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-   -   Nikko pre-amplifier Beta II schematics for driving my F4 (http://www.diyaudio.com/forums/solid-state/106299-nikko-pre-amplifier-beta-ii-schematics-driving-my-f4.html)

lykkedk 3rd August 2007 05:35 AM

Nikko pre-amplifier Beta II schematics for driving my F4
 
2 Attachment(s)
Hi, I was in luck, the other day, finding such a baby at the local junk-jard.
I brought it back home, and plug it into the wall-outlet, and woow... everything seem's to work :cool:

At first, i was trying it, with my LeachAmp, and i noticed that the gain from this Nikko, was a lot better than i expected. I then tried to hook it up with a 2,5v 1khz sine (from a dvd-player, only sine-gen i have sry..), well if i give it 2,5v in, it pulls around 25v Out, so this gives me around 20dB of gain i think. I don't know, if this is all enough of, what my F4 will swallow, but it's a good start. I then tried to hook it up, with my 'nearly' finished first F4 monoblock, and it seem's it driving it fairly up to the 25w, but still missing the last bit of power i think, but i can't tell for sure.

I think this little pre, will need a good service, so i would be very interessted if someone have a service manuel or like for it. Or any suggestion's for improvement.
The only data, printed on it is NIKKO PRE-AMPLIFIER BETA II. Around 20years old i guess.

Any help would be appreciated.

Jesper.

steenoe 3rd August 2007 07:24 PM

Wow, my first long answer went down the drain, when the darn "Gates" browser went down! Hmmmmmm...-
Jesper, I was trying to say this: Ask the question in the Solid State, department or make a link from there to this thread!! I am sure you will get a lot more response, that way!!

Steen:)

Edit: Mods, could you please change the spelling of this thread's subject from NIKKE to NIKKO?

lykkedk 3rd August 2007 07:35 PM

Thanks Steen, i see !

Maybe a Moderator would change my mispelling to NIKKO :o - And move this thread to SolidState Thanks.

Jesper.

steenoe 3rd August 2007 07:38 PM

Hey, what do think of this:
http://www.manuals-in-pdf.com/ALPHAII-p-358348.html

Me:cool:

PS I used those guy's several times with good results! I know someone has been sceptical about them! Whatever, they delivered the goods to me!

lykkedk 3rd August 2007 07:47 PM

I actually bought a Servicebook this evening, from http://www.vintageaudiomanuals.com/, The price is the same,and they will sent it to me tomorrow. :) ... But for sure i will need some help, if i decide to shine this baby up.

Jesper.

BTW: I had been listning to my F4 all day, with this nikko pre, as the F4's master :D

mpmarino 3rd August 2007 11:25 PM

I've wanted one of those Betas since I was maybe 15 years old - just because I thought they were cool!

Nice find!;)

GRollins 3rd August 2007 11:58 PM

Enough negative feedback will give you any arbitrary distortion measurement you might desire, but that's not to say it sounds good. I sold Nikko back when I was in retail at [a defunct chain which shall remain nameless to protect the guilty].
Dry. Sterile. Typical specs-are-everything late '70s "hi-fi" sound.
I, for one, don't miss the stuff.
Gut it and build something decent in the chassis.
Better yet, drive a wooden stake through the chassis to make sure it's dead.

Grey

P.S.: The amplifiers were a dead giveaway...100W out of something not much bigger than a hardback book. What does this tell you? Virtually no bias. Power transformer the size of a mouse. Caps? What caps? We don't need no stinkin' caps.
For those who don't think that this indicates anything, note that this was loooong before class D amplifiers arrived on the scene.

lykkedk 4th August 2007 06:18 AM

2 Attachment(s)
:devilr: :devilr: Better yet, drive a wooden stake through the chassis to make sure it's dead.
:devilr: :devilr:

You cruel... ;) - Well your'e proberly right, but it gives me some music, until i finish up a new pre.

I will for sure place some garlic around it... just to be sure :D

Jesper.

GRollins 4th August 2007 10:03 AM

That should do the trick.

Grey

oscarsan 8th November 2009 08:10 AM

Someone has the schematic of this preamp "beta 2".
I really need.
Thanks, Oscar


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