP172 (from RS components ?), film and foil. I use them also as output coupling caps (2x0,47u)
Other changes I've made, not commented in my posts here:
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I was digging in my archives, trying to find what exactly input cap I've put and how. Didn't find that. IIRC I've put two, in V configuration, one output of the HV bridge to mass, another exit of the HT choke to mass. Found some traces of voltag...
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Alex, why do you think you need them? I've never experimented with snubbers at the SiC's directly. I only put two input caps right after the bridge and a dropdown resistor which I use before the input choke. IIRC the value is 10nF/1500V. This rel...
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Just got it (the last copy on German Amazon) and after an initial going through it have same impressions - more of an encyclopedia than a practical guide. Still ind it v valuable, especially in combination with old classics like Leo Beranek and ...
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Thanks for your responses guys. Would be great to learn some practical procedures how to setup a tuner/antenna combo properly.
Any ideas where to find some sort of a tutorial? For example I'd love to learn what are the tuning scope images in t...
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Hi guys,
Thank you for the comments. I'm a complete newbie to RF, long learning curve ahead.
1) Antenna - My guiding was Romy's finding (backed by Dima) that this tuner is easily overdriven with too strong an ant...
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Just incorporated this wonder into my system! haven't heard a live orchestra broadcast yet but even voices from the studio have something special, some magic aura.
This is how I use it:
- cleaned (down to dismant...
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