Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Topic started by: ToolGuyFred on February 22, 2011, 02:01:59 AM

Title: Parabee purchase opportunity - your views?
Post by: ToolGuyFred on February 22, 2011, 02:01:59 AM
I have the opportunity to purchase an un-built Parabee kit. The guy says he just wants what he paid for it. Would this be a good buy or should I keep saving for a pair of Paramounts?

(I am currently running a pair of Parasex amps with just about everything upgraded, including the iron to Magnequest. Speakers are Lowther Acousta 115s with DX3 drivers and are more than loud enough.)
Title: Re: Parabee purchase opportunity - your views?
Post by: Paul Joppa on February 22, 2011, 06:39:28 AM
On the plus side, the TFA-2004 output transformers are truly excellent and worth a large chunk of change, especially the nickel core for 300Bs.

On the minus side, the AC filament power will produce a bit of hum and the Steve Bench hum cancelling circuit helps only a little.

Harder to assess:

* You could make a DC supply for the filament, if your power line voltage is at least 120v. Design details were posted on the old Forum, back in the day...

* The voltage rating on the power supply capacitors and rectifiers has very little margin - especially if your power line voltage exceeds 120v.

* You could probably implement the Paramount soft-start shunt regulated driver, though there are no specific instructions for that adaptation. This is the biggest technical improvement we have adopted since that time.

* The old-style 6" by 10" chassis plate is a bit cramped, and has no IEC socket so the power cord is soldered directly to the circuitry. I know some folks cut a suitable hole in the wood base for that.
Title: Re: Parabee purchase opportunity - your views?
Post by: ToolGuyFred on February 28, 2011, 01:51:58 AM
OK, that gives me food for thought. Thanks, Paul.
Title: Re: Parabee purchase opportunity - your views?
Post by: anystereo on March 14, 2011, 05:11:06 AM
Hi,

I got a pair of parabees and am considering significant changes so i am interested to hear about the improved driver config.  I am in if any one wants to take on this challenge. 

anystereo