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Old 31st January 2009, 03:41 PM   #881
RCruz is offline RCruz  Switzerland
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Already populated the pcb and the sk170 connected as (G+S).

Latter will start building the psu..... TX + Hexfreds + Big cap + shunt.

Ricardo
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Old 31st January 2009, 03:42 PM   #882
Salas is offline Salas  Greece
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Iko:

Better change the orientation of ''J1'' on your RIAA PCB too. Luckily its only a matter of orientation.
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Old 31st January 2009, 03:43 PM   #883
iko is offline iko  Canada
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Still with ripple. What's puzzling is that it holds the output voltage constant, so it does regulate. There is just that ripple. Can someone who has a scope have a look at the output, on 5mV/div and about 5mS/div? Perhaps it's supposed to be that way.
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Old 31st January 2009, 03:48 PM   #884
Salas is offline Salas  Greece
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I have FFT of the phono + shunt with zero 100Hz spike. Can you try what juma made, the one with the current mirror, while you are at it?
Page #34, post 850, has the link.
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Old 31st January 2009, 03:59 PM   #885
Salas is offline Salas  Greece
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Maybe something wrong with the CCS, shows 3.4-3.6V VGS normally. And if it works, a CCS cuts ripple by definition down to a rudimentary amplitude. You can also try a LM317 CCS configured to feed your point to point test, by passing your now CCS. Just to see if it cuts ripple so to know in what part of the circuit the bug is. Also there is at least one company (MICRO ELECTRONICS) that has BC550 as CEB when normal is CBE.
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Old 31st January 2009, 07:29 PM   #886
Salas is offline Salas  Greece
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Default Nice one!

Fresh double mono shunt PSUs, point to point & Soviet caps galore.
Zero hum or buzz, dead black background. Burning in phase, will let you know more of any subjective gains at this level of construction soon. The good work is done by Michael here in Athens.

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Old 31st January 2009, 08:31 PM   #887
hoktuna is offline hoktuna  Sweden
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Hi Salas!
Today i have build post 110 ver.
4x9v recharg. is psu.
Sound is impressive for such low budget.
My friends at www.hififorum.nu advice me not to build the shunt psu.
They say zeners buzz etc.
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Old 31st January 2009, 08:42 PM   #888
RCruz is offline RCruz  Switzerland
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Default Re: Nice one!

Quote:
Originally posted by salas
Fresh double mono shunt PSUs, point to point & Soviet caps galore.
Zero hum or buzz, dead black background. Burning in phase, will let you know more of any subjective gains at this level of construction soon. The good work is done by Michael here in Athens.

Quite cool indeed

It seems the shunt does not need a lot of capacitance in the input... I was planning a 10.000u but now I doubt if it is benefitial...

Also I am using several 1/2w resistors... (Only R1 will be 2W).. is it dangerous ?

Ricardo
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Old 31st January 2009, 08:57 PM   #889
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Well done Salas!!

tx and diode ?
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Old 31st January 2009, 09:29 PM   #890
Salas is offline Salas  Greece
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Quote:
Originally posted by hoktuna
Hi Salas!
Today i have build post 110 ver.
4x9v recharg. is psu.
Sound is impressive for such low budget.
My friends at www.hififorum.nu advice me not to build the shunt psu.
They say zeners buzz etc.
Thanks for your nice comments. As for advices from people that had never made the shunt...think simple. Would someone ever decide to build a double mono with 2X100W TXs, Mlytics, HFA diodes, Silmc 2 output, copiously in P2P, after having used large batteries (PanaFC bypassed), LM317, vbe & LED shunt, just to enjoy a buzz?????
Fellas, get a grip!

''Mpravo file mou - einai omorfia auto to kukloma, sugxaristiria !

I tried a quick mock-up of your shunt (point-to-point) and it works like a charm. Input was from wall-wart with very high ripple (200 mV peak) and instead of your discrete CCS I used LM317 as CCS set for 85 mA. I loaded the shunt with 10mA to 60 mA and there was no sign of ripple or oscillation on my scope (10mV/DIV sensitivity). I used the parts that I had at hand and it worked nicely from the start.

Test with JFET BOZ (circuit with no PSR at all) was successful - no hum, no hiss, completely black background, sounds lovely, noticeably better than 7815.

Good job, thank you ! ''

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''Salas,
Tried the shunt-reg with CCS and cap bypass-loved it! Really made the RIAA sing. I added a .1uf pp to the diode bypass cap and reduced the output bypass to 100uf and .1uf pp. I think it works better with the 100uf/.1uf pp on the output.
Just for grins I hooked it up to my all tube RIAA (runs on 24V battery). WOW what a difference. If it wasn't for the fact the tubes are to noisy for my Audioquest LO MC (.23 mV), I would just use it. If I still had my Blue Point HO MC I would have never tried this RIAA. Anyone who is using this HAS TO use the shunt-reg.''

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''I got to listen to the HV shunt late last night, background is "blacker", overall sound is faster without harshness, voicing and timber has improved. I'm running one per channel in the line stage. Needless to say the Lambda No. 28 is now up for sale. Didn't think anything would beat the LCLCLC filter and the No. 28. I have tried the Allen Wright SuperReg and the Janus, both have ICs. While both are very good, I prefer the KISS approach and it does sound better. Anyone who is looking for a GREAT simple shunt regular, this IS the way to go. Again a big "thanks" to Salas.

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Please guys, enough is enough, with shunt this shunt that. Anybody who can't tackle a simple reg, revert to batteries. Seriously.
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