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Paramour w/ TF-204 MagnaQuest output transformer

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mrclassicman:
There is a long story involved with this but the short version is this. I am looking for the schematic that this conversion/upgrade was. It removed the parafeed choke to the power supply and the TF 204 was then put in for the output transformer. Any information on this modification would be greatly appreciated!

Paul Birkeland:
I suspect whether the cathode bias resistor should be changed will depend on whether you have the V1 power transformer from Hammond or the V2 power transformer from our current manufacturer (which would be labeled PT-2).  I could certainly imagine running a little more current at slightly lower operating voltage on the PT-2, but I'm not so sure I would do that on the Hammond power transformers.

Paul Joppa:
From my notes, dated 2003:

"Airgapped Paramour
Replace the output plate choke and parafeed transformer with a TFA-204. Makes a sort of junior WE Model 91 with similar operating point. About 4.5 watts output. This is not a parafeed amp anymore, but a sweet combination in the conventional mode."

Today, I would not say that about the WE 91, but I would still note that the operating point (300v/50mA/4K ohms) is typical of many 300B amps. My own preference is for a lower power/lower distortion operating point (250v/60mA/2.5K ohms, or 275v/55mA/3K ohms, or 300v/50mA/4K ohms). The difference is small but audible, based on listening to the MonAmour at the two different currents it offers.

As PB indicated, the original Paramour used the Hammond power transformer, which is rated 55mA DC maximum. Allowing 5mA for the driver and its C4S plate load leaves only 50mA for the 2A3. I have never in the past recommended increasing the current above the rating, since I did not do the detailed design myself, and I do not know the actual winding schedule.

This was an issue with the earliest parafeed upgrades (BCP-15/BH-5) - the BH-5 was similar to a junior TFA-2004 at 3K ohms, which I somewhat reluctantly accepted when used with the 40-henry BCP-15. But the TFA-204 is only 10 henries. (We eventually commissioned a custom 4K upgrade transformer from another winder to use with the BCP-15.)

I hope that adds some context to the issue.

mrclassicman:
Thanks you Paul & Paul. The amp is using 300B mesh plates and has a 76 as the driver. The power supply has a 310-0-310 v secondary with the appropriate 2.5 v and 6.3 v filament windings. Could the origins of this amp actually have been a ParaBee? Me and my more adventurist side made an attempt to convert these amps to use a 45. For one reason or another the outcome was way less than I had envisioned and I shelved the amps. So talking out loud here I think my best plan would be to isolate the tubes and measure my B+. Then I should have a better Idea of what to do to find the sweet spot. We built so many B-H kits and this amp is the only one without a manual. I also have to admit that it has been a very long time since I have been under the hood so to speak and need to work up some confidence ! A little like Bilbo leaving the Shire! lol Again thank you both for the tips!!!

Terry (mrclassicman) 

Paul Birkeland:
How is a Paramour using 300B mesh plates?

What power transformer is in these amps?  Photos?

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