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Old 9th May 2009, 03:25 PM   #1711
vgeorge is online now vgeorge  Greece
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Well, I have to get a bigger box to do that!
But I am thinking about that. Also to place the regs very close to the circuit. I can not do that with my setup now.
If marginally better, I am going to do it, but not soon.
It' s getting warmer here!
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Old 9th May 2009, 03:35 PM   #1712
Salas is offline Salas  Greece
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I guess that I will have to visit you at a point to hear my RIAA in ultra version. How long a return day trip from Athens to island of Poros can take in time? I visited Poros as a kid. Has it changed a lot from late 70s?
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Old 9th May 2009, 04:03 PM   #1713
vgeorge is online now vgeorge  Greece
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With a hydrofoil it is one hour from Piraeus, 2,5 hours with the normal boats. From the 70s many things have changed, but not as bad as in other places. You are welcome any time! You can PM if you want.
As far as ultra, I do not know!
I try to do my best, but I am getting slow now, as the summer is approaching.
Hope to finish everything when it gets cold again!
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Old 9th May 2009, 04:11 PM   #1714
Salas is offline Salas  Greece
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OK, I may visit. You got nice sensitive big speakers and F5, yes? I may bring a 12B4 line pre over if I do come sometime.
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Old 9th May 2009, 04:22 PM   #1715
vgeorge is online now vgeorge  Greece
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I have made some basszilla speakers. F5 is driving the top. Woofers are Lambda TD15X driven either by DNA-1 or some gainclones I have.
I use a passive pre for the time. I will built your 12b4a after the summer.
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Old 9th May 2009, 04:26 PM   #1716
Salas is offline Salas  Greece
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Nice stuff, it would be cool to listen to it before you start then, so to decide the version better. I will see if I can make Mikvous to come along. Nice TT BTW. I have designed a multi triode front end integrated gainclone that Michael uses for his Paros house. Very well dialed in with snubbers, maidas, etc. Sounds much better than the average GC.
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Old 9th May 2009, 05:26 PM   #1717
vgeorge is online now vgeorge  Greece
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Thanks Salas.
GC are PD with BG capacitors. Nice, but I like F5 better.
Also F5 lower gain helps to match sensitivities. I can' t say I have finish tuning everything, but it's ok now. It's been busy for me latelly.
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Old 9th May 2009, 06:30 PM   #1718
RCruz is offline RCruz  Switzerland
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Quote:
Originally posted by Salas
If you resort to shielding, make sure that you will not close the magnetic circuit from chassis to central bolt of the toroid, you can even kill it. A full peripheral copper band is OK, with connection to chassis GND. Toroids mainly offend with stronger field around the secondary cable exits.
Hi Salas

What do you mean by closing the magnetic circuit and killing the TX ?

Ricardo

PS:
After 24 hours burning, low end bass appeared again but with much better nuances, grip and detail (particularly in the attack / decay area) Jensens are def better than the Nichicon for this aplication.
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Old 9th May 2009, 08:15 PM   #1719
RCruz is offline RCruz  Switzerland
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Now I am sure the hum is due to a field. breaking the AC switch on the riaa, imediately kills all the hum.

The shunt + riaa keeps working for 2 seconds just using the caps voltage and it is dead silent.

Can the noise be originated by the diodes ?!
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Old 9th May 2009, 08:26 PM   #1720
Salas is offline Salas  Greece
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If a toroid is closed with a metal or wire from chassis that sits on to its axial bolt, then, this is called shorted turn. It can even melt enough.

I would orient the toroid differently to hear if the buzz changes or goes away. Your experiment with the switch points firstly to the transformer field.
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