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Old 26th November 2008, 11:00 PM   #341
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nice

Salas I put a 180r tantalum resistor, on rl is very nice more anbient and so , better then dale,kiwane,riken and holco
next a 18k series fixed resistor in my shunt pot ,(before dale)
incredible there is a active riverber on it

all is so big and 3D

hot suggestion, try!
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Old 27th November 2008, 07:07 PM   #342
jonners is offline jonners  United Kingdom
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Quote:
Originally posted by salas

How is your sound by now it burned in a bit? What is your cart and TT and rest of system?

I briefly went back to the Bugle with LM4562s..... but the JFETs remove a veil from the sound, giving better instrumental definition and separation. I feel more involved with the music. (Technics SL1210/ Denon DL110 playing through Hypex UcD amps, OB speaks.)

Now I'm wondering - would a balanced version be a possibility???

John
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Old 27th November 2008, 08:17 PM   #343
Salas is offline Salas  Greece
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It might be, but double the circuitry ain't stiffening up the sonics? Balanced equipment sound always a wee bit more mechanical to me, though always silent. I have measured general self noise floor hovering around -100dB with the shunt on this one on the pic. Is it necessary you go balanced? Current system around that concept I suppose... But hey, with a balanced input we can connect the cartridge balanced as its nature is...hmmm, must think how it may be done nicely.

I auditioned the Simply Kitsch Shunt by the way, and it is marvelous as the Vbe one, but I think it may is a bit more open in the highs. Must listen more to confirm.

Click the image to open in full size.
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Old 27th November 2008, 09:26 PM   #344
jonners is offline jonners  United Kingdom
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Quote:
Originally posted by salas
Is it necessary you go balanced?

No it's not necessary, but my amps accept a balanced input and, as you say, a cartridge is by nature a balanced animal so it seems logical to think about it.....
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Old 27th November 2008, 09:39 PM   #345
Salas is offline Salas  Greece
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OK, will see. I saw that you are about to source some better caps for the RIAA. Look for Soviet stock online too. Great value.
You will listen better with your cap upgrade over the Wimas.
What exactly is your shunt? Complex one?
Lastly are you happy with the shifted resonance main amp modules? What is their sonic fingerprint? Reliability?
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Old 28th November 2008, 03:46 AM   #346
maxpou is offline maxpou  Canada
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Hi Salas,
i have a little question on your shunt PS. How do you calculate the current of shunt mosfet ( Q4 )? Thank you! Maxpou
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Old 28th November 2008, 06:04 AM   #347
Salas is offline Salas  Greece
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The current source sets the current. That current minus what the load consumes is shunted to earth by Q4. Example: In a 28V B+, buffered Salas RIAA that the 2 channels consume 40mA class A, if you set the constant current at 200mA, Q4 is going to dissipate 28V*160mA=4.48W. The excess current is good for low output impedance and headroom ease. 2 times the static load need for class A is good, 3 to 5 times is royal.
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Old 28th November 2008, 09:28 AM   #348
jonners is offline jonners  United Kingdom
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Quote:
Originally posted by salas

What exactly is your shunt? Complex one?
Lastly are you happy with the shifted resonance main amp modules? What is their sonic fingerprint? Reliability?

The shunt is basically the one below, except that there's a diode in series with the led and a 2k resistor in series with the pot.
It may look complex at first glance but the schematic shows two rails, with two TL431s in each for use at higher voltage. So CON10 can in effect be jumpered across, eliminating the lower 431.

I don't know what you mean by 'shifted resonance'. Reliability is fine. I'm not aware of a 'sonic fingerprint' - I prefer them to what I had before, which was a SE triode/horn set-up.
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File Type: jpg shunt2.jpg (73.1 KB, 929 views)
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Old 28th November 2008, 10:59 AM   #349
Salas is offline Salas  Greece
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Bypass R6, R8 with 100uF low ESR capacitors, its better. Maybe audible too. Your amplifier's working principle is some form of phase shifting to control a resonance I roughly remember from a PA magazine. Hence its strong efficiency. So its neutral sounding in your experience. Like a gutsy T-Amp, or even better? I am interested to know a good solution for many efficient Watt in a good price. Many guys here talk ICE. Heard any?
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Old 28th November 2008, 11:41 AM   #350
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http://www.audiodesignguide.com/ClassD/classD.html

here some info but for tripath he use a very cheap unit....
layout are very important in class d , my board use a pcb with 4 layers.....

for fist look at class d , 41hz.com are good place ,kit ,smd or standar ,all power ,single B+ or +/- , panasonic component ,good price and support

I have tre amp , there is a lot difference ,but you pay what you hear

Hope helps
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