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Old 23rd April 2009, 01:48 PM   #31
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sorry got a bit lost in this thread are you still designing the boards or are they ready for purchase,will the power supply boards also be available??
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Old 23rd April 2009, 05:45 PM   #32
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Quote:
Originally posted by Eric Weitzman
By turning it into an A5?
That would lack novelty.

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Old 23rd April 2009, 06:46 PM   #33
Variac is offline Variac  United States
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The boards are in the final stages of design. Cviller has posted them so that he can get feedback from other members.They will be produced by diyAudio as a fundraiser. There won't be any power supply boards in this buy. The main purpose of power supply boards is to connect a bunch of "snap-in" caps, and allow use of discrete diodes rather than diode bridge blocks. They really aren't necessary for the people with the chassis, which have large "computer grade" caps and bridge rectifiers installed. BUT many other power supply boards will work. The ones produced for First Watt amp clones such as the F5 will work, possibly with some modifications.

Cviller has some, as does Peter at Audio Sector. The main purpose of power supply boards is to connect a bunch of "snap-in" caps, and allow use of discrete diodes rather than diode bridge blocks..

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Old 23rd April 2009, 07:04 PM   #34
Variac is offline Variac  United States
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Default Nelson, look here!

I tend to use these diode bridges because they don't require a board so are easy to wire up, yet are properly exotic..

http://www.partsconnexion.com/PDF/l359.pdf

Nelson, I assume they will work even though they are rated at 27A instead of 35A as you spec?

$20 ea. though....
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Old 23rd April 2009, 08:23 PM   #35
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Default Re: Nelson, look here!

Quote:
Originally posted by Variac
....
$20 ea. though....

there is no Graetz for our purposes worth 20 greenies ........

look at my sig
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Old 24th April 2009, 04:13 AM   #36
Variac is offline Variac  United States
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Well.... back to the board- It needs a connection for an LED and a resisitor for the LED... (IMHO)
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Old 24th April 2009, 04:16 AM   #37
Variac is offline Variac  United States
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Hey Papa!+ (other zenlike members)
Could I use the BA1 front end as a preamp to use with my F4's? (without the biasing stuff)
I guess not near enough gain for full output, but what kind of output voltage are we talking about? Prob needs a regulated supply ?
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Old 24th April 2009, 07:42 AM   #38
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I post again here what I wrote few days ago on "Aleph J schematic" thread:

I think that some of the new features intruduced in the BA1 front end schematic colud be applied in the Aleph J too.
I'm referring to the RC filter (R210 + C205 and R211 + C206 on BA1) useful to isolate and clean the PS a bit and to drop a Volt or so to keep the input fets well within their safe voltage range and to the CCS made by a 2SK170 instead of the ZTX550 (Q2 on A-J) plus the (noisy) zener, capacitor (C4) and dropping resistor (R5).
Also R7 could be replaced by a pot as in BA1.
Can we get rid of the IN- coupling cap (C1)?
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Old 24th April 2009, 07:43 AM   #39
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Quote:
Originally posted by Variac
Hey Papa!+ (other zenlike members)
Could I use the BA1 front end as a preamp to use with my F4's?
I guess not near enough gain for full output, but what kind of output voltage are we talking about? Prob needs a regulated supply ?

D+ for pos input of balanced F4
D- for neg input of balanced F4

not full blast , but near enough

isn't easier to make XCCSwhatevercascoded BOSOZ , with altered gain ?
make it with altered positive PSU , and it will drive even bridgedbalancedparalleled F44 .......

ya Kwayzee Mod .......

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Old 24th April 2009, 07:49 AM   #40
Zen Mod is offline Zen Mod  Serbia
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Quote:
Originally posted by massimo
I post again here what I wrote few days ago on "Aleph J schematic" thread:

I think that some of the new features.....

re-read answers in AJ thread

both biasing and modulation of output mosfets ,via input LTP , is referenced to neg supply ;

you can't alter any voltage level there without too much fuss .

improving CCS for input LTP is another issue - do what you think is best

look at Babelfish J schematic ;everything is boiled water ......

http://tiny.pl/zfgp
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