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Old 29th November 2012, 10:31 PM   #8711
Salas is online now Salas  Greece
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Its windy today but not cold, few weak showers too. I am right on the seashore.
The horns are bit lifted for avoiding interference from the midbass cabs as Lynn Olson said to do and there is 1A bias TSSA SMD and through hole amp by Sonny at Sito we run now and the Baby Huey you saw in the link. Mics checked and in room power evened out.
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Old 30th November 2012, 09:50 PM   #8712
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Hi Salas

I hope you've been doing something usefull today...
...and not spending it down the beach, in your shades & shorts.
( just jealous; even colder in Londinium today )

Guess at George's, the Baby Huey warms things up in the evenings !
( Baby Huey & SUPER-Simplistic...Yeah ! )

Cheers.

Si.
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Old 30th November 2012, 10:14 PM   #8713
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Hi George

What do you have there, on your #26 line-amp between the valves ?
Are they some kind of variable resistor ?
( am I nuts ? )

Cheers

Si.
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Old 1st December 2012, 06:04 AM   #8714
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Hi Ricardo

EUREKA !!!

Your question about 'quality' low-noise, low-value wire-wound resistors got me thinking.
As you know I am keen to use WW's to banish resistor-noise.
It seems to me the only way forward.

I got out about 200 low-value WW's I have in stock & started to measure them.
They were all 4.7 Ohms ( I liked your idea of 2 in parallel ).
These are 5% tolerance components; the batch I have, seem to be coming up at about 4.8 or 9 Ohms each.
This gives about 2.5 / 2.4 Ohms; about the 2.3 Ohms in 'the Wallace' schematic.

About 5 hours later.....Zzzzz.....
.....I thought.....DIY !!!

Why not just MAKE the resistors !!!

I think I could make a 100% accurate & matched set of source-resistors here on the kitchen-table.
Non-inductively wound on Teflon; potted in resin; and also non-magnetic.
( magnetic stuff seems to worry audiophiles; although I've never known WHY ? )

What you think Ricardo ?
I have no Simplistic at present to try them on...
...If I hand-made a set of source-resistors, would you be interested to test & try them out, if I mailed them to you ?
I also have some 70s' high-precision WW miniature instrumentation potentiometers; which I think might be very good for 2nd stage source-resistors, for accurate gain-setting.

What you think ?
Is 2.3 Ohms the optimum value for 1st stage source-resistors ?
Of course, I know the regular Simplistic is 33R & 39R.

Cheers.

Si.
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Old 1st December 2012, 06:25 AM   #8715
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IIRC, ecdesigns used mobius loops for his IV resistors over at the very long "Building the ultimate NOS DAC using TDA1541A" thread. Search for mobius loop resistor in diyaudio forums and start digging. A couple of threads pop up.

In all honesty, we are talking very, very, very minimal effects of inductances at these low values and frequencies. It might concern me if I was building a UHF circuit!
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Old 1st December 2012, 06:51 AM   #8716
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Hi kstlfido

Thanks for the 'mobius loop resistor' tip.

Yeah...I figure inductance just aint an issue as well...
...people seem to 'worry' about it though...
...so of course, I start worrying AS WELL !!!
DdaaaRrrrr !

Cheers

Si.
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Old 1st December 2012, 09:17 AM   #8717
RCruz is offline RCruz  Switzerland
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Quote:
Originally Posted by The Space Egg Corp View Post
Hi Ricardo


What you think Ricardo ?
I have no Simplistic at present to try them on...
...If I hand-made a set of source-resistors, would you be interested to test & try them out, if I mailed them to you ?
I also have some 70s' high-precision WW miniature instrumentation potentiometers; which I think might be very good for 2nd stage source-resistors, for accurate gain-setting.

What you think ?
Is 2.3 Ohms the optimum value for 1st stage source-resistors ?
Of course, I know the regular Simplistic is 33R & 39R.

Cheers.

Si.
Those precision WW pots might be good for that purpose and even for cart load setting... good

Thank you for the offer... I am using 3.9 ohm for Rs in my actual build... it is sounding so good I can not imagine what it would be with some ww Rs

In this case minimal size matters.

Let us wait for Salas report and final schematics so we can decide what values we need.
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Old 1st December 2012, 09:24 AM   #8718
RCruz is offline RCruz  Switzerland
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Ayrton-Perry winding - Wikipedia, the free encyclopedia
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Old 1st December 2012, 04:42 PM   #8719
Siberia is online now Siberia  Lithuania
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Quote:
Originally Posted by Salas View Post
Its windy today but not cold, few weak showers too. I am right on the seashore.
The horns are bit lifted for avoiding interference from the midbass cabs as Lynn Olson said to do and there is 1A bias TSSA SMD and through hole amp by Sonny at Sito we run now and the Baby Huey you saw in the link. Mics checked and in room power evened out.
And the updates? Gone with the wind?
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Old 1st December 2012, 06:06 PM   #8720
Salas is online now Salas  Greece
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Just returned. Full report bit later.
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