Eisen Audio DIY 500 series mic preamps

seaneldon · Post by **seaneldon** » Fri Jul 28, 2006 1:38 am

Eisen Audio is a cool guy named Jens Jungkurth in Long Island City, NY who is making high quality DIY kits for 500 series mic preamps with hundreds and hundreds and hundreds of options for transformers and op amps. http://www.eisenaudio.com for the full shebang.

Visited these fine folks today (they're right down the block from my studio) and walked out with 4 channels of Eisen mic preamps (3 different combinations of op amps, input, and output transformers) and 2 channels of Purple Audio Biz.

I'll be doing a long review, and posting a song that I record using only these 6 preamps with several microphones ranging from $100-10,000.

First impression? They're simple, yet look to be of great quality, and the build seems like it'll be extremely easy even if you're a beginner. Haven't passed any audio through them yet. Will get started on that tomorrow. I guess you could say I'm reserving this space for a cool song and an unbiased review. I'll link a post on the "Listen To My Music" forum when the song is done.

Will update ASAP. End result will go here, but play by play will probably go in the blog in my signature. Cheers.

jspartz · Post by **jspartz** » Thu Aug 03, 2006 3:56 pm

I am building a pair myself. I just need to find the time to get back and finish them. Easy to build! It just takes a little time, which I have not had at all. Soon!

I look forward to your review!

Jason

seaneldon · Post by **seaneldon** » Fri Aug 04, 2006 12:07 am

well, i've passed audio through every channel as of like 2 days ago. drums and bass.

i got two rough drum takes of the song that i'll use as a guide for the "real" recording using all the mics i want in all the right places.

so far, i'm EXTREMELY happy with the sounds i'm getting as far as my mic->preamp selection.

drum preamps/mics are as follows:

Eisen A: JFET-992 opamp, JLM Audio 1:4 nickel input transformer - Kick Drum (inside), Audix D6

Eisen B: JFET-992 opamp, JLM Audio 1:4 nickel input transformer - Kick Drum (outside), Soundelux E47

Eisen C: Hardy 990C opamp, 1973 Reichenbach input transformer, Cinemag 1:1 half nickel half steel output transformer - Room mic, Brauner VM1 Klaus Heyne Edition

Eisen D: Hardy 990C, Cinemag input transformer, nickel output transformer - Snare Drum, Audix I5

I've got a Royer SF12 over the kit going into two Purple Audio Biz preamps.

The end tracks will probably be EQ'd and compressed lightly (I'll probably destroy the room mic with a Chandler LTD-2), but I'll let you know what I use and what it was doing. Maybe I'll do the whole shit tomorrow night.

I hope you like really frantic mathrock...

jspartz · Post by **jspartz** » Sun Aug 06, 2006 10:35 am

Do you have a large difference between units?? Also who makes the JFET-992?

Jason

seaneldon · Post by **seaneldon** » Mon Aug 07, 2006 12:20 am

Forssell makes the JFET opamps.

Each preamp (the first two channels being the exception, as they're identical circuits) does indeed sound quite different. I matched mics to preamps accordingly.

Drums, bass, and one of two guitars is done. I'll finish up tomorrow and try to get a rough mix up for everyone to hear. Sounds absolutely fucking fantastic. HUGE kick and snare! Huge! Room mic very detailed (that's got a lot to do with the mic, of course).

JohnDavisNYC · Post by **JohnDavisNYC** » Tue Aug 08, 2006 6:42 am

aaron and i built a pair with hardy 990Cs, Lundahl input and cinemag output transformers, and they are AMAZING... the beat everything else we have in terms of depth, headroom, punch... really amazing. defintely HUGE like sean says. and super easy to make.

i'm getting at least 2 more kits.

john

EisenAudio · Post by **EisenAudio** » Wed Aug 09, 2006 9:36 pm

Hi Guys,

Just thought I'd stop in and say a few things...

Satisfied or not, it's always exciting to hear from DIY500 users! I've started a uers page and would love to add your comments and/or a link to your website.

Op Amps are listed in the information tables. Never hesitate to contact me with questions!

bantam · Post by **bantam** » Fri Aug 18, 2006 8:45 pm

these kits sound cool.

anyone know of a great DIY solution for a lunchbox? best price for commercial units is around 500. anyone try this or know of a budget option?

thanks

EisenAudio · Post by **EisenAudio** » Wed Aug 23, 2006 3:40 pm

buschfsu wrote:best price for commercial units is around 500.

Not so! The API 500-6B goes for $425 USD. 6-slot lunchbox with a decent, built-in power supply.

operator_tape · Post by **operator_tape** » Sat Aug 26, 2006 5:59 am

what are some proven combinaions that would work.

EisenAudio · Post by **EisenAudio** » Sat Aug 26, 2006 11:06 am

operator_tape wrote:what are some proven combinaions that would work.

Too many!!! I need a target application and/or color in mind to answer that. E-mail me.

calaverasgrandes · Post by **calaverasgrandes** » Wed Aug 01, 2007 12:49 am

well it looks like I cant find the eisen website. did it move? I thought I was looking at it a few days ago.

edanderson · Post by **edanderson** » Wed Aug 01, 2007 4:38 am

jens is changing web hosts for his site. apparently the home page is broken right now, but you can still get to the product page:

http://www.eisenaudio.com/diy500/

ed

Message Board

Eisen Audio DIY 500 series mic preamps

Eisen Audio DIY 500 series mic preamps

I am the undertaker

Who is online