A one-of-a-kind Bella Extreme 3205 power amp

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Bill Baker

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A one-of-a-kind Bella Extreme 3205 power amp
« on: 25 Jul 2008, 09:18 pm »
 After so many years of building the 3205 amplifiers, I have gathered many extra parts so I figured I would build a custom amplifier for personal use. I had some extra wood laying around so I figured why not make a wood chassis.

 Below are a few pictures of a custom 3205 power amp that I have been working on during my down time and when I come in the evenings to relax. It was started a couple years ago, when we were still in our first building, and has been sitting in a corner. (I don't get much down time). The amp is being built for fun (personal use) and to use up some extra 'stuff' I had around. I will use it in the showroom but will not make these for resale.

 The pictures are only of a dry fit of parts. The chassis is made of Cherry sides and Black Walnut top and still needs several more sessions of sanding and finishing. Maybe I will be able to finish it by the end of this year :duh:

 This amp uses no curcuit boards except for the power supply. The main circuit is all hardwired.






rpf

Re: A one-of-a-kind Bella Extreme 3205 power amp
« Reply #1 on: 25 Jul 2008, 09:23 pm »
Beautiful and  8)

JoshK

Re: A one-of-a-kind Bella Extreme 3205 power amp
« Reply #2 on: 26 Jul 2008, 12:29 am »
That chassis is gorgeous!  You should be very proud.

I might be concerned about the heat damaging the wood via drying and splitting.  You might want to consider something like the aluminum dressing plates that go around tube socket holes shown here...

http://www.vt4c.com/shop/program/main.php?cat_id=1021&group_id=2&hit_cat=

I am just thinking they may reflect some of the radiated heat from the output tubes and protect the wood plate.

Bill Baker

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Re: A one-of-a-kind Bella Extreme 3205 power amp
« Reply #3 on: 26 Jul 2008, 12:44 am »
Hi Josh,
 First, thanks for the comments.
 Very interesting timing you have on bringing the aluminum plates up as these (similar anyway) are what I am using on the Musica Bella Musicale mono bloc amplifiers as the 'chimney effect' will also help draw air through the chassis providing a constant air flow.

 As far as this 3205 amplifier goes, heat has never been an issue with wooden chassis in the past. I have several vintage console amplifiers, which I still use regularly, where the tubes, including the rectifier, are within a quarter inch from the wood with no heat problems. The tubes in this 3205 should not effect the wood with them being on top of the unit in free space. I have a few other custom amps here that I have built over the years with no heat issues as well.

 By the way, here is an early rear end view of the chassis. The hole next to the blue Power Con connector is where the power switch will be located.


JoshK

Re: A one-of-a-kind Bella Extreme 3205 power amp
« Reply #4 on: 26 Jul 2008, 01:36 am »
As Borat would say, "Vair-ry Niiiice"

Big Red Machine

Re: A one-of-a-kind Bella Extreme 3205 power amp
« Reply #5 on: 26 Jul 2008, 01:39 am »
I noticed the photos on the website show a knob on the front.  And this one does not.  I am thinking about trying bi-amping with a tube amp on top while I use the Sunfire amp.  Are there both integrateds and straight amp versions of the 3205 available?

Bill Baker

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Re: A one-of-a-kind Bella Extreme 3205 power amp
« Reply #6 on: 26 Jul 2008, 01:44 am »
Hi BRM,

 Yes, the 3205 is available as a straight power amp, full integrated or with a single volume control knob to help dial in the amp in a bi-amp setup or for those with only one source.
 This amp above was built as a straight power amp to be used in conjunction with our new Musicale phono/preamplifier.

 Here is one of the 3205 amplifiers used in our facility. This one has only one input and a volume control


Big Red Machine

Re: A one-of-a-kind Bella Extreme 3205 power amp
« Reply #7 on: 26 Jul 2008, 01:53 am »
Ooh, that single vol control might be the ticket, although I suspect I may need it more on the Sunfire than here.  But then again I have never bi-amped before so what do I know.  I didn't want to spend more than a kilo though to do this. :scratch:

Big Red Machine

Re: A one-of-a-kind Bella Extreme 3205 power amp
« Reply #8 on: 28 Jul 2008, 02:13 pm »
Hi BRM,

 Yes, the 3205 is available as a straight power amp, full integrated or with a single volume control knob to help dial in the amp in a bi-amp setup or for those with only one source.
 This amp above was built as a straight power amp to be used in conjunction with our new Musicale phono/preamplifier.

 Here is one of the 3205 amplifiers used in our facility. This one has only one input and a volume control



Is the "volume control" like going through another preamp section?  I don't want to flavor the sound twice, if you know what I mean.

Bill Baker

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Re: A one-of-a-kind Bella Extreme 3205 power amp
« Reply #9 on: 28 Jul 2008, 02:17 pm »
Quote
Is the "volume control" like going through another preamp section?  I don't want to flavor the sound twice, if you know what I mean.

 The 3205 intergated amplifiers, as well as the piece in the picture, are no more than a power amp with a passive control stage in front of them. There is no 'active' preamp stage. What you see is a power amp with a volume control for attenuation.