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Old 14th June 2007, 05:42 AM   #261
Vix is offline Vix  Yugoslavia
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Quote:
Originally posted by Nelson Pass


OK, I won't. I do have something different, though.

I knew it!


Quote:
Originally posted by steenoe
Funny enough I was out of 10r's too, so I had to use two 27r's in parallel.
Steen
Maybe that's good luck. Most probably two 27's in parallel work better than a single 10 ohm resistor...

Vix

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Old 14th June 2007, 08:24 AM   #262
lykkedk is offline lykkedk  Denmark
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Damn, this look's good (and easy ) - BUT i was planning to make my future upcomming 2x F4 balanced mono-bloks. But as i see it, it is not possible to make this circuit balanced (unbal to bal converter is my only need through! as i only intend to run the signal balanced from pre ---> Poweramps).

Any suggestion's

Nelson Pass, i think you know the solution to this, what does it take for you tell hehe... ?

Thank's anyway for this great forum.

Jesper.
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Old 14th June 2007, 08:30 AM   #263
juma is offline juma  Serbia
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Quote:
Originally posted by steenoe
It really rocks the F4 to clipping...

Hi steenoe,
please help me understand how did you drive F4 to clipping with this preamp. Its power supply is 18V and it cannot be swinging more than 5-6V peak. It takes 20V peak to drive F4 to clipping.

Maybe I'm missing something?

Thanks
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Old 14th June 2007, 08:33 AM   #264
Zen Mod is offline Zen Mod  Serbia
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Quote:
Originally posted by lykkedk
................But as i see it, it is not possible to make this circuit balanced (unbal to bal converter is my only need through! as i only intend to run the signal balanced from pre ---> Poweramps).

Any suggestion's
..............

really piece of cake, but count on few additional things:

negative supply
doubling number of jfets (hehe - that's funny) to make LTP

CCS for tail of that LTP
at least one stereo pot per channel, if not balanced stereo pot

and you're there - balanced jfet BOZ
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Old 14th June 2007, 08:56 AM   #265
steenoe is offline steenoe  Denmark
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Quote:
Originally posted by juma



Hi steenoe,
please help me understand how did you drive F4 to clipping with this preamp. Its power supply is 18V and it cannot be swinging more than 5-6V peak. It takes 20V peak to drive F4 to clipping.

Maybe I'm missing something?

Thanks
You are probably right. It was more likely the speakers that were tortured. In any case the J-fet BoZ can play more than loud enough with the F4. The speakers are Abby-clones with Fostex FE166's.

Jesper, take a look at the Pumpkin-mans latest creation also It should have gain and voltage swing enough for the F4. Very promising......

Steen

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Old 14th June 2007, 09:14 AM   #266
ROVSING is offline ROVSING  Denmark
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Old 14th June 2007, 09:28 AM   #267
Magura is offline Magura  Denmark
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Quote:
Originally posted by ROVSING
OOH there you are Lucky - couldn't find you

OK Bjarne....det var dråben!

Go build something

Magura
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Old 14th June 2007, 10:27 AM   #268
massimo is offline massimo  Italy
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Quote:
Originally posted by steenoe


Excactly, those eyes are hypnotizing

Steen
We can hide them, if you wish (Choky's eyes, I mean)
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Old 14th June 2007, 11:57 AM   #269
ROVSING is offline ROVSING  Denmark
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Quote:
Originally posted by Magura



OK Bjarne....det var dråben!

Go build something

Magura

Yes your probably right, might make this preamp to get something finished should be possible - i think i'll make it in 1 hour just to beat "Lucky" Steenoe
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Old 14th June 2007, 12:04 PM   #270
Magura is offline Magura  Denmark
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Quote:
Originally posted by ROVSING



Yes your probably right, might make this preamp to get something finished should be possible - i think i'll make it in 1 hour just to beat "Lucky" Steenoe
If you do the footwork, and go buy two cordless powerdrills, you can make one in like 30 minutes

The reason to buy two is that you use one charger for actually charging the batteries (you can get el-cheapo chordless drills sporting 18V), and one for building the amp in. The all you need to do is to swap the batteries from the charger to the preamp (which has a socket for the batteri since it's the box from the second charger), and off you go


Magura
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