Custom made - show your pictures!

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FullRangeMan

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Re: Custom made - show your pictures!
« Reply #20 on: 14 Aug 2015, 01:52 pm »
Why BIG caps were used?

neobop

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Re: Custom made - show your pictures!
« Reply #21 on: 14 Aug 2015, 03:15 pm »
FullRangeMan,
The big blue caps are for energy storage and delivery.  They make the speakers play.  Each is 5400 MFD @ 200 V.  Connected in series adds up to 16,200 MFD @ 600 V.  Overkill?
The smaller caps and resistors across the terminals are to speed up the discharge.  Those are conventional x-over caps 400 to 600V rated.

The speakers are super cool!

And the amplifier... is that power transformer in the background of the lower picture? Love those capacitors, by the way  :thumb:

Thanks,  the credit for the amp goes to Dan Fanny.  Yes, that's the power transformer behind the amp.   It vibrated, so I had him take it off the chassis.  That left a space or should I say opportunity?   I saw those caps advertised in the back of Audio magazine (I believe),  and Dan gave them his seal of approval.  I knew the benefit of storage caps from my electrostatic direct drive amps, also built/designed by Dan.  They make the amp sound effortless, like it's not there.  He designed the boards - input, inside, and rectifier. 
I had some work done on the amp and two different techs commented on how nice it sounds.  It needs a good cleaning.  I haven't been using it lately as it needs some more work. 

This is my custom version of AHT phono stage:



Power supply:



It has the Teflon boards w/silver traces.  I have some regular Vishay 102's.  The super version has space shuttle Vishays - encapsulated and immune to temp change.  Those cost $60/ea wholesale in '90.   The Non-Signature also has a bigger power supply and a fancy box.  Cost about $5.5K direct in the '90's.  I was told it was the only 5 star component in TAS for 3 years running. 
neo


FullRangeMan

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Re: Custom made - show your pictures!
« Reply #22 on: 15 Aug 2015, 11:33 am »
Thanks NEOBOP. :thumb:
I surpised;

Audiovista

Re: Custom made - show your pictures!
« Reply #23 on: 15 Aug 2015, 07:44 pm »
Each is 5400 MFD @ 200 V.  Connected in series adds up to 16,200 MFD @ 600 V.  Overkill?

Just one correction - the three capacitors connected in series will yield equivalent capacitance of 1800MFD. Still, at 450 or 500V of operating voltage they can store a lot of energy... equivalent to  145000-180000MFD at 50V which would be voltage inside a high power solid state amp.  :thumb:

Audiovista

Re: Custom made - show your pictures!
« Reply #24 on: 15 Aug 2015, 07:52 pm »
"....It has the Teflon boards w/silver traces..."

Teflon boards... hmmm... something to think about  :thumb:

neobop

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Re: Custom made - show your pictures!
« Reply #25 on: 16 Aug 2015, 07:46 pm »
Oops, caps in series is like resistors in parallel.   Guess I was so used to adding value of caps in parallel I had a brain fart.

I deferred all electronics decisions to Danny.  He was a tube god before AHT and modified high end gear like ARC and Levinson.  He would point out the flaws in their designs, and they were many.  When I asked him about the phono stage performance and where I could skimp, he indicated the Teflon board (already made w/silver traces) was worthwhile.  The space shuttle resistors would have been nice because the piece is temp sensitive and DC offset is set manually. There's 2 plug-in resistors on each channel, 1 for gain and 1 for load.  Perhaps you'd be interested in the ICs and configuration?  It's deceptively simple and the IC is still highly regarded.  This design is now owned by Walker ($20K/pop) so I don't want to post a photo of the inside.  When Dan left the audio biz he was considering selling to both Walker, Basis and Herron, all expressed interest.

I wish I had photos of the electrostatic tube amps.  They were made on the chassis of the Acoustat amps and used the original power transformer.  Dan designed new configuration and had boards made.  Each (mono) had 4 cap tubes.  I found some relatively high voltage photoflash caps and we made banks of them (20?) to get 5KV.  Those suckers packed a wallop.  5KV storage caps are hard to source.

BTW, I want to order a phono stage, go to the web site?
neo


Audiovista

Re: Custom made - show your pictures!
« Reply #26 on: 16 Aug 2015, 08:06 pm »
Quality of resistors is very important for noise performance of phono amplifiers, and even more important for your preamp to prevent offset drift.

5kV capacitor bank - too bad no pictures are available of that amp.

For the order you can contact me via website or directly at audio @ engineeringvista . com (I added blank spaces hoping to confuse web crawlers - there are no spaces in the actual address).

Thanks,
Boris

Audiovista

Re: Custom made - show your pictures!
« Reply #27 on: 26 Aug 2015, 09:16 pm »
Tara 30a, custom designed preamplifier from Trafomatic. A real massive beauty!


Audiovista

Re: Custom made - show your pictures!
« Reply #28 on: 5 Sep 2015, 06:15 pm »
Customized Menuetto integrated amplifier, by Dayens.


Audiovista

Re: Custom made - show your pictures!
« Reply #29 on: 9 Oct 2015, 01:05 pm »
More pictures, this time a real integrated amplifier: tube amplifier paired with a dedicated preamplifier, including headphone amplifier and tone controls. Custom made for a NY company Symbol Audio.







Custom amplifiers by Vista Audio

Folsom

Re: Custom made - show your pictures!
« Reply #30 on: 9 Oct 2015, 07:13 pm »
More pictures, this time a real integrated amplifier: tube amplifier paired with a dedicated preamplifier, including headphone amplifier and tone controls. Custom made for a NY company Symbol Audio.







Custom amplifiers by Vista Audio

That's boss.

Audiovista

Re: Custom made - show your pictures!
« Reply #31 on: 28 Feb 2016, 12:18 pm »
The "desktop amplifier" from the first post in the final assembly stage. Finished unit will have four levels.




Guy 13

Re: Custom made - show your pictures!
« Reply #32 on: 28 Feb 2016, 01:35 pm »
That's my first and last amplifier built.
I was around 19 years old and studying basic electronic
(Tubes only, no transistor)
at Institut Teccart in Montreal.
I did my own design and schematic and gather parts from
old TV parts that I got from left and right.
The tubes were (If my memory serve me right) 6SN7, 6F6 and 5Y3 ???
of course it was mono and the 6F6 penthode connected
gave probably a big maximum of 4 watts.
By the way, it worked fine first time it was connected
and did not blow up to my surprise.  :lol:
 


That's where I did the built, the captain's mess...
A real pig style...  :lol:



I hope all of you had a good laught at those pictures, because I did.

Guy 13

By the way:
My basic electronic diploma was not a waste.
It was usefull for different types of works all my life
and-or until now.

FullRangeMan

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Re: Custom made - show your pictures!
« Reply #33 on: 28 Feb 2016, 02:23 pm »
The "desktop amplifier" from the first post in the final assembly stage. Finished unit will have four levels.



Wow impressive!

Audiovista

Re: Custom made - show your pictures!
« Reply #34 on: 29 Feb 2016, 05:52 pm »
Hi Guy 13 - thanks for the pictures! Not laughing at all - that reminds me of some of my early work (I think I posted pictures before). I am trying to find another picture of my bench while testing a 4kW class D amplifier, some 15 years ago. Definition of "creative mess" :)

Mr. FullRangeMan - in a few days I hope to get picture of designers standing next to this monoblock - I think you will be even more impressed when you get proper size reference :). In the meantime, I'll post few more pics of an almost-finished assembly.

Thank you both for chiming in  :thumb:

S Clark

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Re: Custom made - show your pictures!
« Reply #35 on: 29 Feb 2016, 06:19 pm »
Gary Dodd built this for me a few years back from a Knight Kit KB-85 amp from around 1960.  It puts out about 50+wpc using 6L6GC's 


Audiovista

Re: Custom made - show your pictures!
« Reply #36 on: 29 Feb 2016, 09:24 pm »
Nice! Love instruments on the front. Good, robust, tubes. Only heard them in a good guitar amp and inexpensive Chi-fi. I wonder how they really sound in a competently designed audio amplifier?

S Clark

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Re: Custom made - show your pictures!
« Reply #37 on: 1 Mar 2016, 12:32 am »
The original Knight Kit amp used EL37 tubes.  Most users switched to the 6L6GC since the EL 37's are incredibly rare/expensive.  The rest of the amp has Sylvania fat base 5AR4's and 6H30Pi's.  It stays in my system Oct.- June.  During the summers it's just too hot in Texas for tubes. 

Audiovista

Re: Custom made - show your pictures!
« Reply #38 on: 1 Mar 2016, 08:54 pm »
...During the summers it's just too hot in Texas for tubes.

Then you definitely wouldn't want this one...  :nono:

 :lol:











hi5harry

Re: Custom made - show your pictures!
« Reply #39 on: 4 Mar 2016, 03:57 pm »
I'm attempting to build a DIY turntable. I now have all the parts back from the machine shop so I'm getting excited!