Iron upgrade for a Paramour II running 45's

Natural Sound · 4897

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Offline Natural Sound

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on: January 06, 2013, 06:41:32 AM
I have an Orca system with subs on the way next month. In celebration of that I would like to spruce up my Paramour II's a little. The first thing that you should know is that the amps have the resistor changes and I'm running 45's. I REALLY like the sound of the 45's over the 2A3's so it is going to stay wired this way. Less relevant (if at all) is that I have a FP III up front driving them. So my question is this. Should I buy a set of MagneQuest BH-5/BH-6 or are there better options available?

Thanks in advance,
Tom



Offline braubeat

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Reply #1 on: January 06, 2013, 08:41:22 AM
Hard to beat the BH-5 outputs. Especially the nickel. For the ultimate get the Dowdy plate chokes. This may require a larger parafeed cap though.
Also the Dowdy chokes are larger.

Michael



Offline saildoctor

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Reply #2 on: January 06, 2013, 09:44:30 AM
I demoed a pair of orcas/subs at Blumenstein HQ about a week ago with my 45 paramounts and FP3. A quickie was tried a few times in place of the FP3 and it was very clear to me how the FP3 had more drive to the 45s and accuracy. I'm totally not dissing the quickie- it sounded good and better than most preamps I have heard.  I can't comment on MQ because I have not yet heard a system using them. If you look up forum posts both here and on the forum page linked on the magnequest.us site there are plenty of rave reviews.

Kerry Sherwin

45 Paramounts, 6SN7 Extended FPIII, OC3 regulated Seduction
Blumenstein Orca Deluxe / 2x Orca Subs
VPI Classic / ADC CD-100x


Offline tsingle999

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Reply #3 on: January 06, 2013, 04:01:19 PM
I think the mq iron is a big upgrade in any flavor. I love nickel in my sr45. I am running the tfa2004 m4/cobalt in them right now and love it as much or more than the nickel. And there happens to be a pair of these transformers on ebay right now but at an exorbitant price. I would also highly recommend an mq grid choke. This gave the amp a lot more bass weight/slam. So much so i am contemplating removing my sub.

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Offline 2wo

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Reply #4 on: January 06, 2013, 07:02:57 PM
I switched in a set of nickel EXO-45s, into my SR-45. I like them a lot...John 

John Scanlon


Offline Grainger49

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Reply #5 on: January 07, 2013, 01:16:45 AM
There are four things to know:

MQ iron is well built and fine sounding
Nickel
Nickel
Nickel

I wasn't aware of the impact of the nickel when I bought upgrade iron for my Paramours.  But then I heard Paully's 45 Paramount with all nickel outputs.  It was a dramatic change in detail, delicacy and imaging.



Offline Natural Sound

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Reply #6 on: January 08, 2013, 08:33:45 AM
There are four things to know:

MQ iron is well built and fine sounding
Nickel
Nickel
Nickel

I wasn't aware of the impact of the nickel when I bought upgrade iron for my Paramours.  But then I heard Paully's 45 Paramount with all nickel outputs.  It was a dramatic change in detail, delicacy and imaging.

Yeah, I was planning on going all out with nickel. Its going to cost $600 but from what I've been reading its worth every penny.



Offline awsjr

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Reply #7 on: February 15, 2013, 11:43:22 PM
I switched in a set of nickel EXO-45s, into my SR-45. I like them a lot...John
hey John... when you put the EXO-45 in did you change any cap or resistor values for the 5K ohm vs 3K for the BH-5 ?
thanks

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Offline 2wo

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Reply #8 on: February 16, 2013, 04:26:52 AM
No I left the cathode resistor at 1.3K. Later on I may measure my plate voltage and current...John   
« Last Edit: February 16, 2013, 10:21:39 AM by 2wo »

John Scanlon


Offline 2wo

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Reply #9 on: February 16, 2013, 10:31:22 AM
OK at 250V on the plate, the 45 is running about 36ma, which is about the upper limit. I don't have my notes handy as to the current with the BH-5, but I don't think I was pushing that hard. I think I am going to raise the value of the cathode resistor...John   

John Scanlon


Offline awsjr

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Reply #10 on: February 16, 2013, 11:28:15 PM
hi John... thanks... I saw this post from Paul...

"My original notes show an optimal 28mA current with a 5K load; that's an 1800 ohm cathode resistor. (Stock was 36mA,  1300 ohm cathode resistor.) This would however increase the shunt regulator dissipation to 7 watts, and the 6CM7 is rated 6 watts maximum. Ideally I would re-design around the 6DN7, but in practice just reduce the C4S current  to 51mA (R1 16.5 ohms) to get the dissipation right at 6 watts.

The reduced plate current from this change will improve the deep-bass regulator current margin; however keeping a higher current will reduce the distortion. Both are very small effects, and it's not obvious which is more important - probably depends on your personal preferences and music. So in the end I'd suggest you split the difference and use a 1500 ohm cathode resistor, which conveniently requires no other changes."

I had a couple mills 1.5K 5W so I changed resistor and OPT to the exo-45... the sound is great... maybe a bit less gain but not an issue for me.... thanks again...
Al

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