Last Of The Paramour (one) Mods

Grainger49 · 16544

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Offline VoltSecond

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Reply #30 on: March 24, 2014, 07:05:40 PM
Have you tried the cathode mod? 

http://www.siteswithstyle.com/Voltsecond/Paramour_cathode_mod/Paramour_cathode_mod.html

With the speaker ground attached to Single Point Ground (SPG), 60V on varnished magnet wire inside a transformer is fine.

-Corona doesn't start until ~205V peak ( JPL D-8208 ) at 20kHz at room pressure. However, I wouldn't trust 60V on magnet wire used for point to point wiring because of the higher amount of abrasion on the enamel from handling.
-Should Murphy cause a short, the wire to SPG keeps anyone from being shocked. Output rtn to SPG is even a point where I would use Ying-Yang diodes if I needed to break a ground loop.

You may want to also play with a power on delay.
http://www.siteswithstyle.com/Voltsecond/B+_Paramour_delay/Paramour_delay.html

Using a  capacitive multiplier on the cathode, sounds like an OUCH project that could be fun!




Offline Grainger49

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Reply #31 on: March 25, 2014, 03:57:22 AM
V-S, Yes, I returned the OPT to the top of the cathode resistor/capacitor when I upgraded to MQ Iron. 

Does this make a better Cathode bypass cap irrelevant?



Offline VoltSecond

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Reply #32 on: March 25, 2014, 10:07:13 PM

Does this make a better Cathode bypass cap irrelevant?


"Irrelevant" is too strong of a word.  If it sounds better, do it. 

My concerns is that a physically large cathode bypass cap can cause coupling to adjacent parts that could be hard to fix. 



Offline Grainger49

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Reply #33 on: March 25, 2014, 10:49:43 PM
Check the picture in reply #20 on the second page.  I think those would have to sit outboard to the base.  There is no room under the hood to put much of anything.

There are no children to worry about, you know my age.



Offline Paul Joppa

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Reply #34 on: March 26, 2014, 07:07:47 AM
Because of the finite inductance of the plate choke, you do get deeper bass with the bypass cap in place. It may make more difference in theory than in practice (most of the effect is below 40Hz) so try it and see, as VS says!

Paul Joppa


Offline VoltSecond

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Reply #35 on: March 27, 2014, 06:29:04 AM
The cathode cap also helps flatten the frequency response in the presence of parasitic capacitance (Transformer primary to Secondary)

Externally mounted  with twisted wires from the cap to inside should solve any coupling problems.

Insulate the leads on that external cap, I know adults that can't resist touching every thing or who can't point at something (instead of touching it) and say "What's that do?"



Offline Grainger49

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Reply #36 on: March 27, 2014, 06:53:11 AM
    .  .  .    Insulate the leads on that external cap, I know adults that can't resist touching every thing or who can't point at something (instead of touching it) and say "What's that do?"

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi244.photobucket.com%2Falbums%2Fgg7%2FGrainger49%2FSmiles%2FROLF.gif&hash=d8c25de5059c9863b539eef0d5a5f9c5fb975e51)  .  .  .    (https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi244.photobucket.com%2Falbums%2Fgg7%2FGrainger49%2FSmiles%2FROLF.gif&hash=d8c25de5059c9863b539eef0d5a5f9c5fb975e51)  .  .  .    (https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi244.photobucket.com%2Falbums%2Fgg7%2FGrainger49%2FSmiles%2FROLF.gif&hash=d8c25de5059c9863b539eef0d5a5f9c5fb975e51)  .  .  .   

I was fine till the last sentence.  Then I thought of way, way too many people I know.  Most are afraid of touching my stereo, but then....



Offline JamieMcC

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Reply #37 on: May 16, 2014, 08:44:36 AM
Grainger how are those Icar 200uf's working out?

Shoot for the moon if you miss you will still be amongst the stars!


Offline Grainger49

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Reply #38 on: May 16, 2014, 12:46:00 PM
They are still sitting on my shelf.  I intend to wire them in with long wires coming out the back of the amps.  I just have been working in the yard so much I spend all audio time listening rather than tinkering.

I will report back.