Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Paramount => Topic started by: Jim R. on October 21, 2013, 10:59:25 AM

Title: Plate choke upgrade for 300b paramount?
Post by: Jim R. on October 21, 2013, 10:59:25 AM

I'm thinking about experimenting with the 300b version of the paramounts but problem is that I only have plate chokes that will work with 2a3s or 45s -- nothing with enough current capability for a 300b (btw, what is the operating point of the 300b in the paramount?0) so I've been looking for something that will work in this configuration.

Looking at the MQ offerings the only one that looks like it may work is the bac-80 which would be an upgrade in terms of inductance, but I have no idea how big they are or how much they cost -- I'm guessing not cheap. There is the bh7 but those are not available a la carte.

Any suggestions (or offers to sell some bac-80s to me :-) ) appreciated.

Thanks,

Jim

Title: Re: Plate choke upgrade for 300b paramount?
Post by: xcortes on October 21, 2013, 11:30:07 AM

Exo 03

Title: Re: Plate choke upgrade for 300b paramount?
Post by: johnsonad on October 21, 2013, 01:21:32 PM

Or lower your operating point and use the 60H Dowdy

Title: Re: Plate choke upgrade for 300b paramount?
Post by: Paul Joppa on October 21, 2013, 01:50:04 PM

The Paramount draws 70mA through the 300B. The EXO-003 (a.k.a. EXO-03) is only rated 60mA, but we used it in the old ParaBee for years, with great success. The rating is pretty conservative, both current and inductance (more like 48 henries, not the published 40 henries).

As for BAC-80 size - you do know that BAC is short for Big-Ass Choke, right? - it probably weighs 10-12 pounds, around 4" square and 4.5" tall.

Title: Re: Plate choke upgrade for 300b paramount?
Post by: 2wo on October 21, 2013, 07:07:17 PM

I would try the Dowdy. I don't know the DC resistance but I bet its higher than the stock, which will lower the voltage and current a bit...John 

Title: Re: Plate choke upgrade for 300b paramount?
Post by: johnsonad on October 22, 2013, 01:34:59 AM

Or contact Eileen and pick up a pair of PC-2's. If you don't like the 300B you can use them in the PS.

Title: Re: Plate choke upgrade for 300b paramount?
Post by: Jim R. on October 25, 2013, 07:18:47 AM

Guys,

Sorry, I neverr got any notice of replies to this thread.

Anyway, I have a pair of BH7s on order. Paul, that's wwhat I figured BAS stood for :-) Should I take a guess at TFA?

I have settled on one amp for each of the classic tube types:

sr-45, Paramour II w/SS board for 2a3, and paramount 1.1 for 300b.

Most of these will have to wait until the Spring and between now and then I'll be experimenting with different configurations to the sr-45 to get it perfectly coiced to my new speaks -- If they everr arrive.

Thanks again,

Jim