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jFET phono preamp - boozhoundlabs
http://diyaudioprojects.com/Forum/viewtopic.php?f=10&t=2933
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Author:  HT Performance [ 14 Aug 2011, 05:07 ]
Post subject:  Re: jFET phono preamp - boozhoundlabs

Magnus are you intentionally using 2200uF electrolytic capacitors?

I believe I saw 220uF in the original schematic...


Cheers,

Miguel

Author:  Soundbrigade [ 14 Aug 2011, 05:20 ]
Post subject:  Re: jFET phono preamp - boozhoundlabs

To be honest, I never saw the "correct" values and simply dug up the 2200uF caps, but they were 16V only. Also had a bunch of 1000uF/25V which is far to little and finally decided to order 220uF/50V.
I have the two 12V battery packs soldered and will think about HOW TO mount them in the box.

Author:  HT Performance [ 14 Aug 2011, 05:32 ]
Post subject:  Re: jFET phono preamp - boozhoundlabs

I donĀ“t know how much current does the pre-amp draw, but what about 3 x 9v batteries?

Maybe you can find some rechargable ones for a nice price?

You could have a double switch, so when you turn the switch to one side (off), it charges de batteries, on the other position it eliminates the external DC charger and runs on batteries (on) while listening.

Just an idea...


Miguel

Author:  mwhouston [ 14 Aug 2011, 17:01 ]
Post subject:  Re: jFET phono preamp - boozhoundlabs

If I'm right about 15mA in total.

Author:  HT Performance [ 14 Aug 2011, 17:19 ]
Post subject:  Re: jFET phono preamp - boozhoundlabs

Thanks!

15mA seems OK to 9V batteries.

You can find 9V 300mA (NI-MH) ones for $3USD (shipping included) on eBay.

Hard to believe (300mA) or not... becauce they are made in C_ _ _ A!

Worth a try???

Author:  Soundbrigade [ 14 Aug 2011, 23:44 ]
Post subject:  Re: jFET phono preamp - boozhoundlabs

California???!!!

Author:  mwhouston [ 15 Aug 2011, 03:35 ]
Post subject:  Re: jFET phono preamp - boozhoundlabs

Soundbrigade wrote:
California???!!!

You R a funny man.

I thought "Calithumpia". An aussie term for a far off and stange land.

Author:  Soundbrigade [ 15 Aug 2011, 12:19 ]
Post subject:  Re: jFET phono preamp - boozhoundlabs

Got the tubes together but several of the soldering tabs got off (easily) :x .
Image

The whole packet, sqeezed together on an "aluminiumsledge" fits perfectly in the box.
Image

Author:  mwhouston [ 15 Aug 2011, 16:47 ]
Post subject:  Re: jFET phono preamp - boozhoundlabs

You should get about 100 hours of play. The preamp draws 15mA I think.

Author:  Soundbrigade [ 16 Aug 2011, 05:44 ]
Post subject:  Re: jFET phono preamp - boozhoundlabs

I think I would need a player ....

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