madbeanpedals::forum

General => Open Discussion => Topic started by: copachino on September 30, 2014, 11:45:26 PM

Title: what its this preamp??
Post by: copachino on September 30, 2014, 11:45:26 PM
http://www225.pair.com/audio/waltzingbear/Schematics/API/API_312.htm

im not so sure if its my lack of knwoledge but, i think something its missing on this schematic
Title: Re: what its this preamp??
Post by: selfdestroyer on September 30, 2014, 11:58:54 PM
This?
http://www.diyrecordingequipment.com/projects/access-312-preamp-pcb/ (http://www.diyrecordingequipment.com/projects/access-312-preamp-pcb/)

Massive photo for the win!
(http://static.squarespace.com/static/504f880084aeceeb930d517f/5058ba2f84aef359132b5e5f/508322d5e4b0f4598aa77b77/1350771413174/DSC_3158.JPG)

Cody
Title: Re: what its this preamp??
Post by: copachino on October 01, 2014, 12:43:59 AM
that its really cool but i dont undestand some parts to make my own layout, and seems that tthe 2520 OP amp its imposssible to find so im out of luck
Title: Re: what its this preamp??
Post by: davent on October 01, 2014, 01:30:44 AM
You're in luck... and more then 10 available, API2520.

http://www.ebay.ca/itm/SonicImageryLabs-990Enh-Ticha-Discrete-OpAmp-JE990-API2520-audio-upgrade-/251482765348?pt=US_Live_Studio_Mixers&hash=item3a8d8a7824
Title: Re: what its this preamp??
Post by: copachino on October 01, 2014, 01:38:38 AM
they look a bit different, i have also see some pcbs that supposed to simulate that op amp with transistors, but im not so sure, how they would sound, im like helping some friends to make they very own recording place, but, things are getting hard to find on vintage equipment
Title: Re: what its this preamp??
Post by: oldhousescott on October 01, 2014, 02:25:34 AM
There are plenty of 2520/990 opamp clones and work-alikes (even DIY). Actually, the 312 is just the amplifier part. It needs a gain pot, phantom power, pad, and phase switching to make it a full-featured preamp. Check out the VPR and 51X alliances for kits and parts for 500 series gear.
Title: Re: what its this preamp??
Post by: Haberdasher on October 01, 2014, 02:32:45 AM
whistlerock audio in canada sells cheap pcb's & kits for 2520 footprint discrete opamps
you can also get kits from classic audio products of illinois and five fish i think
Title: Re: what its this preamp??
Post by: copachino on October 01, 2014, 02:32:52 AM
Quote from: oldhousescott on October 01, 2014, 02:25:34 AM
There are plenty of 2520/990 opamp clones and work-alikes (even DIY). Actually, the 312 is just the amplifier part. It needs a gain pot, phantom power, pad, and phase switching to make it a full-featured preamp. Check out the VPR and 51X alliances for kits and parts for 500 series gear.

i know, and i have seen the kits, but you think  those DIY OP amps sound nice??, that all about, i was thinking make my own layout, but there are some parts im missing on understanding this schematic
Title: Re: what its this preamp??
Post by: copachino on October 01, 2014, 02:34:17 AM
Quote from: Haberdasher on October 01, 2014, 02:32:45 AM
whistlerock audio in canada sells cheap pcb's & kits for 2520 footprint discrete opamps
you can also get kits from classic audio products of illinois and five fish i think

those are the kits ive been watching, only 210 USD without op amp and 65 builded DIY op amp and 18 USD op amp kit, sounds really cheapo
Title: Re: what its this preamp??
Post by: Haberdasher on October 01, 2014, 02:38:03 AM
i built 2 doa's from whistlerock.  it was a little tedious and small, but pretty easy for someone who holds a soldering iron a few times a week.
Title: Re: what its this preamp??
Post by: copachino on October 01, 2014, 02:56:10 AM
Quote from: Haberdasher on October 01, 2014, 02:38:03 AM
i built 2 doa's from whistlerock.  it was a little tedious and small, but pretty easy for someone who holds a soldering iron a few times a week.

and how they sounded??
Title: Re: what its this preamp??
Post by: lincolnic on October 01, 2014, 03:20:17 AM
You guys should know that the 2520 and the 990 are very, very different sounding op-amps. The 2520 is a big part of the API sound.

I have two VP28s from Classic API in my studio and I use them all the time. They sound great and are damn near indistinguishable from the 212s we have in our console. They're pretty easy builds, too. If you're looking for kits, you can't go wrong with CAPI. I believe they have a 312 kit as well.
Title: Re: what its this preamp??
Post by: peterc on October 01, 2014, 12:43:31 PM
Whistlerock's 2520 prices have come down, $25 for a built opamp...

http://www.whistlerockaudio.com/cart/index.php?main_page=index&cPath=35_59

Title: Re: what its this preamp??
Post by: alanp on October 01, 2014, 03:14:01 PM
Buy two or four, then you can use them in a Klone, and really cook!
Title: Re: what its this preamp??
Post by: copachino on October 01, 2014, 03:58:33 PM
Quote from: alanp on October 01, 2014, 03:14:01 PM
Buy two or four, then you can use them in a Klone, and really cook!

that would be something different. :) :) :)
Title: Re: what its this preamp??
Post by: Haberdasher on October 01, 2014, 04:04:32 PM
Quote from: copachino on October 01, 2014, 02:56:10 AM
Quote from: Haberdasher on October 01, 2014, 02:38:03 AM
i built 2 doa's from whistlerock.  it was a little tedious and small, but pretty easy for someone who holds a soldering iron a few times a week.

and how they sounded??
they seem to sound good, but to be honest i have nothing to compare them to
Title: Re: what its this preamp??
Post by: neve1272 on October 03, 2014, 12:02:52 AM
http://www.seventhcircleaudio.com/OpAmps/sc10_about.htm

this is what i used the seventh circle stuff is amazing ....this is my go to preamp for drums especially the kik