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 Post subject: Re: Arizona Capacitors
PostPosted: 29 Nov 2016, 08:48 
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Joined: 06 Jun 2008, 18:23
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Location: Australia
Fortunately we all have plenty of choice.

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 Post subject: Re: Arizona Capacitors
PostPosted: 29 Nov 2016, 08:58 
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mwhouston wrote:
Fortunately we all have plenty of choice.


Yes we do,
Its very interesting to try and get a feel for the mix of parts.
For me esoteric is the area that interests me.
I went out of my way to listen to Ongaku then some Old PYE equipment etc

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M. Gregg

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 Post subject: Re: Arizona Capacitors
PostPosted: 29 Nov 2016, 16:53 
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My parents first radiogram was a tube PYE with a 12" speaker in the 50's.

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 Post subject: Re: Arizona Capacitors
PostPosted: 29 Nov 2016, 18:51 
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mwhouston wrote:
My parents first radiogram was a tube PYE with a 12" speaker in the 50's.


I saw a number of vintage PYE radios when I was working in Saudi. Not bad sound, wretched build quality, worse parts quality. I restored two for my Saudi radio-collector friends, so I have hands-on experience. I am, really, surprised that any actually worked six months after seeing service.

What really got them going were US-made Zenith TransOceanics. I could more-or-less name my price, but I did not take advantage.

I also restored a Grundig owned by a past King of Bahrain for the Bahrain National Museum. Quite the privilege to do so, and they were appreciative.


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 Post subject: Re: Arizona Capacitors
PostPosted: 08 Dec 2016, 09:29 
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Just for interest,

I have done a reassessment of the brown devil resistors on the cathode load ccs.
However this isn't the main interest..

One very strange thing a particular wire in the ccs has an effect.
I have tried again solid copper, solid silver and litz three core made from enamelled silver.
The impact is an increase in clarity of ambience in the sound. (Room echo etc in the recording)
Just for interest I have shown the position of this wire on the diagram and yes its 20mm long.
Another anomaly in my reality. :D
With PTFE insulated multi strand plain copper the sound was muffled >>why I have no idea.
It can't be the resistance of the wire because of the current set resistor. (strange) but no stranger than the change in sound with resistor type.

NB the CCS circuit isn't exactly correct showing it as a source but the wire position is correct. ( it was a pic I had to hand)

The only thing I can think of is litz construction reduces inductance, but its still strange.

Regards
M. Gregg


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 Post subject: Re: Arizona Capacitors
PostPosted: 09 Dec 2016, 14:53 
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I would think that Litz Wire would increase. especially enameled silver, may reduce inductance if twisted - but would certainly increase capacitance, even if only at the 'gimmick' level.

But the first thing I notice is the proximity of the connector wire to the induction field (however slight) of the wire-wound resistor.


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 Post subject: Re: Arizona Capacitors
PostPosted: 09 Dec 2016, 17:51 
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I can confirm that increasing inductance in the R1 position of the CCS will reduce performance. For that reason wire-wound resistors should not be used here. Carbon is not a good choice because of poor temperature stability. My preference is to parallel metal-film types.

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 Post subject: Re: Arizona Capacitors
PostPosted: 11 Dec 2016, 04:36 
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Quote:
My preference is to parallel metal-film types


Just a reflection,

MF resistors are still inductive Ayrton Perry WW are non-inductive.
However both sound different in this position.
I agree carbon are not a good choice because of temperature changing the CCS setting. :)
Pulse withstand of WW is higher than MF.
Years ago Vellman made the K4000 which used multiple parallel MF I had one for a while.
A flash over in a tube caused the MF resistors to explode it was quite spectacular at the time because I was setting the bias with the case open on a new set of tubes :eek: :hot:

Regards
M. Gregg

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 Post subject: Re: Arizona Capacitors
PostPosted: 26 Apr 2017, 08:50 
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Just for interest,

This is the first trial of Amtranz.
Thinking about real sound and the ever testing of components.
I tried the AMRG Amtranz resistor in place of the AB carbon. (Input grid stopper)
Impact on sound similar to the AB resistor with increased detail. (PIC)
Good depth of sound, increased detail, good bandwidth of sound.

Its only my impression however I thought it was a good improvement.
I just used the 0.75Watt.
Obviously I have no idea what the resistor is inside the metal case but I'm always a sucker for curiosity. :D
In this same position I have tried tantalum/CC/Z foil/etc.

Regards
M. Gregg


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 Post subject: Re: Arizona Capacitors
PostPosted: 29 Apr 2017, 14:27 
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For anyone that likes the old warm sound,

YMMV..
I have tried the 0.25 Watt Allen Bradley CC resistor on the input grid stopper. (pic)
This carries no current so the idea of using 2 watt is moot.
Again using the epoxy seal idea.

So from a sound point of view:
Allen Bradley warm old school sound.
Arcol not so warm more treble.
Amtranz very open and increased treble.

Using Piher Carbon film grid to ground..
Anyway its whatever rocks your boat.. :)
At this point I'll leave it for others to try things.

Regards
M. Gregg


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